/* Storage allocation and gc for GNU Emacs Lisp interpreter.
Copyright (C) 1985-1986, 1988, 1993-1995, 1997-2012
Free Software Foundation, Inc.
This file is part of GNU Emacs.
GNU Emacs is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GNU Emacs. If not, see . */
#include
#include
#include /* For CHAR_BIT. */
#include
#include
#ifdef HAVE_PTHREAD
#include
#endif
/* This file is part of the core Lisp implementation, and thus must
deal with the real data structures. If the Lisp implementation is
replaced, this file likely will not be used. */
#undef HIDE_LISP_IMPLEMENTATION
#include "lisp.h"
#include "process.h"
#include "intervals.h"
#include "puresize.h"
#include "buffer.h"
#include "window.h"
#include "keyboard.h"
#include "frame.h"
#include "blockinput.h"
#include "character.h"
#include "syssignal.h"
#include "termhooks.h" /* For struct terminal. */
#include
#include
/* GC_MALLOC_CHECK defined means perform validity checks of malloc'd
memory. Can do this only if using gmalloc.c. */
#if defined SYSTEM_MALLOC || defined DOUG_LEA_MALLOC
#undef GC_MALLOC_CHECK
#endif
#include
#ifndef HAVE_UNISTD_H
extern POINTER_TYPE *sbrk ();
#endif
#include
#ifdef WINDOWSNT
#include "w32.h"
#endif
#ifdef DOUG_LEA_MALLOC
#include
/* Specify maximum number of areas to mmap. It would be nice to use a
value that explicitly means "no limit". */
#define MMAP_MAX_AREAS 100000000
#else /* not DOUG_LEA_MALLOC */
/* The following come from gmalloc.c. */
extern size_t _bytes_used;
extern size_t __malloc_extra_blocks;
#endif /* not DOUG_LEA_MALLOC */
#if ! defined SYSTEM_MALLOC && ! defined SYNC_INPUT
#ifdef HAVE_PTHREAD
/* When GTK uses the file chooser dialog, different backends can be loaded
dynamically. One such a backend is the Gnome VFS backend that gets loaded
if you run Gnome. That backend creates several threads and also allocates
memory with malloc.
Also, gconf and gsettings may create several threads.
If Emacs sets malloc hooks (! SYSTEM_MALLOC) and the emacs_blocked_*
functions below are called from malloc, there is a chance that one
of these threads preempts the Emacs main thread and the hook variables
end up in an inconsistent state. So we have a mutex to prevent that (note
that the backend handles concurrent access to malloc within its own threads
but Emacs code running in the main thread is not included in that control).
When UNBLOCK_INPUT is called, reinvoke_input_signal may be called. If this
happens in one of the backend threads we will have two threads that tries
to run Emacs code at once, and the code is not prepared for that.
To prevent that, we only call BLOCK/UNBLOCK from the main thread. */
static pthread_mutex_t alloc_mutex;
#define BLOCK_INPUT_ALLOC \
do \
{ \
if (pthread_equal (pthread_self (), main_thread)) \
BLOCK_INPUT; \
pthread_mutex_lock (&alloc_mutex); \
} \
while (0)
#define UNBLOCK_INPUT_ALLOC \
do \
{ \
pthread_mutex_unlock (&alloc_mutex); \
if (pthread_equal (pthread_self (), main_thread)) \
UNBLOCK_INPUT; \
} \
while (0)
#else /* ! defined HAVE_PTHREAD */
#define BLOCK_INPUT_ALLOC BLOCK_INPUT
#define UNBLOCK_INPUT_ALLOC UNBLOCK_INPUT
#endif /* ! defined HAVE_PTHREAD */
#endif /* ! defined SYSTEM_MALLOC && ! defined SYNC_INPUT */
/* Mark, unmark, query mark bit of a Lisp string. S must be a pointer
to a struct Lisp_String. */
#define MARK_STRING(S) ((S)->size |= ARRAY_MARK_FLAG)
#define UNMARK_STRING(S) ((S)->size &= ~ARRAY_MARK_FLAG)
#define STRING_MARKED_P(S) (((S)->size & ARRAY_MARK_FLAG) != 0)
#define VECTOR_MARK(V) ((V)->header.size |= ARRAY_MARK_FLAG)
#define VECTOR_UNMARK(V) ((V)->header.size &= ~ARRAY_MARK_FLAG)
#define VECTOR_MARKED_P(V) (((V)->header.size & ARRAY_MARK_FLAG) != 0)
/* Value is the number of bytes of S, a pointer to a struct Lisp_String.
Be careful during GC, because S->size contains the mark bit for
strings. */
#define GC_STRING_BYTES(S) (STRING_BYTES (S))
/* Global variables. */
struct emacs_globals globals;
/* Number of bytes of consing done since the last gc. */
EMACS_INT consing_since_gc;
/* Similar minimum, computed from Vgc_cons_percentage. */
EMACS_INT gc_relative_threshold;
/* Minimum number of bytes of consing since GC before next GC,
when memory is full. */
EMACS_INT memory_full_cons_threshold;
/* Nonzero during GC. */
int gc_in_progress;
/* Nonzero means abort if try to GC.
This is for code which is written on the assumption that
no GC will happen, so as to verify that assumption. */
int abort_on_gc;
/* Number of live and free conses etc. */
static EMACS_INT total_conses, total_markers, total_symbols, total_vector_size;
static EMACS_INT total_free_conses, total_free_markers, total_free_symbols;
static EMACS_INT total_free_floats, total_floats;
/* Points to memory space allocated as "spare", to be freed if we run
out of memory. We keep one large block, four cons-blocks, and
two string blocks. */
static char *spare_memory[7];
/* Amount of spare memory to keep in large reserve block, or to see
whether this much is available when malloc fails on a larger request. */
#define SPARE_MEMORY (1 << 14)
/* Number of extra blocks malloc should get when it needs more core. */
static int malloc_hysteresis;
/* Initialize it to a nonzero value to force it into data space
(rather than bss space). That way unexec will remap it into text
space (pure), on some systems. We have not implemented the
remapping on more recent systems because this is less important
nowadays than in the days of small memories and timesharing. */
EMACS_INT pure[(PURESIZE + sizeof (EMACS_INT) - 1) / sizeof (EMACS_INT)] = {1,};
#define PUREBEG (char *) pure
/* Pointer to the pure area, and its size. */
static char *purebeg;
static ptrdiff_t pure_size;
/* Number of bytes of pure storage used before pure storage overflowed.
If this is non-zero, this implies that an overflow occurred. */
static ptrdiff_t pure_bytes_used_before_overflow;
/* Value is non-zero if P points into pure space. */
#define PURE_POINTER_P(P) \
((uintptr_t) (P) - (uintptr_t) purebeg <= pure_size)
/* Index in pure at which next pure Lisp object will be allocated.. */
static EMACS_INT pure_bytes_used_lisp;
/* Number of bytes allocated for non-Lisp objects in pure storage. */
static EMACS_INT pure_bytes_used_non_lisp;
/* If nonzero, this is a warning delivered by malloc and not yet
displayed. */
const char *pending_malloc_warning;
/* Maximum amount of C stack to save when a GC happens. */
#ifndef MAX_SAVE_STACK
#define MAX_SAVE_STACK 16000
#endif
/* Buffer in which we save a copy of the C stack at each GC. */
#if MAX_SAVE_STACK > 0
static char *stack_copy;
static ptrdiff_t stack_copy_size;
#endif
/* Non-zero means ignore malloc warnings. Set during initialization.
Currently not used. */
static int ignore_warnings;
static Lisp_Object Qgc_cons_threshold;
Lisp_Object Qchar_table_extra_slots;
/* Hook run after GC has finished. */
static Lisp_Object Qpost_gc_hook;
static void mark_buffer (Lisp_Object);
static void mark_terminals (void);
static void gc_sweep (void);
static void mark_glyph_matrix (struct glyph_matrix *);
static void mark_face_cache (struct face_cache *);
#if !defined REL_ALLOC || defined SYSTEM_MALLOC
static void refill_memory_reserve (void);
#endif
static struct Lisp_String *allocate_string (void);
static void compact_small_strings (void);
static void free_large_strings (void);
static void sweep_strings (void);
static void free_misc (Lisp_Object);
extern Lisp_Object which_symbols (Lisp_Object, EMACS_INT) EXTERNALLY_VISIBLE;
/* When scanning the C stack for live Lisp objects, Emacs keeps track
of what memory allocated via lisp_malloc is intended for what
purpose. This enumeration specifies the type of memory. */
enum mem_type
{
MEM_TYPE_NON_LISP,
MEM_TYPE_BUFFER,
MEM_TYPE_CONS,
MEM_TYPE_STRING,
MEM_TYPE_MISC,
MEM_TYPE_SYMBOL,
MEM_TYPE_FLOAT,
/* We used to keep separate mem_types for subtypes of vectors such as
process, hash_table, frame, terminal, and window, but we never made
use of the distinction, so it only caused source-code complexity
and runtime slowdown. Minor but pointless. */
MEM_TYPE_VECTORLIKE
};
static POINTER_TYPE *lisp_align_malloc (size_t, enum mem_type);
static POINTER_TYPE *lisp_malloc (size_t, enum mem_type);
#if GC_MARK_STACK || defined GC_MALLOC_CHECK
#if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
#include /* For fprintf. */
#endif
/* A unique object in pure space used to make some Lisp objects
on free lists recognizable in O(1). */
static Lisp_Object Vdead;
#define DEADP(x) EQ (x, Vdead)
#ifdef GC_MALLOC_CHECK
enum mem_type allocated_mem_type;
static int dont_register_blocks;
#endif /* GC_MALLOC_CHECK */
/* A node in the red-black tree describing allocated memory containing
Lisp data. Each such block is recorded with its start and end
address when it is allocated, and removed from the tree when it
is freed.
A red-black tree is a balanced binary tree with the following
properties:
1. Every node is either red or black.
2. Every leaf is black.
3. If a node is red, then both of its children are black.
4. Every simple path from a node to a descendant leaf contains
the same number of black nodes.
5. The root is always black.
When nodes are inserted into the tree, or deleted from the tree,
the tree is "fixed" so that these properties are always true.
A red-black tree with N internal nodes has height at most 2
log(N+1). Searches, insertions and deletions are done in O(log N).
Please see a text book about data structures for a detailed
description of red-black trees. Any book worth its salt should
describe them. */
struct mem_node
{
/* Children of this node. These pointers are never NULL. When there
is no child, the value is MEM_NIL, which points to a dummy node. */
struct mem_node *left, *right;
/* The parent of this node. In the root node, this is NULL. */
struct mem_node *parent;
/* Start and end of allocated region. */
void *start, *end;
/* Node color. */
enum {MEM_BLACK, MEM_RED} color;
/* Memory type. */
enum mem_type type;
};
/* Base address of stack. Set in main. */
Lisp_Object *stack_base;
/* Root of the tree describing allocated Lisp memory. */
static struct mem_node *mem_root;
/* Lowest and highest known address in the heap. */
static void *min_heap_address, *max_heap_address;
/* Sentinel node of the tree. */
static struct mem_node mem_z;
#define MEM_NIL &mem_z
static struct Lisp_Vector *allocate_vectorlike (EMACS_INT);
static void lisp_free (POINTER_TYPE *);
static void mark_stack (void);
static int live_vector_p (struct mem_node *, void *);
static int live_buffer_p (struct mem_node *, void *);
static int live_string_p (struct mem_node *, void *);
static int live_cons_p (struct mem_node *, void *);
static int live_symbol_p (struct mem_node *, void *);
static int live_float_p (struct mem_node *, void *);
static int live_misc_p (struct mem_node *, void *);
static void mark_maybe_object (Lisp_Object);
static void mark_memory (void *, void *);
static void mem_init (void);
static struct mem_node *mem_insert (void *, void *, enum mem_type);
static void mem_insert_fixup (struct mem_node *);
static void mem_rotate_left (struct mem_node *);
static void mem_rotate_right (struct mem_node *);
static void mem_delete (struct mem_node *);
static void mem_delete_fixup (struct mem_node *);
static inline struct mem_node *mem_find (void *);
#if GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS
static void check_gcpros (void);
#endif
#endif /* GC_MARK_STACK || GC_MALLOC_CHECK */
#ifndef DEADP
# define DEADP(x) 0
#endif
/* Recording what needs to be marked for gc. */
struct gcpro *gcprolist;
/* Addresses of staticpro'd variables. Initialize it to a nonzero
value; otherwise some compilers put it into BSS. */
#define NSTATICS 0x640
static Lisp_Object *staticvec[NSTATICS] = {&Vpurify_flag};
/* Index of next unused slot in staticvec. */
static int staticidx = 0;
static POINTER_TYPE *pure_alloc (size_t, int);
/* Value is SZ rounded up to the next multiple of ALIGNMENT.
ALIGNMENT must be a power of 2. */
#define ALIGN(ptr, ALIGNMENT) \
((POINTER_TYPE *) ((((uintptr_t) (ptr)) + (ALIGNMENT) - 1) \
& ~((ALIGNMENT) - 1)))
/************************************************************************
Malloc
************************************************************************/
/* Function malloc calls this if it finds we are near exhausting storage. */
void
malloc_warning (const char *str)
{
pending_malloc_warning = str;
}
/* Display an already-pending malloc warning. */
void
display_malloc_warning (void)
{
call3 (intern ("display-warning"),
intern ("alloc"),
build_string (pending_malloc_warning),
intern ("emergency"));
pending_malloc_warning = 0;
}
/* Called if we can't allocate relocatable space for a buffer. */
void
buffer_memory_full (EMACS_INT nbytes)
{
/* If buffers use the relocating allocator, no need to free
spare_memory, because we may have plenty of malloc space left
that we could get, and if we don't, the malloc that fails will
itself cause spare_memory to be freed. If buffers don't use the
relocating allocator, treat this like any other failing
malloc. */
#ifndef REL_ALLOC
memory_full (nbytes);
#endif
/* This used to call error, but if we've run out of memory, we could
get infinite recursion trying to build the string. */
xsignal (Qnil, Vmemory_signal_data);
}
#ifndef XMALLOC_OVERRUN_CHECK
#define XMALLOC_OVERRUN_CHECK_OVERHEAD 0
#else
/* Check for overrun in malloc'ed buffers by wrapping a header and trailer
around each block.
The header consists of XMALLOC_OVERRUN_CHECK_SIZE fixed bytes
followed by XMALLOC_OVERRUN_SIZE_SIZE bytes containing the original
block size in little-endian order. The trailer consists of
XMALLOC_OVERRUN_CHECK_SIZE fixed bytes.
The header is used to detect whether this block has been allocated
through these functions, as some low-level libc functions may
bypass the malloc hooks. */
#define XMALLOC_OVERRUN_CHECK_SIZE 16
#define XMALLOC_OVERRUN_CHECK_OVERHEAD \
(2 * XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE)
/* Define XMALLOC_OVERRUN_SIZE_SIZE so that (1) it's large enough to
hold a size_t value and (2) the header size is a multiple of the
alignment that Emacs needs for C types and for USE_LSB_TAG. */
#define XMALLOC_BASE_ALIGNMENT \
offsetof ( \
struct { \
union { long double d; intmax_t i; void *p; } u; \
char c; \
}, \
c)
#ifdef USE_LSB_TAG
/* A common multiple of the positive integers A and B. Ideally this
would be the least common multiple, but there's no way to do that
as a constant expression in C, so do the best that we can easily do. */
# define COMMON_MULTIPLE(a, b) \
((a) % (b) == 0 ? (a) : (b) % (a) == 0 ? (b) : (a) * (b))
# define XMALLOC_HEADER_ALIGNMENT \
COMMON_MULTIPLE (1 << GCTYPEBITS, XMALLOC_BASE_ALIGNMENT)
#else
# define XMALLOC_HEADER_ALIGNMENT XMALLOC_BASE_ALIGNMENT
#endif
#define XMALLOC_OVERRUN_SIZE_SIZE \
(((XMALLOC_OVERRUN_CHECK_SIZE + sizeof (size_t) \
+ XMALLOC_HEADER_ALIGNMENT - 1) \
/ XMALLOC_HEADER_ALIGNMENT * XMALLOC_HEADER_ALIGNMENT) \
- XMALLOC_OVERRUN_CHECK_SIZE)
static char const xmalloc_overrun_check_header[XMALLOC_OVERRUN_CHECK_SIZE] =
{ '\x9a', '\x9b', '\xae', '\xaf',
'\xbf', '\xbe', '\xce', '\xcf',
'\xea', '\xeb', '\xec', '\xed',
'\xdf', '\xde', '\x9c', '\x9d' };
static char const xmalloc_overrun_check_trailer[XMALLOC_OVERRUN_CHECK_SIZE] =
{ '\xaa', '\xab', '\xac', '\xad',
'\xba', '\xbb', '\xbc', '\xbd',
'\xca', '\xcb', '\xcc', '\xcd',
'\xda', '\xdb', '\xdc', '\xdd' };
/* Insert and extract the block size in the header. */
static void
xmalloc_put_size (unsigned char *ptr, size_t size)
{
int i;
for (i = 0; i < XMALLOC_OVERRUN_SIZE_SIZE; i++)
{
*--ptr = size & ((1 << CHAR_BIT) - 1);
size >>= CHAR_BIT;
}
}
static size_t
xmalloc_get_size (unsigned char *ptr)
{
size_t size = 0;
int i;
ptr -= XMALLOC_OVERRUN_SIZE_SIZE;
for (i = 0; i < XMALLOC_OVERRUN_SIZE_SIZE; i++)
{
size <<= CHAR_BIT;
size += *ptr++;
}
return size;
}
/* The call depth in overrun_check functions. For example, this might happen:
xmalloc()
overrun_check_malloc()
-> malloc -> (via hook)_-> emacs_blocked_malloc
-> overrun_check_malloc
call malloc (hooks are NULL, so real malloc is called).
malloc returns 10000.
add overhead, return 10016.
<- (back in overrun_check_malloc)
add overhead again, return 10032
xmalloc returns 10032.
(time passes).
xfree(10032)
overrun_check_free(10032)
decrease overhead
free(10016) <- crash, because 10000 is the original pointer. */
static ptrdiff_t check_depth;
/* Like malloc, but wraps allocated block with header and trailer. */
static POINTER_TYPE *
overrun_check_malloc (size_t size)
{
register unsigned char *val;
int overhead = ++check_depth == 1 ? XMALLOC_OVERRUN_CHECK_OVERHEAD : 0;
if (SIZE_MAX - overhead < size)
abort ();
val = (unsigned char *) malloc (size + overhead);
if (val && check_depth == 1)
{
memcpy (val, xmalloc_overrun_check_header, XMALLOC_OVERRUN_CHECK_SIZE);
val += XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE;
xmalloc_put_size (val, size);
memcpy (val + size, xmalloc_overrun_check_trailer,
XMALLOC_OVERRUN_CHECK_SIZE);
}
--check_depth;
return (POINTER_TYPE *)val;
}
/* Like realloc, but checks old block for overrun, and wraps new block
with header and trailer. */
static POINTER_TYPE *
overrun_check_realloc (POINTER_TYPE *block, size_t size)
{
register unsigned char *val = (unsigned char *) block;
int overhead = ++check_depth == 1 ? XMALLOC_OVERRUN_CHECK_OVERHEAD : 0;
if (SIZE_MAX - overhead < size)
abort ();
if (val
&& check_depth == 1
&& memcmp (xmalloc_overrun_check_header,
val - XMALLOC_OVERRUN_CHECK_SIZE - XMALLOC_OVERRUN_SIZE_SIZE,
XMALLOC_OVERRUN_CHECK_SIZE) == 0)
{
size_t osize = xmalloc_get_size (val);
if (memcmp (xmalloc_overrun_check_trailer, val + osize,
XMALLOC_OVERRUN_CHECK_SIZE))
abort ();
memset (val + osize, 0, XMALLOC_OVERRUN_CHECK_SIZE);
val -= XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE;
memset (val, 0, XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE);
}
val = (unsigned char *) realloc ((POINTER_TYPE *)val, size + overhead);
if (val && check_depth == 1)
{
memcpy (val, xmalloc_overrun_check_header, XMALLOC_OVERRUN_CHECK_SIZE);
val += XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE;
xmalloc_put_size (val, size);
memcpy (val + size, xmalloc_overrun_check_trailer,
XMALLOC_OVERRUN_CHECK_SIZE);
}
--check_depth;
return (POINTER_TYPE *)val;
}
/* Like free, but checks block for overrun. */
static void
overrun_check_free (POINTER_TYPE *block)
{
unsigned char *val = (unsigned char *) block;
++check_depth;
if (val
&& check_depth == 1
&& memcmp (xmalloc_overrun_check_header,
val - XMALLOC_OVERRUN_CHECK_SIZE - XMALLOC_OVERRUN_SIZE_SIZE,
XMALLOC_OVERRUN_CHECK_SIZE) == 0)
{
size_t osize = xmalloc_get_size (val);
if (memcmp (xmalloc_overrun_check_trailer, val + osize,
XMALLOC_OVERRUN_CHECK_SIZE))
abort ();
#ifdef XMALLOC_CLEAR_FREE_MEMORY
val -= XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE;
memset (val, 0xff, osize + XMALLOC_OVERRUN_CHECK_OVERHEAD);
#else
memset (val + osize, 0, XMALLOC_OVERRUN_CHECK_SIZE);
val -= XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE;
memset (val, 0, XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE);
#endif
}
free (val);
--check_depth;
}
#undef malloc
#undef realloc
#undef free
#define malloc overrun_check_malloc
#define realloc overrun_check_realloc
#define free overrun_check_free
#endif
#ifdef SYNC_INPUT
/* When using SYNC_INPUT, we don't call malloc from a signal handler, so
there's no need to block input around malloc. */
#define MALLOC_BLOCK_INPUT ((void)0)
#define MALLOC_UNBLOCK_INPUT ((void)0)
#else
#define MALLOC_BLOCK_INPUT BLOCK_INPUT
#define MALLOC_UNBLOCK_INPUT UNBLOCK_INPUT
#endif
/* Like malloc but check for no memory and block interrupt input.. */
POINTER_TYPE *
xmalloc (size_t size)
{
register POINTER_TYPE *val;
MALLOC_BLOCK_INPUT;
val = (POINTER_TYPE *) malloc (size);
MALLOC_UNBLOCK_INPUT;
if (!val && size)
memory_full (size);
return val;
}
/* Like realloc but check for no memory and block interrupt input.. */
POINTER_TYPE *
xrealloc (POINTER_TYPE *block, size_t size)
{
register POINTER_TYPE *val;
MALLOC_BLOCK_INPUT;
/* We must call malloc explicitly when BLOCK is 0, since some
reallocs don't do this. */
if (! block)
val = (POINTER_TYPE *) malloc (size);
else
val = (POINTER_TYPE *) realloc (block, size);
MALLOC_UNBLOCK_INPUT;
if (!val && size)
memory_full (size);
return val;
}
/* Like free but block interrupt input. */
void
xfree (POINTER_TYPE *block)
{
if (!block)
return;
MALLOC_BLOCK_INPUT;
free (block);
MALLOC_UNBLOCK_INPUT;
/* We don't call refill_memory_reserve here
because that duplicates doing so in emacs_blocked_free
and the criterion should go there. */
}
/* Other parts of Emacs pass large int values to allocator functions
expecting ptrdiff_t. This is portable in practice, but check it to
be safe. */
verify (INT_MAX <= PTRDIFF_MAX);
/* Allocate an array of NITEMS items, each of size ITEM_SIZE.
Signal an error on memory exhaustion, and block interrupt input. */
void *
xnmalloc (ptrdiff_t nitems, ptrdiff_t item_size)
{
xassert (0 <= nitems && 0 < item_size);
if (min (PTRDIFF_MAX, SIZE_MAX) / item_size < nitems)
memory_full (SIZE_MAX);
return xmalloc (nitems * item_size);
}
/* Reallocate an array PA to make it of NITEMS items, each of size ITEM_SIZE.
Signal an error on memory exhaustion, and block interrupt input. */
void *
xnrealloc (void *pa, ptrdiff_t nitems, ptrdiff_t item_size)
{
xassert (0 <= nitems && 0 < item_size);
if (min (PTRDIFF_MAX, SIZE_MAX) / item_size < nitems)
memory_full (SIZE_MAX);
return xrealloc (pa, nitems * item_size);
}
/* Grow PA, which points to an array of *NITEMS items, and return the
location of the reallocated array, updating *NITEMS to reflect its
new size. The new array will contain at least NITEMS_INCR_MIN more
items, but will not contain more than NITEMS_MAX items total.
ITEM_SIZE is the size of each item, in bytes.
ITEM_SIZE and NITEMS_INCR_MIN must be positive. *NITEMS must be
nonnegative. If NITEMS_MAX is -1, it is treated as if it were
infinity.
If PA is null, then allocate a new array instead of reallocating
the old one. Thus, to grow an array A without saving its old
contents, invoke xfree (A) immediately followed by xgrowalloc (0,
&NITEMS, ...).
Block interrupt input as needed. If memory exhaustion occurs, set
*NITEMS to zero if PA is null, and signal an error (i.e., do not
return). */
void *
xpalloc (void *pa, ptrdiff_t *nitems, ptrdiff_t nitems_incr_min,
ptrdiff_t nitems_max, ptrdiff_t item_size)
{
/* The approximate size to use for initial small allocation
requests. This is the largest "small" request for the GNU C
library malloc. */
enum { DEFAULT_MXFAST = 64 * sizeof (size_t) / 4 };
/* If the array is tiny, grow it to about (but no greater than)
DEFAULT_MXFAST bytes. Otherwise, grow it by about 50%. */
ptrdiff_t n = *nitems;
ptrdiff_t tiny_max = DEFAULT_MXFAST / item_size - n;
ptrdiff_t half_again = n >> 1;
ptrdiff_t incr_estimate = max (tiny_max, half_again);
/* Adjust the increment according to three constraints: NITEMS_INCR_MIN,
NITEMS_MAX, and what the C language can represent safely. */
ptrdiff_t C_language_max = min (PTRDIFF_MAX, SIZE_MAX) / item_size;
ptrdiff_t n_max = (0 <= nitems_max && nitems_max < C_language_max
? nitems_max : C_language_max);
ptrdiff_t nitems_incr_max = n_max - n;
ptrdiff_t incr = max (nitems_incr_min, min (incr_estimate, nitems_incr_max));
xassert (0 < item_size && 0 < nitems_incr_min && 0 <= n && -1 <= nitems_max);
if (! pa)
*nitems = 0;
if (nitems_incr_max < incr)
memory_full (SIZE_MAX);
n += incr;
pa = xrealloc (pa, n * item_size);
*nitems = n;
return pa;
}
/* Like strdup, but uses xmalloc. */
char *
xstrdup (const char *s)
{
size_t len = strlen (s) + 1;
char *p = (char *) xmalloc (len);
memcpy (p, s, len);
return p;
}
/* Unwind for SAFE_ALLOCA */
Lisp_Object
safe_alloca_unwind (Lisp_Object arg)
{
register struct Lisp_Save_Value *p = XSAVE_VALUE (arg);
p->dogc = 0;
xfree (p->pointer);
p->pointer = 0;
free_misc (arg);
return Qnil;
}
/* Like malloc but used for allocating Lisp data. NBYTES is the
number of bytes to allocate, TYPE describes the intended use of the
allocated memory block (for strings, for conses, ...). */
#ifndef USE_LSB_TAG
static void *lisp_malloc_loser;
#endif
static POINTER_TYPE *
lisp_malloc (size_t nbytes, enum mem_type type)
{
register void *val;
MALLOC_BLOCK_INPUT;
#ifdef GC_MALLOC_CHECK
allocated_mem_type = type;
#endif
val = (void *) malloc (nbytes);
#ifndef USE_LSB_TAG
/* If the memory just allocated cannot be addressed thru a Lisp
object's pointer, and it needs to be,
that's equivalent to running out of memory. */
if (val && type != MEM_TYPE_NON_LISP)
{
Lisp_Object tem;
XSETCONS (tem, (char *) val + nbytes - 1);
if ((char *) XCONS (tem) != (char *) val + nbytes - 1)
{
lisp_malloc_loser = val;
free (val);
val = 0;
}
}
#endif
#if GC_MARK_STACK && !defined GC_MALLOC_CHECK
if (val && type != MEM_TYPE_NON_LISP)
mem_insert (val, (char *) val + nbytes, type);
#endif
MALLOC_UNBLOCK_INPUT;
if (!val && nbytes)
memory_full (nbytes);
return val;
}
/* Free BLOCK. This must be called to free memory allocated with a
call to lisp_malloc. */
static void
lisp_free (POINTER_TYPE *block)
{
MALLOC_BLOCK_INPUT;
free (block);
#if GC_MARK_STACK && !defined GC_MALLOC_CHECK
mem_delete (mem_find (block));
#endif
MALLOC_UNBLOCK_INPUT;
}
/* Allocation of aligned blocks of memory to store Lisp data. */
/* The entry point is lisp_align_malloc which returns blocks of at most */
/* BLOCK_BYTES and guarantees they are aligned on a BLOCK_ALIGN boundary. */
/* Use posix_memalloc if the system has it and we're using the system's
malloc (because our gmalloc.c routines don't have posix_memalign although
its memalloc could be used). */
#if defined (HAVE_POSIX_MEMALIGN) && defined (SYSTEM_MALLOC)
#define USE_POSIX_MEMALIGN 1
#endif
/* BLOCK_ALIGN has to be a power of 2. */
#define BLOCK_ALIGN (1 << 10)
/* Padding to leave at the end of a malloc'd block. This is to give
malloc a chance to minimize the amount of memory wasted to alignment.
It should be tuned to the particular malloc library used.
On glibc-2.3.2, malloc never tries to align, so a padding of 0 is best.
posix_memalign on the other hand would ideally prefer a value of 4
because otherwise, there's 1020 bytes wasted between each ablocks.
In Emacs, testing shows that those 1020 can most of the time be
efficiently used by malloc to place other objects, so a value of 0 can
still preferable unless you have a lot of aligned blocks and virtually
nothing else. */
#define BLOCK_PADDING 0
#define BLOCK_BYTES \
(BLOCK_ALIGN - sizeof (struct ablocks *) - BLOCK_PADDING)
/* Internal data structures and constants. */
#define ABLOCKS_SIZE 16
/* An aligned block of memory. */
struct ablock
{
union
{
char payload[BLOCK_BYTES];
struct ablock *next_free;
} x;
/* `abase' is the aligned base of the ablocks. */
/* It is overloaded to hold the virtual `busy' field that counts
the number of used ablock in the parent ablocks.
The first ablock has the `busy' field, the others have the `abase'
field. To tell the difference, we assume that pointers will have
integer values larger than 2 * ABLOCKS_SIZE. The lowest bit of `busy'
is used to tell whether the real base of the parent ablocks is `abase'
(if not, the word before the first ablock holds a pointer to the
real base). */
struct ablocks *abase;
/* The padding of all but the last ablock is unused. The padding of
the last ablock in an ablocks is not allocated. */
#if BLOCK_PADDING
char padding[BLOCK_PADDING];
#endif
};
/* A bunch of consecutive aligned blocks. */
struct ablocks
{
struct ablock blocks[ABLOCKS_SIZE];
};
/* Size of the block requested from malloc or memalign. */
#define ABLOCKS_BYTES (sizeof (struct ablocks) - BLOCK_PADDING)
#define ABLOCK_ABASE(block) \
(((uintptr_t) (block)->abase) <= (1 + 2 * ABLOCKS_SIZE) \
? (struct ablocks *)(block) \
: (block)->abase)
/* Virtual `busy' field. */
#define ABLOCKS_BUSY(abase) ((abase)->blocks[0].abase)
/* Pointer to the (not necessarily aligned) malloc block. */
#ifdef USE_POSIX_MEMALIGN
#define ABLOCKS_BASE(abase) (abase)
#else
#define ABLOCKS_BASE(abase) \
(1 & (intptr_t) ABLOCKS_BUSY (abase) ? abase : ((void**)abase)[-1])
#endif
/* The list of free ablock. */
static struct ablock *free_ablock;
/* Allocate an aligned block of nbytes.
Alignment is on a multiple of BLOCK_ALIGN and `nbytes' has to be
smaller or equal to BLOCK_BYTES. */
static POINTER_TYPE *
lisp_align_malloc (size_t nbytes, enum mem_type type)
{
void *base, *val;
struct ablocks *abase;
eassert (nbytes <= BLOCK_BYTES);
MALLOC_BLOCK_INPUT;
#ifdef GC_MALLOC_CHECK
allocated_mem_type = type;
#endif
if (!free_ablock)
{
int i;
intptr_t aligned; /* int gets warning casting to 64-bit pointer. */
#ifdef DOUG_LEA_MALLOC
/* Prevent mmap'ing the chunk. Lisp data may not be mmap'ed
because mapped region contents are not preserved in
a dumped Emacs. */
mallopt (M_MMAP_MAX, 0);
#endif
#ifdef USE_POSIX_MEMALIGN
{
int err = posix_memalign (&base, BLOCK_ALIGN, ABLOCKS_BYTES);
if (err)
base = NULL;
abase = base;
}
#else
base = malloc (ABLOCKS_BYTES);
abase = ALIGN (base, BLOCK_ALIGN);
#endif
if (base == 0)
{
MALLOC_UNBLOCK_INPUT;
memory_full (ABLOCKS_BYTES);
}
aligned = (base == abase);
if (!aligned)
((void**)abase)[-1] = base;
#ifdef DOUG_LEA_MALLOC
/* Back to a reasonable maximum of mmap'ed areas. */
mallopt (M_MMAP_MAX, MMAP_MAX_AREAS);
#endif
#ifndef USE_LSB_TAG
/* If the memory just allocated cannot be addressed thru a Lisp
object's pointer, and it needs to be, that's equivalent to
running out of memory. */
if (type != MEM_TYPE_NON_LISP)
{
Lisp_Object tem;
char *end = (char *) base + ABLOCKS_BYTES - 1;
XSETCONS (tem, end);
if ((char *) XCONS (tem) != end)
{
lisp_malloc_loser = base;
free (base);
MALLOC_UNBLOCK_INPUT;
memory_full (SIZE_MAX);
}
}
#endif
/* Initialize the blocks and put them on the free list.
Is `base' was not properly aligned, we can't use the last block. */
for (i = 0; i < (aligned ? ABLOCKS_SIZE : ABLOCKS_SIZE - 1); i++)
{
abase->blocks[i].abase = abase;
abase->blocks[i].x.next_free = free_ablock;
free_ablock = &abase->blocks[i];
}
ABLOCKS_BUSY (abase) = (struct ablocks *) aligned;
eassert (0 == ((uintptr_t) abase) % BLOCK_ALIGN);
eassert (ABLOCK_ABASE (&abase->blocks[3]) == abase); /* 3 is arbitrary */
eassert (ABLOCK_ABASE (&abase->blocks[0]) == abase);
eassert (ABLOCKS_BASE (abase) == base);
eassert (aligned == (intptr_t) ABLOCKS_BUSY (abase));
}
abase = ABLOCK_ABASE (free_ablock);
ABLOCKS_BUSY (abase) =
(struct ablocks *) (2 + (intptr_t) ABLOCKS_BUSY (abase));
val = free_ablock;
free_ablock = free_ablock->x.next_free;
#if GC_MARK_STACK && !defined GC_MALLOC_CHECK
if (type != MEM_TYPE_NON_LISP)
mem_insert (val, (char *) val + nbytes, type);
#endif
MALLOC_UNBLOCK_INPUT;
eassert (0 == ((uintptr_t) val) % BLOCK_ALIGN);
return val;
}
static void
lisp_align_free (POINTER_TYPE *block)
{
struct ablock *ablock = block;
struct ablocks *abase = ABLOCK_ABASE (ablock);
MALLOC_BLOCK_INPUT;
#if GC_MARK_STACK && !defined GC_MALLOC_CHECK
mem_delete (mem_find (block));
#endif
/* Put on free list. */
ablock->x.next_free = free_ablock;
free_ablock = ablock;
/* Update busy count. */
ABLOCKS_BUSY (abase) =
(struct ablocks *) (-2 + (intptr_t) ABLOCKS_BUSY (abase));
if (2 > (intptr_t) ABLOCKS_BUSY (abase))
{ /* All the blocks are free. */
int i = 0, aligned = (intptr_t) ABLOCKS_BUSY (abase);
struct ablock **tem = &free_ablock;
struct ablock *atop = &abase->blocks[aligned ? ABLOCKS_SIZE : ABLOCKS_SIZE - 1];
while (*tem)
{
if (*tem >= (struct ablock *) abase && *tem < atop)
{
i++;
*tem = (*tem)->x.next_free;
}
else
tem = &(*tem)->x.next_free;
}
eassert ((aligned & 1) == aligned);
eassert (i == (aligned ? ABLOCKS_SIZE : ABLOCKS_SIZE - 1));
#ifdef USE_POSIX_MEMALIGN
eassert ((uintptr_t) ABLOCKS_BASE (abase) % BLOCK_ALIGN == 0);
#endif
free (ABLOCKS_BASE (abase));
}
MALLOC_UNBLOCK_INPUT;
}
/* Return a new buffer structure allocated from the heap with
a call to lisp_malloc. */
struct buffer *
allocate_buffer (void)
{
struct buffer *b
= (struct buffer *) lisp_malloc (sizeof (struct buffer),
MEM_TYPE_BUFFER);
XSETPVECTYPESIZE (b, PVEC_BUFFER,
((sizeof (struct buffer) + sizeof (EMACS_INT) - 1)
/ sizeof (EMACS_INT)));
return b;
}
#ifndef SYSTEM_MALLOC
/* Arranging to disable input signals while we're in malloc.
This only works with GNU malloc. To help out systems which can't
use GNU malloc, all the calls to malloc, realloc, and free
elsewhere in the code should be inside a BLOCK_INPUT/UNBLOCK_INPUT
pair; unfortunately, we have no idea what C library functions
might call malloc, so we can't really protect them unless you're
using GNU malloc. Fortunately, most of the major operating systems
can use GNU malloc. */
#ifndef SYNC_INPUT
/* When using SYNC_INPUT, we don't call malloc from a signal handler, so
there's no need to block input around malloc. */
#ifndef DOUG_LEA_MALLOC
extern void * (*__malloc_hook) (size_t, const void *);
extern void * (*__realloc_hook) (void *, size_t, const void *);
extern void (*__free_hook) (void *, const void *);
/* Else declared in malloc.h, perhaps with an extra arg. */
#endif /* DOUG_LEA_MALLOC */
static void * (*old_malloc_hook) (size_t, const void *);
static void * (*old_realloc_hook) (void *, size_t, const void*);
static void (*old_free_hook) (void*, const void*);
#ifdef DOUG_LEA_MALLOC
# define BYTES_USED (mallinfo ().uordblks)
#else
# define BYTES_USED _bytes_used
#endif
static size_t bytes_used_when_reconsidered;
/* Value of _bytes_used, when spare_memory was freed. */
static size_t bytes_used_when_full;
/* This function is used as the hook for free to call. */
static void
emacs_blocked_free (void *ptr, const void *ptr2)
{
BLOCK_INPUT_ALLOC;
#ifdef GC_MALLOC_CHECK
if (ptr)
{
struct mem_node *m;
m = mem_find (ptr);
if (m == MEM_NIL || m->start != ptr)
{
fprintf (stderr,
"Freeing `%p' which wasn't allocated with malloc\n", ptr);
abort ();
}
else
{
/* fprintf (stderr, "free %p...%p (%p)\n", m->start, m->end, ptr); */
mem_delete (m);
}
}
#endif /* GC_MALLOC_CHECK */
__free_hook = old_free_hook;
free (ptr);
/* If we released our reserve (due to running out of memory),
and we have a fair amount free once again,
try to set aside another reserve in case we run out once more. */
if (! NILP (Vmemory_full)
/* Verify there is enough space that even with the malloc
hysteresis this call won't run out again.
The code here is correct as long as SPARE_MEMORY
is substantially larger than the block size malloc uses. */
&& (bytes_used_when_full
> ((bytes_used_when_reconsidered = BYTES_USED)
+ max (malloc_hysteresis, 4) * SPARE_MEMORY)))
refill_memory_reserve ();
__free_hook = emacs_blocked_free;
UNBLOCK_INPUT_ALLOC;
}
/* This function is the malloc hook that Emacs uses. */
static void *
emacs_blocked_malloc (size_t size, const void *ptr)
{
void *value;
BLOCK_INPUT_ALLOC;
__malloc_hook = old_malloc_hook;
#ifdef DOUG_LEA_MALLOC
/* Segfaults on my system. --lorentey */
/* mallopt (M_TOP_PAD, malloc_hysteresis * 4096); */
#else
__malloc_extra_blocks = malloc_hysteresis;
#endif
value = (void *) malloc (size);
#ifdef GC_MALLOC_CHECK
{
struct mem_node *m = mem_find (value);
if (m != MEM_NIL)
{
fprintf (stderr, "Malloc returned %p which is already in use\n",
value);
fprintf (stderr, "Region in use is %p...%p, %u bytes, type %d\n",
m->start, m->end, (char *) m->end - (char *) m->start,
m->type);
abort ();
}
if (!dont_register_blocks)
{
mem_insert (value, (char *) value + max (1, size), allocated_mem_type);
allocated_mem_type = MEM_TYPE_NON_LISP;
}
}
#endif /* GC_MALLOC_CHECK */
__malloc_hook = emacs_blocked_malloc;
UNBLOCK_INPUT_ALLOC;
/* fprintf (stderr, "%p malloc\n", value); */
return value;
}
/* This function is the realloc hook that Emacs uses. */
static void *
emacs_blocked_realloc (void *ptr, size_t size, const void *ptr2)
{
void *value;
BLOCK_INPUT_ALLOC;
__realloc_hook = old_realloc_hook;
#ifdef GC_MALLOC_CHECK
if (ptr)
{
struct mem_node *m = mem_find (ptr);
if (m == MEM_NIL || m->start != ptr)
{
fprintf (stderr,
"Realloc of %p which wasn't allocated with malloc\n",
ptr);
abort ();
}
mem_delete (m);
}
/* fprintf (stderr, "%p -> realloc\n", ptr); */
/* Prevent malloc from registering blocks. */
dont_register_blocks = 1;
#endif /* GC_MALLOC_CHECK */
value = (void *) realloc (ptr, size);
#ifdef GC_MALLOC_CHECK
dont_register_blocks = 0;
{
struct mem_node *m = mem_find (value);
if (m != MEM_NIL)
{
fprintf (stderr, "Realloc returns memory that is already in use\n");
abort ();
}
/* Can't handle zero size regions in the red-black tree. */
mem_insert (value, (char *) value + max (size, 1), MEM_TYPE_NON_LISP);
}
/* fprintf (stderr, "%p <- realloc\n", value); */
#endif /* GC_MALLOC_CHECK */
__realloc_hook = emacs_blocked_realloc;
UNBLOCK_INPUT_ALLOC;
return value;
}
#ifdef HAVE_PTHREAD
/* Called from Fdump_emacs so that when the dumped Emacs starts, it has a
normal malloc. Some thread implementations need this as they call
malloc before main. The pthread_self call in BLOCK_INPUT_ALLOC then
calls malloc because it is the first call, and we have an endless loop. */
void
reset_malloc_hooks (void)
{
__free_hook = old_free_hook;
__malloc_hook = old_malloc_hook;
__realloc_hook = old_realloc_hook;
}
#endif /* HAVE_PTHREAD */
/* Called from main to set up malloc to use our hooks. */
void
uninterrupt_malloc (void)
{
#ifdef HAVE_PTHREAD
#ifdef DOUG_LEA_MALLOC
pthread_mutexattr_t attr;
/* GLIBC has a faster way to do this, but let's keep it portable.
This is according to the Single UNIX Specification. */
pthread_mutexattr_init (&attr);
pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_RECURSIVE);
pthread_mutex_init (&alloc_mutex, &attr);
#else /* !DOUG_LEA_MALLOC */
/* Some systems such as Solaris 2.6 don't have a recursive mutex,
and the bundled gmalloc.c doesn't require it. */
pthread_mutex_init (&alloc_mutex, NULL);
#endif /* !DOUG_LEA_MALLOC */
#endif /* HAVE_PTHREAD */
if (__free_hook != emacs_blocked_free)
old_free_hook = __free_hook;
__free_hook = emacs_blocked_free;
if (__malloc_hook != emacs_blocked_malloc)
old_malloc_hook = __malloc_hook;
__malloc_hook = emacs_blocked_malloc;
if (__realloc_hook != emacs_blocked_realloc)
old_realloc_hook = __realloc_hook;
__realloc_hook = emacs_blocked_realloc;
}
#endif /* not SYNC_INPUT */
#endif /* not SYSTEM_MALLOC */
/***********************************************************************
Interval Allocation
***********************************************************************/
/* Number of intervals allocated in an interval_block structure.
The 1020 is 1024 minus malloc overhead. */
#define INTERVAL_BLOCK_SIZE \
((1020 - sizeof (struct interval_block *)) / sizeof (struct interval))
/* Intervals are allocated in chunks in form of an interval_block
structure. */
struct interval_block
{
/* Place `intervals' first, to preserve alignment. */
struct interval intervals[INTERVAL_BLOCK_SIZE];
struct interval_block *next;
};
/* Current interval block. Its `next' pointer points to older
blocks. */
static struct interval_block *interval_block;
/* Index in interval_block above of the next unused interval
structure. */
static int interval_block_index;
/* Number of free and live intervals. */
static EMACS_INT total_free_intervals, total_intervals;
/* List of free intervals. */
static INTERVAL interval_free_list;
/* Initialize interval allocation. */
static void
init_intervals (void)
{
interval_block = NULL;
interval_block_index = INTERVAL_BLOCK_SIZE;
interval_free_list = 0;
}
/* Return a new interval. */
INTERVAL
make_interval (void)
{
INTERVAL val;
/* eassert (!handling_signal); */
MALLOC_BLOCK_INPUT;
if (interval_free_list)
{
val = interval_free_list;
interval_free_list = INTERVAL_PARENT (interval_free_list);
}
else
{
if (interval_block_index == INTERVAL_BLOCK_SIZE)
{
register struct interval_block *newi;
newi = (struct interval_block *) lisp_malloc (sizeof *newi,
MEM_TYPE_NON_LISP);
newi->next = interval_block;
interval_block = newi;
interval_block_index = 0;
}
val = &interval_block->intervals[interval_block_index++];
}
MALLOC_UNBLOCK_INPUT;
consing_since_gc += sizeof (struct interval);
intervals_consed++;
RESET_INTERVAL (val);
val->gcmarkbit = 0;
return val;
}
/* Mark Lisp objects in interval I. */
static void
mark_interval (register INTERVAL i, Lisp_Object dummy)
{
eassert (!i->gcmarkbit); /* Intervals are never shared. */
i->gcmarkbit = 1;
mark_object (i->plist);
}
/* Mark the interval tree rooted in TREE. Don't call this directly;
use the macro MARK_INTERVAL_TREE instead. */
static void
mark_interval_tree (register INTERVAL tree)
{
/* No need to test if this tree has been marked already; this
function is always called through the MARK_INTERVAL_TREE macro,
which takes care of that. */
traverse_intervals_noorder (tree, mark_interval, Qnil);
}
/* Mark the interval tree rooted in I. */
#define MARK_INTERVAL_TREE(i) \
do { \
if (!NULL_INTERVAL_P (i) && !i->gcmarkbit) \
mark_interval_tree (i); \
} while (0)
#define UNMARK_BALANCE_INTERVALS(i) \
do { \
if (! NULL_INTERVAL_P (i)) \
(i) = balance_intervals (i); \
} while (0)
/* Number support. If USE_LISP_UNION_TYPE is in effect, we
can't create number objects in macros. */
#ifndef make_number
Lisp_Object
make_number (EMACS_INT n)
{
Lisp_Object obj;
obj.s.val = n;
obj.s.type = Lisp_Int;
return obj;
}
#endif
/***********************************************************************
String Allocation
***********************************************************************/
/* Lisp_Strings are allocated in string_block structures. When a new
string_block is allocated, all the Lisp_Strings it contains are
added to a free-list string_free_list. When a new Lisp_String is
needed, it is taken from that list. During the sweep phase of GC,
string_blocks that are entirely free are freed, except two which
we keep.
String data is allocated from sblock structures. Strings larger
than LARGE_STRING_BYTES, get their own sblock, data for smaller
strings is sub-allocated out of sblocks of size SBLOCK_SIZE.
Sblocks consist internally of sdata structures, one for each
Lisp_String. The sdata structure points to the Lisp_String it
belongs to. The Lisp_String points back to the `u.data' member of
its sdata structure.
When a Lisp_String is freed during GC, it is put back on
string_free_list, and its `data' member and its sdata's `string'
pointer is set to null. The size of the string is recorded in the
`u.nbytes' member of the sdata. So, sdata structures that are no
longer used, can be easily recognized, and it's easy to compact the
sblocks of small strings which we do in compact_small_strings. */
/* Size in bytes of an sblock structure used for small strings. This
is 8192 minus malloc overhead. */
#define SBLOCK_SIZE 8188
/* Strings larger than this are considered large strings. String data
for large strings is allocated from individual sblocks. */
#define LARGE_STRING_BYTES 1024
/* Structure describing string memory sub-allocated from an sblock.
This is where the contents of Lisp strings are stored. */
struct sdata
{
/* Back-pointer to the string this sdata belongs to. If null, this
structure is free, and the NBYTES member of the union below
contains the string's byte size (the same value that STRING_BYTES
would return if STRING were non-null). If non-null, STRING_BYTES
(STRING) is the size of the data, and DATA contains the string's
contents. */
struct Lisp_String *string;
#ifdef GC_CHECK_STRING_BYTES
EMACS_INT nbytes;
unsigned char data[1];
#define SDATA_NBYTES(S) (S)->nbytes
#define SDATA_DATA(S) (S)->data
#define SDATA_SELECTOR(member) member
#else /* not GC_CHECK_STRING_BYTES */
union
{
/* When STRING is non-null. */
unsigned char data[1];
/* When STRING is null. */
EMACS_INT nbytes;
} u;
#define SDATA_NBYTES(S) (S)->u.nbytes
#define SDATA_DATA(S) (S)->u.data
#define SDATA_SELECTOR(member) u.member
#endif /* not GC_CHECK_STRING_BYTES */
#define SDATA_DATA_OFFSET offsetof (struct sdata, SDATA_SELECTOR (data))
};
/* Structure describing a block of memory which is sub-allocated to
obtain string data memory for strings. Blocks for small strings
are of fixed size SBLOCK_SIZE. Blocks for large strings are made
as large as needed. */
struct sblock
{
/* Next in list. */
struct sblock *next;
/* Pointer to the next free sdata block. This points past the end
of the sblock if there isn't any space left in this block. */
struct sdata *next_free;
/* Start of data. */
struct sdata first_data;
};
/* Number of Lisp strings in a string_block structure. The 1020 is
1024 minus malloc overhead. */
#define STRING_BLOCK_SIZE \
((1020 - sizeof (struct string_block *)) / sizeof (struct Lisp_String))
/* Structure describing a block from which Lisp_String structures
are allocated. */
struct string_block
{
/* Place `strings' first, to preserve alignment. */
struct Lisp_String strings[STRING_BLOCK_SIZE];
struct string_block *next;
};
/* Head and tail of the list of sblock structures holding Lisp string
data. We always allocate from current_sblock. The NEXT pointers
in the sblock structures go from oldest_sblock to current_sblock. */
static struct sblock *oldest_sblock, *current_sblock;
/* List of sblocks for large strings. */
static struct sblock *large_sblocks;
/* List of string_block structures. */
static struct string_block *string_blocks;
/* Free-list of Lisp_Strings. */
static struct Lisp_String *string_free_list;
/* Number of live and free Lisp_Strings. */
static EMACS_INT total_strings, total_free_strings;
/* Number of bytes used by live strings. */
static EMACS_INT total_string_size;
/* Given a pointer to a Lisp_String S which is on the free-list
string_free_list, return a pointer to its successor in the
free-list. */
#define NEXT_FREE_LISP_STRING(S) (*(struct Lisp_String **) (S))
/* Return a pointer to the sdata structure belonging to Lisp string S.
S must be live, i.e. S->data must not be null. S->data is actually
a pointer to the `u.data' member of its sdata structure; the
structure starts at a constant offset in front of that. */
#define SDATA_OF_STRING(S) ((struct sdata *) ((S)->data - SDATA_DATA_OFFSET))
#ifdef GC_CHECK_STRING_OVERRUN
/* We check for overrun in string data blocks by appending a small
"cookie" after each allocated string data block, and check for the
presence of this cookie during GC. */
#define GC_STRING_OVERRUN_COOKIE_SIZE 4
static char const string_overrun_cookie[GC_STRING_OVERRUN_COOKIE_SIZE] =
{ '\xde', '\xad', '\xbe', '\xef' };
#else
#define GC_STRING_OVERRUN_COOKIE_SIZE 0
#endif
/* Value is the size of an sdata structure large enough to hold NBYTES
bytes of string data. The value returned includes a terminating
NUL byte, the size of the sdata structure, and padding. */
#ifdef GC_CHECK_STRING_BYTES
#define SDATA_SIZE(NBYTES) \
((SDATA_DATA_OFFSET \
+ (NBYTES) + 1 \
+ sizeof (EMACS_INT) - 1) \
& ~(sizeof (EMACS_INT) - 1))
#else /* not GC_CHECK_STRING_BYTES */
/* The 'max' reserves space for the nbytes union member even when NBYTES + 1 is
less than the size of that member. The 'max' is not needed when
SDATA_DATA_OFFSET is a multiple of sizeof (EMACS_INT), because then the
alignment code reserves enough space. */
#define SDATA_SIZE(NBYTES) \
((SDATA_DATA_OFFSET \
+ (SDATA_DATA_OFFSET % sizeof (EMACS_INT) == 0 \
? NBYTES \
: max (NBYTES, sizeof (EMACS_INT) - 1)) \
+ 1 \
+ sizeof (EMACS_INT) - 1) \
& ~(sizeof (EMACS_INT) - 1))
#endif /* not GC_CHECK_STRING_BYTES */
/* Extra bytes to allocate for each string. */
#define GC_STRING_EXTRA (GC_STRING_OVERRUN_COOKIE_SIZE)
/* Exact bound on the number of bytes in a string, not counting the
terminating null. A string cannot contain more bytes than
STRING_BYTES_BOUND, nor can it be so long that the size_t
arithmetic in allocate_string_data would overflow while it is
calculating a value to be passed to malloc. */
#define STRING_BYTES_MAX \
min (STRING_BYTES_BOUND, \
((SIZE_MAX - XMALLOC_OVERRUN_CHECK_OVERHEAD \
- GC_STRING_EXTRA \
- offsetof (struct sblock, first_data) \
- SDATA_DATA_OFFSET) \
& ~(sizeof (EMACS_INT) - 1)))
/* Initialize string allocation. Called from init_alloc_once. */
static void
init_strings (void)
{
total_strings = total_free_strings = total_string_size = 0;
oldest_sblock = current_sblock = large_sblocks = NULL;
string_blocks = NULL;
string_free_list = NULL;
empty_unibyte_string = make_pure_string ("", 0, 0, 0);
empty_multibyte_string = make_pure_string ("", 0, 0, 1);
}
#ifdef GC_CHECK_STRING_BYTES
static int check_string_bytes_count;
#define CHECK_STRING_BYTES(S) STRING_BYTES (S)
/* Like GC_STRING_BYTES, but with debugging check. */
EMACS_INT
string_bytes (struct Lisp_String *s)
{
EMACS_INT nbytes =
(s->size_byte < 0 ? s->size & ~ARRAY_MARK_FLAG : s->size_byte);
if (!PURE_POINTER_P (s)
&& s->data
&& nbytes != SDATA_NBYTES (SDATA_OF_STRING (s)))
abort ();
return nbytes;
}
/* Check validity of Lisp strings' string_bytes member in B. */
static void
check_sblock (struct sblock *b)
{
struct sdata *from, *end, *from_end;
end = b->next_free;
for (from = &b->first_data; from < end; from = from_end)
{
/* Compute the next FROM here because copying below may
overwrite data we need to compute it. */
EMACS_INT nbytes;
/* Check that the string size recorded in the string is the
same as the one recorded in the sdata structure. */
if (from->string)
CHECK_STRING_BYTES (from->string);
if (from->string)
nbytes = GC_STRING_BYTES (from->string);
else
nbytes = SDATA_NBYTES (from);
nbytes = SDATA_SIZE (nbytes);
from_end = (struct sdata *) ((char *) from + nbytes + GC_STRING_EXTRA);
}
}
/* Check validity of Lisp strings' string_bytes member. ALL_P
non-zero means check all strings, otherwise check only most
recently allocated strings. Used for hunting a bug. */
static void
check_string_bytes (int all_p)
{
if (all_p)
{
struct sblock *b;
for (b = large_sblocks; b; b = b->next)
{
struct Lisp_String *s = b->first_data.string;
if (s)
CHECK_STRING_BYTES (s);
}
for (b = oldest_sblock; b; b = b->next)
check_sblock (b);
}
else
check_sblock (current_sblock);
}
#endif /* GC_CHECK_STRING_BYTES */
#ifdef GC_CHECK_STRING_FREE_LIST
/* Walk through the string free list looking for bogus next pointers.
This may catch buffer overrun from a previous string. */
static void
check_string_free_list (void)
{
struct Lisp_String *s;
/* Pop a Lisp_String off the free-list. */
s = string_free_list;
while (s != NULL)
{
if ((uintptr_t) s < 1024)
abort ();
s = NEXT_FREE_LISP_STRING (s);
}
}
#else
#define check_string_free_list()
#endif
/* Return a new Lisp_String. */
static struct Lisp_String *
allocate_string (void)
{
struct Lisp_String *s;
/* eassert (!handling_signal); */
MALLOC_BLOCK_INPUT;
/* If the free-list is empty, allocate a new string_block, and
add all the Lisp_Strings in it to the free-list. */
if (string_free_list == NULL)
{
struct string_block *b;
int i;
b = (struct string_block *) lisp_malloc (sizeof *b, MEM_TYPE_STRING);
memset (b, 0, sizeof *b);
b->next = string_blocks;
string_blocks = b;
for (i = STRING_BLOCK_SIZE - 1; i >= 0; --i)
{
s = b->strings + i;
NEXT_FREE_LISP_STRING (s) = string_free_list;
string_free_list = s;
}
total_free_strings += STRING_BLOCK_SIZE;
}
check_string_free_list ();
/* Pop a Lisp_String off the free-list. */
s = string_free_list;
string_free_list = NEXT_FREE_LISP_STRING (s);
MALLOC_UNBLOCK_INPUT;
/* Probably not strictly necessary, but play it safe. */
memset (s, 0, sizeof *s);
--total_free_strings;
++total_strings;
++strings_consed;
consing_since_gc += sizeof *s;
#ifdef GC_CHECK_STRING_BYTES
if (!noninteractive)
{
if (++check_string_bytes_count == 200)
{
check_string_bytes_count = 0;
check_string_bytes (1);
}
else
check_string_bytes (0);
}
#endif /* GC_CHECK_STRING_BYTES */
return s;
}
/* Set up Lisp_String S for holding NCHARS characters, NBYTES bytes,
plus a NUL byte at the end. Allocate an sdata structure for S, and
set S->data to its `u.data' member. Store a NUL byte at the end of
S->data. Set S->size to NCHARS and S->size_byte to NBYTES. Free
S->data if it was initially non-null. */
void
allocate_string_data (struct Lisp_String *s,
EMACS_INT nchars, EMACS_INT nbytes)
{
struct sdata *data, *old_data;
struct sblock *b;
EMACS_INT needed, old_nbytes;
if (STRING_BYTES_MAX < nbytes)
string_overflow ();
/* Determine the number of bytes needed to store NBYTES bytes
of string data. */
needed = SDATA_SIZE (nbytes);
old_data = s->data ? SDATA_OF_STRING (s) : NULL;
old_nbytes = GC_STRING_BYTES (s);
MALLOC_BLOCK_INPUT;
if (nbytes > LARGE_STRING_BYTES)
{
size_t size = offsetof (struct sblock, first_data) + needed;
#ifdef DOUG_LEA_MALLOC
/* Prevent mmap'ing the chunk. Lisp data may not be mmap'ed
because mapped region contents are not preserved in
a dumped Emacs.
In case you think of allowing it in a dumped Emacs at the
cost of not being able to re-dump, there's another reason:
mmap'ed data typically have an address towards the top of the
address space, which won't fit into an EMACS_INT (at least on
32-bit systems with the current tagging scheme). --fx */
mallopt (M_MMAP_MAX, 0);
#endif
b = (struct sblock *) lisp_malloc (size + GC_STRING_EXTRA, MEM_TYPE_NON_LISP);
#ifdef DOUG_LEA_MALLOC
/* Back to a reasonable maximum of mmap'ed areas. */
mallopt (M_MMAP_MAX, MMAP_MAX_AREAS);
#endif
b->next_free = &b->first_data;
b->first_data.string = NULL;
b->next = large_sblocks;
large_sblocks = b;
}
else if (current_sblock == NULL
|| (((char *) current_sblock + SBLOCK_SIZE
- (char *) current_sblock->next_free)
< (needed + GC_STRING_EXTRA)))
{
/* Not enough room in the current sblock. */
b = (struct sblock *) lisp_malloc (SBLOCK_SIZE, MEM_TYPE_NON_LISP);
b->next_free = &b->first_data;
b->first_data.string = NULL;
b->next = NULL;
if (current_sblock)
current_sblock->next = b;
else
oldest_sblock = b;
current_sblock = b;
}
else
b = current_sblock;
data = b->next_free;
b->next_free = (struct sdata *) ((char *) data + needed + GC_STRING_EXTRA);
MALLOC_UNBLOCK_INPUT;
data->string = s;
s->data = SDATA_DATA (data);
#ifdef GC_CHECK_STRING_BYTES
SDATA_NBYTES (data) = nbytes;
#endif
s->size = nchars;
s->size_byte = nbytes;
s->data[nbytes] = '\0';
#ifdef GC_CHECK_STRING_OVERRUN
memcpy ((char *) data + needed, string_overrun_cookie,
GC_STRING_OVERRUN_COOKIE_SIZE);
#endif
/* If S had already data assigned, mark that as free by setting its
string back-pointer to null, and recording the size of the data
in it. */
if (old_data)
{
SDATA_NBYTES (old_data) = old_nbytes;
old_data->string = NULL;
}
consing_since_gc += needed;
}
/* Sweep and compact strings. */
static void
sweep_strings (void)
{
struct string_block *b, *next;
struct string_block *live_blocks = NULL;
string_free_list = NULL;
total_strings = total_free_strings = 0;
total_string_size = 0;
/* Scan strings_blocks, free Lisp_Strings that aren't marked. */
for (b = string_blocks; b; b = next)
{
int i, nfree = 0;
struct Lisp_String *free_list_before = string_free_list;
next = b->next;
for (i = 0; i < STRING_BLOCK_SIZE; ++i)
{
struct Lisp_String *s = b->strings + i;
if (s->data)
{
/* String was not on free-list before. */
if (STRING_MARKED_P (s))
{
/* String is live; unmark it and its intervals. */
UNMARK_STRING (s);
if (!NULL_INTERVAL_P (s->intervals))
UNMARK_BALANCE_INTERVALS (s->intervals);
++total_strings;
total_string_size += STRING_BYTES (s);
}
else
{
/* String is dead. Put it on the free-list. */
struct sdata *data = SDATA_OF_STRING (s);
/* Save the size of S in its sdata so that we know
how large that is. Reset the sdata's string
back-pointer so that we know it's free. */
#ifdef GC_CHECK_STRING_BYTES
if (GC_STRING_BYTES (s) != SDATA_NBYTES (data))
abort ();
#else
data->u.nbytes = GC_STRING_BYTES (s);
#endif
data->string = NULL;
/* Reset the strings's `data' member so that we
know it's free. */
s->data = NULL;
/* Put the string on the free-list. */
NEXT_FREE_LISP_STRING (s) = string_free_list;
string_free_list = s;
++nfree;
}
}
else
{
/* S was on the free-list before. Put it there again. */
NEXT_FREE_LISP_STRING (s) = string_free_list;
string_free_list = s;
++nfree;
}
}
/* Free blocks that contain free Lisp_Strings only, except
the first two of them. */
if (nfree == STRING_BLOCK_SIZE
&& total_free_strings > STRING_BLOCK_SIZE)
{
lisp_free (b);
string_free_list = free_list_before;
}
else
{
total_free_strings += nfree;
b->next = live_blocks;
live_blocks = b;
}
}
check_string_free_list ();
string_blocks = live_blocks;
free_large_strings ();
compact_small_strings ();
check_string_free_list ();
}
/* Free dead large strings. */
static void
free_large_strings (void)
{
struct sblock *b, *next;
struct sblock *live_blocks = NULL;
for (b = large_sblocks; b; b = next)
{
next = b->next;
if (b->first_data.string == NULL)
lisp_free (b);
else
{
b->next = live_blocks;
live_blocks = b;
}
}
large_sblocks = live_blocks;
}
/* Compact data of small strings. Free sblocks that don't contain
data of live strings after compaction. */
static void
compact_small_strings (void)
{
struct sblock *b, *tb, *next;
struct sdata *from, *to, *end, *tb_end;
struct sdata *to_end, *from_end;
/* TB is the sblock we copy to, TO is the sdata within TB we copy
to, and TB_END is the end of TB. */
tb = oldest_sblock;
tb_end = (struct sdata *) ((char *) tb + SBLOCK_SIZE);
to = &tb->first_data;
/* Step through the blocks from the oldest to the youngest. We
expect that old blocks will stabilize over time, so that less
copying will happen this way. */
for (b = oldest_sblock; b; b = b->next)
{
end = b->next_free;
xassert ((char *) end <= (char *) b + SBLOCK_SIZE);
for (from = &b->first_data; from < end; from = from_end)
{
/* Compute the next FROM here because copying below may
overwrite data we need to compute it. */
EMACS_INT nbytes;
#ifdef GC_CHECK_STRING_BYTES
/* Check that the string size recorded in the string is the
same as the one recorded in the sdata structure. */
if (from->string
&& GC_STRING_BYTES (from->string) != SDATA_NBYTES (from))
abort ();
#endif /* GC_CHECK_STRING_BYTES */
if (from->string)
nbytes = GC_STRING_BYTES (from->string);
else
nbytes = SDATA_NBYTES (from);
if (nbytes > LARGE_STRING_BYTES)
abort ();
nbytes = SDATA_SIZE (nbytes);
from_end = (struct sdata *) ((char *) from + nbytes + GC_STRING_EXTRA);
#ifdef GC_CHECK_STRING_OVERRUN
if (memcmp (string_overrun_cookie,
(char *) from_end - GC_STRING_OVERRUN_COOKIE_SIZE,
GC_STRING_OVERRUN_COOKIE_SIZE))
abort ();
#endif
/* FROM->string non-null means it's alive. Copy its data. */
if (from->string)
{
/* If TB is full, proceed with the next sblock. */
to_end = (struct sdata *) ((char *) to + nbytes + GC_STRING_EXTRA);
if (to_end > tb_end)
{
tb->next_free = to;
tb = tb->next;
tb_end = (struct sdata *) ((char *) tb + SBLOCK_SIZE);
to = &tb->first_data;
to_end = (struct sdata *) ((char *) to + nbytes + GC_STRING_EXTRA);
}
/* Copy, and update the string's `data' pointer. */
if (from != to)
{
xassert (tb != b || to < from);
memmove (to, from, nbytes + GC_STRING_EXTRA);
to->string->data = SDATA_DATA (to);
}
/* Advance past the sdata we copied to. */
to = to_end;
}
}
}
/* The rest of the sblocks following TB don't contain live data, so
we can free them. */
for (b = tb->next; b; b = next)
{
next = b->next;
lisp_free (b);
}
tb->next_free = to;
tb->next = NULL;
current_sblock = tb;
}
void
string_overflow (void)
{
error ("Maximum string size exceeded");
}
DEFUN ("make-string", Fmake_string, Smake_string, 2, 2, 0,
doc: /* Return a newly created string of length LENGTH, with INIT in each element.
LENGTH must be an integer.
INIT must be an integer that represents a character. */)
(Lisp_Object length, Lisp_Object init)
{
register Lisp_Object val;
register unsigned char *p, *end;
int c;
EMACS_INT nbytes;
CHECK_NATNUM (length);
CHECK_CHARACTER (init);
c = XFASTINT (init);
if (ASCII_CHAR_P (c))
{
nbytes = XINT (length);
val = make_uninit_string (nbytes);
p = SDATA (val);
end = p + SCHARS (val);
while (p != end)
*p++ = c;
}
else
{
unsigned char str[MAX_MULTIBYTE_LENGTH];
int len = CHAR_STRING (c, str);
EMACS_INT string_len = XINT (length);
if (string_len > STRING_BYTES_MAX / len)
string_overflow ();
nbytes = len * string_len;
val = make_uninit_multibyte_string (string_len, nbytes);
p = SDATA (val);
end = p + nbytes;
while (p != end)
{
memcpy (p, str, len);
p += len;
}
}
*p = 0;
return val;
}
DEFUN ("make-bool-vector", Fmake_bool_vector, Smake_bool_vector, 2, 2, 0,
doc: /* Return a new bool-vector of length LENGTH, using INIT for each element.
LENGTH must be a number. INIT matters only in whether it is t or nil. */)
(Lisp_Object length, Lisp_Object init)
{
register Lisp_Object val;
struct Lisp_Bool_Vector *p;
EMACS_INT length_in_chars, length_in_elts;
int bits_per_value;
CHECK_NATNUM (length);
bits_per_value = sizeof (EMACS_INT) * BOOL_VECTOR_BITS_PER_CHAR;
length_in_elts = (XFASTINT (length) + bits_per_value - 1) / bits_per_value;
length_in_chars = ((XFASTINT (length) + BOOL_VECTOR_BITS_PER_CHAR - 1)
/ BOOL_VECTOR_BITS_PER_CHAR);
/* We must allocate one more elements than LENGTH_IN_ELTS for the
slot `size' of the struct Lisp_Bool_Vector. */
val = Fmake_vector (make_number (length_in_elts + 1), Qnil);
/* No Lisp_Object to trace in there. */
XSETPVECTYPESIZE (XVECTOR (val), PVEC_BOOL_VECTOR, 0);
p = XBOOL_VECTOR (val);
p->size = XFASTINT (length);
if (length_in_chars)
{
memset (p->data, ! NILP (init) ? -1 : 0, length_in_chars);
/* Clear any extraneous bits in the last byte. */
p->data[length_in_chars - 1]
&= (1 << (XINT (length) % BOOL_VECTOR_BITS_PER_CHAR)) - 1;
}
return val;
}
/* Make a string from NBYTES bytes at CONTENTS, and compute the number
of characters from the contents. This string may be unibyte or
multibyte, depending on the contents. */
Lisp_Object
make_string (const char *contents, EMACS_INT nbytes)
{
register Lisp_Object val;
EMACS_INT nchars, multibyte_nbytes;
parse_str_as_multibyte ((const unsigned char *) contents, nbytes,
&nchars, &multibyte_nbytes);
if (nbytes == nchars || nbytes != multibyte_nbytes)
/* CONTENTS contains no multibyte sequences or contains an invalid
multibyte sequence. We must make unibyte string. */
val = make_unibyte_string (contents, nbytes);
else
val = make_multibyte_string (contents, nchars, nbytes);
return val;
}
/* Make an unibyte string from LENGTH bytes at CONTENTS. */
Lisp_Object
make_unibyte_string (const char *contents, EMACS_INT length)
{
register Lisp_Object val;
val = make_uninit_string (length);
memcpy (SDATA (val), contents, length);
return val;
}
/* Make a multibyte string from NCHARS characters occupying NBYTES
bytes at CONTENTS. */
Lisp_Object
make_multibyte_string (const char *contents,
EMACS_INT nchars, EMACS_INT nbytes)
{
register Lisp_Object val;
val = make_uninit_multibyte_string (nchars, nbytes);
memcpy (SDATA (val), contents, nbytes);
return val;
}
/* Make a string from NCHARS characters occupying NBYTES bytes at
CONTENTS. It is a multibyte string if NBYTES != NCHARS. */
Lisp_Object
make_string_from_bytes (const char *contents,
EMACS_INT nchars, EMACS_INT nbytes)
{
register Lisp_Object val;
val = make_uninit_multibyte_string (nchars, nbytes);
memcpy (SDATA (val), contents, nbytes);
if (SBYTES (val) == SCHARS (val))
STRING_SET_UNIBYTE (val);
return val;
}
/* Make a string from NCHARS characters occupying NBYTES bytes at
CONTENTS. The argument MULTIBYTE controls whether to label the
string as multibyte. If NCHARS is negative, it counts the number of
characters by itself. */
Lisp_Object
make_specified_string (const char *contents,
EMACS_INT nchars, EMACS_INT nbytes, int multibyte)
{
register Lisp_Object val;
if (nchars < 0)
{
if (multibyte)
nchars = multibyte_chars_in_text ((const unsigned char *) contents,
nbytes);
else
nchars = nbytes;
}
val = make_uninit_multibyte_string (nchars, nbytes);
memcpy (SDATA (val), contents, nbytes);
if (!multibyte)
STRING_SET_UNIBYTE (val);
return val;
}
/* Make a string from the data at STR, treating it as multibyte if the
data warrants. */
Lisp_Object
build_string (const char *str)
{
return make_string (str, strlen (str));
}
/* Return an unibyte Lisp_String set up to hold LENGTH characters
occupying LENGTH bytes. */
Lisp_Object
make_uninit_string (EMACS_INT length)
{
Lisp_Object val;
if (!length)
return empty_unibyte_string;
val = make_uninit_multibyte_string (length, length);
STRING_SET_UNIBYTE (val);
return val;
}
/* Return a multibyte Lisp_String set up to hold NCHARS characters
which occupy NBYTES bytes. */
Lisp_Object
make_uninit_multibyte_string (EMACS_INT nchars, EMACS_INT nbytes)
{
Lisp_Object string;
struct Lisp_String *s;
if (nchars < 0)
abort ();
if (!nbytes)
return empty_multibyte_string;
s = allocate_string ();
allocate_string_data (s, nchars, nbytes);
XSETSTRING (string, s);
string_chars_consed += nbytes;
return string;
}
/***********************************************************************
Float Allocation
***********************************************************************/
/* We store float cells inside of float_blocks, allocating a new
float_block with malloc whenever necessary. Float cells reclaimed
by GC are put on a free list to be reallocated before allocating
any new float cells from the latest float_block. */
#define FLOAT_BLOCK_SIZE \
(((BLOCK_BYTES - sizeof (struct float_block *) \
/* The compiler might add padding at the end. */ \
- (sizeof (struct Lisp_Float) - sizeof (int))) * CHAR_BIT) \
/ (sizeof (struct Lisp_Float) * CHAR_BIT + 1))
#define GETMARKBIT(block,n) \
(((block)->gcmarkbits[(n) / (sizeof (int) * CHAR_BIT)] \
>> ((n) % (sizeof (int) * CHAR_BIT))) \
& 1)
#define SETMARKBIT(block,n) \
(block)->gcmarkbits[(n) / (sizeof (int) * CHAR_BIT)] \
|= 1 << ((n) % (sizeof (int) * CHAR_BIT))
#define UNSETMARKBIT(block,n) \
(block)->gcmarkbits[(n) / (sizeof (int) * CHAR_BIT)] \
&= ~(1 << ((n) % (sizeof (int) * CHAR_BIT)))
#define FLOAT_BLOCK(fptr) \
((struct float_block *) (((uintptr_t) (fptr)) & ~(BLOCK_ALIGN - 1)))
#define FLOAT_INDEX(fptr) \
((((uintptr_t) (fptr)) & (BLOCK_ALIGN - 1)) / sizeof (struct Lisp_Float))
struct float_block
{
/* Place `floats' at the beginning, to ease up FLOAT_INDEX's job. */
struct Lisp_Float floats[FLOAT_BLOCK_SIZE];
int gcmarkbits[1 + FLOAT_BLOCK_SIZE / (sizeof (int) * CHAR_BIT)];
struct float_block *next;
};
#define FLOAT_MARKED_P(fptr) \
GETMARKBIT (FLOAT_BLOCK (fptr), FLOAT_INDEX ((fptr)))
#define FLOAT_MARK(fptr) \
SETMARKBIT (FLOAT_BLOCK (fptr), FLOAT_INDEX ((fptr)))
#define FLOAT_UNMARK(fptr) \
UNSETMARKBIT (FLOAT_BLOCK (fptr), FLOAT_INDEX ((fptr)))
/* Current float_block. */
static struct float_block *float_block;
/* Index of first unused Lisp_Float in the current float_block. */
static int float_block_index;
/* Free-list of Lisp_Floats. */
static struct Lisp_Float *float_free_list;
/* Initialize float allocation. */
static void
init_float (void)
{
float_block = NULL;
float_block_index = FLOAT_BLOCK_SIZE; /* Force alloc of new float_block. */
float_free_list = 0;
}
/* Return a new float object with value FLOAT_VALUE. */
Lisp_Object
make_float (double float_value)
{
register Lisp_Object val;
/* eassert (!handling_signal); */
MALLOC_BLOCK_INPUT;
if (float_free_list)
{
/* We use the data field for chaining the free list
so that we won't use the same field that has the mark bit. */
XSETFLOAT (val, float_free_list);
float_free_list = float_free_list->u.chain;
}
else
{
if (float_block_index == FLOAT_BLOCK_SIZE)
{
register struct float_block *new;
new = (struct float_block *) lisp_align_malloc (sizeof *new,
MEM_TYPE_FLOAT);
new->next = float_block;
memset (new->gcmarkbits, 0, sizeof new->gcmarkbits);
float_block = new;
float_block_index = 0;
}
XSETFLOAT (val, &float_block->floats[float_block_index]);
float_block_index++;
}
MALLOC_UNBLOCK_INPUT;
XFLOAT_INIT (val, float_value);
eassert (!FLOAT_MARKED_P (XFLOAT (val)));
consing_since_gc += sizeof (struct Lisp_Float);
floats_consed++;
return val;
}
/***********************************************************************
Cons Allocation
***********************************************************************/
/* We store cons cells inside of cons_blocks, allocating a new
cons_block with malloc whenever necessary. Cons cells reclaimed by
GC are put on a free list to be reallocated before allocating
any new cons cells from the latest cons_block. */
#define CONS_BLOCK_SIZE \
(((BLOCK_BYTES - sizeof (struct cons_block *)) * CHAR_BIT) \
/ (sizeof (struct Lisp_Cons) * CHAR_BIT + 1))
#define CONS_BLOCK(fptr) \
((struct cons_block *) ((uintptr_t) (fptr) & ~(BLOCK_ALIGN - 1)))
#define CONS_INDEX(fptr) \
(((uintptr_t) (fptr) & (BLOCK_ALIGN - 1)) / sizeof (struct Lisp_Cons))
struct cons_block
{
/* Place `conses' at the beginning, to ease up CONS_INDEX's job. */
struct Lisp_Cons conses[CONS_BLOCK_SIZE];
int gcmarkbits[1 + CONS_BLOCK_SIZE / (sizeof (int) * CHAR_BIT)];
struct cons_block *next;
};
#define CONS_MARKED_P(fptr) \
GETMARKBIT (CONS_BLOCK (fptr), CONS_INDEX ((fptr)))
#define CONS_MARK(fptr) \
SETMARKBIT (CONS_BLOCK (fptr), CONS_INDEX ((fptr)))
#define CONS_UNMARK(fptr) \
UNSETMARKBIT (CONS_BLOCK (fptr), CONS_INDEX ((fptr)))
/* Current cons_block. */
static struct cons_block *cons_block;
/* Index of first unused Lisp_Cons in the current block. */
static int cons_block_index;
/* Free-list of Lisp_Cons structures. */
static struct Lisp_Cons *cons_free_list;
/* Initialize cons allocation. */
static void
init_cons (void)
{
cons_block = NULL;
cons_block_index = CONS_BLOCK_SIZE; /* Force alloc of new cons_block. */
cons_free_list = 0;
}
/* Explicitly free a cons cell by putting it on the free-list. */
void
free_cons (struct Lisp_Cons *ptr)
{
ptr->u.chain = cons_free_list;
#if GC_MARK_STACK
ptr->car = Vdead;
#endif
cons_free_list = ptr;
}
DEFUN ("cons", Fcons, Scons, 2, 2, 0,
doc: /* Create a new cons, give it CAR and CDR as components, and return it. */)
(Lisp_Object car, Lisp_Object cdr)
{
register Lisp_Object val;
/* eassert (!handling_signal); */
MALLOC_BLOCK_INPUT;
if (cons_free_list)
{
/* We use the cdr for chaining the free list
so that we won't use the same field that has the mark bit. */
XSETCONS (val, cons_free_list);
cons_free_list = cons_free_list->u.chain;
}
else
{
if (cons_block_index == CONS_BLOCK_SIZE)
{
register struct cons_block *new;
new = (struct cons_block *) lisp_align_malloc (sizeof *new,
MEM_TYPE_CONS);
memset (new->gcmarkbits, 0, sizeof new->gcmarkbits);
new->next = cons_block;
cons_block = new;
cons_block_index = 0;
}
XSETCONS (val, &cons_block->conses[cons_block_index]);
cons_block_index++;
}
MALLOC_UNBLOCK_INPUT;
XSETCAR (val, car);
XSETCDR (val, cdr);
eassert (!CONS_MARKED_P (XCONS (val)));
consing_since_gc += sizeof (struct Lisp_Cons);
cons_cells_consed++;
return val;
}
#ifdef GC_CHECK_CONS_LIST
/* Get an error now if there's any junk in the cons free list. */
void
check_cons_list (void)
{
struct Lisp_Cons *tail = cons_free_list;
while (tail)
tail = tail->u.chain;
}
#endif
/* Make a list of 1, 2, 3, 4 or 5 specified objects. */
Lisp_Object
list1 (Lisp_Object arg1)
{
return Fcons (arg1, Qnil);
}
Lisp_Object
list2 (Lisp_Object arg1, Lisp_Object arg2)
{
return Fcons (arg1, Fcons (arg2, Qnil));
}
Lisp_Object
list3 (Lisp_Object arg1, Lisp_Object arg2, Lisp_Object arg3)
{
return Fcons (arg1, Fcons (arg2, Fcons (arg3, Qnil)));
}
Lisp_Object
list4 (Lisp_Object arg1, Lisp_Object arg2, Lisp_Object arg3, Lisp_Object arg4)
{
return Fcons (arg1, Fcons (arg2, Fcons (arg3, Fcons (arg4, Qnil))));
}
Lisp_Object
list5 (Lisp_Object arg1, Lisp_Object arg2, Lisp_Object arg3, Lisp_Object arg4, Lisp_Object arg5)
{
return Fcons (arg1, Fcons (arg2, Fcons (arg3, Fcons (arg4,
Fcons (arg5, Qnil)))));
}
DEFUN ("list", Flist, Slist, 0, MANY, 0,
doc: /* Return a newly created list with specified arguments as elements.
Any number of arguments, even zero arguments, are allowed.
usage: (list &rest OBJECTS) */)
(ptrdiff_t nargs, Lisp_Object *args)
{
register Lisp_Object val;
val = Qnil;
while (nargs > 0)
{
nargs--;
val = Fcons (args[nargs], val);
}
return val;
}
DEFUN ("make-list", Fmake_list, Smake_list, 2, 2, 0,
doc: /* Return a newly created list of length LENGTH, with each element being INIT. */)
(register Lisp_Object length, Lisp_Object init)
{
register Lisp_Object val;
register EMACS_INT size;
CHECK_NATNUM (length);
size = XFASTINT (length);
val = Qnil;
while (size > 0)
{
val = Fcons (init, val);
--size;
if (size > 0)
{
val = Fcons (init, val);
--size;
if (size > 0)
{
val = Fcons (init, val);
--size;
if (size > 0)
{
val = Fcons (init, val);
--size;
if (size > 0)
{
val = Fcons (init, val);
--size;
}
}
}
}
QUIT;
}
return val;
}
/***********************************************************************
Vector Allocation
***********************************************************************/
/* Singly-linked list of all vectors. */
static struct Lisp_Vector *all_vectors;
/* Handy constants for vectorlike objects. */
enum
{
header_size = offsetof (struct Lisp_Vector, contents),
word_size = sizeof (Lisp_Object)
};
/* Value is a pointer to a newly allocated Lisp_Vector structure
with room for LEN Lisp_Objects. */
static struct Lisp_Vector *
allocate_vectorlike (EMACS_INT len)
{
struct Lisp_Vector *p;
size_t nbytes;
MALLOC_BLOCK_INPUT;
#ifdef DOUG_LEA_MALLOC
/* Prevent mmap'ing the chunk. Lisp data may not be mmap'ed
because mapped region contents are not preserved in
a dumped Emacs. */
mallopt (M_MMAP_MAX, 0);
#endif
/* This gets triggered by code which I haven't bothered to fix. --Stef */
/* eassert (!handling_signal); */
nbytes = header_size + len * word_size;
p = (struct Lisp_Vector *) lisp_malloc (nbytes, MEM_TYPE_VECTORLIKE);
#ifdef DOUG_LEA_MALLOC
/* Back to a reasonable maximum of mmap'ed areas. */
mallopt (M_MMAP_MAX, MMAP_MAX_AREAS);
#endif
consing_since_gc += nbytes;
vector_cells_consed += len;
p->header.next.vector = all_vectors;
all_vectors = p;
MALLOC_UNBLOCK_INPUT;
return p;
}
/* Allocate a vector with LEN slots. */
struct Lisp_Vector *
allocate_vector (EMACS_INT len)
{
struct Lisp_Vector *v;
ptrdiff_t nbytes_max = min (PTRDIFF_MAX, SIZE_MAX);
if (min ((nbytes_max - header_size) / word_size, MOST_POSITIVE_FIXNUM) < len)
memory_full (SIZE_MAX);
v = allocate_vectorlike (len);
v->header.size = len;
return v;
}
/* Allocate other vector-like structures. */
struct Lisp_Vector *
allocate_pseudovector (int memlen, int lisplen, EMACS_INT tag)
{
struct Lisp_Vector *v = allocate_vectorlike (memlen);
int i;
/* Only the first lisplen slots will be traced normally by the GC. */
for (i = 0; i < lisplen; ++i)
v->contents[i] = Qnil;
XSETPVECTYPESIZE (v, tag, lisplen);
return v;
}
struct Lisp_Hash_Table *
allocate_hash_table (void)
{
return ALLOCATE_PSEUDOVECTOR (struct Lisp_Hash_Table, count, PVEC_HASH_TABLE);
}
struct window *
allocate_window (void)
{
return ALLOCATE_PSEUDOVECTOR (struct window, current_matrix, PVEC_WINDOW);
}
struct terminal *
allocate_terminal (void)
{
struct terminal *t = ALLOCATE_PSEUDOVECTOR (struct terminal,
next_terminal, PVEC_TERMINAL);
/* Zero out the non-GC'd fields. FIXME: This should be made unnecessary. */
memset (&t->next_terminal, 0,
(char*) (t + 1) - (char*) &t->next_terminal);
return t;
}
struct frame *
allocate_frame (void)
{
struct frame *f = ALLOCATE_PSEUDOVECTOR (struct frame,
face_cache, PVEC_FRAME);
/* Zero out the non-GC'd fields. FIXME: This should be made unnecessary. */
memset (&f->face_cache, 0,
(char *) (f + 1) - (char *) &f->face_cache);
return f;
}
struct Lisp_Process *
allocate_process (void)
{
return ALLOCATE_PSEUDOVECTOR (struct Lisp_Process, pid, PVEC_PROCESS);
}
DEFUN ("make-vector", Fmake_vector, Smake_vector, 2, 2, 0,
doc: /* Return a newly created vector of length LENGTH, with each element being INIT.
See also the function `vector'. */)
(register Lisp_Object length, Lisp_Object init)
{
Lisp_Object vector;
register EMACS_INT sizei;
register EMACS_INT i;
register struct Lisp_Vector *p;
CHECK_NATNUM (length);
sizei = XFASTINT (length);
p = allocate_vector (sizei);
for (i = 0; i < sizei; i++)
p->contents[i] = init;
XSETVECTOR (vector, p);
return vector;
}
DEFUN ("vector", Fvector, Svector, 0, MANY, 0,
doc: /* Return a newly created vector with specified arguments as elements.
Any number of arguments, even zero arguments, are allowed.
usage: (vector &rest OBJECTS) */)
(ptrdiff_t nargs, Lisp_Object *args)
{
register Lisp_Object len, val;
ptrdiff_t i;
register struct Lisp_Vector *p;
XSETFASTINT (len, nargs);
val = Fmake_vector (len, Qnil);
p = XVECTOR (val);
for (i = 0; i < nargs; i++)
p->contents[i] = args[i];
return val;
}
DEFUN ("make-byte-code", Fmake_byte_code, Smake_byte_code, 4, MANY, 0,
doc: /* Create a byte-code object with specified arguments as elements.
The arguments should be the ARGLIST, bytecode-string BYTE-CODE, constant
vector CONSTANTS, maximum stack size DEPTH, (optional) DOCSTRING,
and (optional) INTERACTIVE-SPEC.
The first four arguments are required; at most six have any
significance.
The ARGLIST can be either like the one of `lambda', in which case the arguments
will be dynamically bound before executing the byte code, or it can be an
integer of the form NNNNNNNRMMMMMMM where the 7bit MMMMMMM specifies the
minimum number of arguments, the 7-bit NNNNNNN specifies the maximum number
of arguments (ignoring &rest) and the R bit specifies whether there is a &rest
argument to catch the left-over arguments. If such an integer is used, the
arguments will not be dynamically bound but will be instead pushed on the
stack before executing the byte-code.
usage: (make-byte-code ARGLIST BYTE-CODE CONSTANTS DEPTH &optional DOCSTRING INTERACTIVE-SPEC &rest ELEMENTS) */)
(ptrdiff_t nargs, Lisp_Object *args)
{
register Lisp_Object len, val;
ptrdiff_t i;
register struct Lisp_Vector *p;
XSETFASTINT (len, nargs);
if (!NILP (Vpurify_flag))
val = make_pure_vector (nargs);
else
val = Fmake_vector (len, Qnil);
if (nargs > 1 && STRINGP (args[1]) && STRING_MULTIBYTE (args[1]))
/* BYTECODE-STRING must have been produced by Emacs 20.2 or the
earlier because they produced a raw 8-bit string for byte-code
and now such a byte-code string is loaded as multibyte while
raw 8-bit characters converted to multibyte form. Thus, now we
must convert them back to the original unibyte form. */
args[1] = Fstring_as_unibyte (args[1]);
p = XVECTOR (val);
for (i = 0; i < nargs; i++)
{
if (!NILP (Vpurify_flag))
args[i] = Fpurecopy (args[i]);
p->contents[i] = args[i];
}
XSETPVECTYPE (p, PVEC_COMPILED);
XSETCOMPILED (val, p);
return val;
}
/***********************************************************************
Symbol Allocation
***********************************************************************/
/* Each symbol_block is just under 1020 bytes long, since malloc
really allocates in units of powers of two and uses 4 bytes for its
own overhead. */
#define SYMBOL_BLOCK_SIZE \
((1020 - sizeof (struct symbol_block *)) / sizeof (struct Lisp_Symbol))
struct symbol_block
{
/* Place `symbols' first, to preserve alignment. */
struct Lisp_Symbol symbols[SYMBOL_BLOCK_SIZE];
struct symbol_block *next;
};
/* Current symbol block and index of first unused Lisp_Symbol
structure in it. */
static struct symbol_block *symbol_block;
static int symbol_block_index;
/* List of free symbols. */
static struct Lisp_Symbol *symbol_free_list;
/* Initialize symbol allocation. */
static void
init_symbol (void)
{
symbol_block = NULL;
symbol_block_index = SYMBOL_BLOCK_SIZE;
symbol_free_list = 0;
}
DEFUN ("make-symbol", Fmake_symbol, Smake_symbol, 1, 1, 0,
doc: /* Return a newly allocated uninterned symbol whose name is NAME.
Its value and function definition are void, and its property list is nil. */)
(Lisp_Object name)
{
register Lisp_Object val;
register struct Lisp_Symbol *p;
CHECK_STRING (name);
/* eassert (!handling_signal); */
MALLOC_BLOCK_INPUT;
if (symbol_free_list)
{
XSETSYMBOL (val, symbol_free_list);
symbol_free_list = symbol_free_list->next;
}
else
{
if (symbol_block_index == SYMBOL_BLOCK_SIZE)
{
struct symbol_block *new;
new = (struct symbol_block *) lisp_malloc (sizeof *new,
MEM_TYPE_SYMBOL);
new->next = symbol_block;
symbol_block = new;
symbol_block_index = 0;
}
XSETSYMBOL (val, &symbol_block->symbols[symbol_block_index]);
symbol_block_index++;
}
MALLOC_UNBLOCK_INPUT;
p = XSYMBOL (val);
p->xname = name;
p->plist = Qnil;
p->redirect = SYMBOL_PLAINVAL;
SET_SYMBOL_VAL (p, Qunbound);
p->function = Qunbound;
p->next = NULL;
p->gcmarkbit = 0;
p->interned = SYMBOL_UNINTERNED;
p->constant = 0;
p->declared_special = 0;
consing_since_gc += sizeof (struct Lisp_Symbol);
symbols_consed++;
return val;
}
/***********************************************************************
Marker (Misc) Allocation
***********************************************************************/
/* Allocation of markers and other objects that share that structure.
Works like allocation of conses. */
#define MARKER_BLOCK_SIZE \
((1020 - sizeof (struct marker_block *)) / sizeof (union Lisp_Misc))
struct marker_block
{
/* Place `markers' first, to preserve alignment. */
union Lisp_Misc markers[MARKER_BLOCK_SIZE];
struct marker_block *next;
};
static struct marker_block *marker_block;
static int marker_block_index;
static union Lisp_Misc *marker_free_list;
static void
init_marker (void)
{
marker_block = NULL;
marker_block_index = MARKER_BLOCK_SIZE;
marker_free_list = 0;
}
/* Return a newly allocated Lisp_Misc object, with no substructure. */
Lisp_Object
allocate_misc (void)
{
Lisp_Object val;
/* eassert (!handling_signal); */
MALLOC_BLOCK_INPUT;
if (marker_free_list)
{
XSETMISC (val, marker_free_list);
marker_free_list = marker_free_list->u_free.chain;
}
else
{
if (marker_block_index == MARKER_BLOCK_SIZE)
{
struct marker_block *new;
new = (struct marker_block *) lisp_malloc (sizeof *new,
MEM_TYPE_MISC);
new->next = marker_block;
marker_block = new;
marker_block_index = 0;
total_free_markers += MARKER_BLOCK_SIZE;
}
XSETMISC (val, &marker_block->markers[marker_block_index]);
marker_block_index++;
}
MALLOC_UNBLOCK_INPUT;
--total_free_markers;
consing_since_gc += sizeof (union Lisp_Misc);
misc_objects_consed++;
XMISCANY (val)->gcmarkbit = 0;
return val;
}
/* Free a Lisp_Misc object */
static void
free_misc (Lisp_Object misc)
{
XMISCTYPE (misc) = Lisp_Misc_Free;
XMISC (misc)->u_free.chain = marker_free_list;
marker_free_list = XMISC (misc);
total_free_markers++;
}
/* Return a Lisp_Misc_Save_Value object containing POINTER and
INTEGER. This is used to package C values to call record_unwind_protect.
The unwind function can get the C values back using XSAVE_VALUE. */
Lisp_Object
make_save_value (void *pointer, ptrdiff_t integer)
{
register Lisp_Object val;
register struct Lisp_Save_Value *p;
val = allocate_misc ();
XMISCTYPE (val) = Lisp_Misc_Save_Value;
p = XSAVE_VALUE (val);
p->pointer = pointer;
p->integer = integer;
p->dogc = 0;
return val;
}
DEFUN ("make-marker", Fmake_marker, Smake_marker, 0, 0, 0,
doc: /* Return a newly allocated marker which does not point at any place. */)
(void)
{
register Lisp_Object val;
register struct Lisp_Marker *p;
val = allocate_misc ();
XMISCTYPE (val) = Lisp_Misc_Marker;
p = XMARKER (val);
p->buffer = 0;
p->bytepos = 0;
p->charpos = 0;
p->next = NULL;
p->insertion_type = 0;
return val;
}
/* Put MARKER back on the free list after using it temporarily. */
void
free_marker (Lisp_Object marker)
{
unchain_marker (XMARKER (marker));
free_misc (marker);
}
/* Return a newly created vector or string with specified arguments as
elements. If all the arguments are characters that can fit
in a string of events, make a string; otherwise, make a vector.
Any number of arguments, even zero arguments, are allowed. */
Lisp_Object
make_event_array (register int nargs, Lisp_Object *args)
{
int i;
for (i = 0; i < nargs; i++)
/* The things that fit in a string
are characters that are in 0...127,
after discarding the meta bit and all the bits above it. */
if (!INTEGERP (args[i])
|| (XINT (args[i]) & ~(-CHAR_META)) >= 0200)
return Fvector (nargs, args);
/* Since the loop exited, we know that all the things in it are
characters, so we can make a string. */
{
Lisp_Object result;
result = Fmake_string (make_number (nargs), make_number (0));
for (i = 0; i < nargs; i++)
{
SSET (result, i, XINT (args[i]));
/* Move the meta bit to the right place for a string char. */
if (XINT (args[i]) & CHAR_META)
SSET (result, i, SREF (result, i) | 0x80);
}
return result;
}
}
/************************************************************************
Memory Full Handling
************************************************************************/
/* Called if malloc (NBYTES) returns zero. If NBYTES == SIZE_MAX,
there may have been size_t overflow so that malloc was never
called, or perhaps malloc was invoked successfully but the
resulting pointer had problems fitting into a tagged EMACS_INT. In
either case this counts as memory being full even though malloc did
not fail. */
void
memory_full (size_t nbytes)
{
/* Do not go into hysterics merely because a large request failed. */
int enough_free_memory = 0;
if (SPARE_MEMORY < nbytes)
{
void *p;
MALLOC_BLOCK_INPUT;
p = malloc (SPARE_MEMORY);
if (p)
{
free (p);
enough_free_memory = 1;
}
MALLOC_UNBLOCK_INPUT;
}
if (! enough_free_memory)
{
int i;
Vmemory_full = Qt;
memory_full_cons_threshold = sizeof (struct cons_block);
/* The first time we get here, free the spare memory. */
for (i = 0; i < sizeof (spare_memory) / sizeof (char *); i++)
if (spare_memory[i])
{
if (i == 0)
free (spare_memory[i]);
else if (i >= 1 && i <= 4)
lisp_align_free (spare_memory[i]);
else
lisp_free (spare_memory[i]);
spare_memory[i] = 0;
}
/* Record the space now used. When it decreases substantially,
we can refill the memory reserve. */
#if !defined SYSTEM_MALLOC && !defined SYNC_INPUT
bytes_used_when_full = BYTES_USED;
#endif
}
/* This used to call error, but if we've run out of memory, we could
get infinite recursion trying to build the string. */
xsignal (Qnil, Vmemory_signal_data);
}
/* If we released our reserve (due to running out of memory),
and we have a fair amount free once again,
try to set aside another reserve in case we run out once more.
This is called when a relocatable block is freed in ralloc.c,
and also directly from this file, in case we're not using ralloc.c. */
void
refill_memory_reserve (void)
{
#ifndef SYSTEM_MALLOC
if (spare_memory[0] == 0)
spare_memory[0] = (char *) malloc (SPARE_MEMORY);
if (spare_memory[1] == 0)
spare_memory[1] = (char *) lisp_align_malloc (sizeof (struct cons_block),
MEM_TYPE_CONS);
if (spare_memory[2] == 0)
spare_memory[2] = (char *) lisp_align_malloc (sizeof (struct cons_block),
MEM_TYPE_CONS);
if (spare_memory[3] == 0)
spare_memory[3] = (char *) lisp_align_malloc (sizeof (struct cons_block),
MEM_TYPE_CONS);
if (spare_memory[4] == 0)
spare_memory[4] = (char *) lisp_align_malloc (sizeof (struct cons_block),
MEM_TYPE_CONS);
if (spare_memory[5] == 0)
spare_memory[5] = (char *) lisp_malloc (sizeof (struct string_block),
MEM_TYPE_STRING);
if (spare_memory[6] == 0)
spare_memory[6] = (char *) lisp_malloc (sizeof (struct string_block),
MEM_TYPE_STRING);
if (spare_memory[0] && spare_memory[1] && spare_memory[5])
Vmemory_full = Qnil;
#endif
}
/************************************************************************
C Stack Marking
************************************************************************/
#if GC_MARK_STACK || defined GC_MALLOC_CHECK
/* Conservative C stack marking requires a method to identify possibly
live Lisp objects given a pointer value. We do this by keeping
track of blocks of Lisp data that are allocated in a red-black tree
(see also the comment of mem_node which is the type of nodes in
that tree). Function lisp_malloc adds information for an allocated
block to the red-black tree with calls to mem_insert, and function
lisp_free removes it with mem_delete. Functions live_string_p etc
call mem_find to lookup information about a given pointer in the
tree, and use that to determine if the pointer points to a Lisp
object or not. */
/* Initialize this part of alloc.c. */
static void
mem_init (void)
{
mem_z.left = mem_z.right = MEM_NIL;
mem_z.parent = NULL;
mem_z.color = MEM_BLACK;
mem_z.start = mem_z.end = NULL;
mem_root = MEM_NIL;
}
/* Value is a pointer to the mem_node containing START. Value is
MEM_NIL if there is no node in the tree containing START. */
static inline struct mem_node *
mem_find (void *start)
{
struct mem_node *p;
if (start < min_heap_address || start > max_heap_address)
return MEM_NIL;
/* Make the search always successful to speed up the loop below. */
mem_z.start = start;
mem_z.end = (char *) start + 1;
p = mem_root;
while (start < p->start || start >= p->end)
p = start < p->start ? p->left : p->right;
return p;
}
/* Insert a new node into the tree for a block of memory with start
address START, end address END, and type TYPE. Value is a
pointer to the node that was inserted. */
static struct mem_node *
mem_insert (void *start, void *end, enum mem_type type)
{
struct mem_node *c, *parent, *x;
if (min_heap_address == NULL || start < min_heap_address)
min_heap_address = start;
if (max_heap_address == NULL || end > max_heap_address)
max_heap_address = end;
/* See where in the tree a node for START belongs. In this
particular application, it shouldn't happen that a node is already
present. For debugging purposes, let's check that. */
c = mem_root;
parent = NULL;
#if GC_MARK_STACK != GC_MAKE_GCPROS_NOOPS
while (c != MEM_NIL)
{
if (start >= c->start && start < c->end)
abort ();
parent = c;
c = start < c->start ? c->left : c->right;
}
#else /* GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS */
while (c != MEM_NIL)
{
parent = c;
c = start < c->start ? c->left : c->right;
}
#endif /* GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS */
/* Create a new node. */
#ifdef GC_MALLOC_CHECK
x = (struct mem_node *) _malloc_internal (sizeof *x);
if (x == NULL)
abort ();
#else
x = (struct mem_node *) xmalloc (sizeof *x);
#endif
x->start = start;
x->end = end;
x->type = type;
x->parent = parent;
x->left = x->right = MEM_NIL;
x->color = MEM_RED;
/* Insert it as child of PARENT or install it as root. */
if (parent)
{
if (start < parent->start)
parent->left = x;
else
parent->right = x;
}
else
mem_root = x;
/* Re-establish red-black tree properties. */
mem_insert_fixup (x);
return x;
}
/* Re-establish the red-black properties of the tree, and thereby
balance the tree, after node X has been inserted; X is always red. */
static void
mem_insert_fixup (struct mem_node *x)
{
while (x != mem_root && x->parent->color == MEM_RED)
{
/* X is red and its parent is red. This is a violation of
red-black tree property #3. */
if (x->parent == x->parent->parent->left)
{
/* We're on the left side of our grandparent, and Y is our
"uncle". */
struct mem_node *y = x->parent->parent->right;
if (y->color == MEM_RED)
{
/* Uncle and parent are red but should be black because
X is red. Change the colors accordingly and proceed
with the grandparent. */
x->parent->color = MEM_BLACK;
y->color = MEM_BLACK;
x->parent->parent->color = MEM_RED;
x = x->parent->parent;
}
else
{
/* Parent and uncle have different colors; parent is
red, uncle is black. */
if (x == x->parent->right)
{
x = x->parent;
mem_rotate_left (x);
}
x->parent->color = MEM_BLACK;
x->parent->parent->color = MEM_RED;
mem_rotate_right (x->parent->parent);
}
}
else
{
/* This is the symmetrical case of above. */
struct mem_node *y = x->parent->parent->left;
if (y->color == MEM_RED)
{
x->parent->color = MEM_BLACK;
y->color = MEM_BLACK;
x->parent->parent->color = MEM_RED;
x = x->parent->parent;
}
else
{
if (x == x->parent->left)
{
x = x->parent;
mem_rotate_right (x);
}
x->parent->color = MEM_BLACK;
x->parent->parent->color = MEM_RED;
mem_rotate_left (x->parent->parent);
}
}
}
/* The root may have been changed to red due to the algorithm. Set
it to black so that property #5 is satisfied. */
mem_root->color = MEM_BLACK;
}
/* (x) (y)
/ \ / \
a (y) ===> (x) c
/ \ / \
b c a b */
static void
mem_rotate_left (struct mem_node *x)
{
struct mem_node *y;
/* Turn y's left sub-tree into x's right sub-tree. */
y = x->right;
x->right = y->left;
if (y->left != MEM_NIL)
y->left->parent = x;
/* Y's parent was x's parent. */
if (y != MEM_NIL)
y->parent = x->parent;
/* Get the parent to point to y instead of x. */
if (x->parent)
{
if (x == x->parent->left)
x->parent->left = y;
else
x->parent->right = y;
}
else
mem_root = y;
/* Put x on y's left. */
y->left = x;
if (x != MEM_NIL)
x->parent = y;
}
/* (x) (Y)
/ \ / \
(y) c ===> a (x)
/ \ / \
a b b c */
static void
mem_rotate_right (struct mem_node *x)
{
struct mem_node *y = x->left;
x->left = y->right;
if (y->right != MEM_NIL)
y->right->parent = x;
if (y != MEM_NIL)
y->parent = x->parent;
if (x->parent)
{
if (x == x->parent->right)
x->parent->right = y;
else
x->parent->left = y;
}
else
mem_root = y;
y->right = x;
if (x != MEM_NIL)
x->parent = y;
}
/* Delete node Z from the tree. If Z is null or MEM_NIL, do nothing. */
static void
mem_delete (struct mem_node *z)
{
struct mem_node *x, *y;
if (!z || z == MEM_NIL)
return;
if (z->left == MEM_NIL || z->right == MEM_NIL)
y = z;
else
{
y = z->right;
while (y->left != MEM_NIL)
y = y->left;
}
if (y->left != MEM_NIL)
x = y->left;
else
x = y->right;
x->parent = y->parent;
if (y->parent)
{
if (y == y->parent->left)
y->parent->left = x;
else
y->parent->right = x;
}
else
mem_root = x;
if (y != z)
{
z->start = y->start;
z->end = y->end;
z->type = y->type;
}
if (y->color == MEM_BLACK)
mem_delete_fixup (x);
#ifdef GC_MALLOC_CHECK
_free_internal (y);
#else
xfree (y);
#endif
}
/* Re-establish the red-black properties of the tree, after a
deletion. */
static void
mem_delete_fixup (struct mem_node *x)
{
while (x != mem_root && x->color == MEM_BLACK)
{
if (x == x->parent->left)
{
struct mem_node *w = x->parent->right;
if (w->color == MEM_RED)
{
w->color = MEM_BLACK;
x->parent->color = MEM_RED;
mem_rotate_left (x->parent);
w = x->parent->right;
}
if (w->left->color == MEM_BLACK && w->right->color == MEM_BLACK)
{
w->color = MEM_RED;
x = x->parent;
}
else
{
if (w->right->color == MEM_BLACK)
{
w->left->color = MEM_BLACK;
w->color = MEM_RED;
mem_rotate_right (w);
w = x->parent->right;
}
w->color = x->parent->color;
x->parent->color = MEM_BLACK;
w->right->color = MEM_BLACK;
mem_rotate_left (x->parent);
x = mem_root;
}
}
else
{
struct mem_node *w = x->parent->left;
if (w->color == MEM_RED)
{
w->color = MEM_BLACK;
x->parent->color = MEM_RED;
mem_rotate_right (x->parent);
w = x->parent->left;
}
if (w->right->color == MEM_BLACK && w->left->color == MEM_BLACK)
{
w->color = MEM_RED;
x = x->parent;
}
else
{
if (w->left->color == MEM_BLACK)
{
w->right->color = MEM_BLACK;
w->color = MEM_RED;
mem_rotate_left (w);
w = x->parent->left;
}
w->color = x->parent->color;
x->parent->color = MEM_BLACK;
w->left->color = MEM_BLACK;
mem_rotate_right (x->parent);
x = mem_root;
}
}
}
x->color = MEM_BLACK;
}
/* Value is non-zero if P is a pointer to a live Lisp string on
the heap. M is a pointer to the mem_block for P. */
static inline int
live_string_p (struct mem_node *m, void *p)
{
if (m->type == MEM_TYPE_STRING)
{
struct string_block *b = (struct string_block *) m->start;
ptrdiff_t offset = (char *) p - (char *) &b->strings[0];
/* P must point to the start of a Lisp_String structure, and it
must not be on the free-list. */
return (offset >= 0
&& offset % sizeof b->strings[0] == 0
&& offset < (STRING_BLOCK_SIZE * sizeof b->strings[0])
&& ((struct Lisp_String *) p)->data != NULL);
}
else
return 0;
}
/* Value is non-zero if P is a pointer to a live Lisp cons on
the heap. M is a pointer to the mem_block for P. */
static inline int
live_cons_p (struct mem_node *m, void *p)
{
if (m->type == MEM_TYPE_CONS)
{
struct cons_block *b = (struct cons_block *) m->start;
ptrdiff_t offset = (char *) p - (char *) &b->conses[0];
/* P must point to the start of a Lisp_Cons, not be
one of the unused cells in the current cons block,
and not be on the free-list. */
return (offset >= 0
&& offset % sizeof b->conses[0] == 0
&& offset < (CONS_BLOCK_SIZE * sizeof b->conses[0])
&& (b != cons_block
|| offset / sizeof b->conses[0] < cons_block_index)
&& !EQ (((struct Lisp_Cons *) p)->car, Vdead));
}
else
return 0;
}
/* Value is non-zero if P is a pointer to a live Lisp symbol on
the heap. M is a pointer to the mem_block for P. */
static inline int
live_symbol_p (struct mem_node *m, void *p)
{
if (m->type == MEM_TYPE_SYMBOL)
{
struct symbol_block *b = (struct symbol_block *) m->start;
ptrdiff_t offset = (char *) p - (char *) &b->symbols[0];
/* P must point to the start of a Lisp_Symbol, not be
one of the unused cells in the current symbol block,
and not be on the free-list. */
return (offset >= 0
&& offset % sizeof b->symbols[0] == 0
&& offset < (SYMBOL_BLOCK_SIZE * sizeof b->symbols[0])
&& (b != symbol_block
|| offset / sizeof b->symbols[0] < symbol_block_index)
&& !EQ (((struct Lisp_Symbol *) p)->function, Vdead));
}
else
return 0;
}
/* Value is non-zero if P is a pointer to a live Lisp float on
the heap. M is a pointer to the mem_block for P. */
static inline int
live_float_p (struct mem_node *m, void *p)
{
if (m->type == MEM_TYPE_FLOAT)
{
struct float_block *b = (struct float_block *) m->start;
ptrdiff_t offset = (char *) p - (char *) &b->floats[0];
/* P must point to the start of a Lisp_Float and not be
one of the unused cells in the current float block. */
return (offset >= 0
&& offset % sizeof b->floats[0] == 0
&& offset < (FLOAT_BLOCK_SIZE * sizeof b->floats[0])
&& (b != float_block
|| offset / sizeof b->floats[0] < float_block_index));
}
else
return 0;
}
/* Value is non-zero if P is a pointer to a live Lisp Misc on
the heap. M is a pointer to the mem_block for P. */
static inline int
live_misc_p (struct mem_node *m, void *p)
{
if (m->type == MEM_TYPE_MISC)
{
struct marker_block *b = (struct marker_block *) m->start;
ptrdiff_t offset = (char *) p - (char *) &b->markers[0];
/* P must point to the start of a Lisp_Misc, not be
one of the unused cells in the current misc block,
and not be on the free-list. */
return (offset >= 0
&& offset % sizeof b->markers[0] == 0
&& offset < (MARKER_BLOCK_SIZE * sizeof b->markers[0])
&& (b != marker_block
|| offset / sizeof b->markers[0] < marker_block_index)
&& ((union Lisp_Misc *) p)->u_any.type != Lisp_Misc_Free);
}
else
return 0;
}
/* Value is non-zero if P is a pointer to a live vector-like object.
M is a pointer to the mem_block for P. */
static inline int
live_vector_p (struct mem_node *m, void *p)
{
return (p == m->start && m->type == MEM_TYPE_VECTORLIKE);
}
/* Value is non-zero if P is a pointer to a live buffer. M is a
pointer to the mem_block for P. */
static inline int
live_buffer_p (struct mem_node *m, void *p)
{
/* P must point to the start of the block, and the buffer
must not have been killed. */
return (m->type == MEM_TYPE_BUFFER
&& p == m->start
&& !NILP (((struct buffer *) p)->BUFFER_INTERNAL_FIELD (name)));
}
#endif /* GC_MARK_STACK || defined GC_MALLOC_CHECK */
#if GC_MARK_STACK
#if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
/* Array of objects that are kept alive because the C stack contains
a pattern that looks like a reference to them . */
#define MAX_ZOMBIES 10
static Lisp_Object zombies[MAX_ZOMBIES];
/* Number of zombie objects. */
static EMACS_INT nzombies;
/* Number of garbage collections. */
static EMACS_INT ngcs;
/* Average percentage of zombies per collection. */
static double avg_zombies;
/* Max. number of live and zombie objects. */
static EMACS_INT max_live, max_zombies;
/* Average number of live objects per GC. */
static double avg_live;
DEFUN ("gc-status", Fgc_status, Sgc_status, 0, 0, "",
doc: /* Show information about live and zombie objects. */)
(void)
{
Lisp_Object args[8], zombie_list = Qnil;
EMACS_INT i;
for (i = 0; i < min (MAX_ZOMBIES, nzombies); i++)
zombie_list = Fcons (zombies[i], zombie_list);
args[0] = build_string ("%d GCs, avg live/zombies = %.2f/%.2f (%f%%), max %d/%d\nzombies: %S");
args[1] = make_number (ngcs);
args[2] = make_float (avg_live);
args[3] = make_float (avg_zombies);
args[4] = make_float (avg_zombies / avg_live / 100);
args[5] = make_number (max_live);
args[6] = make_number (max_zombies);
args[7] = zombie_list;
return Fmessage (8, args);
}
#endif /* GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES */
/* Mark OBJ if we can prove it's a Lisp_Object. */
static inline void
mark_maybe_object (Lisp_Object obj)
{
void *po;
struct mem_node *m;
if (INTEGERP (obj))
return;
po = (void *) XPNTR (obj);
m = mem_find (po);
if (m != MEM_NIL)
{
int mark_p = 0;
switch (XTYPE (obj))
{
case Lisp_String:
mark_p = (live_string_p (m, po)
&& !STRING_MARKED_P ((struct Lisp_String *) po));
break;
case Lisp_Cons:
mark_p = (live_cons_p (m, po) && !CONS_MARKED_P (XCONS (obj)));
break;
case Lisp_Symbol:
mark_p = (live_symbol_p (m, po) && !XSYMBOL (obj)->gcmarkbit);
break;
case Lisp_Float:
mark_p = (live_float_p (m, po) && !FLOAT_MARKED_P (XFLOAT (obj)));
break;
case Lisp_Vectorlike:
/* Note: can't check BUFFERP before we know it's a
buffer because checking that dereferences the pointer
PO which might point anywhere. */
if (live_vector_p (m, po))
mark_p = !SUBRP (obj) && !VECTOR_MARKED_P (XVECTOR (obj));
else if (live_buffer_p (m, po))
mark_p = BUFFERP (obj) && !VECTOR_MARKED_P (XBUFFER (obj));
break;
case Lisp_Misc:
mark_p = (live_misc_p (m, po) && !XMISCANY (obj)->gcmarkbit);
break;
default:
break;
}
if (mark_p)
{
#if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
if (nzombies < MAX_ZOMBIES)
zombies[nzombies] = obj;
++nzombies;
#endif
mark_object (obj);
}
}
}
/* If P points to Lisp data, mark that as live if it isn't already
marked. */
static inline void
mark_maybe_pointer (void *p)
{
struct mem_node *m;
/* Quickly rule out some values which can't point to Lisp data. */
if ((intptr_t) p %
#ifdef USE_LSB_TAG
8 /* USE_LSB_TAG needs Lisp data to be aligned on multiples of 8. */
#else
2 /* We assume that Lisp data is aligned on even addresses. */
#endif
)
return;
m = mem_find (p);
if (m != MEM_NIL)
{
Lisp_Object obj = Qnil;
switch (m->type)
{
case MEM_TYPE_NON_LISP:
/* Nothing to do; not a pointer to Lisp memory. */
break;
case MEM_TYPE_BUFFER:
if (live_buffer_p (m, p) && !VECTOR_MARKED_P ((struct buffer *)p))
XSETVECTOR (obj, p);
break;
case MEM_TYPE_CONS:
if (live_cons_p (m, p) && !CONS_MARKED_P ((struct Lisp_Cons *) p))
XSETCONS (obj, p);
break;
case MEM_TYPE_STRING:
if (live_string_p (m, p)
&& !STRING_MARKED_P ((struct Lisp_String *) p))
XSETSTRING (obj, p);
break;
case MEM_TYPE_MISC:
if (live_misc_p (m, p) && !((struct Lisp_Free *) p)->gcmarkbit)
XSETMISC (obj, p);
break;
case MEM_TYPE_SYMBOL:
if (live_symbol_p (m, p) && !((struct Lisp_Symbol *) p)->gcmarkbit)
XSETSYMBOL (obj, p);
break;
case MEM_TYPE_FLOAT:
if (live_float_p (m, p) && !FLOAT_MARKED_P (p))
XSETFLOAT (obj, p);
break;
case MEM_TYPE_VECTORLIKE:
if (live_vector_p (m, p))
{
Lisp_Object tem;
XSETVECTOR (tem, p);
if (!SUBRP (tem) && !VECTOR_MARKED_P (XVECTOR (tem)))
obj = tem;
}
break;
default:
abort ();
}
if (!NILP (obj))
mark_object (obj);
}
}
/* Alignment of Lisp_Object and pointer values. Use offsetof, as it
sometimes returns a smaller alignment than GCC's __alignof__ and
mark_memory might miss objects if __alignof__ were used. For
example, on x86 with WIDE_EMACS_INT, __alignof__ (Lisp_Object) is 8
but GC_LISP_OBJECT_ALIGNMENT should be 4. */
#ifndef GC_LISP_OBJECT_ALIGNMENT
# define GC_LISP_OBJECT_ALIGNMENT offsetof (struct {char a; Lisp_Object b;}, b)
#endif
#define GC_POINTER_ALIGNMENT offsetof (struct {char a; void *b;}, b)
/* Mark Lisp objects referenced from the address range START+OFFSET..END
or END+OFFSET..START. */
static void
mark_memory (void *start, void *end)
{
Lisp_Object *p;
void **pp;
int i;
#if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
nzombies = 0;
#endif
/* Make START the pointer to the start of the memory region,
if it isn't already. */
if (end < start)
{
void *tem = start;
start = end;
end = tem;
}
/* Mark Lisp_Objects. */
for (p = start; (void *) p < end; p++)
for (i = 0; i < sizeof *p; i += GC_LISP_OBJECT_ALIGNMENT)
mark_maybe_object (*(Lisp_Object *) ((char *) p + i));
/* Mark Lisp data pointed to. This is necessary because, in some
situations, the C compiler optimizes Lisp objects away, so that
only a pointer to them remains. Example:
DEFUN ("testme", Ftestme, Stestme, 0, 0, 0, "")
()
{
Lisp_Object obj = build_string ("test");
struct Lisp_String *s = XSTRING (obj);
Fgarbage_collect ();
fprintf (stderr, "test `%s'\n", s->data);
return Qnil;
}
Here, `obj' isn't really used, and the compiler optimizes it
away. The only reference to the life string is through the
pointer `s'. */
for (pp = start; (void *) pp < end; pp++)
for (i = 0; i < sizeof *pp; i += GC_POINTER_ALIGNMENT)
mark_maybe_pointer (*(void **) ((char *) pp + i));
}
/* setjmp will work with GCC unless NON_SAVING_SETJMP is defined in
the GCC system configuration. In gcc 3.2, the only systems for
which this is so are i386-sco5 non-ELF, i386-sysv3 (maybe included
by others?) and ns32k-pc532-min. */
#if !defined GC_SAVE_REGISTERS_ON_STACK && !defined GC_SETJMP_WORKS
static int setjmp_tested_p, longjmps_done;
#define SETJMP_WILL_LIKELY_WORK "\
\n\
Emacs garbage collector has been changed to use conservative stack\n\
marking. Emacs has determined that the method it uses to do the\n\
marking will likely work on your system, but this isn't sure.\n\
\n\
If you are a system-programmer, or can get the help of a local wizard\n\
who is, please take a look at the function mark_stack in alloc.c, and\n\
verify that the methods used are appropriate for your system.\n\
\n\
Please mail the result to .\n\
"
#define SETJMP_WILL_NOT_WORK "\
\n\
Emacs garbage collector has been changed to use conservative stack\n\
marking. Emacs has determined that the default method it uses to do the\n\
marking will not work on your system. We will need a system-dependent\n\
solution for your system.\n\
\n\
Please take a look at the function mark_stack in alloc.c, and\n\
try to find a way to make it work on your system.\n\
\n\
Note that you may get false negatives, depending on the compiler.\n\
In particular, you need to use -O with GCC for this test.\n\
\n\
Please mail the result to .\n\
"
/* Perform a quick check if it looks like setjmp saves registers in a
jmp_buf. Print a message to stderr saying so. When this test
succeeds, this is _not_ a proof that setjmp is sufficient for
conservative stack marking. Only the sources or a disassembly
can prove that. */
static void
test_setjmp (void)
{
char buf[10];
register int x;
jmp_buf jbuf;
int result = 0;
/* Arrange for X to be put in a register. */
sprintf (buf, "1");
x = strlen (buf);
x = 2 * x - 1;
setjmp (jbuf);
if (longjmps_done == 1)
{
/* Came here after the longjmp at the end of the function.
If x == 1, the longjmp has restored the register to its
value before the setjmp, and we can hope that setjmp
saves all such registers in the jmp_buf, although that
isn't sure.
For other values of X, either something really strange is
taking place, or the setjmp just didn't save the register. */
if (x == 1)
fprintf (stderr, SETJMP_WILL_LIKELY_WORK);
else
{
fprintf (stderr, SETJMP_WILL_NOT_WORK);
exit (1);
}
}
++longjmps_done;
x = 2;
if (longjmps_done == 1)
longjmp (jbuf, 1);
}
#endif /* not GC_SAVE_REGISTERS_ON_STACK && not GC_SETJMP_WORKS */
#if GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS
/* Abort if anything GCPRO'd doesn't survive the GC. */
static void
check_gcpros (void)
{
struct gcpro *p;
ptrdiff_t i;
for (p = gcprolist; p; p = p->next)
for (i = 0; i < p->nvars; ++i)
if (!survives_gc_p (p->var[i]))
/* FIXME: It's not necessarily a bug. It might just be that the
GCPRO is unnecessary or should release the object sooner. */
abort ();
}
#elif GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
static void
dump_zombies (void)
{
int i;
fprintf (stderr, "\nZombies kept alive = %"pI"d:\n", nzombies);
for (i = 0; i < min (MAX_ZOMBIES, nzombies); ++i)
{
fprintf (stderr, " %d = ", i);
debug_print (zombies[i]);
}
}
#endif /* GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES */
/* Mark live Lisp objects on the C stack.
There are several system-dependent problems to consider when
porting this to new architectures:
Processor Registers
We have to mark Lisp objects in CPU registers that can hold local
variables or are used to pass parameters.
If GC_SAVE_REGISTERS_ON_STACK is defined, it should expand to
something that either saves relevant registers on the stack, or
calls mark_maybe_object passing it each register's contents.
If GC_SAVE_REGISTERS_ON_STACK is not defined, the current
implementation assumes that calling setjmp saves registers we need
to see in a jmp_buf which itself lies on the stack. This doesn't
have to be true! It must be verified for each system, possibly
by taking a look at the source code of setjmp.
If __builtin_unwind_init is available (defined by GCC >= 2.8) we
can use it as a machine independent method to store all registers
to the stack. In this case the macros described in the previous
two paragraphs are not used.
Stack Layout
Architectures differ in the way their processor stack is organized.
For example, the stack might look like this
+----------------+
| Lisp_Object | size = 4
+----------------+
| something else | size = 2
+----------------+
| Lisp_Object | size = 4
+----------------+
| ... |
In such a case, not every Lisp_Object will be aligned equally. To
find all Lisp_Object on the stack it won't be sufficient to walk
the stack in steps of 4 bytes. Instead, two passes will be
necessary, one starting at the start of the stack, and a second
pass starting at the start of the stack + 2. Likewise, if the
minimal alignment of Lisp_Objects on the stack is 1, four passes
would be necessary, each one starting with one byte more offset
from the stack start. */
static void
mark_stack (void)
{
void *end;
#ifdef HAVE___BUILTIN_UNWIND_INIT
/* Force callee-saved registers and register windows onto the stack.
This is the preferred method if available, obviating the need for
machine dependent methods. */
__builtin_unwind_init ();
end = &end;
#else /* not HAVE___BUILTIN_UNWIND_INIT */
#ifndef GC_SAVE_REGISTERS_ON_STACK
/* jmp_buf may not be aligned enough on darwin-ppc64 */
union aligned_jmpbuf {
Lisp_Object o;
jmp_buf j;
} j;
volatile int stack_grows_down_p = (char *) &j > (char *) stack_base;
#endif
/* This trick flushes the register windows so that all the state of
the process is contained in the stack. */
/* Fixme: Code in the Boehm GC suggests flushing (with `flushrs') is
needed on ia64 too. See mach_dep.c, where it also says inline
assembler doesn't work with relevant proprietary compilers. */
#ifdef __sparc__
#if defined (__sparc64__) && defined (__FreeBSD__)
/* FreeBSD does not have a ta 3 handler. */
asm ("flushw");
#else
asm ("ta 3");
#endif
#endif
/* Save registers that we need to see on the stack. We need to see
registers used to hold register variables and registers used to
pass parameters. */
#ifdef GC_SAVE_REGISTERS_ON_STACK
GC_SAVE_REGISTERS_ON_STACK (end);
#else /* not GC_SAVE_REGISTERS_ON_STACK */
#ifndef GC_SETJMP_WORKS /* If it hasn't been checked yet that
setjmp will definitely work, test it
and print a message with the result
of the test. */
if (!setjmp_tested_p)
{
setjmp_tested_p = 1;
test_setjmp ();
}
#endif /* GC_SETJMP_WORKS */
setjmp (j.j);
end = stack_grows_down_p ? (char *) &j + sizeof j : (char *) &j;
#endif /* not GC_SAVE_REGISTERS_ON_STACK */
#endif /* not HAVE___BUILTIN_UNWIND_INIT */
/* This assumes that the stack is a contiguous region in memory. If
that's not the case, something has to be done here to iterate
over the stack segments. */
mark_memory (stack_base, end);
/* Allow for marking a secondary stack, like the register stack on the
ia64. */
#ifdef GC_MARK_SECONDARY_STACK
GC_MARK_SECONDARY_STACK ();
#endif
#if GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS
check_gcpros ();
#endif
}
#endif /* GC_MARK_STACK != 0 */
/* Determine whether it is safe to access memory at address P. */
static int
valid_pointer_p (void *p)
{
#ifdef WINDOWSNT
return w32_valid_pointer_p (p, 16);
#else
int fd[2];
/* Obviously, we cannot just access it (we would SEGV trying), so we
trick the o/s to tell us whether p is a valid pointer.
Unfortunately, we cannot use NULL_DEVICE here, as emacs_write may
not validate p in that case. */
if (pipe (fd) == 0)
{
int valid = (emacs_write (fd[1], (char *) p, 16) == 16);
emacs_close (fd[1]);
emacs_close (fd[0]);
return valid;
}
return -1;
#endif
}
/* Return 1 if OBJ is a valid lisp object.
Return 0 if OBJ is NOT a valid lisp object.
Return -1 if we cannot validate OBJ.
This function can be quite slow,
so it should only be used in code for manual debugging. */
int
valid_lisp_object_p (Lisp_Object obj)
{
void *p;
#if GC_MARK_STACK
struct mem_node *m;
#endif
if (INTEGERP (obj))
return 1;
p = (void *) XPNTR (obj);
if (PURE_POINTER_P (p))
return 1;
#if !GC_MARK_STACK
return valid_pointer_p (p);
#else
m = mem_find (p);
if (m == MEM_NIL)
{
int valid = valid_pointer_p (p);
if (valid <= 0)
return valid;
if (SUBRP (obj))
return 1;
return 0;
}
switch (m->type)
{
case MEM_TYPE_NON_LISP:
return 0;
case MEM_TYPE_BUFFER:
return live_buffer_p (m, p);
case MEM_TYPE_CONS:
return live_cons_p (m, p);
case MEM_TYPE_STRING:
return live_string_p (m, p);
case MEM_TYPE_MISC:
return live_misc_p (m, p);
case MEM_TYPE_SYMBOL:
return live_symbol_p (m, p);
case MEM_TYPE_FLOAT:
return live_float_p (m, p);
case MEM_TYPE_VECTORLIKE:
return live_vector_p (m, p);
default:
break;
}
return 0;
#endif
}
/***********************************************************************
Pure Storage Management
***********************************************************************/
/* Allocate room for SIZE bytes from pure Lisp storage and return a
pointer to it. TYPE is the Lisp type for which the memory is
allocated. TYPE < 0 means it's not used for a Lisp object. */
static POINTER_TYPE *
pure_alloc (size_t size, int type)
{
POINTER_TYPE *result;
#ifdef USE_LSB_TAG
size_t alignment = (1 << GCTYPEBITS);
#else
size_t alignment = sizeof (EMACS_INT);
/* Give Lisp_Floats an extra alignment. */
if (type == Lisp_Float)
{
#if defined __GNUC__ && __GNUC__ >= 2
alignment = __alignof (struct Lisp_Float);
#else
alignment = sizeof (struct Lisp_Float);
#endif
}
#endif
again:
if (type >= 0)
{
/* Allocate space for a Lisp object from the beginning of the free
space with taking account of alignment. */
result = ALIGN (purebeg + pure_bytes_used_lisp, alignment);
pure_bytes_used_lisp = ((char *)result - (char *)purebeg) + size;
}
else
{
/* Allocate space for a non-Lisp object from the end of the free
space. */
pure_bytes_used_non_lisp += size;
result = purebeg + pure_size - pure_bytes_used_non_lisp;
}
pure_bytes_used = pure_bytes_used_lisp + pure_bytes_used_non_lisp;
if (pure_bytes_used <= pure_size)
return result;
/* Don't allocate a large amount here,
because it might get mmap'd and then its address
might not be usable. */
purebeg = (char *) xmalloc (10000);
pure_size = 10000;
pure_bytes_used_before_overflow += pure_bytes_used - size;
pure_bytes_used = 0;
pure_bytes_used_lisp = pure_bytes_used_non_lisp = 0;
goto again;
}
/* Print a warning if PURESIZE is too small. */
void
check_pure_size (void)
{
if (pure_bytes_used_before_overflow)
message (("emacs:0:Pure Lisp storage overflow (approx. %"pI"d"
" bytes needed)"),
pure_bytes_used + pure_bytes_used_before_overflow);
}
/* Find the byte sequence {DATA[0], ..., DATA[NBYTES-1], '\0'} from
the non-Lisp data pool of the pure storage, and return its start
address. Return NULL if not found. */
static char *
find_string_data_in_pure (const char *data, EMACS_INT nbytes)
{
int i;
EMACS_INT skip, bm_skip[256], last_char_skip, infinity, start, start_max;
const unsigned char *p;
char *non_lisp_beg;
if (pure_bytes_used_non_lisp < nbytes + 1)
return NULL;
/* Set up the Boyer-Moore table. */
skip = nbytes + 1;
for (i = 0; i < 256; i++)
bm_skip[i] = skip;
p = (const unsigned char *) data;
while (--skip > 0)
bm_skip[*p++] = skip;
last_char_skip = bm_skip['\0'];
non_lisp_beg = purebeg + pure_size - pure_bytes_used_non_lisp;
start_max = pure_bytes_used_non_lisp - (nbytes + 1);
/* See the comments in the function `boyer_moore' (search.c) for the
use of `infinity'. */
infinity = pure_bytes_used_non_lisp + 1;
bm_skip['\0'] = infinity;
p = (const unsigned char *) non_lisp_beg + nbytes;
start = 0;
do
{
/* Check the last character (== '\0'). */
do
{
start += bm_skip[*(p + start)];
}
while (start <= start_max);
if (start < infinity)
/* Couldn't find the last character. */
return NULL;
/* No less than `infinity' means we could find the last
character at `p[start - infinity]'. */
start -= infinity;
/* Check the remaining characters. */
if (memcmp (data, non_lisp_beg + start, nbytes) == 0)
/* Found. */
return non_lisp_beg + start;
start += last_char_skip;
}
while (start <= start_max);
return NULL;
}
/* Return a string allocated in pure space. DATA is a buffer holding
NCHARS characters, and NBYTES bytes of string data. MULTIBYTE
non-zero means make the result string multibyte.
Must get an error if pure storage is full, since if it cannot hold
a large string it may be able to hold conses that point to that
string; then the string is not protected from gc. */
Lisp_Object
make_pure_string (const char *data,
EMACS_INT nchars, EMACS_INT nbytes, int multibyte)
{
Lisp_Object string;
struct Lisp_String *s;
s = (struct Lisp_String *) pure_alloc (sizeof *s, Lisp_String);
s->data = (unsigned char *) find_string_data_in_pure (data, nbytes);
if (s->data == NULL)
{
s->data = (unsigned char *) pure_alloc (nbytes + 1, -1);
memcpy (s->data, data, nbytes);
s->data[nbytes] = '\0';
}
s->size = nchars;
s->size_byte = multibyte ? nbytes : -1;
s->intervals = NULL_INTERVAL;
XSETSTRING (string, s);
return string;
}
/* Return a string a string allocated in pure space. Do not allocate
the string data, just point to DATA. */
Lisp_Object
make_pure_c_string (const char *data)
{
Lisp_Object string;
struct Lisp_String *s;
EMACS_INT nchars = strlen (data);
s = (struct Lisp_String *) pure_alloc (sizeof *s, Lisp_String);
s->size = nchars;
s->size_byte = -1;
s->data = (unsigned char *) data;
s->intervals = NULL_INTERVAL;
XSETSTRING (string, s);
return string;
}
/* Return a cons allocated from pure space. Give it pure copies
of CAR as car and CDR as cdr. */
Lisp_Object
pure_cons (Lisp_Object car, Lisp_Object cdr)
{
register Lisp_Object new;
struct Lisp_Cons *p;
p = (struct Lisp_Cons *) pure_alloc (sizeof *p, Lisp_Cons);
XSETCONS (new, p);
XSETCAR (new, Fpurecopy (car));
XSETCDR (new, Fpurecopy (cdr));
return new;
}
/* Value is a float object with value NUM allocated from pure space. */
static Lisp_Object
make_pure_float (double num)
{
register Lisp_Object new;
struct Lisp_Float *p;
p = (struct Lisp_Float *) pure_alloc (sizeof *p, Lisp_Float);
XSETFLOAT (new, p);
XFLOAT_INIT (new, num);
return new;
}
/* Return a vector with room for LEN Lisp_Objects allocated from
pure space. */
Lisp_Object
make_pure_vector (EMACS_INT len)
{
Lisp_Object new;
struct Lisp_Vector *p;
size_t size = (offsetof (struct Lisp_Vector, contents)
+ len * sizeof (Lisp_Object));
p = (struct Lisp_Vector *) pure_alloc (size, Lisp_Vectorlike);
XSETVECTOR (new, p);
XVECTOR (new)->header.size = len;
return new;
}
DEFUN ("purecopy", Fpurecopy, Spurecopy, 1, 1, 0,
doc: /* Make a copy of object OBJ in pure storage.
Recursively copies contents of vectors and cons cells.
Does not copy symbols. Copies strings without text properties. */)
(register Lisp_Object obj)
{
if (NILP (Vpurify_flag))
return obj;
if (PURE_POINTER_P (XPNTR (obj)))
return obj;
if (HASH_TABLE_P (Vpurify_flag)) /* Hash consing. */
{
Lisp_Object tmp = Fgethash (obj, Vpurify_flag, Qnil);
if (!NILP (tmp))
return tmp;
}
if (CONSP (obj))
obj = pure_cons (XCAR (obj), XCDR (obj));
else if (FLOATP (obj))
obj = make_pure_float (XFLOAT_DATA (obj));
else if (STRINGP (obj))
obj = make_pure_string (SSDATA (obj), SCHARS (obj),
SBYTES (obj),
STRING_MULTIBYTE (obj));
else if (COMPILEDP (obj) || VECTORP (obj))
{
register struct Lisp_Vector *vec;
register EMACS_INT i;
EMACS_INT size;
size = ASIZE (obj);
if (size & PSEUDOVECTOR_FLAG)
size &= PSEUDOVECTOR_SIZE_MASK;
vec = XVECTOR (make_pure_vector (size));
for (i = 0; i < size; i++)
vec->contents[i] = Fpurecopy (XVECTOR (obj)->contents[i]);
if (COMPILEDP (obj))
{
XSETPVECTYPE (vec, PVEC_COMPILED);
XSETCOMPILED (obj, vec);
}
else
XSETVECTOR (obj, vec);
}
else if (MARKERP (obj))
error ("Attempt to copy a marker to pure storage");
else
/* Not purified, don't hash-cons. */
return obj;
if (HASH_TABLE_P (Vpurify_flag)) /* Hash consing. */
Fputhash (obj, obj, Vpurify_flag);
return obj;
}
/***********************************************************************
Protection from GC
***********************************************************************/
/* Put an entry in staticvec, pointing at the variable with address
VARADDRESS. */
void
staticpro (Lisp_Object *varaddress)
{
staticvec[staticidx++] = varaddress;
if (staticidx >= NSTATICS)
abort ();
}
/***********************************************************************
Protection from GC
***********************************************************************/
/* Temporarily prevent garbage collection. */
int
inhibit_garbage_collection (void)
{
int count = SPECPDL_INDEX ();
specbind (Qgc_cons_threshold, make_number (MOST_POSITIVE_FIXNUM));
return count;
}
DEFUN ("garbage-collect", Fgarbage_collect, Sgarbage_collect, 0, 0, "",
doc: /* Reclaim storage for Lisp objects no longer needed.
Garbage collection happens automatically if you cons more than
`gc-cons-threshold' bytes of Lisp data since previous garbage collection.
`garbage-collect' normally returns a list with info on amount of space in use:
((USED-CONSES . FREE-CONSES) (USED-SYMS . FREE-SYMS)
(USED-MARKERS . FREE-MARKERS) USED-STRING-CHARS USED-VECTOR-SLOTS
(USED-FLOATS . FREE-FLOATS) (USED-INTERVALS . FREE-INTERVALS)
(USED-STRINGS . FREE-STRINGS))
However, if there was overflow in pure space, `garbage-collect'
returns nil, because real GC can't be done. */)
(void)
{
register struct specbinding *bind;
char stack_top_variable;
ptrdiff_t i;
int message_p;
Lisp_Object total[8];
int count = SPECPDL_INDEX ();
EMACS_TIME t1, t2, t3;
if (abort_on_gc)
abort ();
/* Can't GC if pure storage overflowed because we can't determine
if something is a pure object or not. */
if (pure_bytes_used_before_overflow)
return Qnil;
CHECK_CONS_LIST ();
/* Don't keep undo information around forever.
Do this early on, so it is no problem if the user quits. */
{
register struct buffer *nextb = all_buffers;
while (nextb)
{
/* If a buffer's undo list is Qt, that means that undo is
turned off in that buffer. Calling truncate_undo_list on
Qt tends to return NULL, which effectively turns undo back on.
So don't call truncate_undo_list if undo_list is Qt. */
if (! NILP (nextb->BUFFER_INTERNAL_FIELD (name)) && ! EQ (nextb->BUFFER_INTERNAL_FIELD (undo_list), Qt))
truncate_undo_list (nextb);
/* Shrink buffer gaps, but skip indirect and dead buffers. */
if (nextb->base_buffer == 0 && !NILP (nextb->BUFFER_INTERNAL_FIELD (name))
&& ! nextb->text->inhibit_shrinking)
{
/* If a buffer's gap size is more than 10% of the buffer
size, or larger than 2000 bytes, then shrink it
accordingly. Keep a minimum size of 20 bytes. */
int size = min (2000, max (20, (nextb->text->z_byte / 10)));
if (nextb->text->gap_size > size)
{
struct buffer *save_current = current_buffer;
current_buffer = nextb;
make_gap (-(nextb->text->gap_size - size));
current_buffer = save_current;
}
}
nextb = nextb->header.next.buffer;
}
}
EMACS_GET_TIME (t1);
/* In case user calls debug_print during GC,
don't let that cause a recursive GC. */
consing_since_gc = 0;
/* Save what's currently displayed in the echo area. */
message_p = push_message ();
record_unwind_protect (pop_message_unwind, Qnil);
/* Save a copy of the contents of the stack, for debugging. */
#if MAX_SAVE_STACK > 0
if (NILP (Vpurify_flag))
{
char *stack;
ptrdiff_t stack_size;
if (&stack_top_variable < stack_bottom)
{
stack = &stack_top_variable;
stack_size = stack_bottom - &stack_top_variable;
}
else
{
stack = stack_bottom;
stack_size = &stack_top_variable - stack_bottom;
}
if (stack_size <= MAX_SAVE_STACK)
{
if (stack_copy_size < stack_size)
{
stack_copy = (char *) xrealloc (stack_copy, stack_size);
stack_copy_size = stack_size;
}
memcpy (stack_copy, stack, stack_size);
}
}
#endif /* MAX_SAVE_STACK > 0 */
if (garbage_collection_messages)
message1_nolog ("Garbage collecting...");
BLOCK_INPUT;
shrink_regexp_cache ();
gc_in_progress = 1;
/* clear_marks (); */
/* Mark all the special slots that serve as the roots of accessibility. */
for (i = 0; i < staticidx; i++)
mark_object (*staticvec[i]);
for (bind = specpdl; bind != specpdl_ptr; bind++)
{
mark_object (bind->symbol);
mark_object (bind->old_value);
}
mark_terminals ();
mark_kboards ();
mark_ttys ();
#ifdef USE_GTK
{
extern void xg_mark_data (void);
xg_mark_data ();
}
#endif
#if (GC_MARK_STACK == GC_MAKE_GCPROS_NOOPS \
|| GC_MARK_STACK == GC_MARK_STACK_CHECK_GCPROS)
mark_stack ();
#else
{
register struct gcpro *tail;
for (tail = gcprolist; tail; tail = tail->next)
for (i = 0; i < tail->nvars; i++)
mark_object (tail->var[i]);
}
mark_byte_stack ();
{
struct catchtag *catch;
struct handler *handler;
for (catch = catchlist; catch; catch = catch->next)
{
mark_object (catch->tag);
mark_object (catch->val);
}
for (handler = handlerlist; handler; handler = handler->next)
{
mark_object (handler->handler);
mark_object (handler->var);
}
}
mark_backtrace ();
#endif
#ifdef HAVE_WINDOW_SYSTEM
mark_fringe_data ();
#endif
#if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
mark_stack ();
#endif
/* Everything is now marked, except for the things that require special
finalization, i.e. the undo_list.
Look thru every buffer's undo list
for elements that update markers that were not marked,
and delete them. */
{
register struct buffer *nextb = all_buffers;
while (nextb)
{
/* If a buffer's undo list is Qt, that means that undo is
turned off in that buffer. Calling truncate_undo_list on
Qt tends to return NULL, which effectively turns undo back on.
So don't call truncate_undo_list if undo_list is Qt. */
if (! EQ (nextb->BUFFER_INTERNAL_FIELD (undo_list), Qt))
{
Lisp_Object tail, prev;
tail = nextb->BUFFER_INTERNAL_FIELD (undo_list);
prev = Qnil;
while (CONSP (tail))
{
if (CONSP (XCAR (tail))
&& MARKERP (XCAR (XCAR (tail)))
&& !XMARKER (XCAR (XCAR (tail)))->gcmarkbit)
{
if (NILP (prev))
nextb->BUFFER_INTERNAL_FIELD (undo_list) = tail = XCDR (tail);
else
{
tail = XCDR (tail);
XSETCDR (prev, tail);
}
}
else
{
prev = tail;
tail = XCDR (tail);
}
}
}
/* Now that we have stripped the elements that need not be in the
undo_list any more, we can finally mark the list. */
mark_object (nextb->BUFFER_INTERNAL_FIELD (undo_list));
nextb = nextb->header.next.buffer;
}
}
gc_sweep ();
/* Clear the mark bits that we set in certain root slots. */
unmark_byte_stack ();
VECTOR_UNMARK (&buffer_defaults);
VECTOR_UNMARK (&buffer_local_symbols);
#if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES && 0
dump_zombies ();
#endif
UNBLOCK_INPUT;
CHECK_CONS_LIST ();
/* clear_marks (); */
gc_in_progress = 0;
consing_since_gc = 0;
if (gc_cons_threshold < 10000)
gc_cons_threshold = 10000;
gc_relative_threshold = 0;
if (FLOATP (Vgc_cons_percentage))
{ /* Set gc_cons_combined_threshold. */
double tot = 0;
tot += total_conses * sizeof (struct Lisp_Cons);
tot += total_symbols * sizeof (struct Lisp_Symbol);
tot += total_markers * sizeof (union Lisp_Misc);
tot += total_string_size;
tot += total_vector_size * sizeof (Lisp_Object);
tot += total_floats * sizeof (struct Lisp_Float);
tot += total_intervals * sizeof (struct interval);
tot += total_strings * sizeof (struct Lisp_String);
tot *= XFLOAT_DATA (Vgc_cons_percentage);
if (0 < tot)
{
if (tot < TYPE_MAXIMUM (EMACS_INT))
gc_relative_threshold = tot;
else
gc_relative_threshold = TYPE_MAXIMUM (EMACS_INT);
}
}
if (garbage_collection_messages)
{
if (message_p || minibuf_level > 0)
restore_message ();
else
message1_nolog ("Garbage collecting...done");
}
unbind_to (count, Qnil);
total[0] = Fcons (make_number (total_conses),
make_number (total_free_conses));
total[1] = Fcons (make_number (total_symbols),
make_number (total_free_symbols));
total[2] = Fcons (make_number (total_markers),
make_number (total_free_markers));
total[3] = make_number (total_string_size);
total[4] = make_number (total_vector_size);
total[5] = Fcons (make_number (total_floats),
make_number (total_free_floats));
total[6] = Fcons (make_number (total_intervals),
make_number (total_free_intervals));
total[7] = Fcons (make_number (total_strings),
make_number (total_free_strings));
#if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
{
/* Compute average percentage of zombies. */
double nlive = 0;
for (i = 0; i < 7; ++i)
if (CONSP (total[i]))
nlive += XFASTINT (XCAR (total[i]));
avg_live = (avg_live * ngcs + nlive) / (ngcs + 1);
max_live = max (nlive, max_live);
avg_zombies = (avg_zombies * ngcs + nzombies) / (ngcs + 1);
max_zombies = max (nzombies, max_zombies);
++ngcs;
}
#endif
if (!NILP (Vpost_gc_hook))
{
int gc_count = inhibit_garbage_collection ();
safe_run_hooks (Qpost_gc_hook);
unbind_to (gc_count, Qnil);
}
/* Accumulate statistics. */
EMACS_GET_TIME (t2);
EMACS_SUB_TIME (t3, t2, t1);
if (FLOATP (Vgc_elapsed))
Vgc_elapsed = make_float (XFLOAT_DATA (Vgc_elapsed) +
EMACS_SECS (t3) +
EMACS_USECS (t3) * 1.0e-6);
gcs_done++;
return Flist (sizeof total / sizeof *total, total);
}
/* Mark Lisp objects in glyph matrix MATRIX. Currently the
only interesting objects referenced from glyphs are strings. */
static void
mark_glyph_matrix (struct glyph_matrix *matrix)
{
struct glyph_row *row = matrix->rows;
struct glyph_row *end = row + matrix->nrows;
for (; row < end; ++row)
if (row->enabled_p)
{
int area;
for (area = LEFT_MARGIN_AREA; area < LAST_AREA; ++area)
{
struct glyph *glyph = row->glyphs[area];
struct glyph *end_glyph = glyph + row->used[area];
for (; glyph < end_glyph; ++glyph)
if (STRINGP (glyph->object)
&& !STRING_MARKED_P (XSTRING (glyph->object)))
mark_object (glyph->object);
}
}
}
/* Mark Lisp faces in the face cache C. */
static void
mark_face_cache (struct face_cache *c)
{
if (c)
{
int i, j;
for (i = 0; i < c->used; ++i)
{
struct face *face = FACE_FROM_ID (c->f, i);
if (face)
{
for (j = 0; j < LFACE_VECTOR_SIZE; ++j)
mark_object (face->lface[j]);
}
}
}
}
/* Mark reference to a Lisp_Object.
If the object referred to has not been seen yet, recursively mark
all the references contained in it. */
#define LAST_MARKED_SIZE 500
static Lisp_Object last_marked[LAST_MARKED_SIZE];
static int last_marked_index;
/* For debugging--call abort when we cdr down this many
links of a list, in mark_object. In debugging,
the call to abort will hit a breakpoint.
Normally this is zero and the check never goes off. */
ptrdiff_t mark_object_loop_halt EXTERNALLY_VISIBLE;
static void
mark_vectorlike (struct Lisp_Vector *ptr)
{
EMACS_INT size = ptr->header.size;
EMACS_INT i;
eassert (!VECTOR_MARKED_P (ptr));
VECTOR_MARK (ptr); /* Else mark it */
if (size & PSEUDOVECTOR_FLAG)
size &= PSEUDOVECTOR_SIZE_MASK;
/* Note that this size is not the memory-footprint size, but only
the number of Lisp_Object fields that we should trace.
The distinction is used e.g. by Lisp_Process which places extra
non-Lisp_Object fields at the end of the structure. */
for (i = 0; i < size; i++) /* and then mark its elements */
mark_object (ptr->contents[i]);
}
/* Like mark_vectorlike but optimized for char-tables (and
sub-char-tables) assuming that the contents are mostly integers or
symbols. */
static void
mark_char_table (struct Lisp_Vector *ptr)
{
int size = ptr->header.size & PSEUDOVECTOR_SIZE_MASK;
int i;
eassert (!VECTOR_MARKED_P (ptr));
VECTOR_MARK (ptr);
for (i = 0; i < size; i++)
{
Lisp_Object val = ptr->contents[i];
if (INTEGERP (val) || (SYMBOLP (val) && XSYMBOL (val)->gcmarkbit))
continue;
if (SUB_CHAR_TABLE_P (val))
{
if (! VECTOR_MARKED_P (XVECTOR (val)))
mark_char_table (XVECTOR (val));
}
else
mark_object (val);
}
}
void
mark_object (Lisp_Object arg)
{
register Lisp_Object obj = arg;
#ifdef GC_CHECK_MARKED_OBJECTS
void *po;
struct mem_node *m;
#endif
ptrdiff_t cdr_count = 0;
loop:
if (PURE_POINTER_P (XPNTR (obj)))
return;
last_marked[last_marked_index++] = obj;
if (last_marked_index == LAST_MARKED_SIZE)
last_marked_index = 0;
/* Perform some sanity checks on the objects marked here. Abort if
we encounter an object we know is bogus. This increases GC time
by ~80%, and requires compilation with GC_MARK_STACK != 0. */
#ifdef GC_CHECK_MARKED_OBJECTS
po = (void *) XPNTR (obj);
/* Check that the object pointed to by PO is known to be a Lisp
structure allocated from the heap. */
#define CHECK_ALLOCATED() \
do { \
m = mem_find (po); \
if (m == MEM_NIL) \
abort (); \
} while (0)
/* Check that the object pointed to by PO is live, using predicate
function LIVEP. */
#define CHECK_LIVE(LIVEP) \
do { \
if (!LIVEP (m, po)) \
abort (); \
} while (0)
/* Check both of the above conditions. */
#define CHECK_ALLOCATED_AND_LIVE(LIVEP) \
do { \
CHECK_ALLOCATED (); \
CHECK_LIVE (LIVEP); \
} while (0) \
#else /* not GC_CHECK_MARKED_OBJECTS */
#define CHECK_LIVE(LIVEP) (void) 0
#define CHECK_ALLOCATED_AND_LIVE(LIVEP) (void) 0
#endif /* not GC_CHECK_MARKED_OBJECTS */
switch (SWITCH_ENUM_CAST (XTYPE (obj)))
{
case Lisp_String:
{
register struct Lisp_String *ptr = XSTRING (obj);
if (STRING_MARKED_P (ptr))
break;
CHECK_ALLOCATED_AND_LIVE (live_string_p);
MARK_INTERVAL_TREE (ptr->intervals);
MARK_STRING (ptr);
#ifdef GC_CHECK_STRING_BYTES
/* Check that the string size recorded in the string is the
same as the one recorded in the sdata structure. */
CHECK_STRING_BYTES (ptr);
#endif /* GC_CHECK_STRING_BYTES */
}
break;
case Lisp_Vectorlike:
if (VECTOR_MARKED_P (XVECTOR (obj)))
break;
#ifdef GC_CHECK_MARKED_OBJECTS
m = mem_find (po);
if (m == MEM_NIL && !SUBRP (obj)
&& po != &buffer_defaults
&& po != &buffer_local_symbols)
abort ();
#endif /* GC_CHECK_MARKED_OBJECTS */
if (BUFFERP (obj))
{
#ifdef GC_CHECK_MARKED_OBJECTS
if (po != &buffer_defaults && po != &buffer_local_symbols)
{
struct buffer *b;
for (b = all_buffers; b && b != po; b = b->header.next.buffer)
;
if (b == NULL)
abort ();
}
#endif /* GC_CHECK_MARKED_OBJECTS */
mark_buffer (obj);
}
else if (SUBRP (obj))
break;
else if (COMPILEDP (obj))
/* We could treat this just like a vector, but it is better to
save the COMPILED_CONSTANTS element for last and avoid
recursion there. */
{
register struct Lisp_Vector *ptr = XVECTOR (obj);
int size = ptr->header.size & PSEUDOVECTOR_SIZE_MASK;
int i;
CHECK_LIVE (live_vector_p);
VECTOR_MARK (ptr); /* Else mark it */
for (i = 0; i < size; i++) /* and then mark its elements */
{
if (i != COMPILED_CONSTANTS)
mark_object (ptr->contents[i]);
}
obj = ptr->contents[COMPILED_CONSTANTS];
goto loop;
}
else if (FRAMEP (obj))
{
register struct frame *ptr = XFRAME (obj);
mark_vectorlike (XVECTOR (obj));
mark_face_cache (ptr->face_cache);
}
else if (WINDOWP (obj))
{
register struct Lisp_Vector *ptr = XVECTOR (obj);
struct window *w = XWINDOW (obj);
mark_vectorlike (ptr);
/* Mark glyphs for leaf windows. Marking window matrices is
sufficient because frame matrices use the same glyph
memory. */
if (NILP (w->hchild)
&& NILP (w->vchild)
&& w->current_matrix)
{
mark_glyph_matrix (w->current_matrix);
mark_glyph_matrix (w->desired_matrix);
}
}
else if (HASH_TABLE_P (obj))
{
struct Lisp_Hash_Table *h = XHASH_TABLE (obj);
mark_vectorlike ((struct Lisp_Vector *)h);
/* If hash table is not weak, mark all keys and values.
For weak tables, mark only the vector. */
if (NILP (h->weak))
mark_object (h->key_and_value);
else
VECTOR_MARK (XVECTOR (h->key_and_value));
}
else if (CHAR_TABLE_P (obj))
mark_char_table (XVECTOR (obj));
else
mark_vectorlike (XVECTOR (obj));
break;
case Lisp_Symbol:
{
register struct Lisp_Symbol *ptr = XSYMBOL (obj);
struct Lisp_Symbol *ptrx;
if (ptr->gcmarkbit)
break;
CHECK_ALLOCATED_AND_LIVE (live_symbol_p);
ptr->gcmarkbit = 1;
mark_object (ptr->function);
mark_object (ptr->plist);
switch (ptr->redirect)
{
case SYMBOL_PLAINVAL: mark_object (SYMBOL_VAL (ptr)); break;
case SYMBOL_VARALIAS:
{
Lisp_Object tem;
XSETSYMBOL (tem, SYMBOL_ALIAS (ptr));
mark_object (tem);
break;
}
case SYMBOL_LOCALIZED:
{
struct Lisp_Buffer_Local_Value *blv = SYMBOL_BLV (ptr);
/* If the value is forwarded to a buffer or keyboard field,
these are marked when we see the corresponding object.
And if it's forwarded to a C variable, either it's not
a Lisp_Object var, or it's staticpro'd already. */
mark_object (blv->where);
mark_object (blv->valcell);
mark_object (blv->defcell);
break;
}
case SYMBOL_FORWARDED:
/* If the value is forwarded to a buffer or keyboard field,
these are marked when we see the corresponding object.
And if it's forwarded to a C variable, either it's not
a Lisp_Object var, or it's staticpro'd already. */
break;
default: abort ();
}
if (!PURE_POINTER_P (XSTRING (ptr->xname)))
MARK_STRING (XSTRING (ptr->xname));
MARK_INTERVAL_TREE (STRING_INTERVALS (ptr->xname));
ptr = ptr->next;
if (ptr)
{
ptrx = ptr; /* Use of ptrx avoids compiler bug on Sun */
XSETSYMBOL (obj, ptrx);
goto loop;
}
}
break;
case Lisp_Misc:
CHECK_ALLOCATED_AND_LIVE (live_misc_p);
if (XMISCANY (obj)->gcmarkbit)
break;
XMISCANY (obj)->gcmarkbit = 1;
switch (XMISCTYPE (obj))
{
case Lisp_Misc_Marker:
/* DO NOT mark thru the marker's chain.
The buffer's markers chain does not preserve markers from gc;
instead, markers are removed from the chain when freed by gc. */
break;
case Lisp_Misc_Save_Value:
#if GC_MARK_STACK
{
register struct Lisp_Save_Value *ptr = XSAVE_VALUE (obj);
/* If DOGC is set, POINTER is the address of a memory
area containing INTEGER potential Lisp_Objects. */
if (ptr->dogc)
{
Lisp_Object *p = (Lisp_Object *) ptr->pointer;
ptrdiff_t nelt;
for (nelt = ptr->integer; nelt > 0; nelt--, p++)
mark_maybe_object (*p);
}
}
#endif
break;
case Lisp_Misc_Overlay:
{
struct Lisp_Overlay *ptr = XOVERLAY (obj);
mark_object (ptr->start);
mark_object (ptr->end);
mark_object (ptr->plist);
if (ptr->next)
{
XSETMISC (obj, ptr->next);
goto loop;
}
}
break;
default:
abort ();
}
break;
case Lisp_Cons:
{
register struct Lisp_Cons *ptr = XCONS (obj);
if (CONS_MARKED_P (ptr))
break;
CHECK_ALLOCATED_AND_LIVE (live_cons_p);
CONS_MARK (ptr);
/* If the cdr is nil, avoid recursion for the car. */
if (EQ (ptr->u.cdr, Qnil))
{
obj = ptr->car;
cdr_count = 0;
goto loop;
}
mark_object (ptr->car);
obj = ptr->u.cdr;
cdr_count++;
if (cdr_count == mark_object_loop_halt)
abort ();
goto loop;
}
case Lisp_Float:
CHECK_ALLOCATED_AND_LIVE (live_float_p);
FLOAT_MARK (XFLOAT (obj));
break;
case_Lisp_Int:
break;
default:
abort ();
}
#undef CHECK_LIVE
#undef CHECK_ALLOCATED
#undef CHECK_ALLOCATED_AND_LIVE
}
/* Mark the pointers in a buffer structure. */
static void
mark_buffer (Lisp_Object buf)
{
register struct buffer *buffer = XBUFFER (buf);
register Lisp_Object *ptr, tmp;
Lisp_Object base_buffer;
eassert (!VECTOR_MARKED_P (buffer));
VECTOR_MARK (buffer);
MARK_INTERVAL_TREE (BUF_INTERVALS (buffer));
/* For now, we just don't mark the undo_list. It's done later in
a special way just before the sweep phase, and after stripping
some of its elements that are not needed any more. */
if (buffer->overlays_before)
{
XSETMISC (tmp, buffer->overlays_before);
mark_object (tmp);
}
if (buffer->overlays_after)
{
XSETMISC (tmp, buffer->overlays_after);
mark_object (tmp);
}
/* buffer-local Lisp variables start at `undo_list',
tho only the ones from `name' on are GC'd normally. */
for (ptr = &buffer->BUFFER_INTERNAL_FIELD (name);
ptr <= &PER_BUFFER_VALUE (buffer,
PER_BUFFER_VAR_OFFSET (LAST_FIELD_PER_BUFFER));
ptr++)
mark_object (*ptr);
/* If this is an indirect buffer, mark its base buffer. */
if (buffer->base_buffer && !VECTOR_MARKED_P (buffer->base_buffer))
{
XSETBUFFER (base_buffer, buffer->base_buffer);
mark_buffer (base_buffer);
}
}
/* Mark the Lisp pointers in the terminal objects.
Called by the Fgarbage_collector. */
static void
mark_terminals (void)
{
struct terminal *t;
for (t = terminal_list; t; t = t->next_terminal)
{
eassert (t->name != NULL);
#ifdef HAVE_WINDOW_SYSTEM
/* If a terminal object is reachable from a stacpro'ed object,
it might have been marked already. Make sure the image cache
gets marked. */
mark_image_cache (t->image_cache);
#endif /* HAVE_WINDOW_SYSTEM */
if (!VECTOR_MARKED_P (t))
mark_vectorlike ((struct Lisp_Vector *)t);
}
}
/* Value is non-zero if OBJ will survive the current GC because it's
either marked or does not need to be marked to survive. */
int
survives_gc_p (Lisp_Object obj)
{
int survives_p;
switch (XTYPE (obj))
{
case_Lisp_Int:
survives_p = 1;
break;
case Lisp_Symbol:
survives_p = XSYMBOL (obj)->gcmarkbit;
break;
case Lisp_Misc:
survives_p = XMISCANY (obj)->gcmarkbit;
break;
case Lisp_String:
survives_p = STRING_MARKED_P (XSTRING (obj));
break;
case Lisp_Vectorlike:
survives_p = SUBRP (obj) || VECTOR_MARKED_P (XVECTOR (obj));
break;
case Lisp_Cons:
survives_p = CONS_MARKED_P (XCONS (obj));
break;
case Lisp_Float:
survives_p = FLOAT_MARKED_P (XFLOAT (obj));
break;
default:
abort ();
}
return survives_p || PURE_POINTER_P ((void *) XPNTR (obj));
}
/* Sweep: find all structures not marked, and free them. */
static void
gc_sweep (void)
{
/* Remove or mark entries in weak hash tables.
This must be done before any object is unmarked. */
sweep_weak_hash_tables ();
sweep_strings ();
#ifdef GC_CHECK_STRING_BYTES
if (!noninteractive)
check_string_bytes (1);
#endif
/* Put all unmarked conses on free list */
{
register struct cons_block *cblk;
struct cons_block **cprev = &cons_block;
register int lim = cons_block_index;
EMACS_INT num_free = 0, num_used = 0;
cons_free_list = 0;
for (cblk = cons_block; cblk; cblk = *cprev)
{
register int i = 0;
int this_free = 0;
int ilim = (lim + BITS_PER_INT - 1) / BITS_PER_INT;
/* Scan the mark bits an int at a time. */
for (i = 0; i < ilim; i++)
{
if (cblk->gcmarkbits[i] == -1)
{
/* Fast path - all cons cells for this int are marked. */
cblk->gcmarkbits[i] = 0;
num_used += BITS_PER_INT;
}
else
{
/* Some cons cells for this int are not marked.
Find which ones, and free them. */
int start, pos, stop;
start = i * BITS_PER_INT;
stop = lim - start;
if (stop > BITS_PER_INT)
stop = BITS_PER_INT;
stop += start;
for (pos = start; pos < stop; pos++)
{
if (!CONS_MARKED_P (&cblk->conses[pos]))
{
this_free++;
cblk->conses[pos].u.chain = cons_free_list;
cons_free_list = &cblk->conses[pos];
#if GC_MARK_STACK
cons_free_list->car = Vdead;
#endif
}
else
{
num_used++;
CONS_UNMARK (&cblk->conses[pos]);
}
}
}
}
lim = CONS_BLOCK_SIZE;
/* If this block contains only free conses and we have already
seen more than two blocks worth of free conses then deallocate
this block. */
if (this_free == CONS_BLOCK_SIZE && num_free > CONS_BLOCK_SIZE)
{
*cprev = cblk->next;
/* Unhook from the free list. */
cons_free_list = cblk->conses[0].u.chain;
lisp_align_free (cblk);
}
else
{
num_free += this_free;
cprev = &cblk->next;
}
}
total_conses = num_used;
total_free_conses = num_free;
}
/* Put all unmarked floats on free list */
{
register struct float_block *fblk;
struct float_block **fprev = &float_block;
register int lim = float_block_index;
EMACS_INT num_free = 0, num_used = 0;
float_free_list = 0;
for (fblk = float_block; fblk; fblk = *fprev)
{
register int i;
int this_free = 0;
for (i = 0; i < lim; i++)
if (!FLOAT_MARKED_P (&fblk->floats[i]))
{
this_free++;
fblk->floats[i].u.chain = float_free_list;
float_free_list = &fblk->floats[i];
}
else
{
num_used++;
FLOAT_UNMARK (&fblk->floats[i]);
}
lim = FLOAT_BLOCK_SIZE;
/* If this block contains only free floats and we have already
seen more than two blocks worth of free floats then deallocate
this block. */
if (this_free == FLOAT_BLOCK_SIZE && num_free > FLOAT_BLOCK_SIZE)
{
*fprev = fblk->next;
/* Unhook from the free list. */
float_free_list = fblk->floats[0].u.chain;
lisp_align_free (fblk);
}
else
{
num_free += this_free;
fprev = &fblk->next;
}
}
total_floats = num_used;
total_free_floats = num_free;
}
/* Put all unmarked intervals on free list */
{
register struct interval_block *iblk;
struct interval_block **iprev = &interval_block;
register int lim = interval_block_index;
EMACS_INT num_free = 0, num_used = 0;
interval_free_list = 0;
for (iblk = interval_block; iblk; iblk = *iprev)
{
register int i;
int this_free = 0;
for (i = 0; i < lim; i++)
{
if (!iblk->intervals[i].gcmarkbit)
{
SET_INTERVAL_PARENT (&iblk->intervals[i], interval_free_list);
interval_free_list = &iblk->intervals[i];
this_free++;
}
else
{
num_used++;
iblk->intervals[i].gcmarkbit = 0;
}
}
lim = INTERVAL_BLOCK_SIZE;
/* If this block contains only free intervals and we have already
seen more than two blocks worth of free intervals then
deallocate this block. */
if (this_free == INTERVAL_BLOCK_SIZE && num_free > INTERVAL_BLOCK_SIZE)
{
*iprev = iblk->next;
/* Unhook from the free list. */
interval_free_list = INTERVAL_PARENT (&iblk->intervals[0]);
lisp_free (iblk);
}
else
{
num_free += this_free;
iprev = &iblk->next;
}
}
total_intervals = num_used;
total_free_intervals = num_free;
}
/* Put all unmarked symbols on free list */
{
register struct symbol_block *sblk;
struct symbol_block **sprev = &symbol_block;
register int lim = symbol_block_index;
EMACS_INT num_free = 0, num_used = 0;
symbol_free_list = NULL;
for (sblk = symbol_block; sblk; sblk = *sprev)
{
int this_free = 0;
struct Lisp_Symbol *sym = sblk->symbols;
struct Lisp_Symbol *end = sym + lim;
for (; sym < end; ++sym)
{
/* Check if the symbol was created during loadup. In such a case
it might be pointed to by pure bytecode which we don't trace,
so we conservatively assume that it is live. */
int pure_p = PURE_POINTER_P (XSTRING (sym->xname));
if (!sym->gcmarkbit && !pure_p)
{
if (sym->redirect == SYMBOL_LOCALIZED)
xfree (SYMBOL_BLV (sym));
sym->next = symbol_free_list;
symbol_free_list = sym;
#if GC_MARK_STACK
symbol_free_list->function = Vdead;
#endif
++this_free;
}
else
{
++num_used;
if (!pure_p)
UNMARK_STRING (XSTRING (sym->xname));
sym->gcmarkbit = 0;
}
}
lim = SYMBOL_BLOCK_SIZE;
/* If this block contains only free symbols and we have already
seen more than two blocks worth of free symbols then deallocate
this block. */
if (this_free == SYMBOL_BLOCK_SIZE && num_free > SYMBOL_BLOCK_SIZE)
{
*sprev = sblk->next;
/* Unhook from the free list. */
symbol_free_list = sblk->symbols[0].next;
lisp_free (sblk);
}
else
{
num_free += this_free;
sprev = &sblk->next;
}
}
total_symbols = num_used;
total_free_symbols = num_free;
}
/* Put all unmarked misc's on free list.
For a marker, first unchain it from the buffer it points into. */
{
register struct marker_block *mblk;
struct marker_block **mprev = &marker_block;
register int lim = marker_block_index;
EMACS_INT num_free = 0, num_used = 0;
marker_free_list = 0;
for (mblk = marker_block; mblk; mblk = *mprev)
{
register int i;
int this_free = 0;
for (i = 0; i < lim; i++)
{
if (!mblk->markers[i].u_any.gcmarkbit)
{
if (mblk->markers[i].u_any.type == Lisp_Misc_Marker)
unchain_marker (&mblk->markers[i].u_marker);
/* Set the type of the freed object to Lisp_Misc_Free.
We could leave the type alone, since nobody checks it,
but this might catch bugs faster. */
mblk->markers[i].u_marker.type = Lisp_Misc_Free;
mblk->markers[i].u_free.chain = marker_free_list;
marker_free_list = &mblk->markers[i];
this_free++;
}
else
{
num_used++;
mblk->markers[i].u_any.gcmarkbit = 0;
}
}
lim = MARKER_BLOCK_SIZE;
/* If this block contains only free markers and we have already
seen more than two blocks worth of free markers then deallocate
this block. */
if (this_free == MARKER_BLOCK_SIZE && num_free > MARKER_BLOCK_SIZE)
{
*mprev = mblk->next;
/* Unhook from the free list. */
marker_free_list = mblk->markers[0].u_free.chain;
lisp_free (mblk);
}
else
{
num_free += this_free;
mprev = &mblk->next;
}
}
total_markers = num_used;
total_free_markers = num_free;
}
/* Free all unmarked buffers */
{
register struct buffer *buffer = all_buffers, *prev = 0, *next;
while (buffer)
if (!VECTOR_MARKED_P (buffer))
{
if (prev)
prev->header.next = buffer->header.next;
else
all_buffers = buffer->header.next.buffer;
next = buffer->header.next.buffer;
lisp_free (buffer);
buffer = next;
}
else
{
VECTOR_UNMARK (buffer);
UNMARK_BALANCE_INTERVALS (BUF_INTERVALS (buffer));
prev = buffer, buffer = buffer->header.next.buffer;
}
}
/* Free all unmarked vectors */
{
register struct Lisp_Vector *vector = all_vectors, *prev = 0, *next;
total_vector_size = 0;
while (vector)
if (!VECTOR_MARKED_P (vector))
{
if (prev)
prev->header.next = vector->header.next;
else
all_vectors = vector->header.next.vector;
next = vector->header.next.vector;
lisp_free (vector);
vector = next;
}
else
{
VECTOR_UNMARK (vector);
if (vector->header.size & PSEUDOVECTOR_FLAG)
total_vector_size += PSEUDOVECTOR_SIZE_MASK & vector->header.size;
else
total_vector_size += vector->header.size;
prev = vector, vector = vector->header.next.vector;
}
}
#ifdef GC_CHECK_STRING_BYTES
if (!noninteractive)
check_string_bytes (1);
#endif
}
/* Debugging aids. */
DEFUN ("memory-limit", Fmemory_limit, Smemory_limit, 0, 0, 0,
doc: /* Return the address of the last byte Emacs has allocated, divided by 1024.
This may be helpful in debugging Emacs's memory usage.
We divide the value by 1024 to make sure it fits in a Lisp integer. */)
(void)
{
Lisp_Object end;
XSETINT (end, (intptr_t) (char *) sbrk (0) / 1024);
return end;
}
DEFUN ("memory-use-counts", Fmemory_use_counts, Smemory_use_counts, 0, 0, 0,
doc: /* Return a list of counters that measure how much consing there has been.
Each of these counters increments for a certain kind of object.
The counters wrap around from the largest positive integer to zero.
Garbage collection does not decrease them.
The elements of the value are as follows:
(CONSES FLOATS VECTOR-CELLS SYMBOLS STRING-CHARS MISCS INTERVALS STRINGS)
All are in units of 1 = one object consed
except for VECTOR-CELLS and STRING-CHARS, which count the total length of
objects consed.
MISCS include overlays, markers, and some internal types.
Frames, windows, buffers, and subprocesses count as vectors
(but the contents of a buffer's text do not count here). */)
(void)
{
Lisp_Object consed[8];
consed[0] = make_number (min (MOST_POSITIVE_FIXNUM, cons_cells_consed));
consed[1] = make_number (min (MOST_POSITIVE_FIXNUM, floats_consed));
consed[2] = make_number (min (MOST_POSITIVE_FIXNUM, vector_cells_consed));
consed[3] = make_number (min (MOST_POSITIVE_FIXNUM, symbols_consed));
consed[4] = make_number (min (MOST_POSITIVE_FIXNUM, string_chars_consed));
consed[5] = make_number (min (MOST_POSITIVE_FIXNUM, misc_objects_consed));
consed[6] = make_number (min (MOST_POSITIVE_FIXNUM, intervals_consed));
consed[7] = make_number (min (MOST_POSITIVE_FIXNUM, strings_consed));
return Flist (8, consed);
}
/* Find at most FIND_MAX symbols which have OBJ as their value or
function. This is used in gdbinit's `xwhichsymbols' command. */
Lisp_Object
which_symbols (Lisp_Object obj, EMACS_INT find_max)
{
struct symbol_block *sblk;
int gc_count = inhibit_garbage_collection ();
Lisp_Object found = Qnil;
if (! DEADP (obj))
{
for (sblk = symbol_block; sblk; sblk = sblk->next)
{
struct Lisp_Symbol *sym = sblk->symbols;
int bn;
for (bn = 0; bn < SYMBOL_BLOCK_SIZE; bn++, sym++)
{
Lisp_Object val;
Lisp_Object tem;
if (sblk == symbol_block && bn >= symbol_block_index)
break;
XSETSYMBOL (tem, sym);
val = find_symbol_value (tem);
if (EQ (val, obj)
|| EQ (sym->function, obj)
|| (!NILP (sym->function)
&& COMPILEDP (sym->function)
&& EQ (AREF (sym->function, COMPILED_BYTECODE), obj))
|| (!NILP (val)
&& COMPILEDP (val)
&& EQ (AREF (val, COMPILED_BYTECODE), obj)))
{
found = Fcons (tem, found);
if (--find_max == 0)
goto out;
}
}
}
}
out:
unbind_to (gc_count, Qnil);
return found;
}
#ifdef ENABLE_CHECKING
int suppress_checking;
void
die (const char *msg, const char *file, int line)
{
fprintf (stderr, "\r\n%s:%d: Emacs fatal error: %s\r\n",
file, line, msg);
abort ();
}
#endif
/* Initialization */
void
init_alloc_once (void)
{
/* Used to do Vpurify_flag = Qt here, but Qt isn't set up yet! */
purebeg = PUREBEG;
pure_size = PURESIZE;
pure_bytes_used = 0;
pure_bytes_used_lisp = pure_bytes_used_non_lisp = 0;
pure_bytes_used_before_overflow = 0;
/* Initialize the list of free aligned blocks. */
free_ablock = NULL;
#if GC_MARK_STACK || defined GC_MALLOC_CHECK
mem_init ();
Vdead = make_pure_string ("DEAD", 4, 4, 0);
#endif
all_vectors = 0;
ignore_warnings = 1;
#ifdef DOUG_LEA_MALLOC
mallopt (M_TRIM_THRESHOLD, 128*1024); /* trim threshold */
mallopt (M_MMAP_THRESHOLD, 64*1024); /* mmap threshold */
mallopt (M_MMAP_MAX, MMAP_MAX_AREAS); /* max. number of mmap'ed areas */
#endif
init_strings ();
init_cons ();
init_symbol ();
init_marker ();
init_float ();
init_intervals ();
init_weak_hash_tables ();
#ifdef REL_ALLOC
malloc_hysteresis = 32;
#else
malloc_hysteresis = 0;
#endif
refill_memory_reserve ();
ignore_warnings = 0;
gcprolist = 0;
byte_stack_list = 0;
staticidx = 0;
consing_since_gc = 0;
gc_cons_threshold = 100000 * sizeof (Lisp_Object);
gc_relative_threshold = 0;
}
void
init_alloc (void)
{
gcprolist = 0;
byte_stack_list = 0;
#if GC_MARK_STACK
#if !defined GC_SAVE_REGISTERS_ON_STACK && !defined GC_SETJMP_WORKS
setjmp_tested_p = longjmps_done = 0;
#endif
#endif
Vgc_elapsed = make_float (0.0);
gcs_done = 0;
}
void
syms_of_alloc (void)
{
DEFVAR_INT ("gc-cons-threshold", gc_cons_threshold,
doc: /* *Number of bytes of consing between garbage collections.
Garbage collection can happen automatically once this many bytes have been
allocated since the last garbage collection. All data types count.
Garbage collection happens automatically only when `eval' is called.
By binding this temporarily to a large number, you can effectively
prevent garbage collection during a part of the program.
See also `gc-cons-percentage'. */);
DEFVAR_LISP ("gc-cons-percentage", Vgc_cons_percentage,
doc: /* *Portion of the heap used for allocation.
Garbage collection can happen automatically once this portion of the heap
has been allocated since the last garbage collection.
If this portion is smaller than `gc-cons-threshold', this is ignored. */);
Vgc_cons_percentage = make_float (0.1);
DEFVAR_INT ("pure-bytes-used", pure_bytes_used,
doc: /* Number of bytes of shareable Lisp data allocated so far. */);
DEFVAR_INT ("cons-cells-consed", cons_cells_consed,
doc: /* Number of cons cells that have been consed so far. */);
DEFVAR_INT ("floats-consed", floats_consed,
doc: /* Number of floats that have been consed so far. */);
DEFVAR_INT ("vector-cells-consed", vector_cells_consed,
doc: /* Number of vector cells that have been consed so far. */);
DEFVAR_INT ("symbols-consed", symbols_consed,
doc: /* Number of symbols that have been consed so far. */);
DEFVAR_INT ("string-chars-consed", string_chars_consed,
doc: /* Number of string characters that have been consed so far. */);
DEFVAR_INT ("misc-objects-consed", misc_objects_consed,
doc: /* Number of miscellaneous objects that have been consed so far. */);
DEFVAR_INT ("intervals-consed", intervals_consed,
doc: /* Number of intervals that have been consed so far. */);
DEFVAR_INT ("strings-consed", strings_consed,
doc: /* Number of strings that have been consed so far. */);
DEFVAR_LISP ("purify-flag", Vpurify_flag,
doc: /* Non-nil means loading Lisp code in order to dump an executable.
This means that certain objects should be allocated in shared (pure) space.
It can also be set to a hash-table, in which case this table is used to
do hash-consing of the objects allocated to pure space. */);
DEFVAR_BOOL ("garbage-collection-messages", garbage_collection_messages,
doc: /* Non-nil means display messages at start and end of garbage collection. */);
garbage_collection_messages = 0;
DEFVAR_LISP ("post-gc-hook", Vpost_gc_hook,
doc: /* Hook run after garbage collection has finished. */);
Vpost_gc_hook = Qnil;
DEFSYM (Qpost_gc_hook, "post-gc-hook");
DEFVAR_LISP ("memory-signal-data", Vmemory_signal_data,
doc: /* Precomputed `signal' argument for memory-full error. */);
/* We build this in advance because if we wait until we need it, we might
not be able to allocate the memory to hold it. */
Vmemory_signal_data
= pure_cons (Qerror,
pure_cons (make_pure_c_string ("Memory exhausted--use M-x save-some-buffers then exit and restart Emacs"), Qnil));
DEFVAR_LISP ("memory-full", Vmemory_full,
doc: /* Non-nil means Emacs cannot get much more Lisp memory. */);
Vmemory_full = Qnil;
DEFSYM (Qgc_cons_threshold, "gc-cons-threshold");
DEFSYM (Qchar_table_extra_slots, "char-table-extra-slots");
DEFVAR_LISP ("gc-elapsed", Vgc_elapsed,
doc: /* Accumulated time elapsed in garbage collections.
The time is in seconds as a floating point value. */);
DEFVAR_INT ("gcs-done", gcs_done,
doc: /* Accumulated number of garbage collections done. */);
defsubr (&Scons);
defsubr (&Slist);
defsubr (&Svector);
defsubr (&Smake_byte_code);
defsubr (&Smake_list);
defsubr (&Smake_vector);
defsubr (&Smake_string);
defsubr (&Smake_bool_vector);
defsubr (&Smake_symbol);
defsubr (&Smake_marker);
defsubr (&Spurecopy);
defsubr (&Sgarbage_collect);
defsubr (&Smemory_limit);
defsubr (&Smemory_use_counts);
#if GC_MARK_STACK == GC_USE_GCPROS_CHECK_ZOMBIES
defsubr (&Sgc_status);
#endif
}