From a5eb17ceb961d630c1c1c9f6963e95595c071a40 Mon Sep 17 00:00:00 2001
From: Pip Cet <pipcet@gmail.com>
Date: Tue, 17 Mar 2020 13:51:31 +0000
Subject: [PATCH] more debugging

---
 src/alloc.c  | 19 +++++++++++++++++--
 src/bignum.c |  2 ++
 src/lisp.h   |  2 +-
 3 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/src/alloc.c b/src/alloc.c
index 469c4445bb..70e1736b01 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -234,7 +234,7 @@ #define GC_DEFAULT_THRESHOLD (100000 * word_size)
 
 /* True during GC.  */
 
-bool gc_in_progress;
+volatile bool gc_in_progress;
 
 /* System byte and object counts reported by GC.  */
 
@@ -711,6 +711,8 @@ xmalloc (size_t size)
   if (!val && size)
     memory_full (size);
   MALLOC_PROBE (size);
+  if (val)
+    memset (val, 0xaa, size);
   return val;
 }
 
@@ -1301,7 +1303,10 @@ lmalloc (size_t size)
     {
       void *p = malloc (size);
       if (laligned (p, size))
-	return p;
+	{
+	  memset (p, 0x5a, size);
+	  return p;
+	}
       free (p);
       size_t bigger = size + LISP_ALIGNMENT;
       if (size < bigger)
@@ -3095,6 +3100,7 @@ sweep_vectors (void)
 #ifndef GC_MALLOC_CHECK
 	  mem_delete (mem_find (block->data));
 #endif
+	  memset (block, 0x55, VECTOR_BLOCK_BYTES);
 	  xfree (block);
 	}
       else
@@ -3140,6 +3146,10 @@ #define VECTOR_ELTS_MAX \
 static struct Lisp_Vector *
 allocate_vectorlike (ptrdiff_t len)
 {
+  eassert (!gc_in_progress);
+  gc_in_progress = true;
+  struct timespec ts = make_timespec (0, 1000000);
+  nanosleep (&ts, NULL);
   eassert (0 < len && len <= VECTOR_ELTS_MAX);
   ptrdiff_t nbytes = header_size + len * word_size;
   struct Lisp_Vector *p;
@@ -3175,6 +3185,7 @@ allocate_vectorlike (ptrdiff_t len)
 
   MALLOC_UNBLOCK_INPUT;
 
+  gc_in_progress = false;
   return ptr_bounds_clip (p, nbytes);
 }
 
@@ -5869,6 +5880,8 @@ garbage_collect (void)
   if (garbage_collection_inhibited)
     return;
 
+  eassert (!gc_in_progress);
+
   /* Record this function, so it appears on the profiler's backtraces.  */
   record_in_backtrace (QAutomatic_GC, 0, 0);
 
@@ -5935,6 +5948,8 @@ garbage_collect (void)
   shrink_regexp_cache ();
 
   gc_in_progress = 1;
+  struct timespec ts = make_timespec (0, 1000000);
+  nanosleep (&ts, NULL);
 
   /* Mark all the special slots that serve as the roots of accessibility.  */
 
diff --git a/src/bignum.c b/src/bignum.c
index 51d90ffaef..8e0c0ead01 100644
--- a/src/bignum.c
+++ b/src/bignum.c
@@ -90,6 +90,7 @@ make_bignum_bits (size_t bits)
   if (integer_width < bits && 2 * max (INTMAX_WIDTH, UINTMAX_WIDTH) < bits)
     overflow_error ();
 
+  eassert (!gc_in_progress);
   struct Lisp_Bignum *b = ALLOCATE_PLAIN_PSEUDOVECTOR (struct Lisp_Bignum,
 						       PVEC_BIGNUM);
   mpz_init (b->value);
@@ -424,6 +425,7 @@ bignum_to_string (Lisp_Object num, int base)
 Lisp_Object
 make_bignum_str (char const *num, int base)
 {
+  eassert (!gc_in_progress);
   struct Lisp_Bignum *b = ALLOCATE_PLAIN_PSEUDOVECTOR (struct Lisp_Bignum,
 						       PVEC_BIGNUM);
   mpz_init (b->value);
diff --git a/src/lisp.h b/src/lisp.h
index 8674fe11a6..4c94085170 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -4006,7 +4006,7 @@ #define ALLOCATE_ZEROED_PSEUDOVECTOR(type, field, tag)		       \
 				   PSEUDOVECSIZE (type, field),	       \
 				   VECSIZE (type), tag))
 
-extern bool gc_in_progress;
+extern volatile bool gc_in_progress;
 extern Lisp_Object make_float (double);
 extern void display_malloc_warning (void);
 extern ptrdiff_t inhibit_garbage_collection (void);
-- 
2.25.1