From: Philipp Stephani <p.stephani2@gmail.com>
To: emacs-devel@gnu.org, eliz@gnu.org
Cc: Philipp Stephani <phst@google.com>
Subject: [PATCH] Ignore pending_signals when checking for quits.
Date: Mon, 11 Feb 2019 21:17:39 +0100 [thread overview]
Message-ID: <20190211201739.25229-1-phst@google.com> (raw)
In-Reply-To: <83y36nl7rl.fsf@gnu.org>
pending_signals is often set if no quit is pending. This results in
bugs in module code if the module returns but no quit is actually
pending.
As a better alternative, add a new process_input environment function
for Emacs 27. That function processes signals (like maybe_quit).
* configure.ac: Add module snippet for Emacs 27.
* src/module-env-27.h: New file.
* src/emacs-module.h.in: Add process_input function to environment
interface.
* src/emacs-module.c (module_should_quit): Use QUITP macro to check
whether the caller should quit.
(module_process_input): New function.
(initialize_environment): Use it.
* src/eval.c: Remove obsolete comment.
* test/data/emacs-module/mod-test.c (signal_wrong_type_argument)
(signal_errno): New helper functions.
(Fmod_test_sleep_until): New test module function.
* test/src/emacs-module-tests.el (mod-test-sleep-until): New unit
test.
* doc/lispref/internals.texi (Module Misc): Document process_input.
---
configure.ac | 2 +
doc/lispref/internals.texi | 22 +++++++++-
etc/NEWS | 3 ++
src/emacs-module.c | 15 +++++--
src/emacs-module.h.in | 21 +++++++++-
src/eval.c | 5 +--
src/module-env-27.h | 4 ++
test/data/emacs-module/mod-test.c | 69 ++++++++++++++++++++++++++++++-
test/src/emacs-module-tests.el | 20 +++++++++
9 files changed, 151 insertions(+), 10 deletions(-)
create mode 100644 src/module-env-27.h
diff --git a/configure.ac b/configure.ac
index 58579008f3..3318f04a5a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3689,8 +3689,10 @@ AC_DEFUN
AC_CONFIG_FILES([src/emacs-module.h])
AC_SUBST_FILE([module_env_snippet_25])
AC_SUBST_FILE([module_env_snippet_26])
+AC_SUBST_FILE([module_env_snippet_27])
module_env_snippet_25="$srcdir/src/module-env-25.h"
module_env_snippet_26="$srcdir/src/module-env-26.h"
+module_env_snippet_27="$srcdir/src/module-env-27.h"
### Use -lpng if available, unless '--with-png=no'.
HAVE_PNG=no
diff --git a/doc/lispref/internals.texi b/doc/lispref/internals.texi
index 3fbff266ad..56465126f4 100644
--- a/doc/lispref/internals.texi
+++ b/doc/lispref/internals.texi
@@ -1623,7 +1623,27 @@ Module Misc
@deftypefn Function bool should_quit (emacs_env *@var{env})
This function returns @code{true} if the user wants to quit. In that
case, we recommend that your module function aborts any on-going
-processing and returns as soon as possible.
+processing and returns as soon as possible. In most cases, use
+@code{process_input} instead.
+@end deftypefn
+
+To process input events in addition to checking whether the user wants
+to quit, use the following function, which is available since Emacs
+27.1.
+
+@anchor{process_input}
+@deftypefn Function enum emacs_process_input_result process_input (emacs_env *@var{env})
+This function processes pending input events. It returns
+@code{emacs_process_input_quit} if the user wants to quit or an error
+occurred while processing signals. In that case, we recommend that
+your module function aborts any on-going processing and returns as
+soon as possible. If the module code may continue running,
+@code{process_input} returns @code{emacs_process_input_continue}. The
+return value is @code{emacs_process_input_continue} if and only if
+there is no pending nonlocal exit in @code{env}. If the module
+continues after calling @code{process_input}, global state such as
+variable values and buffer content may have been modified in arbitrary
+ways.
@end deftypefn
@node Module Nonlocal
diff --git a/etc/NEWS b/etc/NEWS
index 75c8dc0b8e..08e2e0c728 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -1564,6 +1564,9 @@ given frame supports resizing.
This is currently supported on GNUish hosts and on modern versions of
MS-Windows.
+** New module environment function 'process_input' to process user
+input while module code is running.
+
\f
* Changes in Emacs 27.1 on Non-Free Operating Systems
diff --git a/src/emacs-module.c b/src/emacs-module.c
index cbab023420..b70d6cea81 100644
--- a/src/emacs-module.c
+++ b/src/emacs-module.c
@@ -671,13 +671,21 @@ module_vec_size (emacs_env *env, emacs_value vec)
return ASIZE (lvec);
}
-/* This function should return true if and only if maybe_quit would do
- anything. */
+/* This function should return true if and only if maybe_quit would
+ quit. */
static bool
module_should_quit (emacs_env *env)
{
MODULE_FUNCTION_BEGIN_NO_CATCH (false);
- return (! NILP (Vquit_flag) && NILP (Vinhibit_quit)) || pending_signals;
+ return QUITP;
+}
+
+static enum emacs_process_input_result
+module_process_input (emacs_env *env)
+{
+ MODULE_FUNCTION_BEGIN (emacs_process_input_quit);
+ maybe_quit ();
+ return emacs_process_input_continue;
}
\f
@@ -1082,6 +1090,7 @@ initialize_environment (emacs_env *env, struct emacs_env_private *priv)
env->vec_get = module_vec_get;
env->vec_size = module_vec_size;
env->should_quit = module_should_quit;
+ env->process_input = module_process_input;
Vmodule_environments = Fcons (make_mint_ptr (env), Vmodule_environments);
return env;
}
diff --git a/src/emacs-module.h.in b/src/emacs-module.h.in
index 4c5286f625..009d1583fe 100644
--- a/src/emacs-module.h.in
+++ b/src/emacs-module.h.in
@@ -47,7 +47,7 @@ extern "C" {
#endif
/* Current environment. */
-typedef struct emacs_env_26 emacs_env;
+typedef struct emacs_env_27 emacs_env;
/* Opaque pointer representing an Emacs Lisp value.
BEWARE: Do not assume NULL is a valid value! */
@@ -83,6 +83,16 @@ enum emacs_funcall_exit
emacs_funcall_exit_throw = 2
};
+/* Possible return values for emacs_env.process_input. */
+enum emacs_process_input_result
+{
+ /* Module code may continue */
+ emacs_process_input_continue = 0,
+
+ /* Module code should return control to Emacs as soon as possible. */
+ emacs_process_input_quit = 1
+};
+
struct emacs_env_25
{
@module_env_snippet_25@
@@ -95,6 +105,15 @@ struct emacs_env_26
@module_env_snippet_26@
};
+struct emacs_env_27
+{
+@module_env_snippet_25@
+
+@module_env_snippet_26@
+
+@module_env_snippet_27@
+};
+
/* Every module should define a function as follows. */
extern int emacs_module_init (struct emacs_runtime *ert)
EMACS_NOEXCEPT
diff --git a/src/eval.c b/src/eval.c
index b094fc2e66..b6cdfc911d 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -1575,10 +1575,7 @@ process_quit_flag (void)
If quit-flag is set to `kill-emacs' the SIGINT handler has received
a request to exit Emacs when it is safe to do.
- When not quitting, process any pending signals.
-
- If you change this function, also adapt module_should_quit in
- emacs-module.c. */
+ When not quitting, process any pending signals. */
void
maybe_quit (void)
diff --git a/src/module-env-27.h b/src/module-env-27.h
new file mode 100644
index 0000000000..b491b60fbb
--- /dev/null
+++ b/src/module-env-27.h
@@ -0,0 +1,4 @@
+ /* Processes pending input events and returns whether the module
+ function should quit. */
+ enum emacs_process_input_result (*process_input) (emacs_env *env)
+ EMACS_ATTRIBUTE_NONNULL (1);
diff --git a/test/data/emacs-module/mod-test.c b/test/data/emacs-module/mod-test.c
index 98242e85ba..47ea159d0e 100644
--- a/test/data/emacs-module/mod-test.c
+++ b/test/data/emacs-module/mod-test.c
@@ -17,12 +17,20 @@ 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 <https://www.gnu.org/licenses/>. */
+#include "config.h"
+
#include <assert.h>
+#include <errno.h>
+#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
-#include <limits.h>
+#include <string.h>
+#include <time.h>
+
#include <emacs-module.h>
+#include "timespec.h"
+
int plugin_is_GPL_compatible;
#if INTPTR_MAX <= 0
@@ -299,6 +307,64 @@ Fmod_test_invalid_finalizer (emacs_env *env, ptrdiff_t nargs, emacs_value *args,
return env->funcall (env, env->intern (env, "garbage-collect"), 0, NULL);
}
+static void
+signal_wrong_type_argument (emacs_env *env, const char *predicate,
+ emacs_value arg)
+{
+ emacs_value symbol = env->intern (env, "wrong-type-argument");
+ emacs_value elements[2] = {env->intern (env, predicate), arg};
+ emacs_value data = env->funcall (env, env->intern (env, "list"), 2, elements);
+ env->non_local_exit_signal (env, symbol, data);
+}
+
+static void
+signal_errno (emacs_env *env, const char *function)
+{
+ const char *message = strerror (errno);
+ emacs_value message_value = env->make_string (env, message, strlen (message));
+ emacs_value symbol = env->intern (env, "file-error");
+ emacs_value elements[2]
+ = {env->make_string (env, function, strlen (function)), message_value};
+ emacs_value data = env->funcall (env, env->intern (env, "list"), 2, elements);
+ env->non_local_exit_signal (env, symbol, data);
+}
+
+/* A long-running operation that occasionally calls `should_quit' or
+ `process_input'. */
+
+static emacs_value
+Fmod_test_sleep_until (emacs_env *env, ptrdiff_t nargs, emacs_value *args,
+ void *data)
+{
+ assert (nargs == 2);
+ const double until_seconds = env->extract_float (env, args[0]);
+ if (env->non_local_exit_check (env))
+ return NULL;
+ if (until_seconds <= 0)
+ {
+ signal_wrong_type_argument (env, "cl-plusp", args[0]);
+ return NULL;
+ }
+ const bool process_input = env->is_not_nil (env, args[1]);
+ const struct timespec until = dtotimespec (until_seconds);
+ const struct timespec amount = make_timespec(0, 10000000);
+ while (true)
+ {
+ const struct timespec now = current_timespec ();
+ if (timespec_cmp (now, until) >= 0)
+ break;
+ if (nanosleep (&amount, NULL) && errno != EINTR)
+ {
+ signal_errno (env, "nanosleep");
+ return NULL;
+ }
+ if ((process_input
+ && env->process_input (env) == emacs_process_input_quit)
+ || env->should_quit (env))
+ return NULL;
+ }
+ return env->intern (env, "finished");
+}
/* Lisp utilities for easier readability (simple wrappers). */
@@ -367,6 +433,7 @@ emacs_module_init (struct emacs_runtime *ert)
DEFUN ("mod-test-invalid-load", Fmod_test_invalid_load, 0, 0, NULL, NULL);
DEFUN ("mod-test-invalid-finalizer", Fmod_test_invalid_finalizer, 0, 0,
NULL, NULL);
+ DEFUN ("mod-test-sleep-until", Fmod_test_sleep_until, 2, 2, NULL, NULL);
#undef DEFUN
diff --git a/test/src/emacs-module-tests.el b/test/src/emacs-module-tests.el
index e4593044ec..e30980b599 100644
--- a/test/src/emacs-module-tests.el
+++ b/test/src/emacs-module-tests.el
@@ -289,4 +289,24 @@ module--test-assertion
(should (member '(provide . mod-test) entries))
(should (member '(defun . mod-test-sum) entries))))
+(ert-deftest mod-test-sleep-until ()
+ "Check that `mod-test-sleep-until' either returns normally or quits.
+Interactively, you can try hitting \\[keyboard-quit] to quit."
+ (dolist (arg '(nil t))
+ ;; Guard against some caller setting `inhibit-quit'.
+ (with-local-quit
+ (condition-case nil
+ (should (eq (with-local-quit
+ ;; Because `inhibit-quit' is nil here, the next
+ ;; form either quits or returns `finished'.
+ (mod-test-sleep-until
+ ;; Interactively, run for 5 seconds to give the
+ ;; user time to quit. In batch mode, run only
+ ;; briefly since the user can't quit.
+ (float-time (time-add nil (if noninteractive 0.1 5)))
+ ;; should_quit or process_input
+ arg))
+ 'finished))
+ (quit)))))
+
;;; emacs-module-tests.el ends here
--
2.17.2 (Apple Git-113)
next prev parent reply other threads:[~2019-02-11 20:17 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-02 21:22 [PATCH] Ignore pending_signals when checking for quits Philipp Stephani
2019-01-03 14:03 ` Eli Zaretskii
2019-02-10 18:49 ` Philipp Stephani
2019-02-10 19:40 ` Eli Zaretskii
2019-02-10 19:46 ` Philipp Stephani
2019-02-10 20:15 ` Eli Zaretskii
2019-02-11 20:17 ` Philipp Stephani [this message]
2019-02-13 15:28 ` Eli Zaretskii
2019-02-24 21:51 ` Philipp Stephani
2019-04-19 19:06 ` Philipp Stephani
2019-04-19 20:15 ` Eli Zaretskii
2019-04-28 18:19 ` Philipp Stephani
2019-04-28 18:42 ` Eli Zaretskii
2019-08-07 16:22 ` Philipp Stephani
2019-01-03 14:09 ` Eli Zaretskii
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