[guile] Run finalizers from GDB thread

From 4a9919c3e731f0210cfbcfbbb6040189f46a7fbb Mon Sep 17 00:00:00 2001
From: Andy Wingo <wingo@igalia.com>
Date: Tue, 10 Feb 2015 15:26:24 +0100
Subject: [PATCH] [guile] Run finalizers from GDB thread

gdb/ChangeLog:
	* guile/guile.c (_initialize_guile): Disable automatic
	finalization, if Guile offers us that possibility.
	* guile/guile.c (call_initialize_gdb_module):
	* guile/scm-safe-call.c (gdbscm_with_catch): Arrange to run
	finalizers in appropriate places.
	* configure.ac (AC_TRY_LIBGUILE): Add a check for
	scm_set_automatic_finalization_enabled.
	* configure: Regenerated.
---
 gdb/ChangeLog             | 11 +++++++++++
 gdb/configure.ac          |  5 +++++
 gdb/guile/guile.c         | 11 +++++++++++
 gdb/guile/scm-safe-call.c |  4 ++++
 4 files changed, 31 insertions(+)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 3e26864..0b7b4b7 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,14 @@ 
+2015-02-10  Andy Wingo  <wingo@igalia.com>
+
+	* guile/guile.c (_initialize_guile): Disable automatic
+	finalization, if Guile offers us that possibility.
+	* guile/guile.c (call_initialize_gdb_module):
+	* guile/scm-safe-call.c (gdbscm_with_catch): Arrange to run
+	finalizers in appropriate places.
+	* configure.ac (AC_TRY_LIBGUILE): Add a check for
+	scm_set_automatic_finalization_enabled.
+	* configure: Regenerated.
+
 2014-04-17  Andy Wingo  <wingo@igalia.com>
 
 	* configure.ac: When Guile is available, check for the
diff --git a/gdb/configure.ac b/gdb/configure.ac
index 886e83b..3e96016 100644
--- a/gdb/configure.ac
+++ b/gdb/configure.ac
@@ -1085,6 +1085,11 @@  AC_DEFUN([AC_TRY_LIBGUILE],
                     GUILE_CPPFLAGS=$new_CPPFLAGS
                     GUILE_LIBS=$new_LIBS],
                    [found_usable_guile=no])
+    dnl scm_set_automatic_finalization_enabled added in Guile 2.2.
+    AC_CHECK_FUNC(scm_set_automatic_finalization_enabled,
+      AC_DEFINE(HAVE_GUILE_MANUAL_FINALIZATION, 1,
+                [Define if Guile supports manual finalization.])
+    )
     CPPFLAGS=$save_CPPFLAGS
     LIBS=$save_LIBS
     if test "${found_usable_guile}" = no; then
diff --git a/gdb/guile/guile.c b/gdb/guile/guile.c
index 319b583..e9d2aae 100644
--- a/gdb/guile/guile.c
+++ b/gdb/guile/guile.c
@@ -698,6 +698,10 @@  call_initialize_gdb_module (void *data)
      performed within the desired module.  */
   scm_c_define_module (gdbscm_module_name, initialize_gdb_module, NULL);
 
+#if HAVE_GUILE_MANUAL_FINALIZATION
+  scm_run_finalizers ();
+#endif
+
   return NULL;
 }
 
@@ -844,6 +848,13 @@  _initialize_guile (void)
        side to define module "gdb" which imports "_gdb".  There is evidently no
        similar convention in Guile so we skip this.  */
 
+#if HAVE_GUILE_MANUAL_FINALIZATION
+    /* Our SMOB free functions are not thread-safe, as GDB itself is not
+       intended to be thread-safe.  Disable automatic finalization so that
+       finalizers aren't run in other threads.  */
+    scm_set_automatic_finalization_enabled (0);
+#endif
+
 #ifdef HAVE_SIGPROCMASK
     /* Before we initialize Guile, block SIGCHLD.
        This is done so that all threads created during Guile initialization
diff --git a/gdb/guile/scm-safe-call.c b/gdb/guile/scm-safe-call.c
index 9255556..6052214 100644
--- a/gdb/guile/scm-safe-call.c
+++ b/gdb/guile/scm-safe-call.c
@@ -155,6 +155,10 @@  gdbscm_with_catch (void *data)
 		   d->unwind_handler, d,
 		   d->pre_unwind_handler, d);
 
+#if HAVE_GUILE_MANUAL_FINALIZATION
+  scm_run_finalizers ();
+#endif
+
   return NULL;
 }
 
-- 
2.1.4