Fix missing lock while updating GC_in_thread_creation in GC_exit_check

(fix of commit 8e6460052)

* misc.c [!DONT_USE_ATEXIT && THREADS] (GC_exit_check): Wrap each
update of GC_in_thread_creation into LOCK/UNLOCK (but not GC_gcollect
call); add comment.

1 files changed, 11 insertions, 3 deletions

diff --git a/misc.c b/misc.c
index 8b02f53e..b542819d 100644
--- a/misc.c
+++ b/misc.c
@@ -766,11 +766,19 @@ GC_API int GC_CALL GC_is_init_called(void)
   {
     if (GC_find_leak && !skip_gc_atexit) {
 #     ifdef THREADS
+        DCL_LOCK_STATE;
+
+        /* GC_in_thread_creation should always be updated holding the   */
+        /* lock even if we are about to exit.                           */
+        LOCK();
         GC_in_thread_creation = TRUE; /* OK to collect from unknown thread. */
-        GC_gcollect();
+        UNLOCK();
+#     endif
+      GC_gcollect();
+#     ifdef THREADS
+        LOCK();
         GC_in_thread_creation = FALSE;
-#     else
-        GC_gcollect();
+        UNLOCK();
 #     endif
     }
   }