+int _malloc_thread_enabled_p;
+
+static void
+malloc_atfork_handler_prepare ()
+{
+ LOCK ();
+ LOCK_ALIGNED_BLOCKS ();
+}
+
+static void
+malloc_atfork_handler_parent ()
+{
+ UNLOCK_ALIGNED_BLOCKS ();
+ UNLOCK ();
+}
+
+static void
+malloc_atfork_handler_child ()
+{
+ UNLOCK_ALIGNED_BLOCKS ();
+ UNLOCK ();
+}
+
+/* Set up mutexes and make malloc etc. thread-safe. */
+void
+malloc_enable_thread ()
+{
+ if (_malloc_thread_enabled_p)
+ return;
+
+ /* Some pthread implementations call malloc for statically
+ initialized mutexes when they are used first. To avoid such a
+ situation, we initialize mutexes here while their use is
+ disabled in malloc etc. */
+ pthread_mutex_init (&_malloc_mutex, NULL);
+ pthread_mutex_init (&_aligned_blocks_mutex, NULL);
+ pthread_atfork (malloc_atfork_handler_prepare,
+ malloc_atfork_handler_parent,
+ malloc_atfork_handler_child);
+ _malloc_thread_enabled_p = 1;
+}