From: Ivan Maidanski <ivmai@mail.ru>
Date: Wed, 22 Nov 2017 23:19:30 +0000 (+0300)
Subject: Workaround TSan hang in GC_free_inner when called from at-fork handler
X-Git-Tag: v8.0.0~497
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=d8e271ea8ab4477fc3ac8edb884bbf858d401343;p=gc

Workaround TSan hang in GC_free_inner when called from at-fork handler

* pthread_support.c [CAN_HANDLE_FORK] (GC_remove_all_threads_but_me):
Do not call GC_INTERNAL_FREE(p) if THREAD_SANITIZER; add comment.
---

diff --git a/pthread_support.c b/pthread_support.c
index 70b512af..c70ab7da 100644
--- a/pthread_support.c
+++ b/pthread_support.c
@@ -787,7 +787,11 @@ STATIC void GC_remove_all_threads_but_me(void)
               GC_remove_specific_after_fork(GC_thread_key, p -> id);
             }
 #         endif
-          if (p != &first_thread) GC_INTERNAL_FREE(p);
+          /* TODO: To avoid TSan hang (when updating GC_bytes_freed),   */
+          /* we just skip explicit free of GC_threads entries for now.  */
+#         ifndef THREAD_SANITIZER
+            if (p != &first_thread) GC_INTERNAL_FREE(p);
+#         endif
         }
       }
       GC_threads[hv] = me;