From 75bad6260eb43739cede7ec49964ffc7c37ecfa9 Mon Sep 17 00:00:00 2001
From: Anton Likhtarov <alikhtarov@fb.com>
Date: Mon, 22 Jun 2015 19:31:17 -0700
Subject: [PATCH] Futex: ignore errors on wake

Summary: See the comment for details

Reviewed By: @nbronson

Differential Revision: D2181231
---
 folly/detail/Futex.cpp | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/folly/detail/Futex.cpp b/folly/detail/Futex.cpp
index f3d7bb04..bef3c022 100644
--- a/folly/detail/Futex.cpp
+++ b/folly/detail/Futex.cpp
@@ -65,8 +65,13 @@ int nativeFutexWake(void* addr, int count, uint32_t wakeMask) {
                    nullptr, /* addr2 */
                    wakeMask); /* val3 */
 
-  assert(rv >= 0);
-
+  /* NOTE: we ignore errors on wake for the case of a futex
+     guarding its own destruction, similar to this
+     glibc bug with sem_post/sem_wait:
+     https://sourceware.org/bugzilla/show_bug.cgi?id=12674 */
+  if (rv < 0) {
+    return 0;
+  }
   return rv;
 }
 
-- 
2.34.1