From: Argyrios Kyrtzidis <akyrtzi@gmail.com>
Date: Tue, 3 Jul 2012 16:30:52 +0000 (+0000)
Subject: [libclang] Protect against a race condition where a thread
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=817881376e3a40ca54376547dd1cb9ca5def7190;p=clang

[libclang] Protect against a race condition where a thread
may be destroying an ASTUnit while cleanupOnDiskMapAtExit is
getting called.

rdar://11781241

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159664 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Frontend/ASTUnit.cpp b/lib/Frontend/ASTUnit.cpp
index d2f63a80fe..7be25e96b4 100644
--- a/lib/Frontend/ASTUnit.cpp
+++ b/lib/Frontend/ASTUnit.cpp
@@ -116,7 +116,8 @@ static OnDiskDataMap &getOnDiskDataMap() {
 }
 
 static void cleanupOnDiskMapAtExit(void) {
-  // No mutex required here since we are leaving the program.
+  // Use the mutex because there can be an alive thread destroying an ASTUnit.
+  llvm::MutexGuard Guard(getOnDiskMutex());
   OnDiskDataMap &M = getOnDiskDataMap();
   for (OnDiskDataMap::iterator I = M.begin(), E = M.end(); I != E; ++I) {
     // We don't worry about freeing the memory associated with OnDiskDataMap.