Add support for tsan annotations (thread sanitizer, a valgrind-based tool).

These annotations are disabled entirely when either ENABLE_THREADS is off, or
building a release build. When enabled, they add calls to functions with no
statements to ManagedStatic's getters.

Use these annotations to inform tsan that the race used inside ManagedStatic
initialization is actually benign. Thanks to Kostya Serebryany for helping
write this patch!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144567 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 39 insertions, 0 deletions

diff --git a/unittests/Support/ManagedStatic.cpp b/unittests/Support/ManagedStatic.cpp
new file mode 100644
index 0000000000..f1f03208c1
--- /dev/null
+++ b/unittests/Support/ManagedStatic.cpp
@@ -0,0 +1,39 @@
+//===- llvm/unittest/Support/ManagedStatic.cpp - ManagedStatic tests ------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+#include "llvm/Support/ManagedStatic.h"
+#include "llvm/Support/Threading.h"
+#include <pthread.h>
+
+#include "gtest/gtest.h"
+
+using namespace llvm;
+
+namespace {
+
+namespace test1 {
+  llvm::ManagedStatic<int> ms;
+  void *helper(void*) {
+    *ms;
+    return NULL;
+  }
+}
+
+TEST(Initialize, MultipleThreads) {
+  // Run this test under tsan: http://code.google.com/p/data-race-test/
+
+  llvm_start_multithreaded();
+  pthread_t t1, t2;
+  pthread_create(&t1, NULL, test1::helper, NULL);
+  pthread_create(&t2, NULL, test1::helper, NULL);
+  pthread_join(t1, NULL);
+  pthread_join(t2, NULL);
+  llvm_stop_multithreaded();
+}
+
+} // anonymous namespace