1 files changed, 32 insertions, 0 deletions
diff --git a/test/tsan/Darwin/gcd-sync-norace.mm b/test/tsan/Darwin/gcd-sync-norace.mm
new file mode 100644
index 0000000000000..f21cfdedbce1d
--- /dev/null
+++ b/test/tsan/Darwin/gcd-sync-norace.mm
@@ -0,0 +1,32 @@
+// RUN: %clang_tsan %s -o %t -framework Foundation
+// RUN: %run %t 2>&1
+
+#import <Foundation/Foundation.h>
+
+long global;
+
+static const long nIter = 1000;
+
+int main() {
+  NSLog(@"Hello world.");
+
+  global = 42;
+  for (int i = 0; i < nIter; i++) {
+    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
+      dispatch_sync(dispatch_get_main_queue(), ^{
+        global = i;
+
+        if (i == nIter - 1) {
+          CFRunLoopStop(CFRunLoopGetCurrent());
+        }
+      });
+    });
+  }
+
+  CFRunLoopRun();
+  NSLog(@"Done.");
+}
+
+// CHECK: Hello world.
+// CHECK: Done.
+// CHECK-NOT: WARNING: ThreadSanitizer