1 files changed, 45 insertions, 0 deletions
diff --git a/test/tsan/libdispatch/sync-block-copy.cc b/test/tsan/libdispatch/sync-block-copy.cc
new file mode 100644
index 000000000..1f10d958b
--- /dev/null
+++ b/test/tsan/libdispatch/sync-block-copy.cc
@@ -0,0 +1,45 @@
+// This test verifies that dispatch_sync() doesn't actually copy the block under TSan (without TSan, it doesn't).
+
+// RUN: %clangxx_tsan %s -o %t_no_tsan -fno-sanitize=thread
+// RUN: %clangxx_tsan %s -o %t_with_tsan
+
+// RUN: %run %t_no_tsan   2>&1 | FileCheck %s
+// RUN: %run %t_with_tsan 2>&1 | FileCheck %s --implicit-check-not='ThreadSanitizer'
+
+#include <dispatch/dispatch.h>
+
+#include <stdio.h>
+
+struct MyClass {
+  static int copyCount;
+  static void printCopyCount() {
+    fprintf(stderr, "copyCount = %d\n", copyCount);
+  }
+  MyClass(){};
+  MyClass(const MyClass &obj) { copyCount++; };
+  void foo() const {
+    fprintf(stderr, "MyClass::foo\n");
+  }
+};
+int MyClass::copyCount = 0;
+
+int main(int argc, const char* argv[]) {
+  dispatch_queue_t q = dispatch_queue_create("my.queue", NULL);
+  MyClass obj;
+  MyClass::printCopyCount();
+  void (^block)(void) = ^{
+    obj.foo();
+  };
+  MyClass::printCopyCount();
+  dispatch_sync(q, block);
+  MyClass::printCopyCount();
+
+  fprintf(stderr, "Done.\n");
+  return 0;
+}
+
+// CHECK: copyCount = 0
+// CHECK: copyCount = 1
+// CHECK: MyClass::foo
+// CHECK: copyCount = 1
+// CHECK: Done.