Imported Upstream version 6.10.0.49

Former-commit-id: 1d6753294b2993e1fbf92de9366bb9544db4189b

external/llvm-project/compiler-rt/test/tsan/Darwin/osspinlock-norace.cc

@@ -0,0 +1,34 @@
+// RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
+#include <pthread.h>
+#include <stdint.h>
+#include <stdio.h>
+
+typedef int32_t OSSpinLock;
+extern "C" void OSSpinLockLock(OSSpinLock *);
+extern "C" void OSSpinLockUnlock(OSSpinLock *);
+
+int Global;
+OSSpinLock lock;
+
+void *Thread(void *x) {
+  OSSpinLockLock(&lock);
+  Global++;
+  OSSpinLockUnlock(&lock);
+  return NULL;
+}
+
+int main() {
+  fprintf(stderr, "Hello world.\n");
+
+  pthread_t t[2];
+  pthread_create(&t[0], NULL, Thread, NULL);
+  pthread_create(&t[1], NULL, Thread, NULL);
+  pthread_join(t[0], NULL);
+  pthread_join(t[1], NULL);
+
+  fprintf(stderr, "Done.\n");
+}
+
+// CHECK: Hello world.
+// CHECK: Done.
+// CHECK-NOT: WARNING: ThreadSanitizer