Imported Upstream version 6.10.0.49

Former-commit-id: 1d6753294b2993e1fbf92de9366bb9544db4189b

external/llvm-project/compiler-rt/test/tsan/race_on_barrier2.c

@@ -0,0 +1,35 @@
+// RUN: %clang_tsan -O1 %s -o %t && %deflake %run %t | FileCheck %s
+
+// pthread barriers are not available on OS X
+// UNSUPPORTED: darwin
+
+#include <pthread.h>
+#include <stdio.h>
+#include <stddef.h>
+#include <unistd.h>
+
+pthread_barrier_t B;
+int Global;
+
+void *Thread1(void *x) {
+  if (pthread_barrier_wait(&B) == PTHREAD_BARRIER_SERIAL_THREAD)
+    pthread_barrier_destroy(&B);
+  return NULL;
+}
+
+void *Thread2(void *x) {
+  if (pthread_barrier_wait(&B) == PTHREAD_BARRIER_SERIAL_THREAD)
+    pthread_barrier_destroy(&B);
+  return NULL;
+}
+
+int main() {
+  pthread_barrier_init(&B, 0, 2);
+  pthread_t t;
+  pthread_create(&t, NULL, Thread1, NULL);
+  Thread2(0);
+  pthread_join(t, NULL);
+  return 0;
+}
+
+// CHECK:      WARNING: ThreadSanitizer: data race