1 files changed, 80 insertions, 0 deletions
diff --git a/lib/tsan/lit_tests/atomic_race.cc b/lib/tsan/lit_tests/atomic_race.cc
new file mode 100644
index 000000000000..360b81238889
--- /dev/null
+++ b/lib/tsan/lit_tests/atomic_race.cc
@@ -0,0 +1,80 @@
+// RUN: %clangxx_tsan -O1 %s -o %t && %t 2>&1 | FileCheck %s
+#include <pthread.h>
+#include <unistd.h>
+#include <stdio.h>
+
+const int kTestCount = 4;
+typedef long long T;
+T atomics[kTestCount * 2];
+
+void Test(int test, T *p, bool main_thread) {
+  volatile T sink;
+  if (test == 0) {
+    if (main_thread)
+      __atomic_fetch_add(p, 1, __ATOMIC_RELAXED);
+    else
+      *p = 42;
+  } else if (test == 1) {
+    if (main_thread)
+      __atomic_fetch_add(p, 1, __ATOMIC_RELAXED);
+    else
+      sink = *p;
+  } else if (test == 2) {
+    if (main_thread)
+      sink = __atomic_load_n(p, __ATOMIC_SEQ_CST);
+    else
+      *p = 42;
+  } else if (test == 3) {
+    if (main_thread)
+      __atomic_store_n(p, 1, __ATOMIC_SEQ_CST);
+    else
+      sink = *p;
+  }
+}
+
+void *Thread(void *p) {
+  for (int i = 0; i < kTestCount; i++) {
+    Test(i, &atomics[i], false);
+  }
+  sleep(2);
+  for (int i = 0; i < kTestCount; i++) {
+    fprintf(stderr, "Test %d reverse\n", i);
+    Test(i, &atomics[kTestCount + i], false);
+  }
+  return 0;
+}
+
+int main() {
+  pthread_t t;
+  pthread_create(&t, 0, Thread, 0);
+  sleep(1);
+  for (int i = 0; i < kTestCount; i++) {
+    fprintf(stderr, "Test %d\n", i);
+    Test(i, &atomics[i], true);
+  }
+  for (int i = 0; i < kTestCount; i++) {
+    Test(i, &atomics[kTestCount + i], true);
+  }
+  pthread_join(t, 0);
+}
+
+// CHECK: Test 0
+// CHECK: ThreadSanitizer: data race
+// CHECK-NOT: SUMMARY{{.*}}tsan_interface_atomic
+// CHECK: Test 1
+// CHECK: ThreadSanitizer: data race
+// CHECK-NOT: SUMMARY{{.*}}tsan_interface_atomic
+// CHECK: Test 2
+// CHECK: ThreadSanitizer: data race
+// CHECK-NOT: SUMMARY{{.*}}tsan_interface_atomic
+// CHECK: Test 3
+// CHECK: ThreadSanitizer: data race
+// CHECK-NOT: SUMMARY{{.*}}tsan_interface_atomic
+// CHECK: Test 0 reverse
+// CHECK: ThreadSanitizer: data race
+// CHECK: Test 1 reverse
+// CHECK: ThreadSanitizer: data race
+// CHECK: Test 2 reverse
+// CHECK: ThreadSanitizer: data race
+// CHECK: Test 3 reverse
+// CHECK: ThreadSanitizer: data race