1 files changed, 42 insertions, 0 deletions
diff --git a/test/tsan/mutex_cycle_long.c b/test/tsan/mutex_cycle_long.c
new file mode 100644
index 0000000000000..b5d67c16c321d
--- /dev/null
+++ b/test/tsan/mutex_cycle_long.c
@@ -0,0 +1,42 @@
+// RUN: %clangxx_tsan %s -o %t
+// RUN: not %run %t 5 2>&1 | FileCheck %s
+// RUN: not %run %t 10 2>&1 | FileCheck %s
+// RUN: not %run %t 15 2>&1 | FileCheck %s
+// RUN: not %run %t 20 2>&1 | FileCheck %s
+// RUN: %run %t 30 2>&1 | FileCheck %s --check-prefix=CHECK-TOO-LONG-CYCLE
+
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(int argc, char *argv[]) {
+  int num_mutexes = 5;
+  if (argc > 1) num_mutexes = atoi(argv[1]);
+
+  pthread_mutex_t m[num_mutexes];
+  for (int i = 0; i < num_mutexes; ++i)
+    pthread_mutex_init(&m[i], NULL);
+  
+  for (int i = 0; i < num_mutexes - 1; ++i) {
+    pthread_mutex_lock(&m[i]);
+    pthread_mutex_lock(&m[i + 1]);
+
+    pthread_mutex_unlock(&m[i]);
+    pthread_mutex_unlock(&m[i + 1]);
+  }
+
+  pthread_mutex_lock(&m[num_mutexes - 1]);
+  pthread_mutex_lock(&m[0]);
+
+  pthread_mutex_unlock(&m[num_mutexes - 1]);
+  pthread_mutex_unlock(&m[0]);
+
+  for (int i = 0; i < num_mutexes; ++i)
+    pthread_mutex_destroy(&m[i]);
+
+  fprintf(stderr, "PASS\n");
+}
+
+// CHECK: ThreadSanitizer: lock-order-inversion (potential deadlock)
+// CHECK-TOO-LONG-CYCLE: WARNING: too long mutex cycle found
+// CHECK: PASS