[tsan] add a currently-failing test with a must-deadlock

llvm-svn: 212944

compiler-rt/test/tsan/must_deadlock.cc

@@ -0,0 +1,49 @@
+// Test that the deadlock detector can find a deadlock that actually happened.
+// Currently we will fail to report such a deadlock because we check for
+// cycles in lock-order graph after pthread_mutex_lock.
+
+// RUN: %clangxx_tsan %s -o %t
+// RUN: not %run %t 2>&1 | FileCheck %s
+// XFAIL: *
+#include <pthread.h>
+#include <stdio.h>
+#include <unistd.h>
+
+pthread_mutex_t mu1, mu2;
+pthread_barrier_t barrier;
+
+void *Thread(void *p) {
+  // mu2 => mu1
+  pthread_mutex_lock(&mu2);
+  pthread_barrier_wait(&barrier);
+  pthread_mutex_lock(&mu1);
+  // CHECK: ThreadSanitizer: lock-order-inversion (potential deadlock)
+  pthread_mutex_unlock(&mu1);
+  pthread_mutex_unlock(&mu2);
+  return p;
+}
+
+int main() {
+  pthread_mutex_init(&mu1, NULL);
+  pthread_mutex_init(&mu2, NULL);
+  pthread_barrier_init(&barrier, 0, 2);
+
+  alarm(3);
+
+  pthread_t t;
+  pthread_create(&t, 0, Thread, 0);
+
+  // mu1 => mu2
+  pthread_mutex_lock(&mu1);
+  pthread_barrier_wait(&barrier);
+  pthread_mutex_lock(&mu2);
+  pthread_mutex_unlock(&mu2);
+  pthread_mutex_unlock(&mu1);
+
+  pthread_join(t, 0);
+
+  pthread_mutex_destroy(&mu1);
+  pthread_mutex_destroy(&mu2);
+  pthread_barrier_destroy(&barrier);
+  fprintf(stderr, "FAILED\n");
+}