2 files changed, 24 insertions, 7 deletions

diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cc b/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cc
index bb471b02c94..5d54a42141a 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cc
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cc
@@ -45,10 +45,6 @@ void MutexCreate(ThreadState *thr, uptr pc, uptr addr,
   s->is_rw = rw;
   s->is_recursive = recursive;
   s->is_linker_init = linker_init;
-  if (common_flags()->detect_deadlocks) {
-    EnsureDeadlockDetectorID(thr, s);
-    Printf("MutexCreate: %zx\n", s->deadlock_detector_id);
-  }
   s->mtx.Unlock();
 }
 
@@ -66,8 +62,9 @@ void MutexDestroy(ThreadState *thr, uptr pc, uptr addr) {
   if (s == 0)
     return;
   if (common_flags()->detect_deadlocks) {
-    EnsureDeadlockDetectorID(thr, s);
-    Printf("MutexDestroy: %zx\n", s->deadlock_detector_id);
+    if (s->deadlock_detector_id)
+      g_deadlock_detector.removeNode(s->deadlock_detector_id);
+    s->deadlock_detector_id = 0;
   }
   if (IsAppMem(addr)) {
     CHECK(!thr->is_freeing);
@@ -169,7 +166,7 @@ int MutexUnlock(ThreadState *thr, uptr pc, uptr addr, bool all) {
   thr->mset.Del(s->GetId(), true);
   if (common_flags()->detect_deadlocks) {
     EnsureDeadlockDetectorID(thr, s);
-    Printf("MutexUnlock: %zx\n", s->deadlock_detector_id);
+    // Printf("MutexUnlock: %zx\n", s->deadlock_detector_id);
     g_deadlock_detector.onUnlock(&thr->deadlock_detector_tls,
                                  s->deadlock_detector_id);
   }
diff --git a/compiler-rt/test/tsan/deadlock_detector_stress_test.cc b/compiler-rt/test/tsan/deadlock_detector_stress_test.cc
index cb83f56da2f..b62df4df555 100644
--- a/compiler-rt/test/tsan/deadlock_detector_stress_test.cc
+++ b/compiler-rt/test/tsan/deadlock_detector_stress_test.cc
@@ -33,6 +33,7 @@ class LockTest {
     locks_[i].unlock();
   }
 
+  // Simple lock order onversion.
   void Test1() {
     fprintf(stderr, "Starting Test1\n");
     // CHECK: Starting Test1
@@ -42,6 +43,7 @@ class LockTest {
     // CHECK-NOT: ThreadSanitizer:
   }
 
+  // Simple lock order inversion with 3 locks.
   void Test2() {
     fprintf(stderr, "Starting Test2\n");
     // CHECK: Starting Test2
@@ -51,7 +53,24 @@ class LockTest {
     // CHECK-NOT: ThreadSanitizer:
   }
 
+  // Lock order inversion with lots of new locks created (but not used)
+  // between. Since the new locks are not used we should still detect the
+  // deadlock.
+  void Test3() {
+    fprintf(stderr, "Starting Test3\n");
+    // CHECK: Starting Test3
+    L(0); L(1); U(0); U(1);
+    CreateAndDestroyManyLocks();
+    L(1); L(0); U(0); U(1);
+    // CHECK: ThreadSanitizer: lock-order-inversion (potential deadlock)
+    // CHECK-NOT: ThreadSanitizer:
+  }
+
  private:
+  void CreateAndDestroyManyLocks() {
+    PaddedLock create_many_locks_but_never_acquire[kDeadlockGraphSize];
+  }
+  static const size_t kDeadlockGraphSize = 4096;
   size_t n_;
   PaddedLock *locks_;
 };
@@ -59,6 +78,7 @@ class LockTest {
 int main() {
   { LockTest t(5); t.Test1(); }
   { LockTest t(5); t.Test2(); }
+  { LockTest t(5); t.Test3(); }
   fprintf(stderr, "DONE\n");
   // CHECK: DONE
 }