Add lock owner information for class Monitor and add assertions for wait/notify/notifyall.

runtime/vm/os_thread_linux.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/globals.h"  // NOLINT
 #if defined(TARGET_OS_LINUX)
 
 #include "vm/os_thread.h"
 
 #include <errno.h>  // NOLINT
@@ skipping 212 matching lines @@
   VALIDATE_PTHREAD_RESULT(result);
 #endif  // defined(DEBUG)
 
   result = pthread_mutex_init(data_.mutex(), &attr);
   // Verify that creating a pthread_mutex succeeded.
   VALIDATE_PTHREAD_RESULT(result);
 
   result = pthread_mutexattr_destroy(&attr);
   VALIDATE_PTHREAD_RESULT(result);
 
-  // When running with assertions enabled we do track the owner.
 #if defined(DEBUG)
+  // When running with assertions enabled we track the owner.
   owner_ = OSThread::kInvalidThreadId;
 #endif  // defined(DEBUG)
 }
 
 
 Mutex::~Mutex() {
   int result = pthread_mutex_destroy(data_.mutex());
   // Verify that the pthread_mutex was destroyed.
   VALIDATE_PTHREAD_RESULT(result);
 
-  // When running with assertions enabled we do track the owner.
 #if defined(DEBUG)
+  // When running with assertions enabled we track the owner.
   ASSERT(owner_ == OSThread::kInvalidThreadId);
 #endif  // defined(DEBUG)
 }
 
 
 void Mutex::Lock() {
   int result = pthread_mutex_lock(data_.mutex());
   // Specifically check for dead lock to help debugging.
   ASSERT(result != EDEADLK);
   ASSERT_PTHREAD_SUCCESS(result);  // Verify no other errors.
-  // When running with assertions enabled we do track the owner.
 #if defined(DEBUG)
+  // When running with assertions enabled we track the owner.
   owner_ = OSThread::GetCurrentThreadId();
 #endif  // defined(DEBUG)
 }
 
 
 bool Mutex::TryLock() {
   int result = pthread_mutex_trylock(data_.mutex());
   // Return false if the lock is busy and locking failed.
   if (result == EBUSY) {
     return false;
   }
   ASSERT_PTHREAD_SUCCESS(result);  // Verify no other errors.
-  // When running with assertions enabled we do track the owner.
 #if defined(DEBUG)
+  // When running with assertions enabled we track the owner.
   owner_ = OSThread::GetCurrentThreadId();
 #endif  // defined(DEBUG)
   return true;
 }
 
 
 void Mutex::Unlock() {
-  // When running with assertions enabled we do track the owner.
 #if defined(DEBUG)
+  // When running with assertions enabled we track the owner.
   ASSERT(IsOwnedByCurrentThread());
   owner_ = OSThread::kInvalidThreadId;
 #endif  // defined(DEBUG)
   int result = pthread_mutex_unlock(data_.mutex());
   // Specifically check for wrong thread unlocking to aid debugging.
   ASSERT(result != EPERM);
   ASSERT_PTHREAD_SUCCESS(result);  // Verify no other errors.
 }
 
 
@@ skipping 18 matching lines @@
   VALIDATE_PTHREAD_RESULT(result);
 
   result = pthread_condattr_setclock(&cond_attr, CLOCK_MONOTONIC);
   VALIDATE_PTHREAD_RESULT(result);
 
   result = pthread_cond_init(data_.cond(), &cond_attr);
   VALIDATE_PTHREAD_RESULT(result);
 
   result = pthread_condattr_destroy(&cond_attr);
   VALIDATE_PTHREAD_RESULT(result);
+
+#if defined(DEBUG)
+  // When running with assertions enabled we track the owner.
+  owner_ = OSThread::kInvalidThreadId;
+#endif  // defined(DEBUG)
 }
 
 
 Monitor::~Monitor() {
+#if defined(DEBUG)
+  // When running with assertions enabled we track the owner.
+  ASSERT(owner_ == OSThread::kInvalidThreadId);
+#endif  // defined(DEBUG)
+
   int result = pthread_mutex_destroy(data_.mutex());
   VALIDATE_PTHREAD_RESULT(result);
 
   result = pthread_cond_destroy(data_.cond());
   VALIDATE_PTHREAD_RESULT(result);
 }
 
 
 void Monitor::Enter() {
   int result = pthread_mutex_lock(data_.mutex());
   VALIDATE_PTHREAD_RESULT(result);
-  // TODO(iposva): Do we need to track lock owners?
+
+#if defined(DEBUG)
+  // When running with assertions enabled we track the owner.
+  ASSERT(owner_ == OSThread::kInvalidThreadId);
+  owner_ = OSThread::GetCurrentThreadId();
+#endif  // defined(DEBUG)
 }
 
 
 void Monitor::Exit() {
-  // TODO(iposva): Do we need to track lock owners?
+#if defined(DEBUG)
+  // When running with assertions enabled we track the owner.
+  ASSERT(IsOwnedByCurrentThread());
+  owner_ = OSThread::kInvalidThreadId;
+#endif  // defined(DEBUG)
+
   int result = pthread_mutex_unlock(data_.mutex());
   VALIDATE_PTHREAD_RESULT(result);
 }
 
 
 Monitor::WaitResult Monitor::Wait(int64_t millis) {
-  return WaitMicros(millis * kMicrosecondsPerMillisecond);
+  Monitor::WaitResult retval = WaitMicros(millis * kMicrosecondsPerMillisecond);
+  return retval;
 }
 
 
 Monitor::WaitResult Monitor::WaitMicros(int64_t micros) {
-  // TODO(iposva): Do we need to track lock owners?
+#if defined(DEBUG)
+  // When running with assertions enabled we track the owner.
+  ASSERT(IsOwnedByCurrentThread());
+  ThreadId saved_owner = owner_;
+  owner_ = OSThread::kInvalidThreadId;
+#endif  // defined(DEBUG)
+
   Monitor::WaitResult retval = kNotified;
   if (micros == kNoTimeout) {
     // Wait forever.
     int result = pthread_cond_wait(data_.cond(), data_.mutex());
     VALIDATE_PTHREAD_RESULT(result);
   } else {
     struct timespec ts;
     ComputeTimeSpecMicros(&ts, micros);
     int result = pthread_cond_timedwait(data_.cond(), data_.mutex(), &ts);
     ASSERT((result == 0) || (result == ETIMEDOUT));
     if (result == ETIMEDOUT) {
       retval = kTimedOut;
     }
   }
+
+#if defined(DEBUG)
+  // When running with assertions enabled we track the owner.
+  ASSERT(owner_ == OSThread::kInvalidThreadId);
+  owner_ = OSThread::GetCurrentThreadId();
+  ASSERT(owner_ == saved_owner);
+#endif  // defined(DEBUG)
   return retval;
 }
 
 
 void Monitor::Notify() {
-  // TODO(iposva): Do we need to track lock owners?
+  // When running with assertions enabled we track the owner.
+  ASSERT(IsOwnedByCurrentThread());
   int result = pthread_cond_signal(data_.cond());
   VALIDATE_PTHREAD_RESULT(result);
 }
 
 
 void Monitor::NotifyAll() {
-  // TODO(iposva): Do we need to track lock owners?
+  // When running with assertions enabled we track the owner.
+  ASSERT(IsOwnedByCurrentThread());
   int result = pthread_cond_broadcast(data_.cond());
   VALIDATE_PTHREAD_RESULT(result);
 }
 
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_LINUX)