native_client_sdk/src/libraries/sdk_util/auto_lock.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef LIBRARIES_SDK_UTIL_AUTO_LOCK_H_
   6 #define LIBRARIES_SDK_UTIL_AUTO_LOCK_H_
   7
   8 #include <pthread.h>
   9 #include "sdk_util/macros.h"
  10 #include "sdk_util/simple_lock.h"
  11
  12 namespace sdk_util {
  13
  14 // This macro is provided to allow us to quickly instrument locking for
  15 // debugging purposes.
  16 #define AUTO_LOCK(lock)                         \
  17   ::sdk_util::AutoLock Lock##__LINE__(lock);
  18
  19 class AutoLock {
  20  public:
  21   AutoLock(const SimpleLock& lock) {
  22     lock_ = lock.mutex();
  23     pthread_mutex_lock(lock_);
  24   }
  25
  26   ~AutoLock() {
  27     Unlock();
  28   }
  29
  30   void Unlock() {
  31     if (lock_) pthread_mutex_unlock(lock_);
  32     lock_ = NULL;
  33   }
  34
  35  private:
  36   pthread_mutex_t* lock_;
  37
  38   DISALLOW_COPY_AND_ASSIGN(AutoLock);
  39 };
  40
  41 }  // namespace sdk_util
  42
  43 #endif  // LIBRARIES_SDK_UTIL_AUTO_LOCK_H_