EDK: Move mutex.*, cond_var.*, and thread_annotations.h to //mojo/edk/util.

mojo/edk/system/mutex.h

-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// A mutex class, with support for thread annotations.
-//
-// TODO(vtl): Add support for non-exclusive (reader) locks.
-
-#ifndef MOJO_EDK_SYSTEM_MUTEX_H_
-#define MOJO_EDK_SYSTEM_MUTEX_H_
-
-#include <pthread.h>
-
-#include "mojo/edk/system/thread_annotations.h"
-#include "mojo/public/cpp/system/macros.h"
-
-namespace mojo {
-namespace system {
-
-// So |Mutex| can friend it.
-class CondVar;
-
-// Mutex -----------------------------------------------------------------------
-
-class MOJO_LOCKABLE Mutex {
- public:
-#if defined(NDEBUG) && !defined(DCHECK_ALWAYS_ON)
-  Mutex() { pthread_mutex_init(&impl_, nullptr); }
-  ~Mutex() { pthread_mutex_destroy(&impl_); }
-
-  // Takes an exclusive lock.
-  void Lock() MOJO_EXCLUSIVE_LOCK_FUNCTION() { pthread_mutex_lock(&impl_); }
-
-  // Releases a lock.
-  void Unlock() MOJO_UNLOCK_FUNCTION() { pthread_mutex_unlock(&impl_); }
-
-  // Tries to take an exclusive lock, returning true if successful.
-  bool TryLock() MOJO_EXCLUSIVE_TRYLOCK_FUNCTION(true) {
-    return !pthread_mutex_trylock(&impl_);
-  }
-
-  // Asserts that an exclusive lock is held by the calling thread. (Does nothing
-  // for non-Debug builds.)
-  void AssertHeld() MOJO_ASSERT_EXCLUSIVE_LOCK() {}
-#else
-  Mutex();
-  ~Mutex();
-
-  void Lock() MOJO_EXCLUSIVE_LOCK_FUNCTION();
-  void Unlock() MOJO_UNLOCK_FUNCTION();
-
-  bool TryLock() MOJO_EXCLUSIVE_TRYLOCK_FUNCTION(true);
-
-  void AssertHeld() MOJO_ASSERT_EXCLUSIVE_LOCK();
-#endif  // defined(NDEBUG) && !defined(DCHECK_ALWAYS_ON)
-
- private:
-  friend class CondVar;
-
-  pthread_mutex_t impl_;
-
-  MOJO_DISALLOW_COPY_AND_ASSIGN(Mutex);
-};
-
-// MutexLocker -----------------------------------------------------------------
-
-class MOJO_SCOPED_LOCKABLE MutexLocker {
- public:
-  explicit MutexLocker(Mutex* mutex) MOJO_EXCLUSIVE_LOCK_FUNCTION(mutex)
-      : mutex_(mutex) {
-    this->mutex_->Lock();
-  }
-  ~MutexLocker() MOJO_UNLOCK_FUNCTION() { this->mutex_->Unlock(); }
-
- private:
-  Mutex* const mutex_;
-
-  MOJO_DISALLOW_COPY_AND_ASSIGN(MutexLocker);
-};
-
-}  // namespace system
-}  // namespace mojo
-
-#endif  // MOJO_EDK_SYSTEM_MUTEX_H_