Move base to DEPS

base/synchronization/lock.h

-// Copyright (c) 2011 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.
-
-#ifndef BASE_SYNCHRONIZATION_LOCK_H_
-#define BASE_SYNCHRONIZATION_LOCK_H_
-
-#include "base/base_export.h"
-#include "base/synchronization/lock_impl.h"
-#include "base/threading/platform_thread.h"
-
-namespace base {
-
-// A convenient wrapper for an OS specific critical section.  The only real
-// intelligence in this class is in debug mode for the support for the
-// AssertAcquired() method.
-class BASE_EXPORT Lock {
- public:
-#if defined(NDEBUG) && !defined(DCHECK_ALWAYS_ON)
-   // Optimized wrapper implementation
-  Lock() : lock_() {}
-  ~Lock() {}
-  void Acquire() { lock_.Lock(); }
-  void Release() { lock_.Unlock(); }
-
-  // If the lock is not held, take it and return true. If the lock is already
-  // held by another thread, immediately return false. This must not be called
-  // by a thread already holding the lock (what happens is undefined and an
-  // assertion may fail).
-  bool Try() { return lock_.Try(); }
-
-  // Null implementation if not debug.
-  void AssertAcquired() const {}
-#else
-  Lock();
-  ~Lock();
-
-  // NOTE: Although windows critical sections support recursive locks, we do not
-  // allow this, and we will commonly fire a DCHECK() if a thread attempts to
-  // acquire the lock a second time (while already holding it).
-  void Acquire() {
-    lock_.Lock();
-    CheckUnheldAndMark();
-  }
-  void Release() {
-    CheckHeldAndUnmark();
-    lock_.Unlock();
-  }
-
-  bool Try() {
-    bool rv = lock_.Try();
-    if (rv) {
-      CheckUnheldAndMark();
-    }
-    return rv;
-  }
-
-  void AssertAcquired() const;
-#endif  // NDEBUG && !DCHECK_ALWAYS_ON
-
-#if defined(OS_POSIX)
-  // The posix implementation of ConditionVariable needs to be able
-  // to see our lock and tweak our debugging counters, as it releases
-  // and acquires locks inside of pthread_cond_{timed,}wait.
-  friend class ConditionVariable;
-#elif defined(OS_WIN)
-  // The Windows Vista implementation of ConditionVariable needs the
-  // native handle of the critical section.
-  friend class WinVistaCondVar;
-#endif
-
- private:
-#if !defined(NDEBUG) || defined(DCHECK_ALWAYS_ON)
-  // Members and routines taking care of locks assertions.
-  // Note that this checks for recursive locks and allows them
-  // if the variable is set.  This is allowed by the underlying implementation
-  // on windows but not on Posix, so we're doing unneeded checks on Posix.
-  // It's worth it to share the code.
-  void CheckHeldAndUnmark();
-  void CheckUnheldAndMark();
-
-  // All private data is implicitly protected by lock_.
-  // Be VERY careful to only access members under that lock.
-  base::PlatformThreadRef owning_thread_ref_;
-#endif  // !NDEBUG || DCHECK_ALWAYS_ON
-
-  // Platform specific underlying lock implementation.
-  internal::LockImpl lock_;
-
-  DISALLOW_COPY_AND_ASSIGN(Lock);
-};
-
-// A helper class that acquires the given Lock while the AutoLock is in scope.
-class AutoLock {
- public:
-  struct AlreadyAcquired {};
-
-  explicit AutoLock(Lock& lock) : lock_(lock) {
-    lock_.Acquire();
-  }
-
-  AutoLock(Lock& lock, const AlreadyAcquired&) : lock_(lock) {
-    lock_.AssertAcquired();
-  }
-
-  ~AutoLock() {
-    lock_.AssertAcquired();
-    lock_.Release();
-  }
-
- private:
-  Lock& lock_;
-  DISALLOW_COPY_AND_ASSIGN(AutoLock);
-};
-
-// AutoUnlock is a helper that will Release() the |lock| argument in the
-// constructor, and re-Acquire() it in the destructor.
-class AutoUnlock {
- public:
-  explicit AutoUnlock(Lock& lock) : lock_(lock) {
-    // We require our caller to have the lock.
-    lock_.AssertAcquired();
-    lock_.Release();
-  }
-
-  ~AutoUnlock() {
-    lock_.Acquire();
-  }
-
- private:
-  Lock& lock_;
-  DISALLOW_COPY_AND_ASSIGN(AutoUnlock);
-};
-
-}  // namespace base
-
-#endif  // BASE_SYNCHRONIZATION_LOCK_H_