diff options
Diffstat (limited to 'base/lock.h')
-rw-r--r-- | base/lock.h | 125 |
1 files changed, 8 insertions, 117 deletions
diff --git a/base/lock.h b/base/lock.h index 672e3fb..7c90d86 100644 --- a/base/lock.h +++ b/base/lock.h @@ -1,4 +1,4 @@ -// Copyright (c) 2010 The Chromium Authors. All rights reserved. +// 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. @@ -6,122 +6,13 @@ #define BASE_LOCK_H_ #pragma once -#include "base/lock_impl.h" -#include "base/threading/platform_thread.h" +// This is a temporary forwarding file so not every user of lock needs to +// be updated at once. +// TODO(brettw) remove this and fix everybody up to using the new location. +#include "base/synchronization/lock.h" -// 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 Lock { - public: -#if defined(NDEBUG) // 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 - -#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. - // Windows doesn't need to do this as it calls the Lock::* methods. - friend class ConditionVariable; -#endif - - private: -#if !defined(NDEBUG) - // 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. - - // Determines validity of owning_thread_id_. Needed as we don't have - // a null owning_thread_id_ value. - bool owned_by_thread_; - base::PlatformThreadId owning_thread_id_; -#endif // NDEBUG - - LockImpl lock_; // Platform specific underlying lock implementation. - - DISALLOW_COPY_AND_ASSIGN(Lock); -}; - -// A helper class that acquires the given Lock while the AutoLock is in scope. -class AutoLock { - public: - explicit AutoLock(Lock& lock) : lock_(lock) { - lock_.Acquire(); - } - - ~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); -}; +using base::AutoLock; +using base::AutoUnlock; +using base::Lock; #endif // BASE_LOCK_H_ |