--- /dev/null
+// Copyright (c) 2014 Marshall A. Greenblatt. Portions copyright (c) 2011
+// Google Inc. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+// * Neither the name of Google Inc. nor the name Chromium Embedded
+// Framework nor the names of its contributors may be used to endorse
+// or promote products derived from this software without specific prior
+// written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef CEF_INCLUDE_BASE_CEF_LOCK_H_
+#define CEF_INCLUDE_BASE_CEF_LOCK_H_
+#pragma once
+
+#if defined(BASE_SYNCHRONIZATION_LOCK_H_)
+// Do nothing if the Chromium header has already been included.
+// This can happen in cases where Chromium code is used directly by the
+// client application. When using Chromium code directly always include
+// the Chromium header first to avoid type conflicts.
+#elif defined(USING_CHROMIUM_INCLUDES)
+// When building CEF include the Chromium header directly.
+#include "base/synchronization/lock.h"
+#else // !USING_CHROMIUM_INCLUDES
+// The following is substantially similar to the Chromium implementation.
+// If the Chromium implementation diverges the below implementation should be
+// updated to match.
+
+#include "include/base/cef_logging.h"
+#include "include/base/cef_macros.h"
+#include "include/base/cef_platform_thread.h"
+#include "include/base/internal/cef_lock_impl.h"
+
+namespace base {
+namespace cef_internal {
+
+// 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 !DCHECK_IS_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 // !DCHECK_IS_ON()
+
+ private:
+#if DCHECK_IS_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 // DCHECK_IS_ON()
+
+ // Platform specific underlying lock implementation.
+ 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 cef_internal
+
+// Implement classes in the cef_internal namespace and then expose them to the
+// base namespace. This avoids conflicts with the base.lib implementation when
+// linking sandbox support on Windows.
+using cef_internal::Lock;
+using cef_internal::AutoLock;
+using cef_internal::AutoUnlock;
+
+} // namespace base
+
+#endif // !USING_CHROMIUM_INCLUDES
+
+#endif // CEF_INCLUDE_BASE_CEF_LOCK_H_
projects / casparcg / blobdiff