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diff --git a/Source/WTF/wtf/TCSpinLock.h b/Source/WTF/wtf/TCSpinLock.h
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--- a/Source/WTF/wtf/TCSpinLock.h
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-// Copyright (c) 2005, 2006, Google Inc.
-// Copyright (c) 2010, Patrick Gansterer <paroga@paroga.com>
-// 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 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.
-
-// ---
-// Author: Sanjay Ghemawat <opensource@google.com>
-
-#ifndef TCMALLOC_INTERNAL_SPINLOCK_H__
-#define TCMALLOC_INTERNAL_SPINLOCK_H__
-
-#include <wtf/Atomics.h>
-#if OS(UNIX)
-#include <sched.h>
-#endif
-
-#if ENABLE(COMPARE_AND_SWAP)
-
-static void TCMalloc_SlowLock(unsigned* lockword);
-
-// The following is a struct so that it can be initialized at compile time
-struct TCMalloc_SpinLock {
- void Lock() {
- if (!WTF::weakCompareAndSwap(&lockword_, 0, 1))
- TCMalloc_SlowLock(&lockword_);
- WTF::memoryBarrierAfterLock();
- }
-
- void Unlock() {
- WTF::memoryBarrierBeforeUnlock();
- lockword_ = 0;
- }
-
- // Report if we think the lock can be held by this thread.
- // When the lock is truly held by the invoking thread
- // we will always return true.
- // Indended to be used as CHECK(lock.IsHeld());
- bool IsHeld() const {
- return lockword_ != 0;
- }
-
- void Init() { lockword_ = 0; }
- void Finalize() { }
-
- unsigned lockword_;
-};
-
-#define SPINLOCK_INITIALIZER { 0 }
-
-static void TCMalloc_SlowLock(unsigned* lockword) {
- do {
-#if OS(WINDOWS)
- Sleep(0);
-#else
- sched_yield();
-#endif
- } while (!WTF::weakCompareAndSwap(lockword, 0, 1));
-}
-
-#else
-
-#include <pthread.h>
-
-// Portable version
-struct TCMalloc_SpinLock {
- pthread_mutex_t private_lock_;
-
- inline void Init() {
- if (pthread_mutex_init(&private_lock_, NULL) != 0) CRASH();
- }
- inline void Finalize() {
- if (pthread_mutex_destroy(&private_lock_) != 0) CRASH();
- }
- inline void Lock() {
- if (pthread_mutex_lock(&private_lock_) != 0) CRASH();
- }
- inline void Unlock() {
- if (pthread_mutex_unlock(&private_lock_) != 0) CRASH();
- }
- bool IsHeld() {
- if (pthread_mutex_trylock(&private_lock_))
- return true;
-
- Unlock();
- return false;
- }
-};
-
-#define SPINLOCK_INITIALIZER { PTHREAD_MUTEX_INITIALIZER }
-
-#endif
-
-// Corresponding locker object that arranges to acquire a spinlock for
-// the duration of a C++ scope.
-class TCMalloc_SpinLockHolder {
- private:
- TCMalloc_SpinLock* lock_;
- public:
- inline explicit TCMalloc_SpinLockHolder(TCMalloc_SpinLock* l)
- : lock_(l) { l->Lock(); }
- inline ~TCMalloc_SpinLockHolder() { lock_->Unlock(); }
-};
-
-// Short-hands for convenient use by tcmalloc.cc
-typedef TCMalloc_SpinLock SpinLock;
-typedef TCMalloc_SpinLockHolder SpinLockHolder;
-
-#endif // TCMALLOC_INTERNAL_SPINLOCK_H__