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// -*- mode: c++; c-basic-offset: 4 -*-
/*
* This file is part of the KDE libraries
* Copyright (C) 2005 Apple Computer, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA
*
*/
#include "config.h"
#include "JSLock.h"
#include "collector.h"
#if USE(MULTIPLE_THREADS)
#include <pthread.h>
#endif
namespace KJS {
#if USE(MULTIPLE_THREADS)
// Acquire this mutex before accessing lock-related data.
static pthread_mutex_t JSMutex = PTHREAD_MUTEX_INITIALIZER;
// Thread-specific key that tells whether a thread holds the JSMutex.
pthread_key_t didLockJSMutex;
// Lock nesting count.
static int JSLockCount;
static void createDidLockJSMutex()
{
pthread_key_create(&didLockJSMutex, 0);
}
pthread_once_t createDidLockJSMutexOnce = PTHREAD_ONCE_INIT;
void JSLock::lock()
{
pthread_once(&createDidLockJSMutexOnce, createDidLockJSMutex);
if (!pthread_getspecific(didLockJSMutex)) {
int result;
result = pthread_mutex_lock(&JSMutex);
ASSERT(!result);
pthread_setspecific(didLockJSMutex, &didLockJSMutex);
}
++JSLockCount;
}
void JSLock::unlock()
{
ASSERT(JSLockCount);
ASSERT(!!pthread_getspecific(didLockJSMutex));
--JSLockCount;
if (!JSLockCount) {
pthread_setspecific(didLockJSMutex, 0);
int result;
result = pthread_mutex_unlock(&JSMutex);
ASSERT(!result);
}
}
bool JSLock::currentThreadIsHoldingLock()
{
pthread_once(&createDidLockJSMutexOnce, createDidLockJSMutex);
return !!pthread_getspecific(didLockJSMutex);
}
void JSLock::registerThread()
{
Collector::registerThread();
}
JSLock::DropAllLocks::DropAllLocks()
: m_lockCount(0)
{
pthread_once(&createDidLockJSMutexOnce, createDidLockJSMutex);
m_lockCount = !!pthread_getspecific(didLockJSMutex) ? JSLock::lockCount() : 0;
for (int i = 0; i < m_lockCount; i++)
JSLock::unlock();
}
JSLock::DropAllLocks::~DropAllLocks()
{
for (int i = 0; i < m_lockCount; i++)
JSLock::lock();
m_lockCount = 0;
}
#else
// If threading support is off, set the lock count to a constant value of 1 so assertions
// that the lock is held don't fail
const int JSLockCount = 1;
bool JSLock::currentThreadIsHoldingLock()
{
return true;
}
void JSLock::lock()
{
}
void JSLock::unlock()
{
}
void JSLock::registerThread()
{
}
JSLock::DropAllLocks::DropAllLocks()
{
}
JSLock::DropAllLocks::~DropAllLocks()
{
}
#endif // USE(MULTIPLE_THREADS)
int JSLock::lockCount()
{
return JSLockCount;
}
}
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