gecko-dev/js/tamarin/MMgc/GCSpinLockMac.h

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/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version 1.1 (the
* "License"); you may not use this file except in compliance with the License. You may obtain
* a copy of the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis, WITHOUT
* WARRANTY OF ANY KIND, either express or implied. See the License for the specific
* language governing rights and limitations under the License.
*
* The Original Code is [Open Source Virtual Machine.]
*
* The Initial Developer of the Original Code is Adobe System Incorporated. Portions created
* by the Initial Developer are Copyright (C)[ 2004-2006 ] Adobe Systems Incorporated. All Rights
* Reserved.
*
* Contributor(s): Adobe AS3 Team
*
* Alternatively, the contents of this file may be used under the terms of either the GNU
* General Public License Version 2 or later (the "GPL"), or the GNU Lesser General Public
* License Version 2.1 or later (the "LGPL"), in which case the provisions of the GPL or the
* LGPL are applicable instead of those above. If you wish to allow use of your version of this
* file only under the terms of either the GPL or the LGPL, and not to allow others to use your
* version of this file under the terms of the MPL, indicate your decision by deleting provisions
* above and replace them with the notice and other provisions required by the GPL or the
* LGPL. If you do not delete the provisions above, a recipient may use your version of this file
* under the terms of any one of the MPL, the GPL or the LGPL.
*
***** END LICENSE BLOCK ***** */
#ifndef __GCSpinLock__
#define __GCSpinLock__
#ifdef __GNUC__
#include <CoreServices/CoreServices.h>
#else // __GNUC__
#include <Multiprocessing.h>
#endif // __GNUC__
#if TARGET_RT_MAC_MACHO
extern "C"
{
extern void _spin_lock(uint32_t *);
extern void _spin_unlock(uint32_t *);
}
#endif
namespace MMgc
{
/**
* GCSpinLock is a simple spin lock class used by GCHeap to
* ensure mutually exclusive access. The GCHeap may be accessed
* by multiple threads, so this is necessary to ensure that
* the threads do not step on each other.
*/
class GCSpinLock
{
public:
GCSpinLock()
{
#if TARGET_RT_MAC_MACHO
m1 = 0;
#else
OSStatus critErr = ::MPCreateCriticalRegion( &mCriticalRegion );
GCAssert( critErr == noErr );
#endif
}
~GCSpinLock()
{
#if !TARGET_RT_MAC_MACHO
OSStatus critErr = ::MPDeleteCriticalRegion( mCriticalRegion );
GCAssert( critErr == noErr );
#endif
}
inline void Acquire()
{
#if TARGET_RT_MAC_MACHO
_spin_lock(&m1);
#else
OSStatus critErr = ::MPEnterCriticalRegion( mCriticalRegion, kDurationForever );
GCAssert( critErr == noErr );
#endif
}
inline void Release()
{
#if TARGET_RT_MAC_MACHO
_spin_unlock(&m1);
#else
OSStatus critErr = ::MPExitCriticalRegion( mCriticalRegion );
GCAssert( critErr == noErr );
#endif
}
private:
#if TARGET_RT_MAC_MACHO
uint32_t m1;
#else
MPCriticalRegionID mCriticalRegion;
#endif
};
/**
* GCAcquireSpinlock is a convenience class which acquires
* the specified spinlock at construct time, then releases
* the spinlock at desruct time. The single statement
*
* GCAcquireSpinlock acquire(spinlock);
*
* ... will acquire the spinlock at the top of the function
* and release it at the end. This makes for less error-prone
* code than explicit acquire/release.
*/
class GCAcquireSpinlock
{
public:
GCAcquireSpinlock(GCSpinLock& spinlock) : m_spinlock(spinlock)
{
m_spinlock.Acquire();
}
~GCAcquireSpinlock()
{
m_spinlock.Release();
}
private:
GCSpinLock& m_spinlock;
};
}
#endif /* __GCSpinLock__ */