icinga2/lib/base/objectlock.hpp

159 lines
4.2 KiB
C++

/******************************************************************************
* Icinga 2 *
* Copyright (C) 2012-2016 Icinga Development Team (https://www.icinga.org/) *
* *
* This program is free software; you can redistribute it and/or *
* modify it under the terms of the GNU General Public License *
* as published by the Free Software Foundation; either version 2 *
* of the License, or (at your option) any later version. *
* *
* This program 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 General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, write to the Free Software Foundation *
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. *
******************************************************************************/
#ifndef OBJECTLOCK_H
#define OBJECTLOCK_H
#include "base/object.hpp"
#define I2MUTEX_UNLOCKED 0
#define I2MUTEX_LOCKED 1
namespace icinga
{
/**
* A scoped lock for Objects.
*/
struct I2_BASE_API ObjectLock
{
public:
inline ObjectLock(void)
: m_Object(NULL), m_Locked(false)
{ }
inline ~ObjectLock(void)
{
Unlock();
}
inline ObjectLock(const Object::Ptr& object)
: m_Object(object.get()), m_Locked(false)
{
if (m_Object)
Lock();
}
inline ObjectLock(const Object *object)
: m_Object(object), m_Locked(false)
{
if (m_Object)
Lock();
}
inline static void LockMutex(const Object *object)
{
unsigned int it = 0;
#ifdef _WIN32
# ifdef _WIN64
while (likely(InterlockedCompareExchange64((LONGLONG *)&object->m_Mutex, I2MUTEX_LOCKED, I2MUTEX_UNLOCKED) != I2MUTEX_UNLOCKED)) {
# else /* _WIN64 */
while (likely(InterlockedCompareExchange(&object->m_Mutex, I2MUTEX_LOCKED, I2MUTEX_UNLOCKED) != I2MUTEX_UNLOCKED)) {
# endif /* _WIN64 */
#else /* _WIN32 */
while (likely(!__sync_bool_compare_and_swap(&object->m_Mutex, I2MUTEX_UNLOCKED, I2MUTEX_LOCKED))) {
#endif /* _WIN32 */
if (likely(object->m_Mutex > I2MUTEX_LOCKED)) {
boost::recursive_mutex *mtx = reinterpret_cast<boost::recursive_mutex *>(object->m_Mutex);
mtx->lock();
return;
}
Spin(it);
it++;
}
boost::recursive_mutex *mtx = new boost::recursive_mutex();
mtx->lock();
#ifdef _WIN32
# ifdef _WIN64
InterlockedCompareExchange64((LONGLONG *)&object->m_Mutex, reinterpret_cast<LONGLONG>(mtx), I2MUTEX_LOCKED);
# else /* _WIN64 */
InterlockedCompareExchange(&object->m_Mutex, reinterpret_cast<LONG>(mtx), I2MUTEX_LOCKED);
# endif /* _WIN64 */
#else /* _WIN32 */
__sync_bool_compare_and_swap(&object->m_Mutex, I2MUTEX_LOCKED, reinterpret_cast<uintptr_t>(mtx));
#endif /* _WIN32 */
}
inline void Lock(void)
{
ASSERT(!m_Locked && m_Object != NULL);
LockMutex(m_Object);
m_Locked = true;
#ifdef I2_DEBUG
# ifdef _WIN32
InterlockedExchange(&m_Object->m_LockOwner, GetCurrentThreadId());
# else /* _WIN32 */
__sync_lock_test_and_set(&m_Object->m_LockOwner, pthread_self());
# endif /* _WIN32 */
#endif /* I2_DEBUG */
}
inline static void Spin(unsigned int it)
{
if (it < 8) {
/* Do nothing. */
}
#ifdef SPIN_PAUSE
else if (it < 16) {
SPIN_PAUSE();
}
#endif /* SPIN_PAUSE */
else {
#ifdef _WIN32
Sleep(0);
#else /* _WIN32 */
sched_yield();
#endif /* _WIN32 */
}
}
inline void Unlock(void)
{
#ifdef I2_DEBUG
if (m_Locked) {
# ifdef _WIN32
InterlockedExchange(&m_Object->m_LockOwner, 0);
# else /* _WIN32 */
__sync_lock_release(&m_Object->m_LockOwner);
# endif /* _WIN32 */
}
#endif /* I2_DEBUG */
if (m_Locked) {
reinterpret_cast<boost::recursive_mutex *>(m_Object->m_Mutex)->unlock();
m_Locked = false;
}
}
private:
const Object *m_Object;
bool m_Locked;
};
}
#endif /* OBJECTLOCK_H */