icinga2/lib/base/objectlock.cpp

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/* Icinga 2 | (c) 2012 Icinga GmbH | GPLv2+ */
#include "base/objectlock.hpp"
#include <boost/thread/recursive_mutex.hpp>
using namespace icinga;
#define I2MUTEX_UNLOCKED 0
#define I2MUTEX_LOCKED 1
ObjectLock::~ObjectLock()
{
Unlock();
}
ObjectLock::ObjectLock(const Object::Ptr& object)
: m_Object(object.get()), m_Locked(false)
{
if (m_Object)
Lock();
}
ObjectLock::ObjectLock(const Object *object)
: m_Object(object), m_Locked(false)
{
if (m_Object)
Lock();
}
void ObjectLock::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)) {
auto *mtx = reinterpret_cast<boost::recursive_mutex *>(object->m_Mutex);
mtx->lock();
return;
}
Spin(it);
it++;
}
auto *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 */
}
void ObjectLock::Lock()
{
ASSERT(!m_Locked && m_Object);
LockMutex(m_Object);
m_Locked = true;
#ifdef I2_DEBUG
if (++m_Object->m_LockCount == 1u) {
# 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 */
}
void ObjectLock::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 */
}
}
void ObjectLock::Unlock()
{
#ifdef I2_DEBUG
if (m_Locked && !--m_Object->m_LockCount) {
# 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;
}
}