HRESULT ListenerRecord::dequeue(IEvent **aEvent,
LONG aTimeout,
AutoLockBase &aAlock)
{
if (mActive)
return VBOX_E_INVALID_OBJECT_STATE;
// retain listener record
RecordHolder<ListenerRecord> holder(this);
::RTCritSectEnter(&mcsQLock);
mLastRead = RTTimeMilliTS();
/*
* If waiting both desired and necessary, then try grab the event
* semaphore and mark it busy. If it's NIL we've been shut down already.
*/
if (aTimeout != 0 && mQueue.empty())
{
RTSEMEVENT hEvt = mQEvent;
if (hEvt != NIL_RTSEMEVENT)
{
ASMAtomicIncS32(&mQEventBusyCnt);
::RTCritSectLeave(&mcsQLock);
// release lock while waiting, listener will not go away due to above holder
aAlock.release();
::RTSemEventWait(hEvt, aTimeout);
ASMAtomicDecS32(&mQEventBusyCnt);
// reacquire lock
aAlock.acquire();
::RTCritSectEnter(&mcsQLock);
}
}
if (mQueue.empty())
*aEvent = NULL;
else
{
mQueue.front().queryInterfaceTo(aEvent);
mQueue.pop_front();
}
::RTCritSectLeave(&mcsQLock);
return S_OK;
}
HRESULT ListenerRecord::dequeue (IEvent* *aEvent,
LONG aTimeout,
AutoLockBase& aAlock)
{
if (mActive)
return VBOX_E_INVALID_OBJECT_STATE;
// retain listener record
RecordHolder<ListenerRecord> holder(this);
::RTCritSectEnter(&mcsQLock);
mLastRead = RTTimeMilliTS();
if (mQueue.empty()) {
::RTCritSectLeave(&mcsQLock);
// Speed up common case
if (aTimeout == 0)
{
*aEvent = NULL;
return S_OK;
}
// release lock while waiting, listener will not go away due to above holder
aAlock.release();
::RTSemEventWait(mQEvent, aTimeout);
// reacquire lock
aAlock.acquire();
::RTCritSectEnter(&mcsQLock);
}
if (mQueue.empty())
{
*aEvent = NULL;
}
else
{
mQueue.front().queryInterfaceTo(aEvent);
mQueue.pop_front();
}
::RTCritSectLeave(&mcsQLock);
return S_OK;
}