public volatile int lastSeqNumOut; // sequence number of the last message to have been taken from the queue (queue is likely empty if they are both the same)
#endregion Fields
#region Constructors
public QueuedMesgSeqNumRange(ref QueuedMesgSeqNumRange rhs)
{
// grab the out sequence number before the in so that we are most inclusive when making a copy of another QueuedMesgSeqNumRange value.
// order matters here since these are volatile (values may be written in the background by other threads while reading..)
lastSeqNumOut = rhs.lastSeqNumOut;
lastSeqNumIn = rhs.lastSeqNumIn;
}
public bool IsMessageStillInQueue(int testSeqNum)
{
lock (queueMutex)
{
QueuedMesgSeqNumRange queuedMesgSeqNumRangeSnapshot = new QueuedMesgSeqNumRange(ref queuedMesgSeqNumRange);
return(queuedMesgSeqNumRangeSnapshot.IsMesgSeqNumInRange(testSeqNum));
}
}
public bool IsMessageStillInQueue(int testSeqNum)
{
lock (queueMutex)
{
QueuedMesgSeqNumRange queuedMesgSeqNumRangeSnapshot = new QueuedMesgSeqNumRange(ref queuedMesgSeqNumRange);
return queuedMesgSeqNumRangeSnapshot.IsMesgSeqNumInRange(testSeqNum);
}
}
const double minDeliveryThreadSpinWaitPeriod = 0.050; // 20 Hz
/// <summary>
/// This gives the method that is called by the internal service thread to pull messages from the back of the message queue and deliver them to the
/// target LMH instances.
/// </summary>
protected void MainThreadFcn()
{
if (targetLMHArray == null || !mesgQueue.IsEnabled || threadWakeupEvent == null)
{
mesgQueue.DisableQueue();
foreach (var lmh in targetLMHArray ?? emptyLMHArray)
{
lmh.Shutdown();
}
Utils.Asserts.TakeBreakpointAfterFault("QLMH thread Startup test failed");
return;
}
foreach (var lmh in targetLMHArray)
{
lmh.StartIfNeeded();
}
while (mesgQueue.IsEnabled)
{
threadWakeupEvent.Reset();
bool didAnything = false;
// process messages from a non-empty queue (or full)
if (mesgQueue.QueueCount != 0 || mesgQueue.IsQueueFull())
{
didAnything = true;
ServiceQueueDelivery(maxMessagesToDequePerIteration);
}
// detect seqNum based flush request and ask underlying lmh to flush after
// given seqNum is no longer in the mesgQueue
int flushReqSeqNumSnapshot = flushAfterSeqNum;
QueuedMesgSeqNumRange mesgQueueSeqNumRangeSnapshot = mesgQueueSeqNumRange;
if (NullMessageSeqNum != flushReqSeqNumSnapshot &&
!mesgQueueSeqNumRangeSnapshot.IsMesgSeqNumInRange(flushReqSeqNumSnapshot))
{
flushRequested = true;
flushAfterSeqNum = NullMessageSeqNum;
}
if (flushRequested) // when queue is empty then process flush request
{
didAnything = true;
flushRequested = false;
foreach (var lmh in targetLMHArray)
{
lmh.Flush();
}
}
if (!didAnything)
{
threadWakeupEvent.WaitSec(minDeliveryThreadSpinWaitPeriod);
}
}
// service the queue until it is empty
while (mesgQueue.QueueCount != 0 || mesgQueue.IsQueueFull())
{
ServiceQueueDelivery(maxMessagesToDequePerIteration);
}
uint totalDroppedMesgs = mesgQueue.TotalDroppedMesgCount;
if (totalDroppedMesgs != 0)
{
LogShutdownDroppedMessagesMesg(totalDroppedMesgs);
}
foreach (var lmh in targetLMHArray)
{
lmh.Shutdown();
}
}
/// <summary>Query method that may be used to tell if message delivery for a given message is still in progress on this handler.</summary>
public override bool IsMessageDeliveryInProgress(int testMesgSeqNum)
{
QueuedMesgSeqNumRange mesgQueueSeqNumRangeSnapshot = mesgQueueSeqNumRange;
return(mesgQueueSeqNumRangeSnapshot.IsMesgSeqNumInRange(testMesgSeqNum));
}
/// <summary>
/// Copy constructor.
/// <para/>grab the out sequence number before the in so that we are most inclusive when making a copy of another QueuedMesgSeqNumRange value.
/// order matters here since these are volatile (values may be written in the background by other threads while reading..)
/// </summary>
public QueuedMesgSeqNumRange(ref QueuedMesgSeqNumRange rhs)
{
lastSeqNumOut = rhs.lastSeqNumOut;
lastSeqNumIn = rhs.lastSeqNumIn;
}
