Potential hang for eCapture under really rare circumstances about ecapture HOT 2 OPEN

Please wait a moment, let me understand the issue.

from ecapture.

Bug Analysis

In the following code, assuming now the worker routine is before ew.Close()

case _ = <-ew.ticker.C:
			// 输出包
			if ew.tickerCount > MaxTickerCount {
				//ew.processor.GetLogger().Printf("eventWorker TickerCount > %d, event closed.", MaxTickerCount)
				ew.Close()
				return
			}

Just at the same time, multiple events from the same process might be generated and the are passed firstly toEventProcessor.Serve routine through ep.incoming channel(1024) , and then sent to Worker routine through ew.incoming channel(16). These events with same uuid are allocated to the same worker that executed before ew.Close(). Because the worker do not received from the channel at the moment , the event is put in the buffer allocated for the channel and it would not be blocked for now . However, This event will be lost, because this worker will never handle the event in buffer. Moreover, if the many events are generated, the buffer in ew.incoming(size is 16) is full and the EventProcessor.Serve routine hang first which is impossible to recovered.

Again, that is because the worker is about to be removed and will never receive events from that channel.

With the EventProcessor.Serve routine hang, the main routine that generates events will ultimately hang because the ep.incoming channel(with size of 1024) will be full sooner or later.

from top to down                                                         
event generate from main routine
|
|
| ep.incoming channel(1024)          
|
EventProcessor.Serve routine 
|
|
|
| ew.incoming channel(16)
|
|
Worker routine

Root Cause
The hang is due to the fact that worker returned by getWorkerByUUID() may be retired(i.e, never read from the channel). It should be fixed.

from ecapture.