Hang-up on application close

[evgeny-pasynkov]

Hi!

I have a problem with app termination. The trace of hang thread is:

pool-4-thread-1@1497, prio=5, in group 'main', status: 'RUNNING'
at java.net.SocketInputStream.socketRead0(SocketInputStream.java:-1)
at java.net.SocketInputStream.read(SocketInputStream.java:150)
at java.net.SocketInputStream.read(SocketInputStream.java:121)
at java.io.BufferedInputStream.fill(BufferedInputStream.java:235)
at java.io.BufferedInputStream.read1(BufferedInputStream.java:275)
at java.io.BufferedInputStream.read(BufferedInputStream.java:334)
at sun.net.www.http.HttpClient.parseHTTPHeader(HttpClient.java:633)
at sun.net.www.http.HttpClient.parseHTTP(HttpClient.java:579)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1322)
at sun.net.www.protocol.http.HttpURLConnection.getHeaderFields(HttpURLConnection.java:2700)
at com.github.nkzawa.engineio.client.transports.PollingXHR$Request$1.run(PollingXHR.java:204)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:722)

[nkzawa]

Let me know the details of your problem.
What kind of exception is thrown?

[evgeny-pasynkov]

Actually, I have no exceptions.
I have console app, which connects to server with Socket.IO-client/Engine.IO-client.
After the app logic is done, I close the socket, but app doesn't exit, because non-daemon thread is stuck on the stack trace above.

[nkzawa]

Did you close all the sockets you used?

[evgeny-pasynkov]

Exactly, I open the single socket, and then close it.
My opts are:

  final IO.Options opts = new IO.Options();
  opts.forceNew = true;
  opts.multiplex = false;
  opts.reconnection = false;
  opts.sslContext = mySslContext;

This hang is 100% stable, so I can re-run it with any extra logging

[nkzawa]

Is it correct that polling get stopped and no logs are shown anymore, but your application hangs after that too?
Can you run another process after socket is closed (which means that deadlock is not the cause IMO)?

[nkzawa]

Maybe I found the cause of the hang :(
It looks like that ExecutorService which this library uses internally must be shut down to release.

I'm going to fix the problem.
I think you can call System.exit(0) to terminate your app for now.

[evgeny-pasynkov]

Just ping :)

[nkzawa]

@evgeny-pasynkov Fixed. thank you for reporting!

[nkzawa]

Wait. It's broken.

[nkzawa]

fixed 21fb11f

[evgeny-pasynkov]

Thank you, this fixes my scenario