2014/1/8 Daniel Mikusa <dmik...@gopivotal.com>: > On Jan 8, 2014, at 12:04 PM, Yann Simon <yann.simon...@gmail.com> wrote: > >> Hi, >> >> I am trying to write a servlet that asynchronously read data from the >> servlet request input stream. >> I tested my servlet with tomcat 8.0.0-RC5. > > If possible, you might want to try 8.0.0-RC10 or trunk and see if you're > getting the same behavior. > >> >> the symptoms: >> - I must synchronously read the input stream in onDataAvailable() so >> that the upload works >> >> what I expected: >> I want to be more "reactive" (buzzword of the moment) and not read the >> input stream until I am ready (=until the previous chunk is processed) >> I though I could return from onDataAvailable() before having read all >> the data, read the data in another thread. > > Do you have a code sample? It would help to see what you're doing. > >> I expected onDataAvailable() to be called again when I consumed all the data >> (servletInputStream.isReady becomes false) > > Generally this sounds OK. When you call ServletInputStream.isReady() and it > returns false, that should trigger the container to call onDataAvailable() > when more data is available to be read. If you return from onDataAvailable() > and ServletInputStream.isReady() is still true the container won't call > onDataAvailable() again. You'll be responsible for calling it when you're > ready to read more. > >> That way, I could implement back pressure on the browser as long as my >> servlet has not finished its work with the actual chunk >> >> But if I do that, neither onDataAvailable() nor onAllDataRead() is called >> again. > > Again, a code sample would be helpful. Debugging non-blocking IO is tricky. > If you can include a sample Servlet or test case, it would greatly increase > your chance of getting feedback.
Thanks for the quick answer! I have a code sample, but it may be too complicated to help debugging the problem. It is written in Scala. Its purpose is to provide a servlet that runs asynchronous action from Playframework (http://www.playframework.com/) https://github.com/yanns/play2-war-plugin/blob/servlet31/project-code/core/servlet31/src/main/scala/play/core/server/servlet31/RequestHandler31.scala#L74 The line 80 (iteratee = iteratee.pureFlatFold ) use a closure that consumes the input stream asynchronously in another thread. I'll try to take the time to write a much simpler code sample in Java. > > Dan > >> >> When I consume the input stream synchronously in onDataAvailable(), it >> works as expected. >> >> Am I misunderstanding the asynchron IO in Tomcat 8? >> >> Thanks in advance for any ideas! >> Yann >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org >> For additional commands, e-mail: users-h...@tomcat.apache.org >> > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > For additional commands, e-mail: users-h...@tomcat.apache.org > --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
