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.

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

Reply via email to