[CherryPy] #956: wsgiserver's ThreadPool stop() method can take longer than timeout arg to complete

[CherryPy]

#956: wsgiserver's ThreadPool stop() method can take longer than timeout arg to
complete
----------------------------------------------------+-----------------------
Reporter: matt_c...@perceptiveautomation.com | Owner: fumanchu
Type: defect | Status: new
Priority: normal | Milestone:
Component: CherryPy code | Keywords:
----------------------------------------------------+-----------------------
Somewhat related to one of the complaints on this ticket 691, shutting
down CherryPy can take longer than expected. This can happen if you are
using multiple threads to handle requests (server.thread_pool > 1) and a
threaded browser (ex: Firefox on OS X) has recently loaded a page. This
happens because the HTTP 1.1 keep-alive connections are still open, and
the '''worker.join(timeout)''' calls inside '''ThreadPool's'''
'''stop()''' are performed sequentially.

So for example if you have specified a shutdown timeout of 5 seconds and
there are 10 idle but open keep-alive connections, then it can take up to
50 seconds for the shutdown to complete.

My proposed fix is to decrement the timeout by the elapsed time. Note all
the threads are sent a _SHUTDOWNREQUEST at the beginning, so after the
shutdown timeout has elapsed one can safely presume the timeout is
exhausted and immediately fall into the 'forcibly shut down the socket'
case if '''worker.isAlive()''' is still True.

-- Matt Bendiksen

My proposed fix to stop() is to after:
{{{
#!python
for worker in self._threads:
self._queue.put(_SHUTDOWNREQUEST)
}}}
add:
{{{
#!python
start_time = time.time()
}}}

And change:
{{{
#!python
worker.join(timeout)
}}}
to:
{{{
#!python
remaining_timeout = timeout - (time.time() -
start_time)
if remaining_timeout > 0:
worker.join(remaining_timeout)
}}}

--
Ticket URL: <http://www.cherrypy.org/ticket/956>
CherryPy <http://www.cherrypy.org>
CherryPy - a pythonic, object-oriented HTTP framework

[CherryPy]

#956: wsgiserver's ThreadPool stop() method can take longer than timeout arg to
complete
----------------------------------------------------+-----------------------
Reporter: matt_c...@perceptiveautomation.com | Owner: fumanchu

Type: defect | Status: closed
Priority: normal | Milestone: 3.2
Component: CherryPy code | Resolution: fixed
Keywords: |
----------------------------------------------------+-----------------------
Changes (by fumanchu):

* milestone: => 3.2
* resolution: => fixed
* status: new => closed

Comment:

Implemented in [2544].