Agreed.  I think this is the best way to go for now.  I will create a
new patch with this change later tonight.

Mike

On 2/16/07, Roland Weber (JIRA) <[EMAIL PROTECTED]> wrote:

    [ 
https://issues.apache.org/jira/browse/HTTPCLIENT-633?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12473740
 ]

Roland Weber commented on HTTPCLIENT-633:
-----------------------------------------

Hi all,

one more alternative, which Mike already mentioned on the dev list:
(3) Re-throw InterruptedException as a RuntimeException, for example 
IllegalThreadStateException

I'm also for re-throwing, and a RuntimeException would make sure that this 
doesn't trigger application code explicitly handling the 
ConnectionManagerTimeoutException exception. Yes it's an API change, but one 
that only affects the application in situations where MTHCM would be screwing 
up. Applications that work correctly now will work correctly despite the 
change, and applications that fail because of the RuntimeException will be 
better off than before, where they would fail in some unpredictable way because 
of the corrupted state in MTHCM.

That we can't reliably tell whether there is an external InterruptedException 
or not can't be helped. If the thread was interrupted just after getting the 
connection, it would simply return with the connection and have it's 
interrupted flag set. I don't see a problem with keeping this behavior if two 
interruptions occur in quick succession.

cheers,
  Roland


> MultiThreadedHttpConnectionManager does not properly respond to thread 
interrupts
> 
---------------------------------------------------------------------------------
>
>                 Key: HTTPCLIENT-633
>                 URL: https://issues.apache.org/jira/browse/HTTPCLIENT-633
>             Project: HttpComponents HttpClient
>          Issue Type: Bug
>          Components: HttpConn
>    Affects Versions: 3.1 Beta 1
>            Reporter: John Goodwin
>         Attachments: mthcm-interruption.patch
>
>
> MultiThreadedHttpConnectionManager uses interrupts to notify waiting threads 
when a connection is ready for them. Issues arise if the threads are interrupted 
by someone else while they are still waiting on a thread, because doGetConnection 
does not remove the threads from the queue of waiting threads when they are 
interrupted:
>                         connectionPool.wait(timeToWait);
>                         // we have not been interrupted so we need to remove 
ourselves from the
>                         // wait queue
>                         hostPool.waitingThreads.remove(waitingThread);        
                connectionPool.waitingThreads.remove(waitingThread);
>                     } catch (InterruptedException e) {
>                         // do nothing                    } finally {
>                         if (useTimeout) {
>                             endWait = System.currentTimeMillis();
>                             timeToWait -= (endWait - startWait);              
          }                    }
> Under ordinary circumstances, the queue maintenance is done by the 
notifyWaitingThread method. However, if the thread is interrupted by any other 
part of the system, it will (1) not actually be released, since the loop in 
doGetConnection will force it back to the wait, and (2) will be added the waiting 
thread to the queue repeatedly, which basically means that the thread will 
eventually receive the interrupt from notifyWaitingThread at some later point, 
when it is no longer actually waiting for a connection.
> This code could probably be re-architected to make it less error-prone, but 
the fundamental issue seems to be the use of interrupts to signal waiting threads, 
as opposed to something like a notify.

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