[Bug classpath/36269] Bad file exception is thrown in epoll modification

[wzzhu at cs dot hku dot hk]

------- Comment #2 from wzzhu at cs dot hku dot hk  2008-05-21 07:01 -------
(In reply to comment #1)
> Don't those errors imply that you can't modify the epoll fd, because either it
> or the file descriptor you're modifying isn't valid?
> 
> Is there a case where a set of valid operations fails because of this?
> 

The EBADF is returned when the fd (not the epoll fd, epoll fd is valid) is
closed (not necessarily bad file descriptor). I tested on jetty server
(www.mortbay.org/) where a call assigns 0 to the operation set. But the file
handle fd could have been closed somewhere else.
The stack trace is as follows.

java.lang.IllegalArgumentException: java.io.IOException: Bad file descriptor  
at
gnu.java.nio.EpollSelectionKeyImpl.interestOps(EpollSelectionKeyImpl.java:102)  

// the code is 
      // we are not interested in further selecting
                _key.interestOps(0);

   at
org.mortbay.io.nio.SelectChannelEndPoint.dispatch(SelectChannelEndPoint.java:124
)
   at
org.mortbay.io.nio.SelectChannelEndPoint.dispatch(SelectChannelEndPoint.java:64)
  at
org.mortbay.io.nio.SelectorManager$SelectSet.doSelect(SelectorManager.java:471)
   at org.mortbay.io.nio.SelectorManager.doSelect(SelectorManager.java:166)  
at
org.mortbay.jetty.nio.SelectChannelConnector.accept(SelectChannelConnector.java:
124)   at
org.mortbay.jetty.AbstractConnector$Acceptor.run(AbstractConnector.java:515)
   at
org.mortbay.thread.BoundedThreadPool$PoolThread.run(BoundedThreadPool.java:450)
  at java.lang.VMThread.run(VMThread.java:123)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36269