Mail Archives: cygwin/2006/02/23/16:40:42
On Thu, Feb 23, 2006 at 04:33:45PM -0500, Ernie Coskrey wrote:
>There are two hang conditions that we've identified and have developed fixes for. This is a description of the first of the two along with a patch; I'll follow up with a description and patch for the second.
>
>
>If a signal can't be handled because it is blocked, it gets queued (on
>the process's "sigq") to be handled later. Now, whenever the process's
>signal mask changes (e.g., the signal in question gets unblocked), an
>attempt is made to handle all the queued signals (i.e., a signal flush
>occurs). However, if the queueing of the blocked signal happens right
>after the signal mask change, then we miss the signal. This causes the
>process to hang. The signal is on the queue, but the process doesn't
>know to check for it. The process just hangs until another signal gets
>sent to it.
>
>The workaround is basically to force the signal queue to be rescanned
>(flushed) whenever we add something to it, so a queued signal is never
>missed.
Thanks for the analysis and the patch.
But, a backwards goto into a case? Yuck. I'll see if I can come up
with something better.
cgf
--
Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
Problem reports: http://cygwin.com/problems.html
Documentation: http://cygwin.com/docs.html
FAQ: http://cygwin.com/faq/
- Raw text -