On Fri, 12 Jul 2019 17:33:51, Corinna Vinschen wrote: > On Jul 6 19:15, Kenton Varda wrote:
> > I found a second problem which may or may not be related: > > If two threads use pthread_kill() to send each other the same signal, > > such that the signal should be separately pending on both threads at > > the same time, only one of the two signals is actually queued. It > > seems that pthread_kill() is ignored if the same signal is already > > pending on some other thread. > > The current signal mechanism in Cygwin only allows for a signal to be > queued once. Changing that is a pretty ambitioned task, which I simply > don't have enought time for. However, patches to change that are more > than welcome. .. uhm, just a note in the interest of accuracy ... - standard signals (which include USRSIG1 and USRSIG2) are not queued (traditional signal semantics) - only real-time signals should be queued ... The executive (cygwin1.dll) must maintain a record of the signals that are pending for the process as a whole, as well as a record of the signals that are pending for each thread. A call to sigpending() returns the union of the set of signals that are pending for the process and those that are pending for the calling thread. Source: 33.2.1 (How the Unix Signal Model maps to threads) of LPI. Undoubtedly, the signal mechanism in Cygwin must be "adapted", but as far as I can tell, there is no requirement to "queue" any of the standard signals ... Regards Henri -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
