On Jan 22 20:16, Takashi Yano via Cygwin wrote: > On Mon, 22 Jan 2024 10:57:48 +0100 > Corinna Vinschen wrote: > > On Jan 22 10:25, Corinna Vinschen via Cygwin wrote: > > > On Jan 22 12:30, Takashi Yano via Cygwin wrote: > > > > PATCH2: (for cygwin) > > > > Avoid handle leak caused when non-static pthread_once_t is initialized > > > > with PTHREAD_ONCE_INIT > > > > diff --git a/winsup/cygwin/thread.cc b/winsup/cygwin/thread.cc > > > > index 7bb4f9fc8..127569160 100644 > > > > --- a/winsup/cygwin/thread.cc > > > > +++ b/winsup/cygwin/thread.cc > > > > @@ -2060,6 +2060,9 @@ pthread::once (pthread_once_t *once_control, void > > > > (*init_routine) (void)) > > > > { > > > > init_routine (); > > > > once_control->state = 1; > > > > + pthread_mutex_unlock (&once_control->mutex); > > > > + while (pthread_mutex_destroy (&once_control->mutex) == EBUSY); > > > > + return 0; > > > > } > > > > /* Here we must remove our cancellation handler */ > > > > pthread_mutex_unlock (&once_control->mutex); > > > > > > I see what you're doing here. Wouldn't it be simpler, though, to do this? > > > > > > diff --git a/winsup/cygwin/thread.cc b/winsup/cygwin/thread.cc > > > index 7bb4f9fc8341..7ec3aace395d 100644 > > > --- a/winsup/cygwin/thread.cc > > > +++ b/winsup/cygwin/thread.cc > > > @@ -2063,6 +2063,7 @@ pthread::once (pthread_once_t *once_control, void > > > (*init_routine) (void)) > > > } > > > /* Here we must remove our cancellation handler */ > > > > Strange enough, this comment accompanies the code since its inception > > in 2001. It says explicitly "remove" the cancellation handler. > > That sounds like the idea was right, just the programmer forgot about > > it afterwards... > > I am not sure what 'cancellation handler' means here. Is it the > event handler in pthread_mutex_t?
Aaah, no. I just read and re-read the stuff and it occured to me that this is based on the preceeding, longer comment in pthread::once. Theoretically, the comments say, we need to set up a cancellation handler so pthread_once becomes cancellable. However, I don't find this in the standards. pthread_once is neither one of the required cancellation points, nor one of the optional cancellation points. So now I wonder if we shouldn't just get rid of the cokmments talking about the cancellation in pthread::once entirely. Corinna -- Problem reports: https://cygwin.com/problems.html FAQ: https://cygwin.com/faq/ Documentation: https://cygwin.com/docs.html Unsubscribe info: https://cygwin.com/ml/#unsubscribe-simple