diff options
Diffstat (limited to 'src/atimer.c')
| -rw-r--r-- | src/atimer.c | 47 |
1 files changed, 32 insertions, 15 deletions
diff --git a/src/atimer.c b/src/atimer.c index 9b198675ab4..df35603f324 100644 --- a/src/atimer.c +++ b/src/atimer.c @@ -305,18 +305,34 @@ set_alarm (void) #ifdef HAVE_ITIMERSPEC if (0 <= timerfd || alarm_timer_ok) { + bool exit = false; struct itimerspec ispec; ispec.it_value = atimers->expiration; ispec.it_interval.tv_sec = ispec.it_interval.tv_nsec = 0; + if (alarm_timer_ok + && timer_settime (alarm_timer, TIMER_ABSTIME, &ispec, 0) == 0) + exit = true; + + /* Don't start both timerfd and POSIX timers on Cygwin; this + causes a slowdown (bug#51734). Prefer POSIX timers + because the timerfd notifications aren't delivered while + Emacs is busy, which prevents things like the hourglass + pointer from being displayed reliably (bug#19776). */ +# ifdef CYGWIN + if (exit) + return; +# endif + # ifdef HAVE_TIMERFD - if (timerfd_settime (timerfd, TFD_TIMER_ABSTIME, &ispec, 0) == 0) + if (0 <= timerfd + && timerfd_settime (timerfd, TFD_TIMER_ABSTIME, &ispec, 0) == 0) { add_timer_wait_descriptor (timerfd); - return; + exit = true; } # endif - if (alarm_timer_ok - && timer_settime (alarm_timer, TIMER_ABSTIME, &ispec, 0) == 0) + + if (exit) return; } #endif @@ -333,9 +349,8 @@ set_alarm (void) memset (&it, 0, sizeof it); it.it_value = make_timeval (interval); setitimer (ITIMER_REAL, &it, 0); -#else /* not HAVE_SETITIMER */ - alarm (max (interval.tv_sec, 1)); #endif /* not HAVE_SETITIMER */ + alarm (max (interval.tv_sec, 1)); } } @@ -583,15 +598,17 @@ init_atimer (void) timerfd = (egetenv ("EMACS_IGNORE_TIMERFD") || have_buggy_timerfd () ? -1 : timerfd_create (CLOCK_REALTIME, TFD_NONBLOCK | TFD_CLOEXEC)); # endif - if (timerfd < 0) - { - struct sigevent sigev; - sigev.sigev_notify = SIGEV_SIGNAL; - sigev.sigev_signo = SIGALRM; - sigev.sigev_value.sival_ptr = &alarm_timer; - alarm_timer_ok - = timer_create (CLOCK_REALTIME, &sigev, &alarm_timer) == 0; - } + /* We're starting the alarms even if we have timerfd, because + timerfd events do not fire while Emacs Lisp is busy and doesn't + call thread_select. This might or might not mean that the + timerfd code doesn't really give us anything and should be + removed, see discussion in bug#19776. */ + struct sigevent sigev; + sigev.sigev_notify = SIGEV_SIGNAL; + sigev.sigev_signo = SIGALRM; + sigev.sigev_value.sival_ptr = &alarm_timer; + alarm_timer_ok + = timer_create (CLOCK_REALTIME, &sigev, &alarm_timer) == 0; #endif free_atimers = stopped_atimers = atimers = NULL; |