/* Asynchronous timers.
- Copyright (C) 2000-2015 Free Software Foundation, Inc.
+ Copyright (C) 2000-2016 Free Software Foundation, Inc.
This file is part of GNU Emacs.
GNU Emacs is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 3 of the License, or
-(at your option) any later version.
+the Free Software Foundation, either version 3 of the License, or (at
+your option) any later version.
GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
#include "lisp.h"
#include "syssignal.h"
#include "systime.h"
-#include "blockinput.h"
#include "atimer.h"
#include <unistd.h>
+#ifdef HAVE_TIMERFD
+#include <errno.h>
+# include <sys/timerfd.h>
+#endif
+
+#ifdef MSDOS
+#include "msdos.h"
+#endif
+
/* Free-list of atimer structures. */
static struct atimer *free_atimers;
static struct atimer *atimers;
+#ifdef HAVE_ITIMERSPEC
/* The alarm timer and whether it was properly initialized, if
POSIX timers are available. */
-#ifdef HAVE_ITIMERSPEC
static timer_t alarm_timer;
static bool alarm_timer_ok;
+
+# ifdef HAVE_TIMERFD
+/* File descriptor for timer, or -1 if it could not be created. */
+static int timerfd;
+# else
+enum { timerfd = -1 };
+# endif
#endif
/* Block/unblock SIGALRM. */
static void
-sigmask_atimers (int how)
+block_atimers (sigset_t *oldset)
{
sigset_t blocked;
sigemptyset (&blocked);
sigaddset (&blocked, SIGALRM);
- pthread_sigmask (how, &blocked, 0);
-}
-static void
-block_atimers (void)
-{
- sigmask_atimers (SIG_BLOCK);
+ sigaddset (&blocked, SIGINT);
+ pthread_sigmask (SIG_BLOCK, &blocked, oldset);
}
static void
-unblock_atimers (void)
+unblock_atimers (sigset_t const *oldset)
{
- sigmask_atimers (SIG_UNBLOCK);
+ pthread_sigmask (SIG_SETMASK, oldset, 0);
}
/* Function prototypes. */
static struct atimer *append_atimer_lists (struct atimer *,
struct atimer *);
-/* Start a new atimer of type TYPE. TIME specifies when the timer is
+/* Start a new atimer of type TYPE. TIMESTAMP specifies when the timer is
ripe. FN is the function to call when the timer fires.
CLIENT_DATA is stored in the client_data member of the atimer
structure returned and so made available to FN when it is called.
- If TYPE is ATIMER_ABSOLUTE, TIME is the absolute time at which the
+ If TYPE is ATIMER_ABSOLUTE, TIMESTAMP is the absolute time at which the
timer fires.
- If TYPE is ATIMER_RELATIVE, the timer is ripe TIME s/us in the
+ If TYPE is ATIMER_RELATIVE, the timer is ripe TIMESTAMP seconds in the
future.
In both cases, the timer is automatically freed after it has fired.
- If TYPE is ATIMER_CONTINUOUS, the timer fires every TIME s/us.
+ If TYPE is ATIMER_CONTINUOUS, the timer fires every TIMESTAMP seconds.
Value is a pointer to the atimer started. It can be used in calls
to cancel_atimer; don't free it yourself. */
atimer_callback fn, void *client_data)
{
struct atimer *t;
+ sigset_t oldset;
- /* Round TIME up to the next full second if we don't have
- itimers. */
+ /* Round TIMESTAMP up to the next full second if we don't have itimers. */
#ifndef HAVE_SETITIMER
if (timestamp.tv_nsec != 0 && timestamp.tv_sec < TYPE_MAXIMUM (time_t))
timestamp = make_timespec (timestamp.tv_sec + 1, 0);
t->fn = fn;
t->client_data = client_data;
- block_atimers ();
+ block_atimers (&oldset);
/* Compute the timer's expiration time. */
switch (type)
/* Insert the timer in the list of active atimers. */
schedule_atimer (t);
- unblock_atimers ();
+ unblock_atimers (&oldset);
/* Arrange for a SIGALRM at the time the next atimer is ripe. */
set_alarm ();
cancel_atimer (struct atimer *timer)
{
int i;
+ sigset_t oldset;
- block_atimers ();
+ block_atimers (&oldset);
for (i = 0; i < 2; ++i)
{
}
}
- unblock_atimers ();
+ unblock_atimers (&oldset);
}
void
stop_other_atimers (struct atimer *t)
{
- block_atimers ();
+ sigset_t oldset;
+ block_atimers (&oldset);
if (t)
{
stopped_atimers = append_atimer_lists (atimers, stopped_atimers);
atimers = t;
- unblock_atimers ();
+ unblock_atimers (&oldset);
}
{
struct atimer *t = atimers;
struct atimer *next;
+ sigset_t oldset;
- block_atimers ();
+ block_atimers (&oldset);
atimers = stopped_atimers;
stopped_atimers = NULL;
t = next;
}
- unblock_atimers ();
+ unblock_atimers (&oldset);
}
}
struct timespec now, interval;
#ifdef HAVE_ITIMERSPEC
- if (alarm_timer_ok)
+ if (0 <= timerfd || alarm_timer_ok)
{
struct itimerspec ispec;
ispec.it_value = atimers->expiration;
ispec.it_interval.tv_sec = ispec.it_interval.tv_nsec = 0;
- if (timer_settime (alarm_timer, 0, &ispec, 0) == 0)
+# ifdef HAVE_TIMERFD
+ if (timerfd_settime (timerfd, TFD_TIMER_ABSTIME, &ispec, 0) == 0)
+ {
+ add_timer_wait_descriptor (timerfd);
+ return;
+ }
+# endif
+ if (alarm_timer_ok
+ && timer_settime (alarm_timer, TIMER_ABSTIME, &ispec, 0) == 0)
return;
}
#endif
pending_signals = 1;
}
+#ifdef HAVE_TIMERFD
+
+/* Called from wait_reading_process_output when FD, which
+ should be equal to TIMERFD, is available for reading. */
+
+void
+timerfd_callback (int fd, void *arg)
+{
+ ptrdiff_t nbytes;
+ uint64_t expirations;
+
+ eassert (fd == timerfd);
+ nbytes = emacs_read (fd, &expirations, sizeof (expirations));
+
+ if (nbytes == sizeof (expirations))
+ {
+ /* Timer should expire just once. */
+ eassert (expirations == 1);
+ do_pending_atimers ();
+ }
+ else if (nbytes < 0)
+ /* For some not yet known reason, we may get weird event and no
+ data on timer descriptor. This can break Gnus at least, see:
+ http://lists.gnu.org/archive/html/emacs-devel/2014-07/msg00503.html. */
+ eassert (errno == EAGAIN);
+ else
+ /* I don't know what else can happen with this descriptor. */
+ emacs_abort ();
+}
+
+#endif /* HAVE_TIMERFD */
/* Do pending timers. */
{
if (atimers)
{
- block_atimers ();
+ sigset_t oldset;
+ block_atimers (&oldset);
run_timers ();
- unblock_atimers ();
+ unblock_atimers (&oldset);
}
}
if (on)
set_alarm ();
else
- alarm (0);
+ {
+#ifdef HAVE_ITIMERSPEC
+ struct itimerspec ispec;
+ memset (&ispec, 0, sizeof ispec);
+ if (alarm_timer_ok)
+ timer_settime (alarm_timer, TIMER_ABSTIME, &ispec, 0);
+# ifdef HAVE_TIMERFD
+ timerfd_settime (timerfd, TFD_TIMER_ABSTIME, &ispec, 0);
+# endif
+#endif
+ alarm (0);
+ }
+}
+
+/* This is intended to use from automated tests. */
+
+#ifdef ENABLE_CHECKING
+
+#define MAXTIMERS 10
+
+struct atimer_result
+{
+ /* Time when we expect this timer to trigger. */
+ struct timespec expected;
+
+ /* Timer status: -1 if not triggered, 0 if triggered
+ too early or too late, 1 if triggered timely. */
+ int intime;
+};
+
+static void
+debug_timer_callback (struct atimer *t)
+{
+ struct timespec now = current_timespec ();
+ struct atimer_result *r = (struct atimer_result *) t->client_data;
+ int result = timespec_cmp (now, r->expected);
+
+ if (result < 0)
+ /* Too early. */
+ r->intime = 0;
+ else if (result >= 0)
+ {
+#ifdef HAVE_SETITIMER
+ struct timespec delta = timespec_sub (now, r->expected);
+ /* Too late if later than expected + 0.02s. FIXME:
+ this should depend from system clock resolution. */
+ if (timespec_cmp (delta, make_timespec (0, 20000000)) > 0)
+ r->intime = 0;
+ else
+#endif /* HAVE_SETITIMER */
+ r->intime = 1;
+ }
}
+DEFUN ("debug-timer-check", Fdebug_timer_check, Sdebug_timer_check, 0, 0, 0,
+ doc: /* Run internal self-tests to check timers subsystem.
+Return t if all self-tests are passed, nil otherwise. */)
+ (void)
+{
+ int i, ok;
+ struct atimer *timer;
+ struct atimer_result *results[MAXTIMERS];
+ struct timespec t = make_timespec (0, 0);
+
+ /* Arm MAXTIMERS relative timers to trigger with 0.1s intervals. */
+ for (i = 0; i < MAXTIMERS; i++)
+ {
+ results[i] = xmalloc (sizeof (struct atimer_result));
+ t = timespec_add (t, make_timespec (0, 100000000));
+ results[i]->expected = timespec_add (current_timespec (), t);
+ results[i]->intime = -1;
+ timer = start_atimer (ATIMER_RELATIVE, t,
+ debug_timer_callback, results[i]);
+ }
+
+#ifdef HAVE_TIMERFD
+ /* Wait for 1s but process timers. */
+ wait_reading_process_output (1, 0, 0, false, Qnil, NULL, 0);
+#else
+ /* If timerfd is not supported, wait_reading_process_output won't
+ pay attention to timers that expired, and the callbacks won't be
+ called. So we need to run the expired timers' callbacks by
+ hand. */
+ /* Wait 1.2 sec for the timers to expire. */
+ struct timespec tend =
+ timespec_add (current_timespec (), make_timespec (1, 200000000));
+
+ while (timespec_cmp (current_timespec (), tend) < 0)
+ {
+ /* Wait for 5 msec between iterations. */
+ wait_reading_process_output (0, 5000000, 0, false, Qnil, NULL, 0);
+ if (pending_signals)
+ do_pending_atimers ();
+ }
+#endif
+ /* Shut up the compiler by "using" this variable. */
+ (void) timer;
+
+ for (i = 0, ok = 0; i < MAXTIMERS; i++)
+ ok += results[i]->intime, xfree (results[i]);
+
+ return ok == MAXTIMERS ? Qt : Qnil;
+}
+
+#endif /* ENABLE_CHECKING */
void
init_atimer (void)
{
- struct sigaction action;
#ifdef HAVE_ITIMERSPEC
- 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;
+# ifdef HAVE_TIMERFD
+ /* Until this feature is considered stable, you can ask to not use it. */
+ timerfd = (egetenv ("EMACS_IGNORE_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;
+ }
#endif
free_atimers = stopped_atimers = atimers = NULL;
- /* pending_signals is initialized in init_keyboard.*/
+
+ /* pending_signals is initialized in init_keyboard. */
+ struct sigaction action;
emacs_sigaction_init (&action, handle_alarm_signal);
sigaction (SIGALRM, &action, 0);
+
+#ifdef ENABLE_CHECKING
+ defsubr (&Sdebug_timer_check);
+#endif
}