/* Signal handlers...SIG_DFL == 0 so this is initialized correctly. */
static signal_handler sig_handlers[NSIG];
+static sigset_t sig_mask;
+
+static CRITICAL_SECTION crit_sig;
+
/* Improve on the CRT 'signal' implementation so that we could record
- the SIGCHLD handler. */
+ the SIGCHLD handler and fake interval timers. */
signal_handler
sys_signal (int sig, signal_handler handler)
{
signal_handler old;
/* SIGCHLD is needed for supporting subprocesses, see sys_kill
- below. All the others are the only ones supported by the MS
- runtime. */
+ below. SIGALRM and SIGPROF are used by setitimer. All the
+ others are the only ones supported by the MS runtime. */
if (!(sig == SIGCHLD || sig == SIGSEGV || sig == SIGILL
- || sig == SIGFPE || sig == SIGABRT || sig == SIGTERM))
+ || sig == SIGFPE || sig == SIGABRT || sig == SIGTERM
+ || sig == SIGALRM || sig == SIGPROF))
{
errno = EINVAL;
return SIG_ERR;
if (!(sig == SIGABRT && old == term_ntproc))
{
sig_handlers[sig] = handler;
- if (sig != SIGCHLD)
+ if (!(sig == SIGCHLD || sig == SIGALRM || sig == SIGPROF))
signal (sig, handler);
}
return old;
return retval;
}
+/* Emulate signal sets and blocking of signals used by timers. */
+
+int
+sigemptyset (sigset_t *set)
+{
+ *set = 0;
+ return 0;
+}
+
+int
+sigaddset (sigset_t *set, int signo)
+{
+ if (!set)
+ {
+ errno = EINVAL;
+ return -1;
+ }
+ if (signo < 0 || signo >= NSIG)
+ {
+ errno = EINVAL;
+ return -1;
+ }
+
+ *set |= (1U << signo);
+
+ return 0;
+}
+
+int
+sigfillset (sigset_t *set)
+{
+ if (!set)
+ {
+ errno = EINVAL;
+ return -1;
+ }
+
+ *set = 0xFFFFFFFF;
+ return 0;
+}
+
+int
+sigprocmask (int how, const sigset_t *set, sigset_t *oset)
+{
+ if (!(how == SIG_BLOCK || how == SIG_UNBLOCK || how == SIG_SETMASK))
+ {
+ errno = EINVAL;
+ return -1;
+ }
+
+ if (oset)
+ *oset = sig_mask;
+
+ if (!set)
+ return 0;
+
+ switch (how)
+ {
+ case SIG_BLOCK:
+ sig_mask |= *set;
+ break;
+ case SIG_SETMASK:
+ sig_mask = *set;
+ break;
+ case SIG_UNBLOCK:
+ /* FIXME: Catch signals that are blocked and reissue them when
+ they are unblocked. Important for SIGALRM and SIGPROF only. */
+ sig_mask &= ~(*set);
+ break;
+ }
+
+ return 0;
+}
+
+int
+pthread_sigmask (int how, const sigset_t *set, sigset_t *oset)
+{
+ if (sigprocmask (how, set, oset) == -1)
+ return EINVAL;
+ return 0;
+}
+
+int
+sigismember (const sigset_t *set, int signo)
+{
+ if (signo < 0 || signo >= NSIG)
+ {
+ errno = EINVAL;
+ return -1;
+ }
+ if (signo > sizeof (*set) * BITS_PER_CHAR)
+ emacs_abort ();
+
+ return (*set & (1U << signo)) != 0;
+}
+
+int
+setpgrp (int pid, int gid)
+{
+ return 0;
+}
+
+/* Emulations of interval timers.
+
+ Limitations: only ITIMER_REAL and ITIMER_PROF are supported.
+
+ Implementation: a separate thread is started for each timer type,
+ the thread calls the appropriate signal handler when the timer
+ expires, after stopping the thread which installed the timer. */
+
+/* FIXME: clock_t counts overflow after 49 days, need to handle the
+ wrap-around. */
+struct itimer_data {
+ clock_t expire;
+ clock_t reload;
+ int terminate;
+ int type;
+ HANDLE caller_thread;
+ HANDLE timer_thread;
+};
+
+static clock_t ticks_now;
+static struct itimer_data real_itimer, prof_itimer;
+static clock_t clocks_min;
+
+static CRITICAL_SECTION crit_real, crit_prof;
+
+#define MAX_SINGLE_SLEEP 30
+
+static DWORD WINAPI
+timer_loop (LPVOID arg)
+{
+ struct itimer_data *itimer = (struct itimer_data *)arg;
+ int which = itimer->type;
+ int sig = (which == ITIMER_REAL) ? SIGALRM : SIGPROF;
+ CRITICAL_SECTION *crit = (which == ITIMER_REAL) ? &crit_real : &crit_prof;
+ const DWORD max_sleep = MAX_SINGLE_SLEEP * 1000 / CLOCKS_PER_SEC;
+ int new_count = 0;
+
+ while (1)
+ {
+ DWORD sleep_time;
+ signal_handler handler;
+ clock_t now, expire, reload;
+
+ /* Load new values if requested by setitimer. */
+ EnterCriticalSection (crit);
+ expire = itimer->expire;
+ reload = itimer->reload;
+ LeaveCriticalSection (crit);
+ if (itimer->terminate)
+ return 0;
+
+ if (itimer->expire == 0)
+ {
+ /* We are idle. */
+ Sleep (max_sleep);
+ continue;
+ }
+
+ expire = itimer->expire;
+ if (expire > (now = clock ()))
+ sleep_time = expire - now;
+ else
+ sleep_time = 0;
+ /* Don't sleep too long at a time, to be able to see the
+ termination flag without too long a delay. */
+ while (sleep_time > max_sleep)
+ {
+ if (itimer->terminate)
+ return 0;
+ Sleep (max_sleep);
+ expire = itimer->expire;
+ sleep_time = (expire > (now = clock ())) ? expire - now : 0;
+ }
+ if (itimer->terminate)
+ return 0;
+ if (sleep_time > 0)
+ {
+ Sleep (sleep_time * 1000 / CLOCKS_PER_SEC);
+ /* Always sleep past the expiration time, to make sure we
+ never call the handler _before_ the expiration time,
+ always slightly after it. Sleep(0) relinquishes the rest
+ of the scheduled slot, so that we let other threads
+ work. */
+ while (clock () < expire)
+ Sleep (0);
+ }
+
+ if (itimer->expire == 0)
+ continue;
+
+ /* Time's up. */
+ handler = sig_handlers[sig];
+ if (!(handler == SIG_DFL || handler == SIG_IGN || handler == SIG_ERR)
+ /* FIXME: Don't ignore masked signals. Instead, record that
+ they happened and reissue them when the signal is
+ unblocked. */
+ && !sigismember (&sig_mask, sig)
+ /* Simulate masking of SIGALRM and SIGPROF when processing
+ fatal signals. */
+ && !fatal_error_in_progress
+ && itimer->caller_thread)
+ {
+ /* Simulate a signal delivered to the thread which installed
+ the timer, by suspending that thread while the handler
+ runs. */
+ DWORD result = SuspendThread (itimer->caller_thread);
+
+ if (result == (DWORD)-1)
+ {
+ DebPrint (("Thread %d exiting with status 2\n", which));
+ return 2;
+ }
+ handler (sig);
+ ResumeThread (itimer->caller_thread);
+ }
+
+ if (itimer->expire == 0)
+ continue;
+
+ /* Update expiration time and loop. */
+ EnterCriticalSection (crit);
+ expire = itimer->expire;
+ reload = itimer->reload;
+ if (reload > 0)
+ {
+ now = clock ();
+ if (expire <= now)
+ {
+ clock_t lag = now - expire;
+
+ /* If we missed some opportunities (presumably while
+ sleeping or while the signal handler ran), skip
+ them. */
+ if (lag > reload)
+ expire = now - (lag % reload);
+
+ expire += reload;
+ }
+ }
+ else
+ expire = 0; /* become idle */
+ itimer->expire = expire;
+ LeaveCriticalSection (crit);
+ }
+ return 0;
+}
+
+static void
+stop_timer_thread (int which)
+{
+ struct itimer_data *itimer =
+ (which == ITIMER_REAL) ? &real_itimer : &prof_itimer;
+ int i;
+ DWORD exit_code = 255;
+ BOOL status, err;
+
+ /* Signal the thread that it should terminate. */
+ itimer->terminate = 1;
+
+ if (itimer->timer_thread == NULL)
+ return;
+
+ /* Wait for the timer thread to terminate voluntarily, then kill it
+ if it doesn't. This loop waits twice more than the maximum
+ amount of time a timer thread sleeps, see above. */
+ for (i = 0; i < MAX_SINGLE_SLEEP / 5; i++)
+ {
+ if (!((status = GetExitCodeThread (itimer->timer_thread, &exit_code))
+ && exit_code == STILL_ACTIVE))
+ break;
+ Sleep (10);
+ }
+ if ((status == FALSE && (err = GetLastError ()) == ERROR_INVALID_HANDLE)
+ || exit_code == STILL_ACTIVE)
+ {
+ if (!(status == FALSE && err == ERROR_INVALID_HANDLE))
+ TerminateThread (itimer->timer_thread, 0);
+ }
+
+ /* Clean up. */
+ CloseHandle (itimer->timer_thread);
+ itimer->timer_thread = NULL;
+ if (itimer->caller_thread)
+ {
+ CloseHandle (itimer->caller_thread);
+ itimer->caller_thread = NULL;
+ }
+}
+
+/* This is called at shutdown time from term_ntproc. */
+void
+term_timers (void)
+{
+ if (real_itimer.timer_thread)
+ stop_timer_thread (ITIMER_REAL);
+ if (prof_itimer.timer_thread)
+ stop_timer_thread (ITIMER_PROF);
+
+ DeleteCriticalSection (&crit_real);
+ DeleteCriticalSection (&crit_prof);
+ DeleteCriticalSection (&crit_sig);
+}
+
+/* This is called at initialization time from init_ntproc. */
+void
+init_timers (void)
+{
+ /* Make sure we start with zeroed out itimer structures, since
+ dumping may have left there traces of threads long dead. */
+ memset (&real_itimer, 0, sizeof real_itimer);
+ memset (&prof_itimer, 0, sizeof prof_itimer);
+
+ InitializeCriticalSection (&crit_real);
+ InitializeCriticalSection (&crit_prof);
+ InitializeCriticalSection (&crit_sig);
+}
+
+static int
+start_timer_thread (int which)
+{
+ DWORD exit_code;
+ struct itimer_data *itimer =
+ (which == ITIMER_REAL) ? &real_itimer : &prof_itimer;
+
+ if (itimer->timer_thread
+ && GetExitCodeThread (itimer->timer_thread, &exit_code)
+ && exit_code == STILL_ACTIVE)
+ return 0;
+
+ /* Start a new thread. */
+ if (!DuplicateHandle (GetCurrentProcess (), GetCurrentThread (),
+ GetCurrentProcess (), &itimer->caller_thread, 0,
+ FALSE, DUPLICATE_SAME_ACCESS))
+ {
+ errno = ESRCH;
+ return -1;
+ }
+
+ itimer->terminate = 0;
+ itimer->type = which;
+ /* Request that no more than 64KB of stack be reserved for this
+ thread, to avoid reserving too much memory, which would get in
+ the way of threads we start to wait for subprocesses. See also
+ new_child below. */
+ itimer->timer_thread = CreateThread (NULL, 64 * 1024, timer_loop,
+ (void *)itimer, 0x00010000, NULL);
+
+ if (!itimer->timer_thread)
+ {
+ CloseHandle (itimer->caller_thread);
+ itimer->caller_thread = NULL;
+ errno = EAGAIN;
+ return -1;
+ }
+
+ /* This is needed to make sure that the timer thread running for
+ profiling gets CPU as soon as the Sleep call terminates. */
+ if (which == ITIMER_PROF)
+ SetThreadPriority (itimer->caller_thread, THREAD_PRIORITY_TIME_CRITICAL);
+
+ return 0;
+}
+
+/* Most of the code of getitimer and setitimer (but not of their
+ subroutines) was shamelessly stolen from itimer.c in the DJGPP
+ library, see www.delorie.com/djgpp. */
+int
+getitimer (int which, struct itimerval *value)
+{
+ volatile clock_t *t_expire;
+ volatile clock_t *t_reload;
+ clock_t expire, reload;
+ __int64 usecs;
+ CRITICAL_SECTION *crit;
+
+ ticks_now = clock ();
+
+ if (!value)
+ {
+ errno = EFAULT;
+ return -1;
+ }
+
+ if (which != ITIMER_REAL && which != ITIMER_PROF)
+ {
+ errno = EINVAL;
+ return -1;
+ }
+
+ t_expire = (which == ITIMER_REAL) ? &real_itimer.expire: &prof_itimer.expire;
+ t_reload = (which == ITIMER_REAL) ? &real_itimer.reload: &prof_itimer.reload;
+ crit = (which == ITIMER_REAL) ? &crit_real : &crit_prof;
+
+ EnterCriticalSection (crit);
+ reload = *t_reload;
+ expire = *t_expire;
+ LeaveCriticalSection (crit);
+
+ if (expire)
+ expire -= ticks_now;
+
+ value->it_value.tv_sec = expire / CLOCKS_PER_SEC;
+ usecs = (expire % CLOCKS_PER_SEC) * (__int64)1000000 / CLOCKS_PER_SEC;
+ value->it_value.tv_usec = usecs;
+ value->it_interval.tv_sec = reload / CLOCKS_PER_SEC;
+ usecs = (reload % CLOCKS_PER_SEC) * (__int64)1000000 / CLOCKS_PER_SEC;
+ value->it_interval.tv_usec= usecs;
+
+ return 0;
+}
+
+int
+setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
+{
+ volatile clock_t *t_expire, *t_reload;
+ clock_t expire, reload, expire_old, reload_old;
+ __int64 usecs;
+ CRITICAL_SECTION *crit;
+
+ /* Posix systems expect timer values smaller than the resolution of
+ the system clock be rounded up to the clock resolution. First
+ time we are called, measure the clock tick resolution. */
+ if (!clocks_min)
+ {
+ clock_t t1, t2;
+
+ for (t1 = clock (); (t2 = clock ()) == t1; )
+ ;
+ clocks_min = t2 - t1;
+ }
+
+ if (ovalue)
+ {
+ if (getitimer (which, ovalue)) /* also sets ticks_now */
+ return -1; /* errno already set */
+ }
+ else
+ ticks_now = clock ();
+
+ if (which != ITIMER_REAL && which != ITIMER_PROF)
+ {
+ errno = EINVAL;
+ return -1;
+ }
+
+ t_expire =
+ (which == ITIMER_REAL) ? &real_itimer.expire : &prof_itimer.expire;
+ t_reload =
+ (which == ITIMER_REAL) ? &real_itimer.reload : &prof_itimer.reload;
+
+ crit = (which == ITIMER_REAL) ? &crit_real : &crit_prof;
+
+ if (!value
+ || (value->it_value.tv_sec == 0 && value->it_value.tv_usec == 0))
+ {
+ EnterCriticalSection (crit);
+ /* Disable the timer. */
+ *t_expire = 0;
+ *t_reload = 0;
+ LeaveCriticalSection (crit);
+ return 0;
+ }
+
+ reload = value->it_interval.tv_sec * CLOCKS_PER_SEC;
+
+ usecs = value->it_interval.tv_usec;
+ if (value->it_interval.tv_sec == 0
+ && usecs && usecs * CLOCKS_PER_SEC < clocks_min * 1000000)
+ reload = clocks_min;
+ else
+ {
+ usecs *= CLOCKS_PER_SEC;
+ reload += usecs / 1000000;
+ }
+
+ expire = value->it_value.tv_sec * CLOCKS_PER_SEC;
+ usecs = value->it_value.tv_usec;
+ if (value->it_value.tv_sec == 0
+ && usecs * CLOCKS_PER_SEC < clocks_min * 1000000)
+ expire = clocks_min;
+ else
+ {
+ usecs *= CLOCKS_PER_SEC;
+ expire += usecs / 1000000;
+ }
+
+ expire += ticks_now;
+
+ EnterCriticalSection (crit);
+ expire_old = *t_expire;
+ reload_old = *t_reload;
+ if (!(expire == expire_old && reload == reload_old))
+ {
+ *t_reload = reload;
+ *t_expire = expire;
+ }
+ LeaveCriticalSection (crit);
+
+ return start_timer_thread (which);
+}
+
+int
+alarm (int seconds)
+{
+ struct itimerval new_values;
+
+ new_values.it_value.tv_sec = seconds;
+ new_values.it_value.tv_usec = 0;
+ new_values.it_interval.tv_sec = new_values.it_interval.tv_usec = 0;
+
+ setitimer (ITIMER_REAL, &new_values, NULL);
+
+ return seconds;
+}
+
/* Defined in <process.h> which conflicts with the local copy */
#define _P_NOWAIT 1
HCoop / bpt / emacs.git / blobdiff