1 /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002, 2004 Free Software Foundation, Inc.
3 * This library is free software; you can redistribute it and/or
4 * modify it under the terms of the GNU Lesser General Public
5 * License as published by the Free Software Foundation; either
6 * version 2.1 of the License, or (at your option) any later version.
8 * This library is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * Lesser General Public License for more details.
13 * You should have received a copy of the GNU Lesser General Public
14 * License along with this library; if not, write to the Free Software
15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
29 #include "libguile/_scm.h"
31 #include "libguile/async.h"
32 #include "libguile/eval.h"
33 #include "libguile/root.h"
34 #include "libguile/vectors.h"
36 #include "libguile/validate.h"
37 #include "libguile/scmsigs.h"
43 #ifdef HAVE_SYS_TIME_H
49 #define alarm(sec) (0)
50 /* This weird comma expression is because Sleep is void under Windows. */
51 #define sleep(sec) (Sleep ((sec) * 1000), 0)
52 #define usleep(usec) (Sleep ((usec) / 1000), 0)
53 #define kill(pid, sig) raise (sig)
58 /* SIGRETTYPE is the type that signal handlers return. See <signal.h> */
61 # define SIGRETTYPE RETSIGTYPE
64 # define SIGRETTYPE void
66 # define SIGRETTYPE int
72 /* take_signal is installed as the C signal handler whenever a Scheme
73 handler is set. When a signal arrives, take_signal will write a
74 byte into the 'signal pipe'. The 'signal delivery thread' will
75 read this pipe and queue the appropriate asyncs.
77 When Guile is built without threads, the signal handler will
78 install the async directly.
82 /* Scheme vectors with information about a signal. signal_handlers
83 contains the handler procedure or #f, signal_handler_asyncs
84 contains the thunk to be marked as an async when the signal arrives
85 (or the cell with the thunk in a singlethreaded Guile), and
86 signal_handler_threads points to the thread that a signal should be
89 static SCM
*signal_handlers
;
90 static SCM signal_handler_asyncs
;
91 static SCM signal_handler_threads
;
93 /* saves the original C handlers, when a new handler is installed.
94 set to SIG_ERR if the original handler is installed. */
96 static struct sigaction orig_handlers
[NSIG
];
98 static SIGRETTYPE (*orig_handlers
[NSIG
])(int);
102 close_1 (SCM proc
, SCM arg
)
104 return scm_primitive_eval_x (scm_list_3 (scm_sym_lambda
, SCM_EOL
,
105 scm_list_2 (proc
, arg
)));
108 #if SCM_USE_PTHREAD_THREADS
110 static int signal_pipe
[2];
113 take_signal (int signum
)
115 char sigbyte
= signum
;
116 write (signal_pipe
[1], &sigbyte
, 1);
118 #ifndef HAVE_SIGACTION
119 signal (signum
, take_signal
);
128 } read_without_guile_data
;
131 do_read_without_guile (void *raw_data
)
133 read_without_guile_data
*data
= (read_without_guile_data
*)data
;
134 data
->res
= read (data
->fd
, data
->buf
, data
->n
);
139 read_without_guile (int fd
, char *buf
, size_t n
)
141 read_without_guile_data data
;
145 scm_without_guile (do_read_without_guile
, &data
);
150 signal_delivery_thread (void *data
)
156 sigfillset (&all_sigs
);
157 scm_i_pthread_sigmask (SIG_SETMASK
, &all_sigs
, NULL
);
161 n
= read_without_guile (signal_pipe
[0], &sigbyte
, 1);
163 if (n
== 1 && sig
>= 0 && sig
< NSIG
)
167 h
= SCM_SIMPLE_VECTOR_REF (signal_handler_asyncs
, sig
);
168 t
= SCM_SIMPLE_VECTOR_REF (signal_handler_threads
, sig
);
170 scm_system_async_mark_for_thread (h
, t
);
172 else if (n
< 0 && errno
!= EINTR
)
173 perror ("error in signal delivery thread");
176 return SCM_UNSPECIFIED
; /* not reached */
180 start_signal_delivery_thread (void)
182 if (pipe (signal_pipe
) != 0)
184 scm_spawn_thread (signal_delivery_thread
, NULL
,
185 scm_handle_by_message
, "signal delivery thread");
189 ensure_signal_delivery_thread ()
191 static scm_i_pthread_once_t once
= SCM_I_PTHREAD_ONCE_INIT
;
192 scm_i_pthread_once (&once
, start_signal_delivery_thread
);
195 #else /* !SCM_USE_PTHREAD_THREADS */
198 take_signal (int signum
)
200 SCM cell
= SCM_SIMPLE_VECTOR_REF (signal_handler_asyncs
, signum
);
201 scm_i_thread
*t
= SCM_I_CURRENT_THREAD
;
203 if (scm_is_false (SCM_CDR (cell
)))
205 SCM_SETCDR (cell
, t
->active_asyncs
);
206 t
->active_asyncs
= cell
;
207 t
->pending_asyncs
= 1;
210 #ifndef HAVE_SIGACTION
211 signal (signum
, take_signal
);
216 ensure_signal_delivery_thread ()
221 #endif /* !SCM_USE_PTHREAD_THREADS */
224 install_handler (int signum
, SCM thread
, SCM handler
)
226 if (scm_is_false (handler
))
228 SCM_SIMPLE_VECTOR_SET (*signal_handlers
, signum
, SCM_BOOL_F
);
229 SCM_SIMPLE_VECTOR_SET (signal_handler_asyncs
, signum
, SCM_BOOL_F
);
233 SCM async
= close_1 (handler
, scm_from_int (signum
));
234 #if !SCM_USE_PTHREAD_THREADS
235 async
= scm_cons (async
, SCM_BOOL_F
);
237 SCM_SIMPLE_VECTOR_SET (*signal_handlers
, signum
, handler
);
238 SCM_SIMPLE_VECTOR_SET (signal_handler_asyncs
, signum
, async
);
241 SCM_SIMPLE_VECTOR_SET (signal_handler_threads
, signum
, thread
);
245 scm_sigaction (SCM signum
, SCM handler
, SCM flags
)
247 return scm_sigaction_for_thread (signum
, handler
, flags
, SCM_UNDEFINED
);
250 /* user interface for installation of signal handlers. */
251 SCM_DEFINE (scm_sigaction_for_thread
, "sigaction", 1, 3, 0,
252 (SCM signum
, SCM handler
, SCM flags
, SCM thread
),
253 "Install or report the signal handler for a specified signal.\n\n"
254 "@var{signum} is the signal number, which can be specified using the value\n"
255 "of variables such as @code{SIGINT}.\n\n"
256 "If @var{handler} is omitted, @code{sigaction} returns a pair: the\n"
257 "CAR is the current\n"
258 "signal hander, which will be either an integer with the value @code{SIG_DFL}\n"
259 "(default action) or @code{SIG_IGN} (ignore), or the Scheme procedure which\n"
260 "handles the signal, or @code{#f} if a non-Scheme procedure handles the\n"
261 "signal. The CDR contains the current @code{sigaction} flags for the handler.\n\n"
262 "If @var{handler} is provided, it is installed as the new handler for\n"
263 "@var{signum}. @var{handler} can be a Scheme procedure taking one\n"
264 "argument, or the value of @code{SIG_DFL} (default action) or\n"
265 "@code{SIG_IGN} (ignore), or @code{#f} to restore whatever signal handler\n"
266 "was installed before @code{sigaction} was first used. When\n"
267 "a scheme procedure has been specified, that procedure will run\n"
268 "in the given @var{thread}. When no thread has been given, the\n"
269 "thread that made this call to @code{sigaction} is used.\n"
271 "optionally be specified for the new handler (@code{SA_RESTART} will\n"
272 "always be added if it's available and the system is using restartable\n"
273 "system calls.) The return value is a pair with information about the\n"
274 "old handler as described above.\n\n"
275 "This interface does not provide access to the \"signal blocking\"\n"
276 "facility. Maybe this is not needed, since the thread support may\n"
277 "provide solutions to the problem of consistent access to data\n"
279 #define FUNC_NAME s_scm_sigaction_for_thread
282 #ifdef HAVE_SIGACTION
283 struct sigaction action
;
284 struct sigaction old_action
;
286 SIGRETTYPE (* chandler
) (int) = SIG_DFL
;
287 SIGRETTYPE (* old_chandler
) (int);
290 int save_handler
= 0;
294 csig
= scm_to_signed_integer (signum
, 0, NSIG
-1);
296 #if defined(HAVE_SIGACTION)
297 #if defined(SA_RESTART) && defined(HAVE_RESTARTABLE_SYSCALLS)
298 /* don't allow SA_RESTART to be omitted if HAVE_RESTARTABLE_SYSCALLS
299 is defined, since libguile would be likely to produce spurious
301 action
.sa_flags
= SA_RESTART
;
305 if (!SCM_UNBNDP (flags
))
306 action
.sa_flags
|= scm_to_int (flags
);
307 sigemptyset (&action
.sa_mask
);
310 if (SCM_UNBNDP (thread
))
311 thread
= scm_current_thread ();
314 SCM_VALIDATE_THREAD (4, thread
);
315 if (scm_c_thread_exited_p (thread
))
316 SCM_MISC_ERROR ("thread has already exited", SCM_EOL
);
319 ensure_signal_delivery_thread ();
321 SCM_CRITICAL_SECTION_START
;
322 old_handler
= SCM_SIMPLE_VECTOR_REF (*signal_handlers
, csig
);
323 if (SCM_UNBNDP (handler
))
325 else if (scm_is_integer (handler
))
327 long handler_int
= scm_to_long (handler
);
329 if (handler_int
== (long) SIG_DFL
|| handler_int
== (long) SIG_IGN
)
331 #ifdef HAVE_SIGACTION
332 action
.sa_handler
= (SIGRETTYPE (*) (int)) handler_int
;
334 chandler
= (SIGRETTYPE (*) (int)) handler_int
;
336 install_handler (csig
, SCM_BOOL_F
, SCM_BOOL_F
);
339 SCM_OUT_OF_RANGE (2, handler
);
341 else if (scm_is_false (handler
))
343 /* restore the default handler. */
344 #ifdef HAVE_SIGACTION
345 if (orig_handlers
[csig
].sa_handler
== SIG_ERR
)
349 action
= orig_handlers
[csig
];
350 orig_handlers
[csig
].sa_handler
= SIG_ERR
;
351 install_handler (csig
, SCM_BOOL_F
, SCM_BOOL_F
);
354 if (orig_handlers
[csig
] == SIG_ERR
)
358 chandler
= orig_handlers
[csig
];
359 orig_handlers
[csig
] = SIG_ERR
;
360 install_handler (csig
, SCM_BOOL_F
, SCM_BOOL_F
);
366 SCM_VALIDATE_PROC (2, handler
);
367 #ifdef HAVE_SIGACTION
368 action
.sa_handler
= take_signal
;
369 if (orig_handlers
[csig
].sa_handler
== SIG_ERR
)
372 chandler
= take_signal
;
373 if (orig_handlers
[csig
] == SIG_ERR
)
376 install_handler (csig
, thread
, handler
);
379 /* XXX - Silently ignore setting handlers for `program error signals'
380 because they can't currently be handled by Scheme code.
385 /* This list of program error signals is from the GNU Libc
394 #if defined(SIGIOT) && (SIGIOT != SIGABRT)
409 #ifdef HAVE_SIGACTION
412 if (sigaction (csig
, 0, &old_action
) == -1)
417 if (sigaction (csig
, &action
, &old_action
) == -1)
420 orig_handlers
[csig
] = old_action
;
422 if (old_action
.sa_handler
== SIG_DFL
|| old_action
.sa_handler
== SIG_IGN
)
423 old_handler
= scm_from_long ((long) old_action
.sa_handler
);
424 SCM_CRITICAL_SECTION_END
;
425 return scm_cons (old_handler
, scm_from_int (old_action
.sa_flags
));
429 if ((old_chandler
= signal (csig
, SIG_IGN
)) == SIG_ERR
)
431 if (signal (csig
, old_chandler
) == SIG_ERR
)
436 if ((old_chandler
= signal (csig
, chandler
)) == SIG_ERR
)
439 orig_handlers
[csig
] = old_chandler
;
441 if (old_chandler
== SIG_DFL
|| old_chandler
== SIG_IGN
)
442 old_handler
= scm_from_long ((long) old_chandler
);
443 SCM_CRITICAL_SECTION_END
;
444 return scm_cons (old_handler
, scm_from_int (0));
449 SCM_DEFINE (scm_restore_signals
, "restore-signals", 0, 0, 0,
451 "Return all signal handlers to the values they had before any call to\n"
452 "@code{sigaction} was made. The return value is unspecified.")
453 #define FUNC_NAME s_scm_restore_signals
456 for (i
= 0; i
< NSIG
; i
++)
458 #ifdef HAVE_SIGACTION
459 if (orig_handlers
[i
].sa_handler
!= SIG_ERR
)
461 if (sigaction (i
, &orig_handlers
[i
], NULL
) == -1)
463 orig_handlers
[i
].sa_handler
= SIG_ERR
;
464 SCM_SIMPLE_VECTOR_SET (*signal_handlers
, i
, SCM_BOOL_F
);
467 if (orig_handlers
[i
] != SIG_ERR
)
469 if (signal (i
, orig_handlers
[i
]) == SIG_ERR
)
471 orig_handlers
[i
] = SIG_ERR
;
472 SCM_SIMPLE_VECTOR_SET (*signal_handlers
, i
, SCM_BOOL_F
);
476 return SCM_UNSPECIFIED
;
480 SCM_DEFINE (scm_alarm
, "alarm", 1, 0, 0,
482 "Set a timer to raise a @code{SIGALRM} signal after the specified\n"
483 "number of seconds (an integer). It's advisable to install a signal\n"
485 "@code{SIGALRM} beforehand, since the default action is to terminate\n"
487 "The return value indicates the time remaining for the previous alarm,\n"
488 "if any. The new value replaces the previous alarm. If there was\n"
489 "no previous alarm, the return value is zero.")
490 #define FUNC_NAME s_scm_alarm
492 return scm_from_uint (alarm (scm_to_uint (i
)));
496 #ifdef HAVE_SETITIMER
497 SCM_DEFINE (scm_setitimer
, "setitimer", 5, 0, 0,
499 SCM interval_seconds
, SCM interval_microseconds
,
500 SCM value_seconds
, SCM value_microseconds
),
501 "Set the timer specified by @var{which_timer} according to the given\n"
502 "@var{interval_seconds}, @var{interval_microseconds},\n"
503 "@var{value_seconds}, and @var{value_microseconds} values.\n"
505 "Return information about the timer's previous setting."
507 "Errors are handled as described in the guile info pages under ``POSIX\n"
508 "Interface Conventions''.\n"
510 "The timers available are: @code{ITIMER_REAL}, @code{ITIMER_VIRTUAL},\n"
511 "and @code{ITIMER_PROF}.\n"
513 "The return value will be a list of two cons pairs representing the\n"
514 "current state of the given timer. The first pair is the seconds and\n"
515 "microseconds of the timer @code{it_interval}, and the second pair is\n"
516 "the seconds and microseconds of the timer @code{it_value}.")
517 #define FUNC_NAME s_scm_setitimer
521 struct itimerval new_timer
;
522 struct itimerval old_timer
;
524 c_which_timer
= SCM_NUM2INT(1, which_timer
);
525 new_timer
.it_interval
.tv_sec
= SCM_NUM2LONG(2, interval_seconds
);
526 new_timer
.it_interval
.tv_usec
= SCM_NUM2LONG(3, interval_microseconds
);
527 new_timer
.it_value
.tv_sec
= SCM_NUM2LONG(4, value_seconds
);
528 new_timer
.it_value
.tv_usec
= SCM_NUM2LONG(5, value_microseconds
);
530 SCM_SYSCALL(rv
= setitimer(c_which_timer
, &new_timer
, &old_timer
));
535 return scm_list_2 (scm_cons (scm_from_long (old_timer
.it_interval
.tv_sec
),
536 scm_from_long (old_timer
.it_interval
.tv_usec
)),
537 scm_cons (scm_from_long (old_timer
.it_value
.tv_sec
),
538 scm_from_long (old_timer
.it_value
.tv_usec
)));
541 #endif /* HAVE_SETITIMER */
543 #ifdef HAVE_GETITIMER
544 SCM_DEFINE (scm_getitimer
, "getitimer", 1, 0, 0,
546 "Return information about the timer specified by @var{which_timer}"
548 "Errors are handled as described in the guile info pages under ``POSIX\n"
549 "Interface Conventions''.\n"
551 "The timers available are: @code{ITIMER_REAL}, @code{ITIMER_VIRTUAL},\n"
552 "and @code{ITIMER_PROF}.\n"
554 "The return value will be a list of two cons pairs representing the\n"
555 "current state of the given timer. The first pair is the seconds and\n"
556 "microseconds of the timer @code{it_interval}, and the second pair is\n"
557 "the seconds and microseconds of the timer @code{it_value}.")
558 #define FUNC_NAME s_scm_getitimer
562 struct itimerval old_timer
;
564 c_which_timer
= SCM_NUM2INT(1, which_timer
);
566 SCM_SYSCALL(rv
= getitimer(c_which_timer
, &old_timer
));
571 return scm_list_2 (scm_cons (scm_from_long (old_timer
.it_interval
.tv_sec
),
572 scm_from_long (old_timer
.it_interval
.tv_usec
)),
573 scm_cons (scm_from_long (old_timer
.it_value
.tv_sec
),
574 scm_from_long (old_timer
.it_value
.tv_usec
)));
577 #endif /* HAVE_GETITIMER */
580 SCM_DEFINE (scm_pause
, "pause", 0, 0, 0,
582 "Pause the current process (thread?) until a signal arrives whose\n"
583 "action is to either terminate the current process or invoke a\n"
584 "handler procedure. The return value is unspecified.")
585 #define FUNC_NAME s_scm_pause
588 return SCM_UNSPECIFIED
;
593 SCM_DEFINE (scm_sleep
, "sleep", 1, 0, 0,
595 "Wait for the given number of seconds (an integer) or until a signal\n"
596 "arrives. The return value is zero if the time elapses or the number\n"
597 "of seconds remaining otherwise.")
598 #define FUNC_NAME s_scm_sleep
600 return scm_from_uint (scm_std_sleep (scm_to_uint (i
)));
604 SCM_DEFINE (scm_usleep
, "usleep", 1, 0, 0,
606 "Sleep for @var{i} microseconds.")
607 #define FUNC_NAME s_scm_usleep
609 return scm_from_ulong (scm_std_usleep (scm_to_ulong (i
)));
613 SCM_DEFINE (scm_raise
, "raise", 1, 0, 0,
615 "Sends a specified signal @var{sig} to the current process, where\n"
616 "@var{sig} is as described for the kill procedure.")
617 #define FUNC_NAME s_scm_raise
619 if (kill (getpid (), scm_to_int (sig
)) != 0)
621 return SCM_UNSPECIFIED
;
633 SCM_VARIABLE_LOC (scm_c_define ("signal-handlers",
634 scm_c_make_vector (NSIG
, SCM_BOOL_F
)));
635 signal_handler_asyncs
=
636 scm_permanent_object (scm_c_make_vector (NSIG
, SCM_BOOL_F
));
637 signal_handler_threads
=
638 scm_permanent_object (scm_c_make_vector (NSIG
, SCM_BOOL_F
));
640 for (i
= 0; i
< NSIG
; i
++)
642 #ifdef HAVE_SIGACTION
643 orig_handlers
[i
].sa_handler
= SIG_ERR
;
646 orig_handlers
[i
] = SIG_ERR
;
649 #ifdef HAVE_RESTARTABLE_SYSCALLS
650 /* If HAVE_RESTARTABLE_SYSCALLS is defined, it's important that
651 signals really are restartable. don't rely on the same
652 run-time that configure got: reset the default for every signal.
654 #ifdef HAVE_SIGINTERRUPT
656 #elif defined(SA_RESTART)
658 struct sigaction action
;
660 sigaction (i
, NULL
, &action
);
661 if (!(action
.sa_flags
& SA_RESTART
))
663 action
.sa_flags
|= SA_RESTART
;
664 sigaction (i
, &action
, NULL
);
668 /* if neither siginterrupt nor SA_RESTART are available we may
669 as well assume that signals are always restartable. */
673 scm_c_define ("NSIG", scm_from_long (NSIG
));
674 scm_c_define ("SIG_IGN", scm_from_long ((long) SIG_IGN
));
675 scm_c_define ("SIG_DFL", scm_from_long ((long) SIG_DFL
));
677 scm_c_define ("SA_NOCLDSTOP", scm_from_long (SA_NOCLDSTOP
));
680 scm_c_define ("SA_RESTART", scm_from_long (SA_RESTART
));
683 #if defined(HAVE_SETITIMER) || defined(HAVE_GETITIMER)
684 /* Stuff needed by setitimer and getitimer. */
685 scm_c_define ("ITIMER_REAL", scm_from_int (ITIMER_REAL
));
686 scm_c_define ("ITIMER_VIRTUAL", scm_from_int (ITIMER_VIRTUAL
));
687 scm_c_define ("ITIMER_PROF", scm_from_int (ITIMER_PROF
));
688 #endif /* defined(HAVE_SETITIMER) || defined(HAVE_GETITIMER) */
690 #include "libguile/scmsigs.x"