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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
28 #include "libguile/_scm.h"
30 #include "libguile/async.h"
31 #include "libguile/eval.h"
32 #include "libguile/root.h"
33 #include "libguile/vectors.h"
35 #include "libguile/validate.h"
36 #include "libguile/scmsigs.h"
42 #ifdef HAVE_SYS_TIME_H
48 #define alarm(sec) (0)
49 /* This weird comma expression is because Sleep is void under Windows. */
50 #define sleep(sec) (Sleep ((sec) * 1000), 0)
51 #define usleep(usec) (Sleep ((usec) / 1000), 0)
52 #define kill(pid, sig) raise (sig)
57 /* SIGRETTYPE is the type that signal handlers return. See <signal.h> */
60 # define SIGRETTYPE RETSIGTYPE
63 # define SIGRETTYPE void
65 # define SIGRETTYPE int
71 /* take_signal is installed as the C signal handler whenever a Scheme
72 handler is set. when a signal arrives, take_signal will queue the
73 Scheme handler procedure for its thread. */
76 /* Scheme vectors with information about a signal. signal_handlers
77 contains the handler procedure or #f, signal_handler_cells contains
78 pre-queued cells for the handler (since we can't do fancy things
79 during signal delivery), signal_cell_handlers contains the SCM
80 value to be stuffed into the pre-queued cell upon delivery, and
81 signal_handler_threads points to the thread that a signal should be
84 static SCM
*signal_handlers
;
85 static SCM signal_handler_cells
;
86 static SCM signal_cell_handlers
;
87 static SCM signal_handler_threads
;
89 /* saves the original C handlers, when a new handler is installed.
90 set to SIG_ERR if the original handler is installed. */
92 static struct sigaction orig_handlers
[NSIG
];
94 static SIGRETTYPE (*orig_handlers
[NSIG
])(int);
99 take_signal (int signum
)
101 if (signum
>= 0 && signum
< NSIG
)
103 SCM cell
= SCM_VECTOR_REF(signal_handler_cells
, signum
);
104 SCM handler
= SCM_VECTOR_REF(signal_cell_handlers
, signum
);
105 SCM thread
= SCM_VECTOR_REF(signal_handler_threads
, signum
);
106 scm_root_state
*root
= scm_i_thread_root (thread
);
107 if (scm_is_pair (cell
))
109 SCM_SETCAR (cell
, handler
);
110 root
->pending_asyncs
= 1;
114 #ifndef HAVE_SIGACTION
115 signal (signum
, take_signal
);
120 scm_sigaction (SCM signum
, SCM handler
, SCM flags
)
122 return scm_sigaction_for_thread (signum
, handler
, flags
, SCM_UNDEFINED
);
126 close_1 (SCM proc
, SCM arg
)
128 return scm_primitive_eval_x (scm_list_3 (scm_sym_lambda
, SCM_EOL
,
129 scm_list_2 (proc
, arg
)));
132 /* Make sure that signal SIGNUM can be delivered to THREAD, using
133 HANDLER. THREAD and HANDLER must either both be non-#f (which
134 means install the handler), or both #f (which means deinstall an
138 struct install_handler_data
{
145 scm_delq_spine_x (SCM cell
, SCM list
)
147 SCM s
= list
, prev
= SCM_BOOL_F
;
149 while (!scm_is_eq (cell
, s
))
156 if (scm_is_false (prev
))
157 return SCM_CDR (cell
);
160 SCM_SETCDR (prev
, SCM_CDR (cell
));
166 really_install_handler (void *data
)
168 struct install_handler_data
*args
= data
;
169 int signum
= args
->signum
;
170 SCM thread
= args
->thread
;
171 SCM handler
= args
->handler
;
175 /* The following modifications are done while signals can be
176 delivered. That is not a real problem since the signal handler
177 will only touch the car of the handler cell and set the
178 pending_asyncs trigger of a thread. While the data structures
179 are in flux, the signal handler might store the wrong handler in
180 the cell, or set pending_asyncs of the wrong thread. We fix this
181 at the end by making sure that the cell has the right handler in
182 it, if any, and that pending_asyncs is set for the new thread.
185 /* Make sure we have a cell. */
186 cell
= SCM_VECTOR_REF (signal_handler_cells
, signum
);
187 if (scm_is_false (cell
))
189 cell
= scm_cons (SCM_BOOL_F
, SCM_EOL
);
190 SCM_VECTOR_SET (signal_handler_cells
, signum
, cell
);
193 /* Make sure it is queued for the right thread. */
194 old_thread
= SCM_VECTOR_REF (signal_handler_threads
, signum
);
195 if (!scm_is_eq (thread
, old_thread
))
198 if (scm_is_true (old_thread
))
200 r
= scm_i_thread_root (old_thread
);
201 r
->signal_asyncs
= scm_delq_spine_x (cell
, r
->signal_asyncs
);
203 if (scm_is_true (thread
))
205 r
= scm_i_thread_root (thread
);
206 SCM_SETCDR (cell
, r
->signal_asyncs
);
207 r
->signal_asyncs
= cell
;
208 /* Set pending_asyncs just in case. A signal that is
209 delivered while we modify the data structures here might set
210 pending_asyncs of old_thread. */
211 r
->pending_asyncs
= 1;
213 SCM_VECTOR_SET (signal_handler_threads
, signum
, thread
);
216 /* Set the new handler. */
217 if (scm_is_false (handler
))
219 SCM_VECTOR_SET (*signal_handlers
, signum
, SCM_BOOL_F
);
220 SCM_VECTOR_SET (signal_cell_handlers
, signum
, SCM_BOOL_F
);
224 SCM_VECTOR_SET (*signal_handlers
, signum
, handler
);
225 SCM_VECTOR_SET (signal_cell_handlers
, signum
,
226 close_1 (handler
, scm_from_int (signum
)));
229 /* Now fix up the cell. It might contain the old handler but since
230 it is now queued for the new thread, we must make sure that the
231 new handler is run. Any signal that is delivered during the
232 following code will install the new handler, so we have no
235 if (scm_is_true (SCM_CAR (cell
)))
236 SCM_SETCAR (cell
, SCM_VECTOR_REF (signal_cell_handlers
, signum
));
238 /* Phfew. That should be it. */
243 install_handler (int signum
, SCM thread
, SCM handler
)
245 /* We block asyncs while installing the handler. It would be safe
246 to leave them on, but we might run the wrong handler should a
250 struct install_handler_data args
;
251 args
.signum
= signum
;
252 args
.thread
= thread
;
253 args
.handler
= handler
;
254 scm_c_call_with_blocked_asyncs (really_install_handler
, &args
);
257 /* user interface for installation of signal handlers. */
258 SCM_DEFINE (scm_sigaction_for_thread
, "sigaction", 1, 3, 0,
259 (SCM signum
, SCM handler
, SCM flags
, SCM thread
),
260 "Install or report the signal handler for a specified signal.\n\n"
261 "@var{signum} is the signal number, which can be specified using the value\n"
262 "of variables such as @code{SIGINT}.\n\n"
263 "If @var{handler} is omitted, @code{sigaction} returns a pair: the\n"
264 "CAR is the current\n"
265 "signal hander, which will be either an integer with the value @code{SIG_DFL}\n"
266 "(default action) or @code{SIG_IGN} (ignore), or the Scheme procedure which\n"
267 "handles the signal, or @code{#f} if a non-Scheme procedure handles the\n"
268 "signal. The CDR contains the current @code{sigaction} flags for the handler.\n\n"
269 "If @var{handler} is provided, it is installed as the new handler for\n"
270 "@var{signum}. @var{handler} can be a Scheme procedure taking one\n"
271 "argument, or the value of @code{SIG_DFL} (default action) or\n"
272 "@code{SIG_IGN} (ignore), or @code{#f} to restore whatever signal handler\n"
273 "was installed before @code{sigaction} was first used. When\n"
274 "a scheme procedure has been specified, that procedure will run\n"
275 "in the given @var{thread}. When no thread has been given, the\n"
276 "thread that made this call to @code{sigaction} is used.\n"
278 "optionally be specified for the new handler (@code{SA_RESTART} will\n"
279 "always be added if it's available and the system is using restartable\n"
280 "system calls.) The return value is a pair with information about the\n"
281 "old handler as described above.\n\n"
282 "This interface does not provide access to the \"signal blocking\"\n"
283 "facility. Maybe this is not needed, since the thread support may\n"
284 "provide solutions to the problem of consistent access to data\n"
286 #define FUNC_NAME s_scm_sigaction_for_thread
289 #ifdef HAVE_SIGACTION
290 struct sigaction action
;
291 struct sigaction old_action
;
293 SIGRETTYPE (* chandler
) (int) = SIG_DFL
;
294 SIGRETTYPE (* old_chandler
) (int);
297 int save_handler
= 0;
301 csig
= scm_to_signed_integer (signum
, 0, NSIG
-1);
303 #if defined(HAVE_SIGACTION)
304 #if defined(SA_RESTART) && defined(HAVE_RESTARTABLE_SYSCALLS)
305 /* don't allow SA_RESTART to be omitted if HAVE_RESTARTABLE_SYSCALLS
306 is defined, since libguile would be likely to produce spurious
308 action
.sa_flags
= SA_RESTART
;
312 if (!SCM_UNBNDP (flags
))
313 action
.sa_flags
|= scm_to_int (flags
);
314 sigemptyset (&action
.sa_mask
);
317 if (SCM_UNBNDP (thread
))
318 thread
= scm_current_thread ();
321 SCM_VALIDATE_THREAD (4, thread
);
322 if (scm_c_thread_exited_p (thread
))
323 SCM_MISC_ERROR ("thread has already exited", SCM_EOL
);
327 old_handler
= SCM_VECTOR_REF(*signal_handlers
, csig
);
328 if (SCM_UNBNDP (handler
))
330 else if (scm_is_integer (handler
))
332 if (SCM_NUM2LONG (2, handler
) == (long) SIG_DFL
333 || SCM_NUM2LONG (2, handler
) == (long) SIG_IGN
)
335 #ifdef HAVE_SIGACTION
336 action
.sa_handler
= (SIGRETTYPE (*) (int)) scm_to_int (handler
);
338 chandler
= (SIGRETTYPE (*) (int)) scm_to_int (handler
);
340 install_handler (csig
, SCM_BOOL_F
, SCM_BOOL_F
);
343 SCM_OUT_OF_RANGE (2, handler
);
345 else if (scm_is_false (handler
))
347 /* restore the default handler. */
348 #ifdef HAVE_SIGACTION
349 if (orig_handlers
[csig
].sa_handler
== SIG_ERR
)
353 action
= orig_handlers
[csig
];
354 orig_handlers
[csig
].sa_handler
= SIG_ERR
;
355 install_handler (csig
, SCM_BOOL_F
, SCM_BOOL_F
);
358 if (orig_handlers
[csig
] == SIG_ERR
)
362 chandler
= orig_handlers
[csig
];
363 orig_handlers
[csig
] = SIG_ERR
;
364 install_handler (csig
, SCM_BOOL_F
, SCM_BOOL_F
);
370 SCM_VALIDATE_PROC (2, handler
);
371 #ifdef HAVE_SIGACTION
372 action
.sa_handler
= take_signal
;
373 if (orig_handlers
[csig
].sa_handler
== SIG_ERR
)
376 chandler
= take_signal
;
377 if (orig_handlers
[csig
] == SIG_ERR
)
380 install_handler (csig
, thread
, handler
);
383 /* XXX - Silently ignore setting handlers for `program error signals'
384 because they can't currently be handled by Scheme code.
389 /* This list of program error signals is from the GNU Libc
398 #if defined(SIGIOT) && (SIGIOT != SIGABRT)
413 #ifdef HAVE_SIGACTION
416 if (sigaction (csig
, 0, &old_action
) == -1)
421 if (sigaction (csig
, &action
, &old_action
) == -1)
424 orig_handlers
[csig
] = old_action
;
426 if (old_action
.sa_handler
== SIG_DFL
|| old_action
.sa_handler
== SIG_IGN
)
427 old_handler
= scm_from_long ((long) old_action
.sa_handler
);
429 return scm_cons (old_handler
, scm_from_int (old_action
.sa_flags
));
433 if ((old_chandler
= signal (csig
, SIG_IGN
)) == SIG_ERR
)
435 if (signal (csig
, old_chandler
) == SIG_ERR
)
440 if ((old_chandler
= signal (csig
, chandler
)) == SIG_ERR
)
443 orig_handlers
[csig
] = old_chandler
;
445 if (old_chandler
== SIG_DFL
|| old_chandler
== SIG_IGN
)
446 old_handler
= scm_from_long ((long) old_chandler
);
448 return scm_cons (old_handler
, scm_from_int (0));
453 SCM_DEFINE (scm_restore_signals
, "restore-signals", 0, 0, 0,
455 "Return all signal handlers to the values they had before any call to\n"
456 "@code{sigaction} was made. The return value is unspecified.")
457 #define FUNC_NAME s_scm_restore_signals
460 for (i
= 0; i
< NSIG
; i
++)
462 #ifdef HAVE_SIGACTION
463 if (orig_handlers
[i
].sa_handler
!= SIG_ERR
)
465 if (sigaction (i
, &orig_handlers
[i
], NULL
) == -1)
467 orig_handlers
[i
].sa_handler
= SIG_ERR
;
468 SCM_VECTOR_SET (*signal_handlers
, i
, SCM_BOOL_F
);
471 if (orig_handlers
[i
] != SIG_ERR
)
473 if (signal (i
, orig_handlers
[i
]) == SIG_ERR
)
475 orig_handlers
[i
] = SIG_ERR
;
476 SCM_VECTOR_SET (*signal_handlers
, i
, SCM_BOOL_F
);
480 return SCM_UNSPECIFIED
;
484 SCM_DEFINE (scm_alarm
, "alarm", 1, 0, 0,
486 "Set a timer to raise a @code{SIGALRM} signal after the specified\n"
487 "number of seconds (an integer). It's advisable to install a signal\n"
489 "@code{SIGALRM} beforehand, since the default action is to terminate\n"
491 "The return value indicates the time remaining for the previous alarm,\n"
492 "if any. The new value replaces the previous alarm. If there was\n"
493 "no previous alarm, the return value is zero.")
494 #define FUNC_NAME s_scm_alarm
496 return scm_from_uint (alarm (scm_to_uint (i
)));
500 #ifdef HAVE_SETITIMER
501 SCM_DEFINE (scm_setitimer
, "setitimer", 5, 0, 0,
503 SCM interval_seconds
, SCM interval_microseconds
,
504 SCM value_seconds
, SCM value_microseconds
),
505 "Set the timer specified by @var{which_timer} according to the given\n"
506 "@var{interval_seconds}, @var{interval_microseconds},\n"
507 "@var{value_seconds}, and @var{value_microseconds} values.\n"
509 "Return information about the timer's previous setting."
511 "Errors are handled as described in the guile info pages under ``POSIX\n"
512 "Interface Conventions''.\n"
514 "The timers available are: @code{ITIMER_REAL}, @code{ITIMER_VIRTUAL},\n"
515 "and @code{ITIMER_PROF}.\n"
517 "The return value will be a list of two cons pairs representing the\n"
518 "current state of the given timer. The first pair is the seconds and\n"
519 "microseconds of the timer @code{it_interval}, and the second pair is\n"
520 "the seconds and microseconds of the timer @code{it_value}.")
521 #define FUNC_NAME s_scm_setitimer
525 struct itimerval new_timer
;
526 struct itimerval old_timer
;
528 c_which_timer
= SCM_NUM2INT(1, which_timer
);
529 new_timer
.it_interval
.tv_sec
= SCM_NUM2LONG(2, interval_seconds
);
530 new_timer
.it_interval
.tv_usec
= SCM_NUM2LONG(3, interval_microseconds
);
531 new_timer
.it_value
.tv_sec
= SCM_NUM2LONG(4, value_seconds
);
532 new_timer
.it_value
.tv_usec
= SCM_NUM2LONG(5, value_microseconds
);
534 SCM_SYSCALL(rv
= setitimer(c_which_timer
, &new_timer
, &old_timer
));
539 return scm_list_2 (scm_cons (scm_from_long (old_timer
.it_interval
.tv_sec
),
540 scm_from_long (old_timer
.it_interval
.tv_usec
)),
541 scm_cons (scm_from_long (old_timer
.it_value
.tv_sec
),
542 scm_from_long (old_timer
.it_value
.tv_usec
)));
545 #endif /* HAVE_SETITIMER */
547 #ifdef HAVE_GETITIMER
548 SCM_DEFINE (scm_getitimer
, "getitimer", 1, 0, 0,
550 "Return information about the timer specified by @var{which_timer}"
552 "Errors are handled as described in the guile info pages under ``POSIX\n"
553 "Interface Conventions''.\n"
555 "The timers available are: @code{ITIMER_REAL}, @code{ITIMER_VIRTUAL},\n"
556 "and @code{ITIMER_PROF}.\n"
558 "The return value will be a list of two cons pairs representing the\n"
559 "current state of the given timer. The first pair is the seconds and\n"
560 "microseconds of the timer @code{it_interval}, and the second pair is\n"
561 "the seconds and microseconds of the timer @code{it_value}.")
562 #define FUNC_NAME s_scm_getitimer
566 struct itimerval old_timer
;
568 c_which_timer
= SCM_NUM2INT(1, which_timer
);
570 SCM_SYSCALL(rv
= getitimer(c_which_timer
, &old_timer
));
575 return scm_list_2 (scm_cons (scm_from_long (old_timer
.it_interval
.tv_sec
),
576 scm_from_long (old_timer
.it_interval
.tv_usec
)),
577 scm_cons (scm_from_long (old_timer
.it_value
.tv_sec
),
578 scm_from_long (old_timer
.it_value
.tv_usec
)));
581 #endif /* HAVE_GETITIMER */
584 SCM_DEFINE (scm_pause
, "pause", 0, 0, 0,
586 "Pause the current process (thread?) until a signal arrives whose\n"
587 "action is to either terminate the current process or invoke a\n"
588 "handler procedure. The return value is unspecified.")
589 #define FUNC_NAME s_scm_pause
592 return SCM_UNSPECIFIED
;
597 SCM_DEFINE (scm_sleep
, "sleep", 1, 0, 0,
599 "Wait for the given number of seconds (an integer) or until a signal\n"
600 "arrives. The return value is zero if the time elapses or the number\n"
601 "of seconds remaining otherwise.")
602 #define FUNC_NAME s_scm_sleep
604 return scm_from_ulong (scm_thread_sleep (scm_to_int (i
)));
608 SCM_DEFINE (scm_usleep
, "usleep", 1, 0, 0,
610 "Sleep for @var{i} microseconds.")
611 #define FUNC_NAME s_scm_usleep
613 return scm_from_ulong (scm_thread_usleep (scm_to_ulong (i
)));
617 SCM_DEFINE (scm_raise
, "raise", 1, 0, 0,
619 "Sends a specified signal @var{sig} to the current process, where\n"
620 "@var{sig} is as described for the kill procedure.")
621 #define FUNC_NAME s_scm_raise
623 if (kill (getpid (), scm_to_int (sig
)) != 0)
625 return SCM_UNSPECIFIED
;
637 SCM_VARIABLE_LOC (scm_c_define ("signal-handlers",
638 scm_c_make_vector (NSIG
, SCM_BOOL_F
)));
639 signal_handler_cells
=
640 scm_permanent_object (scm_c_make_vector (NSIG
, SCM_BOOL_F
));
641 signal_cell_handlers
=
642 scm_permanent_object (scm_c_make_vector (NSIG
, SCM_BOOL_F
));
643 signal_handler_threads
=
644 scm_permanent_object (scm_c_make_vector (NSIG
, SCM_BOOL_F
));
646 for (i
= 0; i
< NSIG
; i
++)
648 #ifdef HAVE_SIGACTION
649 orig_handlers
[i
].sa_handler
= SIG_ERR
;
652 orig_handlers
[i
] = SIG_ERR
;
655 #ifdef HAVE_RESTARTABLE_SYSCALLS
656 /* If HAVE_RESTARTABLE_SYSCALLS is defined, it's important that
657 signals really are restartable. don't rely on the same
658 run-time that configure got: reset the default for every signal.
660 #ifdef HAVE_SIGINTERRUPT
662 #elif defined(SA_RESTART)
664 struct sigaction action
;
666 sigaction (i
, NULL
, &action
);
667 if (!(action
.sa_flags
& SA_RESTART
))
669 action
.sa_flags
|= SA_RESTART
;
670 sigaction (i
, &action
, NULL
);
674 /* if neither siginterrupt nor SA_RESTART are available we may
675 as well assume that signals are always restartable. */
679 scm_c_define ("NSIG", scm_from_long (NSIG
));
680 scm_c_define ("SIG_IGN", scm_from_long ((long) SIG_IGN
));
681 scm_c_define ("SIG_DFL", scm_from_long ((long) SIG_DFL
));
683 scm_c_define ("SA_NOCLDSTOP", scm_from_long (SA_NOCLDSTOP
));
686 scm_c_define ("SA_RESTART", scm_from_long (SA_RESTART
));
689 #if defined(HAVE_SETITIMER) || defined(HAVE_GETITIMER)
690 /* Stuff needed by setitimer and getitimer. */
691 scm_c_define ("ITIMER_REAL", scm_from_int (ITIMER_REAL
));
692 scm_c_define ("ITIMER_VIRTUAL", scm_from_int (ITIMER_VIRTUAL
));
693 scm_c_define ("ITIMER_PROF", scm_from_int (ITIMER_PROF
));
694 #endif /* defined(HAVE_SETITIMER) || defined(HAVE_GETITIMER) */
696 #include "libguile/scmsigs.x"