1 /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002 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_CONSP (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_EQ_P (cell
, s
))
156 if (SCM_FALSEP (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_FALSEP (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_EQ_P (thread
, old_thread
))
198 if (!SCM_FALSEP (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_FALSEP (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_FALSEP (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_int2num (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_FALSEP (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 SCM_VALIDATE_INUM_COPY (1, signum
, csig
);
302 if (csig
< 0 || csig
> NSIG
)
303 SCM_OUT_OF_RANGE (1, signum
);
304 #if defined(HAVE_SIGACTION)
305 #if defined(SA_RESTART) && defined(HAVE_RESTARTABLE_SYSCALLS)
306 /* don't allow SA_RESTART to be omitted if HAVE_RESTARTABLE_SYSCALLS
307 is defined, since libguile would be likely to produce spurious
309 action
.sa_flags
= SA_RESTART
;
313 if (!SCM_UNBNDP (flags
))
315 SCM_VALIDATE_INUM (3, flags
);
316 action
.sa_flags
|= SCM_INUM (flags
);
318 sigemptyset (&action
.sa_mask
);
321 if (SCM_UNBNDP (thread
))
322 thread
= scm_current_thread ();
325 SCM_VALIDATE_THREAD (4, thread
);
326 if (scm_c_thread_exited_p (thread
))
327 SCM_MISC_ERROR ("thread has already exited", SCM_EOL
);
331 old_handler
= SCM_VECTOR_REF(*signal_handlers
, csig
);
332 if (SCM_UNBNDP (handler
))
334 else if (SCM_EQ_P (scm_integer_p (handler
), SCM_BOOL_T
))
336 if (SCM_NUM2LONG (2, handler
) == (long) SIG_DFL
337 || SCM_NUM2LONG (2, handler
) == (long) SIG_IGN
)
339 #ifdef HAVE_SIGACTION
340 action
.sa_handler
= (SIGRETTYPE (*) (int)) SCM_INUM (handler
);
342 chandler
= (SIGRETTYPE (*) (int)) SCM_INUM (handler
);
344 install_handler (csig
, SCM_BOOL_F
, SCM_BOOL_F
);
347 SCM_OUT_OF_RANGE (2, handler
);
349 else if (SCM_FALSEP (handler
))
351 /* restore the default handler. */
352 #ifdef HAVE_SIGACTION
353 if (orig_handlers
[csig
].sa_handler
== SIG_ERR
)
357 action
= orig_handlers
[csig
];
358 orig_handlers
[csig
].sa_handler
= SIG_ERR
;
359 install_handler (csig
, SCM_BOOL_F
, SCM_BOOL_F
);
362 if (orig_handlers
[csig
] == SIG_ERR
)
366 chandler
= orig_handlers
[csig
];
367 orig_handlers
[csig
] = SIG_ERR
;
368 install_handler (csig
, SCM_BOOL_F
, SCM_BOOL_F
);
374 SCM_VALIDATE_NIM (2, handler
);
375 #ifdef HAVE_SIGACTION
376 action
.sa_handler
= take_signal
;
377 if (orig_handlers
[csig
].sa_handler
== SIG_ERR
)
380 chandler
= take_signal
;
381 if (orig_handlers
[csig
] == SIG_ERR
)
384 install_handler (csig
, thread
, handler
);
387 /* XXX - Silently ignore setting handlers for `program error signals'
388 because they can't currently be handled by Scheme code.
393 /* This list of program error signals is from the GNU Libc
402 #if defined(SIGIOT) && (SIGIOT != SIGABRT)
417 #ifdef HAVE_SIGACTION
420 if (sigaction (csig
, 0, &old_action
) == -1)
425 if (sigaction (csig
, &action
, &old_action
) == -1)
428 orig_handlers
[csig
] = old_action
;
430 if (old_action
.sa_handler
== SIG_DFL
|| old_action
.sa_handler
== SIG_IGN
)
431 old_handler
= scm_long2num ((long) old_action
.sa_handler
);
433 return scm_cons (old_handler
, SCM_MAKINUM (old_action
.sa_flags
));
437 if ((old_chandler
= signal (csig
, SIG_IGN
)) == SIG_ERR
)
439 if (signal (csig
, old_chandler
) == SIG_ERR
)
444 if ((old_chandler
= signal (csig
, chandler
)) == SIG_ERR
)
447 orig_handlers
[csig
] = old_chandler
;
449 if (old_chandler
== SIG_DFL
|| old_chandler
== SIG_IGN
)
450 old_handler
= scm_long2num ((long) old_chandler
);
452 return scm_cons (old_handler
, SCM_MAKINUM (0));
457 SCM_DEFINE (scm_restore_signals
, "restore-signals", 0, 0, 0,
459 "Return all signal handlers to the values they had before any call to\n"
460 "@code{sigaction} was made. The return value is unspecified.")
461 #define FUNC_NAME s_scm_restore_signals
464 for (i
= 0; i
< NSIG
; i
++)
466 #ifdef HAVE_SIGACTION
467 if (orig_handlers
[i
].sa_handler
!= SIG_ERR
)
469 if (sigaction (i
, &orig_handlers
[i
], NULL
) == -1)
471 orig_handlers
[i
].sa_handler
= SIG_ERR
;
472 SCM_VECTOR_SET (*signal_handlers
, i
, SCM_BOOL_F
);
475 if (orig_handlers
[i
] != SIG_ERR
)
477 if (signal (i
, orig_handlers
[i
]) == SIG_ERR
)
479 orig_handlers
[i
] = SIG_ERR
;
480 SCM_VECTOR_SET (*signal_handlers
, i
, SCM_BOOL_F
);
484 return SCM_UNSPECIFIED
;
488 SCM_DEFINE (scm_alarm
, "alarm", 1, 0, 0,
490 "Set a timer to raise a @code{SIGALRM} signal after the specified\n"
491 "number of seconds (an integer). It's advisable to install a signal\n"
493 "@code{SIGALRM} beforehand, since the default action is to terminate\n"
495 "The return value indicates the time remaining for the previous alarm,\n"
496 "if any. The new value replaces the previous alarm. If there was\n"
497 "no previous alarm, the return value is zero.")
498 #define FUNC_NAME s_scm_alarm
501 SCM_VALIDATE_INUM (1, i
);
502 j
= alarm (SCM_INUM (i
));
503 return SCM_MAKINUM (j
);
507 #ifdef HAVE_SETITIMER
508 SCM_DEFINE (scm_setitimer
, "setitimer", 5, 0, 0,
510 SCM interval_seconds
, SCM interval_microseconds
,
511 SCM value_seconds
, SCM value_microseconds
),
512 "Set the timer specified by @var{which_timer} according to the given\n"
513 "@var{interval_seconds}, @var{interval_microseconds},\n"
514 "@var{value_seconds}, and @var{value_microseconds} values.\n"
516 "Return information about the timer's previous setting."
518 "Errors are handled as described in the guile info pages under ``POSIX\n"
519 "Interface Conventions''.\n"
521 "The timers available are: @code{ITIMER_REAL}, @code{ITIMER_VIRTUAL},\n"
522 "and @code{ITIMER_PROF}.\n"
524 "The return value will be a list of two cons pairs representing the\n"
525 "current state of the given timer. The first pair is the seconds and\n"
526 "microseconds of the timer @code{it_interval}, and the second pair is\n"
527 "the seconds and microseconds of the timer @code{it_value}.")
528 #define FUNC_NAME s_scm_setitimer
532 struct itimerval new_timer
;
533 struct itimerval old_timer
;
535 c_which_timer
= SCM_NUM2INT(1, which_timer
);
536 new_timer
.it_interval
.tv_sec
= SCM_NUM2LONG(2, interval_seconds
);
537 new_timer
.it_interval
.tv_usec
= SCM_NUM2LONG(3, interval_microseconds
);
538 new_timer
.it_value
.tv_sec
= SCM_NUM2LONG(4, value_seconds
);
539 new_timer
.it_value
.tv_usec
= SCM_NUM2LONG(5, value_microseconds
);
541 SCM_SYSCALL(rv
= setitimer(c_which_timer
, &new_timer
, &old_timer
));
546 return scm_list_2(scm_cons(scm_long2num(old_timer
.it_interval
.tv_sec
),
547 scm_long2num(old_timer
.it_interval
.tv_usec
)),
548 scm_cons(scm_long2num(old_timer
.it_value
.tv_sec
),
549 scm_long2num(old_timer
.it_value
.tv_usec
)));
552 #endif /* HAVE_SETITIMER */
554 #ifdef HAVE_GETITIMER
555 SCM_DEFINE (scm_getitimer
, "getitimer", 1, 0, 0,
557 "Return information about the timer specified by @var{which_timer}"
559 "Errors are handled as described in the guile info pages under ``POSIX\n"
560 "Interface Conventions''.\n"
562 "The timers available are: @code{ITIMER_REAL}, @code{ITIMER_VIRTUAL},\n"
563 "and @code{ITIMER_PROF}.\n"
565 "The return value will be a list of two cons pairs representing the\n"
566 "current state of the given timer. The first pair is the seconds and\n"
567 "microseconds of the timer @code{it_interval}, and the second pair is\n"
568 "the seconds and microseconds of the timer @code{it_value}.")
569 #define FUNC_NAME s_scm_getitimer
573 struct itimerval old_timer
;
575 c_which_timer
= SCM_NUM2INT(1, which_timer
);
577 SCM_SYSCALL(rv
= getitimer(c_which_timer
, &old_timer
));
582 return scm_list_2(scm_cons(scm_long2num(old_timer
.it_interval
.tv_sec
),
583 scm_long2num(old_timer
.it_interval
.tv_usec
)),
584 scm_cons(scm_long2num(old_timer
.it_value
.tv_sec
),
585 scm_long2num(old_timer
.it_value
.tv_usec
)));
588 #endif /* HAVE_GETITIMER */
591 SCM_DEFINE (scm_pause
, "pause", 0, 0, 0,
593 "Pause the current process (thread?) until a signal arrives whose\n"
594 "action is to either terminate the current process or invoke a\n"
595 "handler procedure. The return value is unspecified.")
596 #define FUNC_NAME s_scm_pause
599 return SCM_UNSPECIFIED
;
604 SCM_DEFINE (scm_sleep
, "sleep", 1, 0, 0,
606 "Wait for the given number of seconds (an integer) or until a signal\n"
607 "arrives. The return value is zero if the time elapses or the number\n"
608 "of seconds remaining otherwise.")
609 #define FUNC_NAME s_scm_sleep
612 SCM_VALIDATE_INUM_MIN (1, i
,0);
613 j
= scm_thread_sleep (SCM_INUM(i
));
614 return scm_ulong2num (j
);
618 SCM_DEFINE (scm_usleep
, "usleep", 1, 0, 0,
620 "Sleep for I microseconds. @code{usleep} is not available on\n"
622 #define FUNC_NAME s_scm_usleep
625 SCM_VALIDATE_INUM_MIN (1, i
,0);
626 j
= scm_thread_usleep (SCM_INUM (i
));
627 return scm_ulong2num (j
);
631 SCM_DEFINE (scm_raise
, "raise", 1, 0, 0,
633 "Sends a specified signal @var{sig} to the current process, where\n"
634 "@var{sig} is as described for the kill procedure.")
635 #define FUNC_NAME s_scm_raise
637 SCM_VALIDATE_INUM (1, sig
);
639 if (kill (getpid (), (int) SCM_INUM (sig
)) != 0)
642 return SCM_UNSPECIFIED
;
654 SCM_VARIABLE_LOC (scm_c_define ("signal-handlers",
655 scm_c_make_vector (NSIG
, SCM_BOOL_F
)));
656 signal_handler_cells
=
657 scm_permanent_object (scm_c_make_vector (NSIG
, SCM_BOOL_F
));
658 signal_cell_handlers
=
659 scm_permanent_object (scm_c_make_vector (NSIG
, SCM_BOOL_F
));
660 signal_handler_threads
=
661 scm_permanent_object (scm_c_make_vector (NSIG
, SCM_BOOL_F
));
663 for (i
= 0; i
< NSIG
; i
++)
665 #ifdef HAVE_SIGACTION
666 orig_handlers
[i
].sa_handler
= SIG_ERR
;
669 orig_handlers
[i
] = SIG_ERR
;
672 #ifdef HAVE_RESTARTABLE_SYSCALLS
673 /* If HAVE_RESTARTABLE_SYSCALLS is defined, it's important that
674 signals really are restartable. don't rely on the same
675 run-time that configure got: reset the default for every signal.
677 #ifdef HAVE_SIGINTERRUPT
679 #elif defined(SA_RESTART)
681 struct sigaction action
;
683 sigaction (i
, NULL
, &action
);
684 if (!(action
.sa_flags
& SA_RESTART
))
686 action
.sa_flags
|= SA_RESTART
;
687 sigaction (i
, &action
, NULL
);
691 /* if neither siginterrupt nor SA_RESTART are available we may
692 as well assume that signals are always restartable. */
696 scm_c_define ("NSIG", scm_long2num (NSIG
));
697 scm_c_define ("SIG_IGN", scm_long2num ((long) SIG_IGN
));
698 scm_c_define ("SIG_DFL", scm_long2num ((long) SIG_DFL
));
700 scm_c_define ("SA_NOCLDSTOP", scm_long2num (SA_NOCLDSTOP
));
703 scm_c_define ("SA_RESTART", scm_long2num (SA_RESTART
));
706 #if defined(HAVE_SETITIMER) || defined(HAVE_GETITIMER)
707 /* Stuff needed by setitimer and getitimer. */
708 scm_c_define ("ITIMER_REAL", SCM_MAKINUM (ITIMER_REAL
));
709 scm_c_define ("ITIMER_VIRTUAL", SCM_MAKINUM (ITIMER_VIRTUAL
));
710 scm_c_define ("ITIMER_PROF", SCM_MAKINUM (ITIMER_PROF
));
711 #endif /* defined(HAVE_SETITIMER) || defined(HAVE_GETITIMER) */
713 #include "libguile/scmsigs.x"