1 /* Copyright (C) 1995, 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 2, or (at your option)
8 * This program 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
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this software; see the file COPYING. If not, write to
15 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
16 * Boston, MA 02111-1307 USA
18 * As a special exception, the Free Software Foundation gives permission
19 * for additional uses of the text contained in its release of GUILE.
21 * The exception is that, if you link the GUILE library with other files
22 * to produce an executable, this does not by itself cause the
23 * resulting executable to be covered by the GNU General Public License.
24 * Your use of that executable is in no way restricted on account of
25 * linking the GUILE library code into it.
27 * This exception does not however invalidate any other reasons why
28 * the executable file might be covered by the GNU General Public License.
30 * This exception applies only to the code released by the
31 * Free Software Foundation under the name GUILE. If you copy
32 * code from other Free Software Foundation releases into a copy of
33 * GUILE, as the General Public License permits, the exception does
34 * not apply to the code that you add in this way. To avoid misleading
35 * anyone as to the status of such modified files, you must delete
36 * this exception notice from them.
38 * If you write modifications of your own for GUILE, it is your choice
39 * whether to permit this exception to apply to your modifications.
40 * If you do not wish that, delete this exception notice. */
55 /* The thread system has its own sleep and usleep functions. */
58 #if defined(MISSING_SLEEP_DECL)
62 #if defined(HAVE_USLEEP) && defined(MISSING_USLEEP_DECL)
70 #ifdef USE_MIT_PTHREADS
72 #define signal pthread_signal
77 /* SIGRETTYPE is the type that signal handlers return. See <signal.h> */
80 # define SIGRETTYPE RETSIGTYPE
83 # define SIGRETTYPE void
85 # define SIGRETTYPE int
91 /* take_signal is installed as the C signal handler whenever a Scheme
92 handler is set. when a signal arrives, take_signal marks the corresponding
93 element of got_signal and marks signal_async. the thunk in signal_async
94 (sys_deliver_signals) will be run at the next opportunity, outside a
95 critical section. sys_deliver_signals runs each Scheme handler for
96 which got_signal is set. */
98 static SCM signal_async
;
100 static char got_signal
[NSIG
];
102 /* a Scheme vector of handler procedures. */
103 static SCM
*signal_handlers
;
105 /* saves the original C handlers, when a new handler is installed.
106 set to SIG_ERR if the original handler is installed. */
107 #ifdef HAVE_SIGACTION
108 static struct sigaction orig_handlers
[NSIG
];
110 static SIGRETTYPE (*orig_handlers
)(int)[NSIG
];
114 take_signal (int signum
)
116 int saved_errno
= errno
;
118 if (!scm_ints_disabled
)
120 /* For reasons of speed, the SCM_NEWCELL macro doesn't defer
121 interrupts. Instead, it first sets its argument to point to
122 the first cell in the list, and then advances the freelist
123 pointer to the next cell. Now, if this procedure is
124 interrupted, the only anomalous state possible is to have
125 both SCM_NEWCELL's argument and scm_freelist pointing to the
126 same cell. To deal with this case, we always throw away the
127 first cell in scm_freelist here.
129 At least, that's the theory. I'm not convinced that that's
130 the only anomalous path we need to worry about. */
131 SCM_NEWCELL (ignored
);
133 got_signal
[signum
] = 1;
135 /* unblock the signal before the scheme handler gets to run, since
136 it may use longjmp to escape (i.e., throw an exception). */
140 sigaddset (&set
, signum
);
141 sigprocmask (SIG_UNBLOCK
, &set
, NULL
);
144 scm_system_async_mark (signal_async
);
149 sys_deliver_signals (void)
153 for (i
= 0; i
< NSIG
; i
++)
157 /* The flag is reset before calling the handler in case the
158 handler doesn't return. If the handler doesn't return
159 but leaves other signals flagged, they their handlers
160 will be applied some time later when the async is checked
161 again. It would probably be better to reset the flags
162 after doing a longjmp. */
164 #ifndef HAVE_SIGACTION
165 signal (i
, take_signal
);
167 scm_apply (SCM_VELTS (*signal_handlers
)[i
],
168 scm_listify (SCM_MAKINUM (i
), SCM_UNDEFINED
),
172 return SCM_UNSPECIFIED
;
175 /* user interface for installation of signal handlers. */
176 SCM_PROC(s_sigaction
, "sigaction", 1, 2, 0, scm_sigaction
);
178 scm_sigaction (SCM signum
, SCM handler
, SCM flags
)
181 #ifdef HAVE_SIGACTION
182 struct sigaction action
;
183 struct sigaction old_action
;
185 SIGRETTYPE (* chandler
) (int);
186 SIGRETTYPE (* old_chandler
) (int);
189 int save_handler
= 0;
190 SCM
*scheme_handlers
= SCM_VELTS (*signal_handlers
);
193 SCM_ASSERT (SCM_INUMP (signum
), signum
, SCM_ARG1
, s_sigaction
);
194 csig
= SCM_INUM (signum
);
195 #ifdef HAVE_SIGACTION
196 /* always use restartable system calls if available. */
198 action
.sa_flags
= SA_RESTART
;
202 if (!SCM_UNBNDP (flags
))
204 SCM_ASSERT (SCM_INUMP (flags
), flags
, SCM_ARG3
, s_sigaction
);
205 action
.sa_flags
|= SCM_INUM (flags
);
207 sigemptyset (&action
.sa_mask
);
210 old_handler
= scheme_handlers
[csig
];
211 if (SCM_UNBNDP (handler
))
213 else if (SCM_INUMP (handler
))
215 /* It's really ugly to assume that SIG_DFL can be nicely cast to
216 a fixnum. This has got to go. */
217 if (SCM_INUM (handler
) == (SCM
) SIG_DFL
218 || SCM_INUM (handler
) == (SCM
) SIG_IGN
)
220 #ifdef HAVE_SIGACTION
221 action
.sa_handler
= (SIGRETTYPE (*) (int)) SCM_INUM (handler
);
223 chandler
= (SIGRETTYPE (*) (int)) SCM_INUM (handler
);
225 scheme_handlers
[csig
] = SCM_BOOL_F
;
228 scm_out_of_range (s_sigaction
, handler
);
230 else if (SCM_FALSEP (handler
))
232 /* restore the default handler. */
233 #ifdef HAVE_SIGACTION
234 if (orig_handlers
[csig
].sa_handler
== SIG_ERR
)
238 action
= orig_handlers
[csig
];
239 orig_handlers
[csig
].sa_handler
= SIG_ERR
;
240 scheme_handlers
[csig
] = SCM_BOOL_F
;
243 if (orig_handlers
[csig
] == SIG_ERR
)
247 chandler
= orig_handlers
[csig
];
248 orig_handlers
[csig
] = SIG_ERR
;
249 scheme_handlers
[csig
] = SCM_BOOL_F
;
255 SCM_ASSERT (SCM_NIMP (handler
), handler
, SCM_ARG2
, s_sigaction
);
256 #ifdef HAVE_SIGACTION
257 action
.sa_handler
= take_signal
;
258 if (orig_handlers
[csig
].sa_handler
== SIG_ERR
)
261 chandler
= take_signal
;
262 if (orig_handlers
[csig
] == SIG_ERR
)
265 scheme_handlers
[csig
] = handler
;
267 #ifdef HAVE_SIGACTION
270 if (sigaction (csig
, 0, &old_action
) == -1)
271 scm_syserror (s_sigaction
);
275 if (sigaction (csig
, &action
, &old_action
) == -1)
276 scm_syserror (s_sigaction
);
278 orig_handlers
[csig
] = old_action
;
280 if (old_action
.sa_handler
== SIG_DFL
|| old_action
.sa_handler
== SIG_IGN
)
281 old_handler
= SCM_MAKINUM ((SCM
) old_action
.sa_handler
);
283 return scm_cons (old_handler
, SCM_MAKINUM (old_action
.sa_flags
));
287 if ((old_chandler
= signal (csig
, SIG_IGN
)) == SIG_ERR
)
288 scm_syserror (s_sigaction
);
289 if (signal (csig
, old_chandler
) == SIG_ERR
)
290 scm_syserror (s_sigaction
);
294 if ((old_chandler
= signal (csig
, chandler
)) == SIG_ERR
)
295 scm_syserror (s_sigaction
);
297 orig_handlers
[csig
] = old_chandler
;
299 if (old_chandler
== SIG_DFL
|| old_chandler
== SIG_IGN
)
300 old_handler
= SCM_MAKINUM ((int) old_chandler
);
302 return scm_cons (old_handler
, SCM_MAKINUM (0));
306 SCM_PROC (s_restore_signals
, "restore-signals", 0, 0, 0, scm_restore_signals
);
308 scm_restore_signals (void)
311 SCM
*scheme_handlers
= SCM_VELTS (*signal_handlers
);
313 for (i
= 0; i
< NSIG
; i
++)
315 #ifdef HAVE_SIGACTION
316 if (orig_handlers
[i
].sa_handler
!= SIG_ERR
)
318 if (sigaction (i
, &orig_handlers
[i
], NULL
) == -1)
319 scm_syserror (s_restore_signals
);
320 orig_handlers
[i
].sa_handler
= SIG_ERR
;
321 scheme_handlers
[i
] = SCM_BOOL_F
;
324 if (orig_handlers
[i
] != SIG_ERR
)
326 if (signal (i
, orig_handlers
[i
]) == SIG_ERR
)
327 scm_syserror (s_restore_signals
);
328 orig_handlers
[i
] = SIG_ERR
;
329 scheme_handlers
[i
] = SCM_BOOL_F
;
333 return SCM_UNSPECIFIED
;
336 SCM_PROC(s_alarm
, "alarm", 1, 0, 0, scm_alarm
);
343 SCM_ASSERT (SCM_INUMP (i
) && (SCM_INUM (i
) >= 0), i
, SCM_ARG1
, s_alarm
);
344 j
= alarm (SCM_INUM (i
));
345 return SCM_MAKINUM (j
);
349 SCM_PROC(s_pause
, "pause", 0, 0, 0, scm_pause
);
355 return SCM_UNSPECIFIED
;
359 SCM_PROC(s_sleep
, "sleep", 1, 0, 0, scm_sleep
);
366 SCM_ASSERT (SCM_INUMP (i
) && (SCM_INUM (i
) >= 0), i
, SCM_ARG1
, s_sleep
);
368 j
= scm_thread_sleep (SCM_INUM(i
));
370 j
= sleep (SCM_INUM(i
));
372 return scm_ulong2num (j
);
375 #if defined(USE_THREADS) || defined(HAVE_USLEEP)
376 SCM_PROC(s_usleep
, "usleep", 1, 0, 0, scm_usleep
);
382 SCM_ASSERT (SCM_INUMP (i
) && (SCM_INUM (i
) >= 0), i
, SCM_ARG1
, s_usleep
);
385 /* If we have threads, we use the thread system's sleep function. */
387 unsigned long j
= scm_thread_usleep (SCM_INUM (i
));
388 return scm_ulong2num (j
);
391 #ifdef USLEEP_RETURNS_VOID
392 usleep (SCM_INUM (i
));
396 int j
= usleep (SCM_INUM (i
));
397 return SCM_MAKINUM (j
);
402 #endif /* GUILE_ISELECT || HAVE_USLEEP */
404 SCM_PROC(s_raise
, "raise", 1, 0, 0, scm_raise
);
410 SCM_ASSERT(SCM_INUMP(sig
), sig
, SCM_ARG1
, s_raise
);
412 if (kill (getpid (), (int) SCM_INUM (sig
)) != 0)
413 scm_syserror (s_raise
);
415 return SCM_UNSPECIFIED
;
427 SCM_CDRLOC (scm_sysintern ("signal-handlers",
428 scm_make_vector (SCM_MAKINUM (NSIG
),
430 thunk
= scm_make_gsubr ("%deliver-signals", 0, 0, 0,
431 sys_deliver_signals
);
432 signal_async
= scm_system_async (thunk
);
434 for (i
= 0; i
< NSIG
; i
++)
437 #ifdef HAVE_SIGACTION
438 orig_handlers
[i
].sa_handler
= SIG_ERR
;
441 orig_handlers
[i
] = SIG_ERR
;
444 #ifdef HAVE_RESTARTABLE_SYSCALLS
445 /* ensure that system calls will be restarted for all signals. */
446 /* sigintterupt would be simpler, but it seems better to avoid
447 dependency on another system call. */
449 struct sigaction action
;
451 sigaction (i
, NULL
, &action
);
452 if (!(action
.sa_flags
& SA_RESTART
))
454 action
.sa_flags
&= SA_RESTART
;
455 sigaction (i
, &action
, NULL
);
461 scm_sysintern ("NSIG", scm_long2num (NSIG
));
462 scm_sysintern ("SIG_IGN", scm_long2num ((long) SIG_IGN
));
463 scm_sysintern ("SIG_DFL", scm_long2num ((long) SIG_DFL
));
465 scm_sysintern ("SA_NOCLDSTOP", scm_long2num (SA_NOCLDSTOP
));
468 scm_sysintern ("SA_RESTART", scm_long2num (SA_RESTART
));