X-Git-Url: http://git.hcoop.net/bpt/guile.git/blobdiff_plain/2ad6b1a531a39fb95500d148e5025f45bca1e20d..eb7e1603ad497d0efff686e26e23af987c567721:/libguile/scmsigs.c?ds=sidebyside diff --git a/libguile/scmsigs.c b/libguile/scmsigs.c dissimilarity index 60% index 2a53c3e44..a4a21c53f 100644 --- a/libguile/scmsigs.c +++ b/libguile/scmsigs.c @@ -1,400 +1,721 @@ -/* Copyright (C) 1995,1996,1997 Free Software Foundation, Inc. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2, or (at your option) - * any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this software; see the file COPYING. If not, write to - * the Free Software Foundation, Inc., 59 Temple Place, Suite 330, - * Boston, MA 02111-1307 USA - * - * As a special exception, the Free Software Foundation gives permission - * for additional uses of the text contained in its release of GUILE. - * - * The exception is that, if you link the GUILE library with other files - * to produce an executable, this does not by itself cause the - * resulting executable to be covered by the GNU General Public License. - * Your use of that executable is in no way restricted on account of - * linking the GUILE library code into it. - * - * This exception does not however invalidate any other reasons why - * the executable file might be covered by the GNU General Public License. - * - * This exception applies only to the code released by the - * Free Software Foundation under the name GUILE. If you copy - * code from other Free Software Foundation releases into a copy of - * GUILE, as the General Public License permits, the exception does - * not apply to the code that you add in this way. To avoid misleading - * anyone as to the status of such modified files, you must delete - * this exception notice from them. - * - * If you write modifications of your own for GUILE, it is your choice - * whether to permit this exception to apply to your modifications. - * If you do not wish that, delete this exception notice. */ - - -#include -#include -#include "_scm.h" - -#include "async.h" -#include "eval.h" -#include "scmsigs.h" - -#ifdef HAVE_UNISTD_H -#include -#endif - - - - -#ifdef USE_MIT_PTHREADS -#undef signal -#define signal pthread_signal -#endif - - - -/* SIGRETTYPE is the type that signal handlers return. See */ - -#ifdef RETSIGTYPE -# define SIGRETTYPE RETSIGTYPE -#else -# ifdef STDC_HEADERS -# define SIGRETTYPE void -# else -# define SIGRETTYPE int -# endif -#endif - - - -/* take_signal is installed as the C signal handler whenever a Scheme - handler is set. when a signal arrives, take_signal marks the corresponding - element of got_signal and marks signal_async. the thunk in signal_async - (sys_deliver_signals) will be run at the next opportunity, outside a - critical section. sys_deliver_signals runs each Scheme handler for - which got_signal is set. */ - -static SCM signal_async; - -static char got_signal[NSIG]; - -/* a Scheme vector of handler procedures. */ -static SCM *signal_handlers; - -/* saves the original C handlers, when a new handler is installed. - set to SIG_ERR if the original handler is installed. */ -#ifdef HAVE_SIGACTION -static struct sigaction orig_handlers[NSIG]; -#else -static SIGRETTYPE (*orig_handlers)(int)[NSIG]; -#endif - -static SIGRETTYPE -take_signal (int signum) -{ - SCM ignored; - if (!scm_ints_disabled) - { - /* For reasons of speed, the SCM_NEWCELL macro doesn't defer - interrupts. Instead, it first sets its argument to point to - the first cell in the list, and then advances the freelist - pointer to the next cell. Now, if this procedure is - interrupted, the only anomalous state possible is to have - both SCM_NEWCELL's argument and scm_freelist pointing to the - same cell. To deal with this case, we always throw away the - first cell in scm_freelist here. - - At least, that's the theory. I'm not convinced that that's - the only anomalous path we need to worry about. */ - SCM_NEWCELL (ignored); - } - got_signal[signum] = 1; -#if HAVE_SIGACTION - /* unblock the signal before the scheme handler gets to run, since - it may use longjmp to escape (i.e., throw an exception). */ - { - sigset_t set; - sigemptyset (&set); - sigaddset (&set, signum); - sigprocmask (SIG_UNBLOCK, &set, NULL); - } -#endif - scm_system_async_mark (signal_async); -} - -static SCM -sys_deliver_signals (void) -{ - int i; - - for (i = 0; i < NSIG; i++) - { - if (got_signal[i]) - { - got_signal[i] = 0; -#ifndef HAVE_SIGACTION - signal (i, take_signal); -#endif - scm_apply (SCM_VELTS (*signal_handlers)[i], - scm_listify (SCM_MAKINUM (i), SCM_UNDEFINED), - SCM_EOL); - } - } - return SCM_UNSPECIFIED; -} - -/* user interface for installation of signal handlers. */ -SCM_PROC(s_sigaction, "sigaction", 1, 2, 0, scm_sigaction); -SCM -scm_sigaction (SCM signum, SCM handler, SCM flags) -{ - int csig; -#ifdef HAVE_SIGACTION - struct sigaction action; - struct sigaction old_action; -#else - SIGRETTYPE (* chandler) (int); - SIGRETTYPE (* old_chandler) (int); -#endif - int query_only = 0; - int save_handler = 0; - SCM *scheme_handlers = SCM_VELTS (*signal_handlers); - SCM old_handler; - - SCM_ASSERT (SCM_INUMP (signum), signum, SCM_ARG1, s_sigaction); - csig = SCM_INUM (signum); -#ifdef HAVE_SIGACTION - /* always use restartable system calls if available. */ -#ifdef SA_RESTART - action.sa_flags = SA_RESTART; -#else - action.sa_flags = 0; -#endif - if (!SCM_UNBNDP (flags)) - { - SCM_ASSERT (SCM_INUMP (flags), flags, SCM_ARG3, s_sigaction); - action.sa_flags |= SCM_INUM (flags); - } - sigemptyset (&action.sa_mask); -#endif - SCM_DEFER_INTS; - old_handler = scheme_handlers[csig]; - if (SCM_UNBNDP (handler)) - query_only = 1; - else if (SCM_INUMP (handler)) - { - if (SCM_INUM (handler) == (int) SIG_DFL - || SCM_INUM (handler) == (int) SIG_IGN) - { -#ifdef HAVE_SIGACTION - action.sa_handler = (SIGRETTYPE (*) (int)) SCM_INUM (handler); -#else - chandler = (SIGRETTYPE (*) (int)) SCM_INUM (handler); -#endif - scheme_handlers[csig] = SCM_BOOL_F; - } - else - scm_out_of_range (s_sigaction, handler); - } - else if (SCM_FALSEP (handler)) - { - /* restore the default handler. */ -#ifdef HAVE_SIGACTION - if (orig_handlers[csig].sa_handler == SIG_ERR) - query_only = 1; - else - { - action = orig_handlers[csig]; - orig_handlers[csig].sa_handler = SIG_ERR; - scheme_handlers[csig] = SCM_BOOL_F; - } -#else - if (orig_handlers[csig] == SIG_ERR) - query_only = 1; - else - { - chandler = orig_handlers[csig]; - orig_handlers[csig] = SIG_ERR; - scheme_handlers[csig] = SCM_BOOL_F; - } -#endif - } - else - { - SCM_ASSERT (SCM_NIMP (handler), handler, SCM_ARG2, s_sigaction); -#ifdef HAVE_SIGACTION - action.sa_handler = take_signal; - if (orig_handlers[csig].sa_handler == SIG_ERR) - save_handler = 1; -#else - chandler = take_signal; - if (orig_handlers[csig] == SIG_ERR) - save_handler = 1; -#endif - scheme_handlers[csig] = handler; - } -#ifdef HAVE_SIGACTION - if (query_only) - { - if (sigaction (csig, 0, &old_action) == -1) - scm_syserror (s_sigaction); - } - else - { - if (sigaction (csig, &action , &old_action) == -1) - scm_syserror (s_sigaction); - if (save_handler) - orig_handlers[csig] = old_action; - } - if (old_action.sa_handler == SIG_DFL || old_action.sa_handler == SIG_IGN) - old_handler = SCM_MAKINUM ((int) old_action.sa_handler); - SCM_ALLOW_INTS; - return scm_cons (old_handler, SCM_MAKINUM (old_action.sa_flags)); -#else - if (query_only) - { - if ((old_chandler = signal (csig, SIG_IGN)) == SIG_ERR) - scm_syserror (s_sigaction); - if (signal (csig, old_chandler) == SIG_ERR) - scm_syserror (s_sigaction); - } - else - { - if ((old_chandler = signal (csig, chandler)) == SIG_ERR) - scm_syserror (s_sigaction); - if (save_handler) - orig_handlers[csig] = old_chandler; - } - if (old_chandler == SIG_DFL || old_chandler == SIG_IGN) - old_handler = SCM_MAKINUM ((int) old_chandler); - SCM_ALLOW_INTS; - return scm_cons (old_handler, SCM_MAKINUM (0)); -#endif -} - -SCM_PROC (s_restore_signals, "restore-signals", 0, 0, 0, scm_restore_signals); -SCM -scm_restore_signals (void) -{ - int i; - SCM *scheme_handlers = SCM_VELTS (*signal_handlers); - - for (i = 0; i < NSIG; i++) - { -#ifdef HAVE_SIGACTION - if (orig_handlers[i].sa_handler != SIG_ERR) - { - if (sigaction (i, &orig_handlers[i], NULL) == -1) - scm_syserror (s_restore_signals); - orig_handlers[i].sa_handler = SIG_ERR; - scheme_handlers[i] = SCM_BOOL_F; - } -#else - if (orig_handlers[i] != SIG_ERR) - { - if (signal (i, orig_handlers[i]) == SIG_ERR) - scm_syserror (s_restore_signals); - orig_handlers[i] = SIG_ERR; - scheme_handlers[i] = SCM_BOOL_F; - } -#endif - } - return SCM_UNSPECIFIED; -} - -SCM_PROC(s_alarm, "alarm", 1, 0, 0, scm_alarm); - -SCM -scm_alarm (i) - SCM i; -{ - unsigned int j; - SCM_ASSERT (SCM_INUMP (i) && (SCM_INUM (i) >= 0), i, SCM_ARG1, s_alarm); - j = alarm (SCM_INUM (i)); - return SCM_MAKINUM (j); -} - -SCM_PROC(s_pause, "pause", 0, 0, 0, scm_pause); - -SCM -scm_pause () -{ - pause (); - return SCM_UNSPECIFIED; -} - -SCM_PROC(s_sleep, "sleep", 1, 0, 0, scm_sleep); - -SCM -scm_sleep (i) - SCM i; -{ - unsigned int j; - SCM_ASSERT (SCM_INUMP (i) && (SCM_INUM (i) >= 0), i, SCM_ARG1, s_sleep); - j = sleep (SCM_INUM(i)); - return SCM_MAKINUM (j); -} - -SCM_PROC(s_raise, "raise", 1, 0, 0, scm_raise); - -SCM -scm_raise(sig) - SCM sig; -{ - SCM_ASSERT(SCM_INUMP(sig), sig, SCM_ARG1, s_raise); - SCM_DEFER_INTS; - if (kill (getpid (), (int) SCM_INUM (sig)) != 0) - scm_syserror (s_raise); - SCM_ALLOW_INTS; - return SCM_UNSPECIFIED; -} - - - -void -scm_init_scmsigs () -{ - SCM thunk; - int i; - - signal_handlers = - SCM_CDRLOC (scm_sysintern ("signal-handlers", - scm_make_vector (SCM_MAKINUM (NSIG), - SCM_BOOL_F, - SCM_BOOL_F))); - thunk = scm_make_gsubr ("%deliver-signals", 0, 0, 0, - sys_deliver_signals); - signal_async = scm_system_async (thunk); - - for (i = 0; i < NSIG; i++) - { - got_signal[i] = 0; -#ifdef HAVE_SIGACTION - orig_handlers[i].sa_handler = SIG_ERR; -#else - orig_handlers[i] = SIG_ERR; -#endif - } - - scm_sysintern ("NSIG", scm_long2num (NSIG)); - scm_sysintern ("SIG_IGN", scm_long2num ((long) SIG_IGN)); - scm_sysintern ("SIG_DFL", scm_long2num ((long) SIG_DFL)); -#ifdef SA_NOCLDSTOP - scm_sysintern ("SA_NOCLDSTOP", scm_long2num (SA_NOCLDSTOP)); -#endif -#ifdef SA_RESTART - scm_sysintern ("SA_RESTART", scm_long2num (SA_RESTART)); -#endif - -#include "scmsigs.x" -} - +/* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002 Free Software Foundation, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + + + + +#if HAVE_CONFIG_H +# include +#endif + +#include +#include + +#include "libguile/_scm.h" + +#include "libguile/async.h" +#include "libguile/eval.h" +#include "libguile/root.h" +#include "libguile/vectors.h" + +#include "libguile/validate.h" +#include "libguile/scmsigs.h" + +#ifdef HAVE_UNISTD_H +#include +#endif + +#ifdef HAVE_SYS_TIME_H +#include +#endif + +#ifdef __MINGW32__ +#include +#define alarm(sec) (0) +/* This weird comma expression is because Sleep is void under Windows. */ +#define sleep(sec) (Sleep ((sec) * 1000), 0) +#define usleep(usec) (Sleep ((usec) / 1000), 0) +#define kill(pid, sig) raise (sig) +#endif + + + +/* SIGRETTYPE is the type that signal handlers return. See */ + +#ifdef RETSIGTYPE +# define SIGRETTYPE RETSIGTYPE +#else +# ifdef STDC_HEADERS +# define SIGRETTYPE void +# else +# define SIGRETTYPE int +# endif +#endif + + + +/* take_signal is installed as the C signal handler whenever a Scheme + handler is set. when a signal arrives, take_signal will queue the + Scheme handler procedure for its thread. */ + + +/* Scheme vectors with information about a signal. signal_handlers + contains the handler procedure or #f, signal_handler_cells contains + pre-queued cells for the handler (since we can't do fancy things + during signal delivery), signal_cell_handlers contains the SCM + value to be stuffed into the pre-queued cell upon delivery, and + signal_handler_threads points to the thread that a signal should be + delivered to. +*/ +static SCM *signal_handlers; +static SCM signal_handler_cells; +static SCM signal_cell_handlers; +static SCM signal_handler_threads; + +/* saves the original C handlers, when a new handler is installed. + set to SIG_ERR if the original handler is installed. */ +#ifdef HAVE_SIGACTION +static struct sigaction orig_handlers[NSIG]; +#else +static SIGRETTYPE (*orig_handlers[NSIG])(int); +#endif + + +static SIGRETTYPE +take_signal (int signum) +{ + if (signum >= 0 && signum < NSIG) + { + SCM cell = SCM_VECTOR_REF(signal_handler_cells, signum); + SCM handler = SCM_VECTOR_REF(signal_cell_handlers, signum); + SCM thread = SCM_VECTOR_REF(signal_handler_threads, signum); + scm_root_state *root = scm_i_thread_root (thread); + if (SCM_CONSP (cell)) + { + SCM_SETCAR (cell, handler); + root->pending_asyncs = 1; + } + } + +#ifndef HAVE_SIGACTION + signal (signum, take_signal); +#endif +} + +SCM +scm_sigaction (SCM signum, SCM handler, SCM flags) +{ + return scm_sigaction_for_thread (signum, handler, flags, SCM_UNDEFINED); +} + +static SCM +close_1 (SCM proc, SCM arg) +{ + return scm_primitive_eval_x (scm_list_3 (scm_sym_lambda, SCM_EOL, + scm_list_2 (proc, arg))); +} + +/* Make sure that signal SIGNUM can be delivered to THREAD, using + HANDLER. THREAD and HANDLER must either both be non-#f (which + means install the handler), or both #f (which means deinstall an + existing handler). +*/ + +struct install_handler_data { + int signum; + SCM thread; + SCM handler; +}; + +static SCM +scm_delq_spine_x (SCM cell, SCM list) +{ + SCM s = list, prev = SCM_BOOL_F; + + while (!SCM_EQ_P (cell, s)) + { + if (SCM_NULLP (s)) + return list; + prev = s; + s = SCM_CDR (s); + } + if (SCM_FALSEP (prev)) + return SCM_CDR (cell); + else + { + SCM_SETCDR (prev, SCM_CDR (cell)); + return list; + } +} + +static void * +really_install_handler (void *data) +{ + struct install_handler_data *args = data; + int signum = args->signum; + SCM thread = args->thread; + SCM handler = args->handler; + SCM cell; + SCM old_thread; + + /* The following modifications are done while signals can be + delivered. That is not a real problem since the signal handler + will only touch the car of the handler cell and set the + pending_asyncs trigger of a thread. While the data structures + are in flux, the signal handler might store the wrong handler in + the cell, or set pending_asyncs of the wrong thread. We fix this + at the end by making sure that the cell has the right handler in + it, if any, and that pending_asyncs is set for the new thread. + */ + + /* Make sure we have a cell. */ + cell = SCM_VECTOR_REF (signal_handler_cells, signum); + if (SCM_FALSEP (cell)) + { + cell = scm_cons (SCM_BOOL_F, SCM_EOL); + SCM_VECTOR_SET (signal_handler_cells, signum, cell); + } + + /* Make sure it is queued for the right thread. */ + old_thread = SCM_VECTOR_REF (signal_handler_threads, signum); + if (!SCM_EQ_P (thread, old_thread)) + { + scm_root_state *r; + if (!SCM_FALSEP (old_thread)) + { + r = scm_i_thread_root (old_thread); + r->signal_asyncs = scm_delq_spine_x (cell, r->signal_asyncs); + } + if (!SCM_FALSEP (thread)) + { + r = scm_i_thread_root (thread); + SCM_SETCDR (cell, r->signal_asyncs); + r->signal_asyncs = cell; + /* Set pending_asyncs just in case. A signal that is + delivered while we modify the data structures here might set + pending_asyncs of old_thread. */ + r->pending_asyncs = 1; + } + SCM_VECTOR_SET (signal_handler_threads, signum, thread); + } + + /* Set the new handler. */ + if (SCM_FALSEP (handler)) + { + SCM_VECTOR_SET (*signal_handlers, signum, SCM_BOOL_F); + SCM_VECTOR_SET (signal_cell_handlers, signum, SCM_BOOL_F); + } + else + { + SCM_VECTOR_SET (*signal_handlers, signum, handler); + SCM_VECTOR_SET (signal_cell_handlers, signum, + close_1 (handler, scm_int2num (signum))); + } + + /* Now fix up the cell. It might contain the old handler but since + it is now queued for the new thread, we must make sure that the + new handler is run. Any signal that is delivered during the + following code will install the new handler, so we have no + problem. + */ + if (!SCM_FALSEP (SCM_CAR (cell))) + SCM_SETCAR (cell, SCM_VECTOR_REF (signal_cell_handlers, signum)); + + /* Phfew. That should be it. */ + return NULL; +} + +static void +install_handler (int signum, SCM thread, SCM handler) +{ + /* We block asyncs while installing the handler. It would be safe + to leave them on, but we might run the wrong handler should a + signal be delivered. + */ + + struct install_handler_data args; + args.signum = signum; + args.thread = thread; + args.handler = handler; + scm_c_call_with_blocked_asyncs (really_install_handler, &args); +} + +/* user interface for installation of signal handlers. */ +SCM_DEFINE (scm_sigaction_for_thread, "sigaction", 1, 3, 0, + (SCM signum, SCM handler, SCM flags, SCM thread), + "Install or report the signal handler for a specified signal.\n\n" + "@var{signum} is the signal number, which can be specified using the value\n" + "of variables such as @code{SIGINT}.\n\n" + "If @var{handler} is omitted, @code{sigaction} returns a pair: the\n" + "CAR is the current\n" + "signal hander, which will be either an integer with the value @code{SIG_DFL}\n" + "(default action) or @code{SIG_IGN} (ignore), or the Scheme procedure which\n" + "handles the signal, or @code{#f} if a non-Scheme procedure handles the\n" + "signal. The CDR contains the current @code{sigaction} flags for the handler.\n\n" + "If @var{handler} is provided, it is installed as the new handler for\n" + "@var{signum}. @var{handler} can be a Scheme procedure taking one\n" + "argument, or the value of @code{SIG_DFL} (default action) or\n" + "@code{SIG_IGN} (ignore), or @code{#f} to restore whatever signal handler\n" + "was installed before @code{sigaction} was first used. When\n" + "a scheme procedure has been specified, that procedure will run\n" + "in the given @var{thread}. When no thread has been given, the\n" + "thread that made this call to @code{sigaction} is used.\n" + "Flags can " + "optionally be specified for the new handler (@code{SA_RESTART} will\n" + "always be added if it's available and the system is using restartable\n" + "system calls.) The return value is a pair with information about the\n" + "old handler as described above.\n\n" + "This interface does not provide access to the \"signal blocking\"\n" + "facility. Maybe this is not needed, since the thread support may\n" + "provide solutions to the problem of consistent access to data\n" + "structures.") +#define FUNC_NAME s_scm_sigaction_for_thread +{ + int csig; +#ifdef HAVE_SIGACTION + struct sigaction action; + struct sigaction old_action; +#else + SIGRETTYPE (* chandler) (int) = SIG_DFL; + SIGRETTYPE (* old_chandler) (int); +#endif + int query_only = 0; + int save_handler = 0; + + SCM old_handler; + + SCM_VALIDATE_INUM_COPY (1, signum, csig); + if (csig < 0 || csig > NSIG) + SCM_OUT_OF_RANGE (1, signum); +#if defined(HAVE_SIGACTION) +#if defined(SA_RESTART) && defined(HAVE_RESTARTABLE_SYSCALLS) + /* don't allow SA_RESTART to be omitted if HAVE_RESTARTABLE_SYSCALLS + is defined, since libguile would be likely to produce spurious + EINTR errors. */ + action.sa_flags = SA_RESTART; +#else + action.sa_flags = 0; +#endif + if (!SCM_UNBNDP (flags)) + { + SCM_VALIDATE_INUM (3, flags); + action.sa_flags |= SCM_INUM (flags); + } + sigemptyset (&action.sa_mask); +#endif + + if (SCM_UNBNDP (thread)) + thread = scm_current_thread (); + else + { + SCM_VALIDATE_THREAD (4, thread); + if (scm_c_thread_exited_p (thread)) + SCM_MISC_ERROR ("thread has already exited", SCM_EOL); + } + + SCM_DEFER_INTS; + old_handler = SCM_VECTOR_REF(*signal_handlers, csig); + if (SCM_UNBNDP (handler)) + query_only = 1; + else if (SCM_EQ_P (scm_integer_p (handler), SCM_BOOL_T)) + { + if (SCM_NUM2LONG (2, handler) == (long) SIG_DFL + || SCM_NUM2LONG (2, handler) == (long) SIG_IGN) + { +#ifdef HAVE_SIGACTION + action.sa_handler = (SIGRETTYPE (*) (int)) SCM_INUM (handler); +#else + chandler = (SIGRETTYPE (*) (int)) SCM_INUM (handler); +#endif + install_handler (csig, SCM_BOOL_F, SCM_BOOL_F); + } + else + SCM_OUT_OF_RANGE (2, handler); + } + else if (SCM_FALSEP (handler)) + { + /* restore the default handler. */ +#ifdef HAVE_SIGACTION + if (orig_handlers[csig].sa_handler == SIG_ERR) + query_only = 1; + else + { + action = orig_handlers[csig]; + orig_handlers[csig].sa_handler = SIG_ERR; + install_handler (csig, SCM_BOOL_F, SCM_BOOL_F); + } +#else + if (orig_handlers[csig] == SIG_ERR) + query_only = 1; + else + { + chandler = orig_handlers[csig]; + orig_handlers[csig] = SIG_ERR; + install_handler (csig, SCM_BOOL_F, SCM_BOOL_F); + } +#endif + } + else + { + SCM_VALIDATE_NIM (2, handler); +#ifdef HAVE_SIGACTION + action.sa_handler = take_signal; + if (orig_handlers[csig].sa_handler == SIG_ERR) + save_handler = 1; +#else + chandler = take_signal; + if (orig_handlers[csig] == SIG_ERR) + save_handler = 1; +#endif + install_handler (csig, thread, handler); + } + + /* XXX - Silently ignore setting handlers for `program error signals' + because they can't currently be handled by Scheme code. + */ + + switch (csig) + { + /* This list of program error signals is from the GNU Libc + Reference Manual */ + case SIGFPE: + case SIGILL: + case SIGSEGV: +#ifdef SIGBUS + case SIGBUS: +#endif + case SIGABRT: +#if defined(SIGIOT) && (SIGIOT != SIGABRT) + case SIGIOT: +#endif +#ifdef SIGTRAP + case SIGTRAP: +#endif +#ifdef SIGEMT + case SIGEMT: +#endif +#ifdef SIGSYS + case SIGSYS: +#endif + query_only = 1; + } + +#ifdef HAVE_SIGACTION + if (query_only) + { + if (sigaction (csig, 0, &old_action) == -1) + SCM_SYSERROR; + } + else + { + if (sigaction (csig, &action , &old_action) == -1) + SCM_SYSERROR; + if (save_handler) + orig_handlers[csig] = old_action; + } + if (old_action.sa_handler == SIG_DFL || old_action.sa_handler == SIG_IGN) + old_handler = scm_long2num ((long) old_action.sa_handler); + SCM_ALLOW_INTS; + return scm_cons (old_handler, SCM_MAKINUM (old_action.sa_flags)); +#else + if (query_only) + { + if ((old_chandler = signal (csig, SIG_IGN)) == SIG_ERR) + SCM_SYSERROR; + if (signal (csig, old_chandler) == SIG_ERR) + SCM_SYSERROR; + } + else + { + if ((old_chandler = signal (csig, chandler)) == SIG_ERR) + SCM_SYSERROR; + if (save_handler) + orig_handlers[csig] = old_chandler; + } + if (old_chandler == SIG_DFL || old_chandler == SIG_IGN) + old_handler = scm_long2num ((long) old_chandler); + SCM_ALLOW_INTS; + return scm_cons (old_handler, SCM_MAKINUM (0)); +#endif +} +#undef FUNC_NAME + +SCM_DEFINE (scm_restore_signals, "restore-signals", 0, 0, 0, + (void), + "Return all signal handlers to the values they had before any call to\n" + "@code{sigaction} was made. The return value is unspecified.") +#define FUNC_NAME s_scm_restore_signals +{ + int i; + for (i = 0; i < NSIG; i++) + { +#ifdef HAVE_SIGACTION + if (orig_handlers[i].sa_handler != SIG_ERR) + { + if (sigaction (i, &orig_handlers[i], NULL) == -1) + SCM_SYSERROR; + orig_handlers[i].sa_handler = SIG_ERR; + SCM_VECTOR_SET (*signal_handlers, i, SCM_BOOL_F); + } +#else + if (orig_handlers[i] != SIG_ERR) + { + if (signal (i, orig_handlers[i]) == SIG_ERR) + SCM_SYSERROR; + orig_handlers[i] = SIG_ERR; + SCM_VECTOR_SET (*signal_handlers, i, SCM_BOOL_F); + } +#endif + } + return SCM_UNSPECIFIED; +} +#undef FUNC_NAME + +SCM_DEFINE (scm_alarm, "alarm", 1, 0, 0, + (SCM i), + "Set a timer to raise a @code{SIGALRM} signal after the specified\n" + "number of seconds (an integer). It's advisable to install a signal\n" + "handler for\n" + "@code{SIGALRM} beforehand, since the default action is to terminate\n" + "the process.\n\n" + "The return value indicates the time remaining for the previous alarm,\n" + "if any. The new value replaces the previous alarm. If there was\n" + "no previous alarm, the return value is zero.") +#define FUNC_NAME s_scm_alarm +{ + unsigned int j; + SCM_VALIDATE_INUM (1, i); + j = alarm (SCM_INUM (i)); + return SCM_MAKINUM (j); +} +#undef FUNC_NAME + +#ifdef HAVE_SETITIMER +SCM_DEFINE (scm_setitimer, "setitimer", 5, 0, 0, + (SCM which_timer, + SCM interval_seconds, SCM interval_microseconds, + SCM value_seconds, SCM value_microseconds), + "Set the timer specified by @var{which_timer} according to the given\n" + "@var{interval_seconds}, @var{interval_microseconds},\n" + "@var{value_seconds}, and @var{value_microseconds} values.\n" + "\n" + "Return information about the timer's previous setting." + "\n" + "Errors are handled as described in the guile info pages under ``POSIX\n" + "Interface Conventions''.\n" + "\n" + "The timers available are: @code{ITIMER_REAL}, @code{ITIMER_VIRTUAL},\n" + "and @code{ITIMER_PROF}.\n" + "\n" + "The return value will be a list of two cons pairs representing the\n" + "current state of the given timer. The first pair is the seconds and\n" + "microseconds of the timer @code{it_interval}, and the second pair is\n" + "the seconds and microseconds of the timer @code{it_value}.") +#define FUNC_NAME s_scm_setitimer +{ + int rv; + int c_which_timer; + struct itimerval new_timer; + struct itimerval old_timer; + + c_which_timer = SCM_NUM2INT(1, which_timer); + new_timer.it_interval.tv_sec = SCM_NUM2LONG(2, interval_seconds); + new_timer.it_interval.tv_usec = SCM_NUM2LONG(3, interval_microseconds); + new_timer.it_value.tv_sec = SCM_NUM2LONG(4, value_seconds); + new_timer.it_value.tv_usec = SCM_NUM2LONG(5, value_microseconds); + + SCM_SYSCALL(rv = setitimer(c_which_timer, &new_timer, &old_timer)); + + if(rv != 0) + SCM_SYSERROR; + + return scm_list_2(scm_cons(scm_long2num(old_timer.it_interval.tv_sec), + scm_long2num(old_timer.it_interval.tv_usec)), + scm_cons(scm_long2num(old_timer.it_value.tv_sec), + scm_long2num(old_timer.it_value.tv_usec))); +} +#undef FUNC_NAME +#endif /* HAVE_SETITIMER */ + +#ifdef HAVE_GETITIMER +SCM_DEFINE (scm_getitimer, "getitimer", 1, 0, 0, + (SCM which_timer), + "Return information about the timer specified by @var{which_timer}" + "\n" + "Errors are handled as described in the guile info pages under ``POSIX\n" + "Interface Conventions''.\n" + "\n" + "The timers available are: @code{ITIMER_REAL}, @code{ITIMER_VIRTUAL},\n" + "and @code{ITIMER_PROF}.\n" + "\n" + "The return value will be a list of two cons pairs representing the\n" + "current state of the given timer. The first pair is the seconds and\n" + "microseconds of the timer @code{it_interval}, and the second pair is\n" + "the seconds and microseconds of the timer @code{it_value}.") +#define FUNC_NAME s_scm_getitimer +{ + int rv; + int c_which_timer; + struct itimerval old_timer; + + c_which_timer = SCM_NUM2INT(1, which_timer); + + SCM_SYSCALL(rv = getitimer(c_which_timer, &old_timer)); + + if(rv != 0) + SCM_SYSERROR; + + return scm_list_2(scm_cons(scm_long2num(old_timer.it_interval.tv_sec), + scm_long2num(old_timer.it_interval.tv_usec)), + scm_cons(scm_long2num(old_timer.it_value.tv_sec), + scm_long2num(old_timer.it_value.tv_usec))); +} +#undef FUNC_NAME +#endif /* HAVE_GETITIMER */ + +#ifdef HAVE_PAUSE +SCM_DEFINE (scm_pause, "pause", 0, 0, 0, + (), + "Pause the current process (thread?) until a signal arrives whose\n" + "action is to either terminate the current process or invoke a\n" + "handler procedure. The return value is unspecified.") +#define FUNC_NAME s_scm_pause +{ + pause (); + return SCM_UNSPECIFIED; +} +#undef FUNC_NAME +#endif + +SCM_DEFINE (scm_sleep, "sleep", 1, 0, 0, + (SCM i), + "Wait for the given number of seconds (an integer) or until a signal\n" + "arrives. The return value is zero if the time elapses or the number\n" + "of seconds remaining otherwise.") +#define FUNC_NAME s_scm_sleep +{ + unsigned long j; + SCM_VALIDATE_INUM_MIN (1, i,0); + j = scm_thread_sleep (SCM_INUM(i)); + return scm_ulong2num (j); +} +#undef FUNC_NAME + +SCM_DEFINE (scm_usleep, "usleep", 1, 0, 0, + (SCM i), + "Sleep for I microseconds. @code{usleep} is not available on\n" + "all platforms.") +#define FUNC_NAME s_scm_usleep +{ + unsigned long j; + SCM_VALIDATE_INUM_MIN (1, i,0); + j = scm_thread_usleep (SCM_INUM (i)); + return scm_ulong2num (j); +} +#undef FUNC_NAME + +SCM_DEFINE (scm_raise, "raise", 1, 0, 0, + (SCM sig), + "Sends a specified signal @var{sig} to the current process, where\n" + "@var{sig} is as described for the kill procedure.") +#define FUNC_NAME s_scm_raise +{ + SCM_VALIDATE_INUM (1, sig); + SCM_DEFER_INTS; + if (kill (getpid (), (int) SCM_INUM (sig)) != 0) + SCM_SYSERROR; + SCM_ALLOW_INTS; + return SCM_UNSPECIFIED; +} +#undef FUNC_NAME + + + +void +scm_init_scmsigs () +{ + int i; + + signal_handlers = + SCM_VARIABLE_LOC (scm_c_define ("signal-handlers", + scm_c_make_vector (NSIG, SCM_BOOL_F))); + signal_handler_cells = + scm_permanent_object (scm_c_make_vector (NSIG, SCM_BOOL_F)); + signal_cell_handlers = + scm_permanent_object (scm_c_make_vector (NSIG, SCM_BOOL_F)); + signal_handler_threads = + scm_permanent_object (scm_c_make_vector (NSIG, SCM_BOOL_F)); + + for (i = 0; i < NSIG; i++) + { +#ifdef HAVE_SIGACTION + orig_handlers[i].sa_handler = SIG_ERR; + +#else + orig_handlers[i] = SIG_ERR; +#endif + +#ifdef HAVE_RESTARTABLE_SYSCALLS + /* If HAVE_RESTARTABLE_SYSCALLS is defined, it's important that + signals really are restartable. don't rely on the same + run-time that configure got: reset the default for every signal. + */ +#ifdef HAVE_SIGINTERRUPT + siginterrupt (i, 0); +#elif defined(SA_RESTART) + { + struct sigaction action; + + sigaction (i, NULL, &action); + if (!(action.sa_flags & SA_RESTART)) + { + action.sa_flags |= SA_RESTART; + sigaction (i, &action, NULL); + } + } +#endif + /* if neither siginterrupt nor SA_RESTART are available we may + as well assume that signals are always restartable. */ +#endif + } + + scm_c_define ("NSIG", scm_long2num (NSIG)); + scm_c_define ("SIG_IGN", scm_long2num ((long) SIG_IGN)); + scm_c_define ("SIG_DFL", scm_long2num ((long) SIG_DFL)); +#ifdef SA_NOCLDSTOP + scm_c_define ("SA_NOCLDSTOP", scm_long2num (SA_NOCLDSTOP)); +#endif +#ifdef SA_RESTART + scm_c_define ("SA_RESTART", scm_long2num (SA_RESTART)); +#endif + +#if defined(HAVE_SETITIMER) || defined(HAVE_GETITIMER) + /* Stuff needed by setitimer and getitimer. */ + scm_c_define ("ITIMER_REAL", SCM_MAKINUM (ITIMER_REAL)); + scm_c_define ("ITIMER_VIRTUAL", SCM_MAKINUM (ITIMER_VIRTUAL)); + scm_c_define ("ITIMER_PROF", SCM_MAKINUM (ITIMER_PROF)); +#endif /* defined(HAVE_SETITIMER) || defined(HAVE_GETITIMER) */ + +#include "libguile/scmsigs.x" +} + + +/* + Local Variables: + c-file-style: "gnu" + End: +*/