/* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2004 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 "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 /* The thread system has its own sleep and usleep functions. */ #ifndef USE_THREADS #if defined(MISSING_SLEEP_DECL) int sleep (); #endif #if defined(HAVE_USLEEP) && defined(MISSING_USLEEP_DECL) int usleep (); #endif #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 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 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[NSIG])(int); #endif static SIGRETTYPE take_signal (int signum) { int saved_errno = errno; 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); errno = saved_errno; } static SCM sys_deliver_signals (void) { int i; for (i = 0; i < NSIG; i++) { if (got_signal[i]) { /* The flag is reset before calling the handler in case the handler doesn't return. If the handler doesn't return but leaves other signals flagged, they their handlers will be applied some time later when the async is checked again. It would probably be better to reset the flags after doing a longjmp. */ got_signal[i] = 0; #ifndef HAVE_SIGACTION signal (i, take_signal); #endif scm_call_1 (SCM_VELTS (*signal_handlers)[i], SCM_MAKINUM (i)); } } return SCM_UNSPECIFIED; } /* user interface for installation of signal handlers. */ SCM_DEFINE (scm_sigaction, "sigaction", 1, 2, 0, (SCM signum, SCM handler, SCM flags), "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{action} 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{action} is provided, it is installed as the new handler for\n" "@var{signum}. @var{action} 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. Flags can\n" "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 { 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_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 SCM_DEFER_INTS; old_handler = scheme_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 scheme_handlers[csig] = 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; 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_VALIDATE_PROC (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 scheme_handlers[csig] = 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; 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; 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; orig_handlers[i] = SIG_ERR; scheme_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); #ifdef USE_THREADS j = scm_thread_sleep (SCM_INUM(i)); #else j = sleep (SCM_INUM(i)); #endif return scm_ulong2num (j); } #undef FUNC_NAME #if defined(USE_THREADS) || defined(HAVE_USLEEP) 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 { SCM_VALIDATE_INUM_MIN (1,i,0); #ifdef USE_THREADS /* If we have threads, we use the thread system's sleep function. */ { unsigned long j = scm_thread_usleep (SCM_INUM (i)); return scm_ulong2num (j); } #else #ifdef USLEEP_RETURNS_VOID usleep (SCM_INUM (i)); return SCM_INUM0; #else { int j = usleep (SCM_INUM (i)); return SCM_MAKINUM (j); } #endif #endif } #undef FUNC_NAME #endif /* GUILE_ISELECT || HAVE_USLEEP */ 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 () { SCM thunk; int i; signal_handlers = SCM_VARIABLE_LOC (scm_c_define ("signal-handlers", scm_c_make_vector (NSIG, SCM_BOOL_F))); /* XXX - use scm_c_make_gsubr here instead of `define'? */ thunk = scm_c_define_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 #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: */