| /*********************************************************** |
| Copyright 1991, 1992, 1993, 1994 by Stichting Mathematisch Centrum, |
| Amsterdam, The Netherlands. |
| |
| All Rights Reserved |
| |
| Permission to use, copy, modify, and distribute this software and its |
| documentation for any purpose and without fee is hereby granted, |
| provided that the above copyright notice appear in all copies and that |
| both that copyright notice and this permission notice appear in |
| supporting documentation, and that the names of Stichting Mathematisch |
| Centrum or CWI not be used in advertising or publicity pertaining to |
| distribution of the software without specific, written prior permission. |
| |
| STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO |
| THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND |
| FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH CENTRUM BE LIABLE |
| FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
| ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT |
| OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| |
| ******************************************************************/ |
| |
| /* Signal module -- many thanks to Lance Ellinghouse */ |
| |
| #include "allobjects.h" |
| #include "modsupport.h" |
| #include "ceval.h" |
| #include "intrcheck.h" |
| |
| #include <signal.h> |
| #include <errno.h> |
| |
| #ifndef SIG_ERR |
| #define SIG_ERR ((RETSIGTYPE (*)())-1) |
| #endif |
| |
| /* |
| NOTES ON THE INTERACTION BETWEEN SIGNALS AND THREADS |
| |
| When threads are supported, we want the following semantics: |
| |
| - only the main thread can set a signal handler |
| - any thread can get a signal handler |
| - signals are only delivered to the main thread |
| |
| I.e. we don't support "synchronous signals" like SIGFPE (catching |
| this doesn't make much sense in Python anyway) nor do we support |
| signals as a means of inter-thread communication, since not all |
| thread implementations support that (at least our thread library |
| doesn't). |
| |
| We still have the problem that in some implementations signals |
| generated by the keyboard (e.g. SIGINT) are delivered to all |
| threads (e.g. SGI), while in others (e.g. Solaris) such signals are |
| delivered to one random thread (an intermediate possibility would |
| be to deliver it to the main thread -- POSIX???). For now, we have |
| a working implementation that works in all three cases -- the |
| handler ignores signals if getpid() isn't the same as in the main |
| thread. XXX This is a hack. |
| |
| */ |
| |
| #ifdef WITH_THREAD |
| #include "thread.h" |
| static long main_thread; |
| static pid_t main_pid; |
| #endif |
| |
| struct signalhandler_list { |
| int tripped; |
| object *func; |
| }; |
| |
| static struct signalhandler_list sig_list[NSIG]; |
| static int tripped = 0; /* Speed up sigcheck() when none tripped */ |
| |
| static object *sig_dfl_object; |
| static object *sig_ign_object; |
| static object *default_int_handler_object; |
| |
| static object * |
| default_int_handler(self, arg) |
| object *self; |
| object *arg; |
| { |
| err_set(KeyboardInterrupt); |
| return NULL; |
| } |
| |
| static RETSIGTYPE |
| signal_handler(sig_num) |
| int sig_num; |
| { |
| #ifdef WITH_THREAD |
| /* See NOTES section above */ |
| if (getpid() == main_pid) { |
| #endif |
| tripped++; |
| sig_list[sig_num].tripped = 1; |
| #ifdef WITH_THREAD |
| } |
| #endif |
| (void *)signal(sig_num, &signal_handler); |
| } |
| |
| |
| static object * |
| signal_alarm(self, args) |
| object *self; /* Not used */ |
| object *args; |
| { |
| int t; |
| if (!getargs(args, "i", &t)) |
| return NULL; |
| alarm(t); |
| INCREF(None); |
| return None; |
| } |
| |
| static object * |
| signal_signal(self, args) |
| object *self; /* Not used */ |
| object *args; |
| { |
| object *obj; |
| int sig_num; |
| object *old_handler; |
| RETSIGTYPE (*func)(); |
| if (!getargs(args, "(iO)", &sig_num, &obj)) |
| return NULL; |
| #ifdef WITH_THREAD |
| if (get_thread_ident() != main_thread) { |
| err_setstr(ValueError, "signal only works in main thread"); |
| return NULL; |
| } |
| #endif |
| if (sig_num < 1 || sig_num >= NSIG) { |
| err_setstr(ValueError, "signal number out of range"); |
| return NULL; |
| } |
| if (obj == sig_ign_object) |
| func = SIG_IGN; |
| else if (obj == sig_dfl_object) |
| func = SIG_DFL; |
| else if (!is_methodobject(obj) && |
| !is_funcobject(obj) && |
| !is_instancemethodobject(obj)) { |
| err_setstr(TypeError, |
| "signal handler must be signal.SIG_IGN, signal.SIG_DFL, or a callable object"); |
| return NULL; |
| } |
| else |
| func = signal_handler; |
| if (signal(sig_num, func) == SIG_ERR) { |
| err_errno(RuntimeError); |
| return NULL; |
| } |
| old_handler = sig_list[sig_num].func; |
| sig_list[sig_num].tripped = 0; |
| INCREF(obj); |
| sig_list[sig_num].func = obj; |
| return old_handler; |
| } |
| |
| static object * |
| signal_getsignal(self, args) |
| object *self; /* Not used */ |
| object *args; |
| { |
| int sig_num; |
| object *old_handler; |
| if (!getargs(args, "i", &sig_num)) |
| return NULL; |
| if (sig_num < 1 || sig_num >= NSIG) { |
| err_setstr(ValueError, "signal number out of range"); |
| return NULL; |
| } |
| old_handler = sig_list[sig_num].func; |
| INCREF(old_handler); |
| return old_handler; |
| } |
| |
| |
| /* List of functions defined in the module */ |
| |
| static struct methodlist signal_methods[] = { |
| {"alarm", signal_alarm}, |
| {"signal", signal_signal}, |
| {"getsignal", signal_getsignal}, |
| {NULL, NULL} /* sentinel */ |
| }; |
| |
| void |
| initsignal() |
| { |
| object *m, *d, *x; |
| object *b_dict; |
| int i; |
| |
| #ifdef WITH_THREAD |
| main_thread = get_thread_ident(); |
| main_pid = getpid(); |
| #endif |
| |
| /* Create the module and add the functions */ |
| m = initmodule("signal", signal_methods); |
| |
| /* Add some symbolic constants to the module */ |
| d = getmoduledict(m); |
| |
| sig_dfl_object = newintobject((long)SIG_DFL); |
| dictinsert(d, "SIG_DFL", sig_dfl_object); |
| sig_ign_object = newintobject((long)SIG_IGN); |
| dictinsert(d, "SIG_IGN", sig_ign_object); |
| dictinsert(d, "NSIG", newintobject((long)NSIG)); |
| default_int_handler_object = newmethodobject("default_int_handler", |
| default_int_handler, |
| (object *)NULL, |
| 0); |
| dictinsert(d, "default_int_handler", default_int_handler_object); |
| |
| sig_list[0].tripped = 0; |
| for (i = 1; i < NSIG; i++) { |
| RETSIGTYPE (*t)(); |
| t = signal(i, SIG_IGN); |
| signal(i, t); |
| sig_list[i].tripped = 0; |
| if (t == SIG_DFL) |
| sig_list[i].func = sig_dfl_object; |
| else if (t == SIG_IGN) |
| sig_list[i].func = sig_ign_object; |
| else |
| sig_list[i].func = None; /* None of our business */ |
| INCREF(sig_list[i].func); |
| } |
| if (sig_list[SIGINT].func == sig_dfl_object) { |
| /* Install default int handler */ |
| DECREF(sig_list[SIGINT].func); |
| sig_list[SIGINT].func = default_int_handler_object; |
| INCREF(default_int_handler_object); |
| signal(SIGINT, &signal_handler); |
| } |
| |
| #ifdef SIGHUP |
| x = newintobject(SIGHUP); |
| dictinsert(d, "SIGHUP", x); |
| #endif |
| #ifdef SIGINT |
| x = newintobject(SIGINT); |
| dictinsert(d, "SIGINT", x); |
| #endif |
| #ifdef SIGQUIT |
| x = newintobject(SIGQUIT); |
| dictinsert(d, "SIGQUIT", x); |
| #endif |
| #ifdef SIGILL |
| x = newintobject(SIGILL); |
| dictinsert(d, "SIGILL", x); |
| #endif |
| #ifdef SIGTRAP |
| x = newintobject(SIGTRAP); |
| dictinsert(d, "SIGTRAP", x); |
| #endif |
| #ifdef SIGIOT |
| x = newintobject(SIGIOT); |
| dictinsert(d, "SIGIOT", x); |
| #endif |
| #ifdef SIGABRT |
| x = newintobject(SIGABRT); |
| dictinsert(d, "SIGABRT", x); |
| #endif |
| #ifdef SIGEMT |
| x = newintobject(SIGEMT); |
| dictinsert(d, "SIGEMT", x); |
| #endif |
| #ifdef SIGFPE |
| x = newintobject(SIGFPE); |
| dictinsert(d, "SIGFPE", x); |
| #endif |
| #ifdef SIGKILL |
| x = newintobject(SIGKILL); |
| dictinsert(d, "SIGKILL", x); |
| #endif |
| #ifdef SIGBUS |
| x = newintobject(SIGBUS); |
| dictinsert(d, "SIGBUS", x); |
| #endif |
| #ifdef SIGSEGV |
| x = newintobject(SIGSEGV); |
| dictinsert(d, "SIGSEGV", x); |
| #endif |
| #ifdef SIGSYS |
| x = newintobject(SIGSYS); |
| dictinsert(d, "SIGSYS", x); |
| #endif |
| #ifdef SIGPIPE |
| x = newintobject(SIGPIPE); |
| dictinsert(d, "SIGPIPE", x); |
| #endif |
| #ifdef SIGALRM |
| x = newintobject(SIGALRM); |
| dictinsert(d, "SIGALRM", x); |
| #endif |
| #ifdef SIGTERM |
| x = newintobject(SIGTERM); |
| dictinsert(d, "SIGTERM", x); |
| #endif |
| #ifdef SIGUSR1 |
| x = newintobject(SIGUSR1); |
| dictinsert(d, "SIGUSR1", x); |
| #endif |
| #ifdef SIGUSR2 |
| x = newintobject(SIGUSR2); |
| dictinsert(d, "SIGUSR2", x); |
| #endif |
| #ifdef SIGCLD |
| x = newintobject(SIGCLD); |
| dictinsert(d, "SIGCLD", x); |
| #endif |
| #ifdef SIGCHLD |
| x = newintobject(SIGCHLD); |
| dictinsert(d, "SIGCHLD", x); |
| #endif |
| #ifdef SIGPWR |
| x = newintobject(SIGPWR); |
| dictinsert(d, "SIGPWR", x); |
| #endif |
| #ifdef SIGIO |
| x = newintobject(SIGIO); |
| dictinsert(d, "SIGIO", x); |
| #endif |
| #ifdef SIGURG |
| x = newintobject(SIGURG); |
| dictinsert(d, "SIGURG", x); |
| #endif |
| #ifdef SIGWINCH |
| x = newintobject(SIGWINCH); |
| dictinsert(d, "SIGWINCH", x); |
| #endif |
| #ifdef SIGPOLL |
| x = newintobject(SIGPOLL); |
| dictinsert(d, "SIGPOLL", x); |
| #endif |
| #ifdef SIGSTOP |
| x = newintobject(SIGSTOP); |
| dictinsert(d, "SIGSTOP", x); |
| #endif |
| #ifdef SIGTSTP |
| x = newintobject(SIGTSTP); |
| dictinsert(d, "SIGTSTP", x); |
| #endif |
| #ifdef SIGCONT |
| x = newintobject(SIGCONT); |
| dictinsert(d, "SIGCONT", x); |
| #endif |
| #ifdef SIGTTIN |
| x = newintobject(SIGTTIN); |
| dictinsert(d, "SIGTTIN", x); |
| #endif |
| #ifdef SIGTTOU |
| x = newintobject(SIGTTOU); |
| dictinsert(d, "SIGTTOU", x); |
| #endif |
| #ifdef SIGVTALRM |
| x = newintobject(SIGVTALRM); |
| dictinsert(d, "SIGVTALRM", x); |
| #endif |
| #ifdef SIGPROF |
| x = newintobject(SIGPROF); |
| dictinsert(d, "SIGPROF", x); |
| #endif |
| #ifdef SIGCPU |
| x = newintobject(SIGCPU); |
| dictinsert(d, "SIGCPU", x); |
| #endif |
| #ifdef SIGFSZ |
| x = newintobject(SIGFSZ); |
| dictinsert(d, "SIGFSZ", x); |
| #endif |
| /* Check for errors */ |
| if (err_occurred()) |
| fatal("can't initialize module signal"); |
| } |
| |
| int |
| sigcheck() |
| { |
| int i; |
| object *f; |
| if (!tripped) |
| return 0; |
| #ifdef WITH_THREAD |
| if (get_thread_ident() != main_thread) |
| return 0; |
| #endif |
| f = getframe(); |
| if (f == NULL) |
| f = None; |
| for (i = 1; i < NSIG; i++) { |
| if (sig_list[i].tripped) { |
| object *arglist, *result; |
| sig_list[i].tripped = 0; |
| arglist = mkvalue("(iO)", i, f); |
| if (arglist == NULL) |
| result = NULL; |
| else { |
| result = call_object(sig_list[i].func,arglist); |
| DECREF(arglist); |
| } |
| if (result == NULL) { |
| return 1; |
| } else { |
| DECREF(result); |
| } |
| } |
| } |
| tripped = 0; |
| return 0; |
| } |
| |
| /* Replacement for intrcheck.c functionality */ |
| |
| void |
| initintr() |
| { |
| initsignal(); |
| } |
| |
| int |
| intrcheck() |
| { |
| if (sig_list[SIGINT].tripped) { |
| #ifdef WITH_THREAD |
| if (get_thread_ident() != main_thread) |
| return 0; |
| #endif |
| sig_list[SIGINT].tripped = 0; |
| return 1; |
| } |
| return 0; |
| } |