/* IBM_PROLOG_BEGIN_TAG */ /* This is an automatically generated prolog. */ /* */ /* gos720 src/gos/2d/XTOP/programs/xsm/signals.c 1.1 */ /* */ /* Licensed Materials - Property of IBM */ /* */ /* COPYRIGHT International Business Machines Corp. 1996 */ /* All Rights Reserved */ /* */ /* US Government Users Restricted Rights - Use, duplication or */ /* disclosure restricted by GSA ADP Schedule Contract with IBM Corp. */ /* */ /* IBM_PROLOG_END_TAG */ /* SCCSID_BEGIN_TAG */ #ifndef lint static char sccsid[] = "@(#)12 1.1 src/gos/2d/XTOP/programs/xsm/signals.c, xsample, gos720 7/16/96 11:56:09"; #endif /* SCCSID_END_TAG */ /* $XConsortium: signals.c /main/4 1995/12/08 09:19:04 mor $ */ /****************************************************************************** Copyright (c) 1994 X Consortium Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. Except as contained in this notice, the name of the X Consortium shall not be used in advertising or otherwise to promote the sale, use or other dealings in this Software without prior written authorization from the X Consortium. ******************************************************************************/ #include #include #include #ifdef USG #ifndef __TYPES__ #include /* forgot to protect it... */ #define __TYPES__ #endif /* __TYPES__ */ #else #if defined(_POSIX_SOURCE) && defined(MOTOROLA) #undef _POSIX_SOURCE #include #define _POSIX_SOURCE #else #include #endif #endif /* USG */ #ifdef X_POSIX_C_SOURCE #define _POSIX_C_SOURCE X_POSIX_C_SOURCE #include #include #undef _POSIX_C_SOURCE #else #if defined(X_NOT_POSIX) || defined(_POSIX_SOURCE) #include #include #else #define _POSIX_SOURCE #include #include #undef _POSIX_SOURCE #endif #endif #if defined(X_NOT_POSIX) && defined(SIGNALRETURNSINT) #define SIGVAL int #else #define SIGVAL void #endif #ifndef X_NOT_POSIX #define USE_POSIX_WAIT #endif #if defined(linux) || defined(SYSV) #define USE_SYSV_SIGNALS #endif #if defined(SCO) || defined(ISC) #undef SIGTSTP /* defined, but not the BSD way */ #endif #if defined(X_NOT_POSIX) && defined(SYSV) #define SIGNALS_RESET_WHEN_CAUGHT #endif #ifndef NULL #define NULL 0 #endif int checkpoint_from_signal = 0; extern Bool wantShutdown; SIGVAL (*Signal (sig, handler))() int sig; SIGVAL (*handler)(); { #ifndef X_NOT_POSIX struct sigaction sigact, osigact; sigact.sa_handler = handler; sigemptyset(&sigact.sa_mask); sigact.sa_flags = 0; sigaction(sig, &sigact, &osigact); return osigact.sa_handler; #else return signal(sig, handler); #endif } void sig_child_handler () { int pid; #if !defined(USE_POSIX_WAIT) && (defined(USE_SYSV_SIGNALS) && \ (defined(CRAY) || !defined(SIGTSTP))) wait (NULL); #endif #ifdef SIGNALS_RESET_WHEN_CAUGHT Signal (SIGCHLD, sig_child_handler); #endif /* * The wait() above must come before re-establishing the signal handler. * In between this time, a new child might have died. If we can do * a non-blocking wait, we can check for this race condition. If we * don't have non-blocking wait, we lose. */ do { #ifdef USE_POSIX_WAIT pid = waitpid (-1, NULL, WNOHANG); #else #if defined(USE_SYSV_SIGNALS) && (defined(CRAY) || !defined(SIGTSTP)) /* cannot do non-blocking wait */ pid = 0; #else union wait status; pid = wait3 (&status, WNOHANG, (struct rusage *)NULL); #endif #endif /* USE_POSIX_WAIT else */ } while (pid > 0); } void sig_term_handler () { wantShutdown = 1; checkpoint_from_signal = 1; DoSave (SmSaveLocal, SmInteractStyleNone, 1 /* fast */); } void sig_usr1_handler () { wantShutdown = 0; checkpoint_from_signal = 1; DoSave (SmSaveLocal, SmInteractStyleNone, 0 /* fast */); } void register_signals () { /* * Ignore SIGPIPE */ Signal (SIGPIPE, SIG_IGN); /* * If child process dies, call our handler */ Signal (SIGCHLD, sig_child_handler); /* * If we get a SIGTERM, do shutdown, fast, local, no interact */ Signal (SIGTERM, sig_term_handler); /* * If we get a SIGUSR1, do checkpoint, local, no interact */ Signal (SIGUSR1, sig_usr1_handler); } int execute_system_command (s) char *s; { int stat; #ifdef X_NOT_POSIX /* * Non-POSIX system() uses wait(). We must disable our sig child * handler because if it catches the signal, system() will block * forever in wait(). */ int pid; Signal (SIGCHLD, SIG_IGN); #endif stat = system (s); #ifdef X_NOT_POSIX /* * Re-enable our sig child handler. We might have missed some signals, * so do non-blocking waits until there are no signals left. */ Signal (SIGCHLD, sig_child_handler); #if !(defined(USE_SYSV_SIGNALS) && (defined(CRAY) || !defined(SIGTSTP))) do { union wait status; pid = wait3 (&status, WNOHANG, (struct rusage *)NULL); } while (pid > 0); #endif #endif /* X_NOT_POSIX */ return (stat); }