Return to signal.c CVS log

Up to [MW Coherent from dump] / coherent / g / usr / lib / uucp / tay104 / unix

Annotation of coherent/g/usr/lib/uucp/tay104/unix/signal.c, revision 1.1

1.1     ! root        1: /* signal.c
        !             2:    Signal handling routines.
        !             3: 
        !             4:    Copyright (C) 1992 Ian Lance Taylor
        !             5: 
        !             6:    This file is part of the Taylor UUCP package.
        !             7: 
        !             8:    This program is free software; you can redistribute it and/or
        !             9:    modify it under the terms of the GNU General Public License as
        !            10:    published by the Free Software Foundation; either version 2 of the
        !            11:    License, or (at your option) any later version.
        !            12: 
        !            13:    This program is distributed in the hope that it will be useful, but
        !            14:    WITHOUT ANY WARRANTY; without even the implied warranty of
        !            15:    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
        !            16:    General Public License for more details.
        !            17: 
        !            18:    You should have received a copy of the GNU General Public License
        !            19:    along with this program; if not, write to the Free Software
        !            20:    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
        !            21: 
        !            22:    The author of the program may be contacted at [email protected] or
        !            23:    c/o Infinity Development Systems, P.O. Box 520, Waltham, MA 02254.
        !            24:    */
        !            25: 
        !            26: #include "uucp.h"
        !            27: 
        !            28: #include "uudefs.h"
        !            29: #include "sysdep.h"
        !            30: #include "system.h"
        !            31: 
        !            32: #include <errno.h>
        !            33: 
        !            34: /* Signal handling routines.  When we catch a signal, we want to set
        !            35:    the appropriate elements of afSignal and afLog_signal to TRUE.  If
        !            36:    we are on a system which restarts system calls, we may also want to
        !            37:    longjmp out.  On a system which does not restart system calls,
        !            38:    these signal handling routines are well-defined by ANSI C.  */
        !            39: 
        !            40: #if HAVE_RESTARTABLE_SYSCALLS
        !            41: volatile sig_atomic_t fSjmp;
        !            42: volatile jmp_buf sSjmp_buf;
        !            43: #endif /* HAVE_RESTARTABLE_SYSCALLS */
        !            44: 
        !            45: /* Some systems, such as SunOS, have a SA_INTERRUPT bit that must be
        !            46:    set in the sigaction structure to force system calls to be
        !            47:    interrupted.  */
        !            48: #ifndef SA_INTERRUPT
        !            49: #define SA_INTERRUPT 0
        !            50: #endif
        !            51: 
        !            52: /* The SVR3 sigset function can be called just like signal, unless
        !            53:    system calls are restarted which is extremely unlikely; we prevent
        !            54:    this case in sysh.unx.  */
        !            55: #if HAVE_SIGSET && ! HAVE_SIGACTION && ! HAVE_SIGVEC
        !            56: #define signal sigset
        !            57: #endif
        !            58: 
        !            59: /* The sigvec structure changed from 4.2BSD to 4.3BSD.  These macros
        !            60:    make the 4.3 code backward compatible.  */
        !            61: #ifndef SV_INTERRUPT
        !            62: #define SV_INTERRUPT 0
        !            63: #endif
        !            64: #if ! HAVE_SIGVEC_SV_FLAGS
        !            65: #define sv_flags sv_onstack
        !            66: #endif
        !            67: 
        !            68: /* Catch a signal.  Reinstall the signal handler if necessary, set the
        !            69:    appropriate variables, and do a longjmp if necessary.  */
        !            70: 
        !            71: RETSIGTYPE
        !            72: ussignal (isig)
        !            73:      int isig;
        !            74: {
        !            75:   int iindex;
        !            76: 
        !            77: #if ! HAVE_SIGACTION && ! HAVE_SIGVEC && ! HAVE_SIGSET
        !            78:   (void) signal (isig, ussignal);
        !            79: #endif
        !            80: 
        !            81:   switch (isig)
        !            82:     {
        !            83:     default: iindex = INDEXSIG_SIGHUP; break;
        !            84: #ifdef SIGINT
        !            85:     case SIGINT: iindex = INDEXSIG_SIGINT; break;
        !            86: #endif
        !            87: #ifdef SIGQUIT
        !            88:     case SIGQUIT: iindex = INDEXSIG_SIGQUIT; break;
        !            89: #endif
        !            90: #ifdef SIGTERM
        !            91:     case SIGTERM: iindex = INDEXSIG_SIGTERM; break;
        !            92: #endif
        !            93: #ifdef SIGPIPE
        !            94:     case SIGPIPE: iindex = INDEXSIG_SIGPIPE; break;
        !            95: #endif
        !            96:     }
        !            97: 
        !            98:   afSignal[iindex] = TRUE;
        !            99:   afLog_signal[iindex] = TRUE;
        !           100: 
        !           101: #if HAVE_RESTARTABLE_SYSCALLS
        !           102:   if (fSjmp)
        !           103:     longjmp (sSjmp_buf, 1);
        !           104: #endif /* HAVE_RESTARTABLE_SYSCALLS */
        !           105: }
        !           106: 
        !           107: /* Prepare to catch a signal.  This is basically the ANSI C routine
        !           108:    signal, but it uses sigaction or sigvec instead if they are
        !           109:    available.  If fforce is FALSE, we do not set the signal if it is
        !           110:    currently being ignored.  If pfignored is not NULL and fforce is
        !           111:    FALSE, then *pfignored will be set to TRUE if the signal was
        !           112:    previously being ignored (if fforce is TRUE the value returned in
        !           113:    *pfignored is meaningless).  If we can't change the signal handler
        !           114:    we give a fatal error.  */
        !           115: 
        !           116: void
        !           117: usset_signal (isig, pfn, fforce, pfignored)
        !           118:      int isig;
        !           119:      RETSIGTYPE (*pfn) P((int));
        !           120:      boolean fforce;
        !           121:      boolean *pfignored;
        !           122: {
        !           123: #if HAVE_SIGACTION
        !           124: 
        !           125:   struct sigaction s;
        !           126: 
        !           127:   if (! fforce)
        !           128:     {
        !           129:       (void) (sigemptyset (&s.sa_mask));
        !           130:       if (sigaction (isig, (struct sigaction *) NULL, &s) != 0)
        !           131:        ulog (LOG_FATAL, "sigaction (%d): %s", isig, strerror (errno));
        !           132: 
        !           133:       if (s.sa_handler == SIG_IGN)
        !           134:        {
        !           135:          if (pfignored != NULL)
        !           136:            *pfignored = TRUE;
        !           137:          return;
        !           138:        }
        !           139: 
        !           140:       if (pfignored != NULL)
        !           141:        *pfignored = FALSE;
        !           142:     }
        !           143: 
        !           144:   s.sa_handler = pfn;
        !           145:   (void) (sigemptyset (&s.sa_mask));
        !           146:   s.sa_flags = SA_INTERRUPT;
        !           147: 
        !           148:   if (sigaction (isig, &s, (struct sigaction *) NULL) != 0)
        !           149:     ulog (LOG_FATAL, "sigaction (%d): %s", isig, strerror (errno));
        !           150: 
        !           151: #else /* ! HAVE_SIGACTION */
        !           152: #if HAVE_SIGVEC
        !           153: 
        !           154:   struct sigvec s;
        !           155: 
        !           156:   if (! fforce)
        !           157:     {
        !           158:       if (sigvec (isig, (struct sigvec *) NULL, &s) != 0)
        !           159:        ulog (LOG_FATAL, "sigvec (%d): %s", isig, strerror (errno));
        !           160: 
        !           161:       if (s.sv_handler == SIG_IGN)
        !           162:        {
        !           163:          if (pfignored != NULL)
        !           164:            *pfignored = TRUE;
        !           165:          return;
        !           166:        }
        !           167: 
        !           168:       if (pfignored != NULL)
        !           169:        *pfignored = FALSE;
        !           170:     }
        !           171: 
        !           172:   s.sv_handler = pfn;
        !           173:   s.sv_mask = 0;
        !           174:   s.sv_flags = SV_INTERRUPT;
        !           175: 
        !           176:   if (sigvec (isig, &s, (struct sigvec *) NULL) != 0)
        !           177:     ulog (LOG_FATAL, "sigvec (%d): %s", isig, strerror (errno));
        !           178: 
        !           179: #else /* ! HAVE_SIGVEC */
        !           180: 
        !           181:   if (! fforce)
        !           182:     {
        !           183:       if (signal (isig, SIG_IGN) == SIG_IGN)
        !           184:        {
        !           185:          if (pfignored != NULL)
        !           186:            *pfignored = TRUE;
        !           187:          return;
        !           188:        }
        !           189: 
        !           190:       if (pfignored != NULL)
        !           191:        *pfignored = FALSE;
        !           192:     }
        !           193: 
        !           194:   (void) signal (isig, pfn);
        !           195: 
        !           196: #endif /* ! HAVE_SIGVEC */
        !           197: #endif /* ! HAVE_SIGACTION */
        !           198: }
        !           199: 
        !           200: /* The routine called by the system independent code, which always
        !           201:    uses the same signal handler.  */
        !           202: 
        !           203: void
        !           204: usysdep_signal (isig)
        !           205:      int isig;
        !           206: {
        !           207:   usset_signal (isig, ussignal, FALSE, (boolean *) NULL);
        !           208: }

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.