Mercurial > hg > xemacs-beta
annotate src/syssignal.h @ 5927:b58b74274fa2 cygwin
changes from long ago, never committed...
| author | Henry Thompson <ht@markup.co.uk> |
|---|---|
| date | Wed, 15 Dec 2021 19:02:33 +0000 |
| parents | 308d34e9f07d |
| children | 574f0cded429 |
| rev | line source |
|---|---|
| 428 | 1 /* syssignal.h - System-dependent definitions for signals. |
| 2 Copyright (C) 1992, 1993 Free Software Foundation, Inc. | |
| 814 | 3 Copyright (C) 1996 Ben Wing. |
| 4 | |
| 428 | 5 This file is part of XEmacs. |
| 6 | |
|
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7 XEmacs is free software: you can redistribute it and/or modify it |
| 428 | 8 under the terms of the GNU General Public License as published by the |
|
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9 Free Software Foundation, either version 3 of the License, or (at your |
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10 option) any later version. |
| 428 | 11 |
| 12 XEmacs is distributed in the hope that it will be useful, but WITHOUT | |
| 13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 15 for more details. | |
| 16 | |
| 17 You should have received a copy of the GNU General Public License | |
|
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18 along with XEmacs. If not, see <http://www.gnu.org/licenses/>. */ |
| 428 | 19 |
| 20 /* Synched up with: FSF 19.30. */ | |
| 21 | |
| 440 | 22 #ifndef INCLUDED_syssignal_h_ |
| 23 #define INCLUDED_syssignal_h_ | |
| 428 | 24 |
| 25 /* In the old world, one could not #include <signal.h> here. The party line | |
| 26 was that that header should always be #included before <config.h>, because | |
| 27 some configuration files (like s/hpux.h) indicate that SIGIO doesn't work | |
| 28 by #undef-ing SIGIO, and if this file #includes <signal.h>, then that will | |
| 29 re-#define SIGIO and confuse things. | |
| 30 | |
| 31 This was, however, a completely fucked up state of affairs, because on some | |
| 32 systems it's necessary for the s/m files to #define things in order to get | |
| 33 <signal.h> to provide the right typedefs, etc. And it's generally a broken | |
| 34 concept for <config.h> to not be the very very first file included. | |
| 35 | |
| 36 So instead of #undef'ing SIGIO in the various s/m files, I've changed them | |
| 37 to define BROKEN_SIGIO instead, then we (syssignal.h) do an #undef SIGIO | |
| 38 at the end, after including signal.h. Therefore, it's important that | |
| 39 <signal.h> not be included after "syssignal.h", but that's the normal state: | |
| 40 nothing should be directly including <signal.h> these days. | |
| 41 -- jwz, 29-nov-93 | |
| 42 */ | |
| 43 | |
| 44 #include <signal.h> | |
| 45 #include <errno.h> | |
| 46 | |
| 47 /* SIGPOLL is the SVR4 signal. Those systems generally define | |
| 48 SIGIO as an alias for SIGPOLL, but just in case ... */ | |
| 49 | |
| 50 #if defined (BROKEN_SIGIO) | |
| 51 # if defined (SIGIO) && defined (SIGPOLL) | |
| 52 # if SIGIO == SIGPOLL | |
| 53 # undef SIGIO | |
| 54 # undef SIGPOLL | |
| 55 # else | |
| 56 # undef SIGIO | |
| 57 # endif | |
| 58 # endif | |
| 59 #else /* Not BROKEN_SIGIO */ | |
| 60 # if !defined (SIGIO) && defined (SIGPOLL) | |
| 61 # define SIGIO SIGPOLL | |
| 62 # endif | |
| 63 #endif | |
| 64 | |
| 65 /* Define SIGCHLD as an alias for SIGCLD. There are many conditionals | |
| 66 testing SIGCHLD. */ | |
| 67 #if defined (SIGCLD) && !defined (SIGCHLD) | |
| 68 # define SIGCHLD SIGCLD | |
| 69 #endif /* SIGCHLD */ | |
| 70 | |
| 71 #ifdef BROKEN_SIGCHLD | |
| 72 #undef SIGCHLD | |
| 73 #endif | |
| 74 | |
| 75 #ifdef SIGCHLD | |
| 76 #define EMACS_BLOCK_SIGCHLD EMACS_BLOCK_SIGNAL (SIGCHLD) | |
| 77 #define EMACS_UNBLOCK_SIGCHLD EMACS_UNBLOCK_SIGNAL (SIGCHLD) | |
| 78 #else | |
| 79 #define EMACS_BLOCK_SIGCHLD | |
| 80 #define EMACS_UNBLOCK_SIGCHLD | |
| 81 #endif | |
| 82 | |
| 83 /* According to W.R. Stevens __Advanced Programming in the Unix | |
| 84 Environment__, there are four different paradigms for handling | |
| 85 signals. We use autoconf to tell us which one applies. | |
| 86 | |
| 87 Note that on some systems, more than one paradigm is implemented | |
| 88 (typically, the POSIX sigaction/sigprocmask and either the older | |
| 89 SYSV or BSD way). In such a case, we prefer the POSIX way. | |
| 90 | |
| 613 | 91 We used to say this: |
| 92 | |
| 93 [[ NOTE: We use EMACS_* macros for most signal operations, but | |
| 428 | 94 just signal() for the standard signal-setting operation. |
| 95 Perhaps we should change this to EMACS_SIGNAL(), but that runs | |
| 96 the risk of someone forgetting this convention and calling | |
| 613 | 97 signal() directly. ]] |
| 98 | |
| 99 But current policy is to avoid playing with macros as much as | |
| 100 possible, since in the long run it really just ends up creating | |
| 101 unmaintainable code -- someone newly reading the code is never | |
| 102 going to realize exactly which calls are redirected, and on | |
| 103 which systems, and where the redirection occurs. | |
| 104 | |
| 105 Possibly we should use the new "qxe" convention. | |
| 106 */ | |
| 428 | 107 |
| 872 | 108 typedef RETSIGTYPE (XCDECL * signal_handler_t) (int); |
| 428 | 109 |
| 110 #if defined (HAVE_SIGPROCMASK) | |
| 111 | |
| 112 /* The POSIX way (sigaction, sigprocmask, sigpending, sigsuspend) */ | |
| 113 | |
| 613 | 114 signal_handler_t qxe_reliable_signal (int signal_number, |
| 115 signal_handler_t action); | |
| 116 | |
| 117 #define EMACS_SIGNAL qxe_reliable_signal | |
| 428 | 118 |
| 119 #define EMACS_BLOCK_SIGNAL(sig) do \ | |
| 120 { \ | |
| 121 sigset_t ES_mask; \ | |
| 122 sigemptyset (&ES_mask); \ | |
| 123 sigaddset (&ES_mask, sig); \ | |
| 124 sigprocmask (SIG_BLOCK, &ES_mask, NULL); \ | |
| 125 } while (0) | |
| 126 #define EMACS_UNBLOCK_SIGNAL(sig) do \ | |
| 127 { \ | |
| 128 sigset_t ES_mask; \ | |
| 129 sigemptyset (&ES_mask); \ | |
| 130 sigaddset (&ES_mask, sig); \ | |
| 131 sigprocmask (SIG_UNBLOCK, &ES_mask, NULL); \ | |
| 132 } while (0) | |
| 133 #define EMACS_UNBLOCK_ALL_SIGNALS() do \ | |
| 134 { \ | |
| 135 sigset_t ES_mask; \ | |
| 136 sigemptyset (&ES_mask); \ | |
| 137 sigprocmask (SIG_SETMASK, &ES_mask, NULL); \ | |
| 138 } while (0) | |
| 139 #define EMACS_WAIT_FOR_SIGNAL(sig) do \ | |
| 140 { \ | |
| 141 sigset_t ES_mask; \ | |
| 142 sigprocmask (0, NULL, &ES_mask); \ | |
| 143 sigdelset (&ES_mask, sig); \ | |
| 144 sigsuspend (&ES_mask); \ | |
| 145 } while (0) | |
| 146 #define EMACS_REESTABLISH_SIGNAL(sig, handler) | |
| 2286 | 147 #define SIG_ARG_MAYBE_UNUSED(decl) UNUSED (decl) |
| 428 | 148 |
| 149 #elif defined (HAVE_SIGBLOCK) | |
| 150 | |
| 151 /* The older BSD way (signal/sigvec, sigblock, sigsetmask, sigpause) */ | |
| 152 | |
| 153 /* It's OK to use signal() here directly. No unreliable signal | |
| 154 problems. However, we use sigvec() because it allows us to | |
| 155 request interruptible I/O. */ | |
| 156 | |
| 613 | 157 #define EMACS_SIGNAL qxe_reliable_signal |
| 428 | 158 |
| 159 /* Is it necessary to define sigmask like this? */ | |
| 160 #ifndef sigmask | |
| 161 # define sigmask(no) (1L << ((no) - 1)) | |
| 162 #endif | |
| 163 | |
| 164 #define EMACS_BLOCK_SIGNAL(sig) sigblock (sigmask (sig)) | |
| 165 #define EMACS_UNBLOCK_SIGNAL(sig) sigsetmask (sigblock (0) & ~sigmask (sig)) | |
| 166 #define EMACS_UNBLOCK_ALL_SIGNALS() sigsetmask (0) | |
| 167 #define EMACS_WAIT_FOR_SIGNAL(sig) do \ | |
| 168 { \ | |
| 169 int ES_mask = sigblock (0); \ | |
| 170 sigpause (ES_mask & ~sigmask (sig)); \ | |
| 171 } while (0) | |
| 172 #define EMACS_REESTABLISH_SIGNAL(sig, handler) | |
| 2286 | 173 #define SIG_ARG_MAYBE_UNUSED(decl) UNUSED (decl) |
| 428 | 174 |
| 175 #elif defined (HAVE_SIGHOLD) | |
| 176 | |
| 177 /* The older SYSV way (signal/sigset, sighold, sigrelse, sigignore, | |
| 178 sigpause) */ | |
| 179 | |
| 613 | 180 #define EMACS_SIGNAL sigset |
| 428 | 181 #define EMACS_BLOCK_SIGNAL(sig) sighold (sig) |
| 182 #define EMACS_UNBLOCK_SIGNAL(sig) sigrelse (sig) | |
| 183 /* #### There's not really any simple way to implement this. | |
| 184 Since EMACS_UNBLOCK_ALL_SIGNALS() is only called once (at startup), | |
| 185 it's probably OK to just ignore it. */ | |
| 186 #define EMACS_UNBLOCK_ALL_SIGNALS() 0 | |
| 187 #define EMACS_WAIT_FOR_SIGNAL(sig) sigpause (sig) | |
| 188 #define EMACS_REESTABLISH_SIGNAL(sig, handler) | |
| 2286 | 189 #define SIG_ARG_MAYBE_UNUSED(decl) UNUSED (decl) |
| 428 | 190 |
| 613 | 191 #elif defined (WIN32_NATIVE) |
| 192 | |
| 193 /* MS Windows signal emulation (in turns emulates the sigset/sighold | |
| 194 paradigm) */ | |
| 195 | |
| 196 #define EMACS_SIGNAL mswindows_sigset | |
| 197 #define EMACS_BLOCK_SIGNAL(sig) mswindows_sighold (sig) | |
| 198 #define EMACS_UNBLOCK_SIGNAL(sig) mswindows_sigrelse (sig) | |
| 199 /* #### There's not really any simple way to implement this. | |
| 200 Since EMACS_UNBLOCK_ALL_SIGNALS() is only called once (at startup), | |
| 201 it's probably OK to just ignore it. */ | |
| 202 #define EMACS_UNBLOCK_ALL_SIGNALS() 0 | |
| 203 #define EMACS_WAIT_FOR_SIGNAL(sig) mswindows_sigpause (sig) | |
| 204 #define EMACS_REESTABLISH_SIGNAL(sig, handler) | |
| 2286 | 205 #define SIG_ARG_MAYBE_UNUSED(decl) UNUSED (decl) |
| 613 | 206 |
| 207 /* Defines that we need that aren't in the standard signal.h */ | |
| 208 #define SIGHUP 1 /* Hang up */ | |
| 209 #define SIGQUIT 3 /* Quit process */ | |
| 210 #define SIGKILL 9 /* Die, die die */ | |
| 211 #define SIGALRM 14 /* Alarm */ | |
| 212 #define SIGPROF 29 /* Profiling timer exp */ | |
| 213 | |
| 428 | 214 #else |
| 215 | |
| 216 /* The oldest SYSV way (signal only; unreliable signals) */ | |
| 217 | |
| 218 /* Old USG systems don't really have signal blocking. | |
| 219 We indicate this by not defining EMACS_BLOCK_SIGNAL or | |
| 220 EMACS_WAIT_FOR_SIGNAL. */ | |
| 613 | 221 #define EMACS_SIGNAL signal |
| 428 | 222 #define EMACS_UNBLOCK_SIGNAL(sig) 0 |
| 223 #define EMACS_UNBLOCK_ALL_SIGNALS() 0 | |
| 224 #define EMACS_REESTABLISH_SIGNAL(sig, handler) do \ | |
| 225 { \ | |
| 226 int old_errno = errno; \ | |
| 227 signal (sig, handler); \ | |
| 228 errno = old_errno; \ | |
| 229 } while (0) | |
| 2286 | 230 #define SIG_ARG_MAYBE_UNUSED(decl) decl |
| 428 | 231 |
| 232 /* Under SYSV, setting a signal handler for SIGCLD causes | |
| 233 SIGCLD to immediately be sent if there any unwaited processes | |
| 234 out there. This means that the SIGCLD handler *must* call | |
| 235 wait() to reap the status of all processes -- it cannot | |
| 236 simply set a flag and then reestablish the handler, because | |
| 237 it will get called again, infinitely. We only need to | |
| 238 worry about this on systems where signals need to be | |
| 239 reestablished (SYSV Release 2 and earlier). */ | |
| 240 #define OBNOXIOUS_SYSV_SIGCLD_BEHAVIOR | |
| 241 | |
| 613 | 242 #endif /* different signalling methods */ |
| 428 | 243 |
| 244 /* On bsd, [man says] kill does not accept a negative number to kill a pgrp. | |
| 245 Must do that using the killpg call. */ | |
| 442 | 246 #ifdef HAVE_KILLPG |
| 247 #define EMACS_KILLPG(pid, signo) killpg (pid, signo) | |
| 814 | 248 #elif defined (WIN32_NATIVE) |
| 249 #define EMACS_KILLPG(pid, signo) should never be called | |
| 428 | 250 #else |
| 442 | 251 #define EMACS_KILLPG(pid, signo) kill (-(pid), signo) |
| 428 | 252 #endif |
| 253 | |
| 254 #ifndef NSIG | |
| 978 | 255 # ifdef USG5_4 |
| 256 /* Some SVr4s don't define NSIG in sys/signal.h for ANSI environments; | |
| 257 * instead, there's a system variable _sys_nsig. Unfortunately, we need the | |
| 258 * constant to dimension an array. So wire in the appropriate value here. | |
| 259 */ | |
| 260 # define NSIG 32 | |
| 261 # else | |
| 262 # define NSIG (SIGUSR2+1) /* guess how many elements are in sys_siglist... */ | |
| 263 # endif | |
| 428 | 264 #endif |
| 265 | |
| 2651 | 266 /* HAVE_DECL_SYS_SIGLIST is determined by configure. On Linux, it seems, |
| 428 | 267 configure incorrectly fails to find it, so s/linux.h defines |
| 268 HAVE_SYS_SIGLIST. */ | |
| 2655 | 269 #if (!defined(HAVE_DECL_SYS_SIGLIST) || !HAVE_DECL_SYS_SIGLIST ) && !defined (HAVE_SYS_SIGLIST) |
| 442 | 270 extern const char *sys_siglist[]; |
| 428 | 271 #endif |
| 272 | |
| 273 #ifdef SIGDANGER | |
| 274 SIGTYPE memory_warning_signal (int sig); | |
| 275 #endif | |
| 276 | |
| 613 | 277 #if defined (WIN32_NATIVE) || defined (CYGWIN_BROKEN_SIGNALS) |
| 442 | 278 typedef void (__cdecl *mswindows_sighandler) (int); |
| 613 | 279 |
| 280 /* Prototypes for signal functions, see win32.c */ | |
| 442 | 281 int mswindows_sighold (int nsig); |
| 282 int mswindows_sigrelse (int nsig); | |
| 283 int mswindows_sigpause (int nsig); | |
| 284 int mswindows_raise (int nsig); | |
| 613 | 285 mswindows_sighandler mswindows_sigset (int sig, mswindows_sighandler handler); |
| 286 | |
| 287 #endif /* defined (WIN32_NATIVE) || defined (CYGWIN_BROKEN_SIGNALS) */ | |
| 288 | |
| 289 signal_handler_t set_timeout_signal (int signal_number, | |
| 290 signal_handler_t action); | |
| 291 | |
| 428 | 292 |
| 440 | 293 #endif /* INCLUDED_syssignal_h_ */ |