Parser/intrcheck.c

   1 /***********************************************************
   2 Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
   3 The Netherlands.
   4
   5                         All Rights Reserved
   6
   7 Permission to use, copy, modify, and distribute this software and its
   8 documentation for any purpose and without fee is hereby granted,
   9 provided that the above copyright notice appear in all copies and that
  10 both that copyright notice and this permission notice appear in
  11 supporting documentation, and that the names of Stichting Mathematisch
  12 Centrum or CWI or Corporation for National Research Initiatives or
  13 CNRI not be used in advertising or publicity pertaining to
  14 distribution of the software without specific, written prior
  15 permission.
  16
  17 While CWI is the initial source for this software, a modified version
  18 is made available by the Corporation for National Research Initiatives
  19 (CNRI) at the Internet address ftp://ftp.python.org.
  20
  21 STICHTING MATHEMATISCH CENTRUM AND CNRI DISCLAIM ALL WARRANTIES WITH
  22 REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
  23 MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH
  24 CENTRUM OR CNRI BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
  25 DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  26 PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  27 TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  28 PERFORMANCE OF THIS SOFTWARE.
  29
  30 ******************************************************************/
  31
  32 /* Check for interrupts */
  33
  34 #include "config.h"
  35
  36 /* config.h may or may not define DL_IMPORT */
  37 #ifndef DL_IMPORT       /* declarations for DLL import/export */
  38 #define DL_IMPORT(RTYPE) RTYPE
  39 #endif
  40
  41 #include "myproto.h"
  42 #include "mymalloc.h" /* For ANY */
  43 #include "intrcheck.h"
  44
  45 /* Copied here from ceval.h -- can't include that file. */
  46 int Py_AddPendingCall Py_PROTO((int (*func) Py_PROTO((ANY *)), ANY *arg));
  47
  48
  49 #ifdef QUICKWIN
  50
  51 #include <io.h>
  52
  53 void
  54 PyOS_InitInterrupts()
  55 {
  56 }
  57
  58 void
  59 PyOS_FiniInterrupts()
  60 {
  61 }
  62
  63 int
  64 PyOS_InterruptOccurred()
  65 {
  66         _wyield();
  67 }
  68
  69 #define OK
  70
  71 #endif /* QUICKWIN */
  72
  73 #if defined(_M_IX86) && !defined(__QNX__)
  74 #include <io.h>
  75 #endif
  76
  77 #if defined(MSDOS) && !defined(QUICKWIN)
  78
  79 #ifdef __GNUC__
  80
  81 /* This is for DJGPP's GO32 extender.  I don't know how to trap
  82  * control-C  (There's no API for ctrl-C, and I don't want to mess with
  83  * the interrupt vectors.)  However, this DOES catch control-break.
  84  * --Amrit
  85  */
  86
  87 #include <go32.h>
  88
  89 void
  90 PyOS_InitInterrupts()
  91 {
  92         _go32_want_ctrl_break(1 /* TRUE */);
  93 }
  94
  95 void
  96 PyOS_FiniInterrupts()
  97 {
  98 }
  99
 100 int
 101 PyOS_InterruptOccurred()
 102 {
 103         return _go32_was_ctrl_break_hit();
 104 }
 105
 106 #else /* !__GNUC__ */
 107
 108 /* This might work for MS-DOS (untested though): */
 109
 110 void
 111 PyOS_InitInterrupts()
 112 {
 113 }
 114
 115 void
 116 PyOS_FiniInterrupts()
 117 {
 118 }
 119
 120 int
 121 PyOS_InterruptOccurred()
 122 {
 123         int interrupted = 0;
 124         while (kbhit()) {
 125                 if (getch() == '\003')
 126                         interrupted = 1;
 127         }
 128         return interrupted;
 129 }
 130
 131 #endif /* __GNUC__ */
 132
 133 #define OK
 134
 135 #endif /* MSDOS && !QUICKWIN */
 136
 137
 138 #ifdef macintosh
 139
 140 /* The Mac interrupt code has moved to macglue.c */
 141 #define OK
 142
 143 #endif /* macintosh */
 144
 145
 146 #ifndef OK
 147
 148 /* Default version -- for real operating systems and for Standard C */
 149
 150 #include <stdio.h>
 151 #include <string.h>
 152 #include <signal.h>
 153 #ifdef HAVE_UNISTD_H
 154 #include <unistd.h>
 155 #endif
 156
 157 static int interrupted;
 158
 159 void
 160 PyErr_SetInterrupt()
 161 {
 162         interrupted = 1;
 163 }
 164
 165 extern int PyErr_CheckSignals();
 166
 167 /* ARGSUSED */
 168 static RETSIGTYPE
 169 #if defined(_M_IX86) && !defined(__QNX__)
 170 intcatcher(int sig)     /* So the C compiler shuts up */
 171 #else /* _M_IX86 */
 172 intcatcher(sig)
 173         int sig; /* Not used by required by interface */
 174 #endif /* _M_IX86 */
 175 {
 176         extern void Py_Exit Py_PROTO((int));
 177         static char message[] =
 178 "python: to interrupt a truly hanging Python program, interrupt once more.\n";
 179         switch (interrupted++) {
 180         case 0:
 181                 break;
 182         case 1:
 183                 write(2, message, strlen(message));
 184                 break;
 185         case 2:
 186                 interrupted = 0;
 187                 Py_Exit(1);
 188                 break;
 189         }
 190         signal(SIGINT, intcatcher);
 191         Py_AddPendingCall(PyErr_CheckSignals, NULL);
 192 }
 193
 194 static RETSIGTYPE (*old_siginthandler)() = SIG_DFL;
 195
 196 void
 197 PyOS_InitInterrupts()
 198 {
 199         if ((old_siginthandler = signal(SIGINT, SIG_IGN)) != SIG_IGN)
 200                 signal(SIGINT, intcatcher);
 201 #ifdef HAVE_SIGINTERRUPT
 202         /* This is for SunOS and other modern BSD derivatives.
 203            It means that system calls (like read()) are not restarted
 204            after an interrupt.  This is necessary so interrupting a
 205            read() or readline() call works as expected.
 206            XXX On old BSD (pure 4.2 or older) you may have to do this
 207            differently! */
 208         siginterrupt(SIGINT, 1);
 209 #endif /* HAVE_SIGINTERRUPT */
 210 }
 211
 212 void
 213 PyOS_FiniInterrupts()
 214 {
 215         signal(SIGINT, old_siginthandler);
 216 }
 217
 218 int
 219 PyOS_InterruptOccurred()
 220 {
 221         if (!interrupted)
 222                 return 0;
 223         interrupted = 0;
 224         return 1;
 225 }
 226
 227 #endif /* !OK */
 228
 229 void
 230 PyOS_AfterFork()
 231 {
 232 }