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      1 /*
      2     SDL - Simple DirectMedia Layer
      3     Copyright (C) 1997-2012 Sam Lantinga
      4 
      5     This library is free software; you can redistribute it and/or
      6     modify it under the terms of the GNU Lesser General Public
      7     License as published by the Free Software Foundation; either
      8     version 2.1 of the License, or (at your option) any later version.
      9 
     10     This library is distributed in the hope that it will be useful,
     11     but WITHOUT ANY WARRANTY; without even the implied warranty of
     12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     13     Lesser General Public License for more details.
     14 
     15     You should have received a copy of the GNU Lesser General Public
     16     License along with this library; if not, write to the Free Software
     17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
     18 
     19     Sam Lantinga
     20     slouken (at) libsdl.org
     21 */
     22 #include "SDL_config.h"
     23 
     24 /* General fatal signal handling code for SDL */
     25 
     26 #ifdef HAVE_SIGNAL_H
     27 
     28 #include <signal.h>
     29 
     30 #include "SDL.h"
     31 #include "SDL_fatal.h"
     32 
     33 /* This installs some signal handlers for the more common fatal signals,
     34    so that if the programmer is lazy, the app doesn't die so horribly if
     35    the program crashes.
     36 */
     37 
     38 static void SDL_Parachute(int sig)
     39 {
     40 	signal(sig, SIG_DFL);
     41 	SDL_Quit();
     42 	raise(sig);
     43 }
     44 
     45 static int SDL_fatal_signals[] = {
     46 	SIGSEGV,
     47 #ifdef SIGBUS
     48 	SIGBUS,
     49 #endif
     50 #ifdef SIGFPE
     51 	SIGFPE,
     52 #endif
     53 #ifdef SIGQUIT
     54 	SIGQUIT,
     55 #endif
     56 	0
     57 };
     58 
     59 void SDL_InstallParachute(void)
     60 {
     61 	/* Set a handler for any fatal signal not already handled */
     62 	int i;
     63 #ifdef HAVE_SIGACTION
     64 	struct sigaction action;
     65 
     66 	for ( i=0; SDL_fatal_signals[i]; ++i ) {
     67 		sigaction(SDL_fatal_signals[i], NULL, &action);
     68 		if ( action.sa_handler == SIG_DFL ) {
     69 			action.sa_handler = SDL_Parachute;
     70 			sigaction(SDL_fatal_signals[i], &action, NULL);
     71 		}
     72 	}
     73 #ifdef SIGALRM
     74 	/* Set SIGALRM to be ignored -- necessary on Solaris */
     75 	sigaction(SIGALRM, NULL, &action);
     76 	if ( action.sa_handler == SIG_DFL ) {
     77 		action.sa_handler = SIG_IGN;
     78 		sigaction(SIGALRM, &action, NULL);
     79 	}
     80 #endif
     81 #else
     82 	void (*ohandler)(int);
     83 
     84 	for ( i=0; SDL_fatal_signals[i]; ++i ) {
     85 		ohandler = signal(SDL_fatal_signals[i], SDL_Parachute);
     86 		if ( ohandler != SIG_DFL ) {
     87 			signal(SDL_fatal_signals[i], ohandler);
     88 		}
     89 	}
     90 #endif /* HAVE_SIGACTION */
     91 	return;
     92 }
     93 
     94 void SDL_UninstallParachute(void)
     95 {
     96 	/* Remove a handler for any fatal signal handled */
     97 	int i;
     98 #ifdef HAVE_SIGACTION
     99 	struct sigaction action;
    100 
    101 	for ( i=0; SDL_fatal_signals[i]; ++i ) {
    102 		sigaction(SDL_fatal_signals[i], NULL, &action);
    103 		if ( action.sa_handler == SDL_Parachute ) {
    104 			action.sa_handler = SIG_DFL;
    105 			sigaction(SDL_fatal_signals[i], &action, NULL);
    106 		}
    107 	}
    108 #else
    109 	void (*ohandler)(int);
    110 
    111 	for ( i=0; SDL_fatal_signals[i]; ++i ) {
    112 		ohandler = signal(SDL_fatal_signals[i], SIG_DFL);
    113 		if ( ohandler != SDL_Parachute ) {
    114 			signal(SDL_fatal_signals[i], ohandler);
    115 		}
    116 	}
    117 #endif /* HAVE_SIGACTION */
    118 }
    119 
    120 #else
    121 
    122 /* No signals on this platform, nothing to do.. */
    123 
    124 void SDL_InstallParachute(void)
    125 {
    126 	return;
    127 }
    128 
    129 void SDL_UninstallParachute(void)
    130 {
    131 	return;
    132 }
    133 
    134 #endif /* HAVE_SIGNAL_H */
    135