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/*
cleanup.c , Copyright 2006 - 2011 Thomas Schmitt <scdbackup@gmx.net>
A signal handler which cleans up an application and exits.
Provided under GPLv2+ license within GPL projects, BSD license elsewise.
*/
/*
cc -g -o cleanup -DCleanup_standalonE cleanup.c
*/
#ifdef HAVE_CONFIG_H
#include "../config.h"
#endif
#include <sys/types.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <signal.h>
typedef void (*sighandler_t)(int);
#include "cleanup.h"
#ifndef Cleanup_has_no_libburn_os_H
#include "../libburn/os.h"
/* see os.h for name of particular os-*.h where this is defined */
static int signal_list[]= { BURN_OS_SIGNAL_MACRO_LIST , -1};
static char *signal_name_list[]= { BURN_OS_SIGNAL_NAME_LIST , "@"};
static int signal_list_count= BURN_OS_SIGNAL_COUNT;
static int non_signal_list[]= { BURN_OS_NON_SIGNAL_MACRO_LIST, -1};
static int non_signal_list_count= BURN_OS_NON_SIGNAL_COUNT;
#else /* ! Cleanup_has_no_libburn_os_H */
/* Outdated. GNU/Linux only.
For backward compatibility with pre-libburn-0.2.3 */
/* Signals to be caught */
static int signal_list[]= {
SIGHUP, SIGINT, SIGQUIT, SIGILL, SIGABRT,
SIGFPE, SIGSEGV, SIGPIPE, SIGALRM, SIGTERM,
SIGUSR1, SIGUSR2, SIGXCPU, SIGTSTP, SIGTTIN,
SIGTTOU,
SIGBUS, SIGPOLL, SIGPROF, SIGSYS, SIGTRAP,
SIGVTALRM, SIGXCPU, SIGXFSZ, -1
};
static char *signal_name_list[]= {
"SIGHUP", "SIGINT", "SIGQUIT", "SIGILL", "SIGABRT",
"SIGFPE", "SIGSEGV", "SIGPIPE", "SIGALRM", "SIGTERM",
"SIGUSR1", "SIGUSR2", "SIGXCPU", "SIGTSTP", "SIGTTIN",
"SIGTTOU",
"SIGBUS", "SIGPOLL", "SIGPROF", "SIGSYS", "SIGTRAP",
"SIGVTALRM", "SIGXCPU", "SIGXFSZ", "@"
};
static int signal_list_count= 24;
/* Signals not to be caught */
static int non_signal_list[]= {
SIGKILL, SIGCHLD, SIGSTOP, SIGURG, SIGWINCH, -1
};
static int non_signal_list_count= 5;
#endif /* Cleanup_has_no_libburn_os_H */
/* run time dynamic part */
static char cleanup_msg[4096]= {""};
static int cleanup_exiting= 0;
static int cleanup_has_reported= -1234567890;
static void *cleanup_app_handle= NULL;
static Cleanup_app_handler_T cleanup_app_handler= NULL;
static int cleanup_perform_app_handler_first= 0;
static int Cleanup_handler_exit(int exit_value, int signum, int flag)
{
int ret;
if(cleanup_msg[0]!=0 && cleanup_has_reported!=signum) {
fprintf(stderr,"\n%s\n",cleanup_msg);
cleanup_has_reported= signum;
}
if(cleanup_perform_app_handler_first)
if(cleanup_app_handler!=NULL) {
ret= (*cleanup_app_handler)(cleanup_app_handle,signum,0);
if(ret==2 || ret==-2)
return(2);
}
if(cleanup_exiting) {
fprintf(stderr,"cleanup: ABORT : repeat by pid=%.f, signum=%d\n",
(double) getpid(), signum);
return(0);
}
cleanup_exiting= 1;
alarm(0);
if(!cleanup_perform_app_handler_first)
if(cleanup_app_handler!=NULL) {
ret= (*cleanup_app_handler)(cleanup_app_handle,signum,0);
if(ret==2 || ret==-2)
return(2);
}
exit(exit_value);
}
static void Cleanup_handler_generic(int signum)
{
int i;
sprintf(cleanup_msg,"UNIX-SIGNAL caught: %d errno= %d",signum,errno);
for(i= 0; i<signal_list_count; i++)
if(signum==signal_list[i]) {
sprintf(cleanup_msg,"UNIX-SIGNAL: %s errno= %d",
signal_name_list[i],errno);
break;
}
Cleanup_handler_exit(1,signum,0);
}
static char *Cleanup_signo_to_name(int signo)
{
int i;
for(i= 0; i < signal_list_count; i++)
if(signal_list[i] == signo)
return(signal_name_list[i]);
return("");
}
int Cleanup_set_handlers(void *handle, Cleanup_app_handler_T handler, int flag)
/*
bit0= set to default handlers
bit1= set to ignore
bit2= set cleanup_perform_app_handler_first
bit3= set SIGABRT to handler (makes sense with bits 0 or 1)
bit8= set SIGPIPE to SIGIGN
*/
{
int i,j,max_sig= -1,min_sig= 0x7fffffff;
char *sig_name;
sighandler_t sig_handler;
cleanup_msg[0]= 0;
cleanup_app_handle= handle;
cleanup_app_handler= handler;
/* <<< make cleanup_exiting thread safe to get rid of this */
if(flag&4)
cleanup_perform_app_handler_first= 1;
if(flag&1)
sig_handler= SIG_DFL;
else if(flag&2)
sig_handler= SIG_IGN;
else
sig_handler= Cleanup_handler_generic;
/* set all signal numbers between the lowest and highest in the list
except those in the non-signal list */
for(i= 0; i<signal_list_count; i++) {
if(signal_list[i]>max_sig)
max_sig= signal_list[i];
if(signal_list[i]<min_sig)
min_sig= signal_list[i];
}
for(i= min_sig; i<=max_sig; i++) {
for(j= 0; j<non_signal_list_count; j++)
if(i==non_signal_list[j])
break;
if(j>=non_signal_list_count) {
/* Avoid to use particular SIG macros which might not be defined.
If they are defined, then their names are in the name list.
*/
if(flag & (8 | 256))
sig_name= Cleanup_signo_to_name(i);
else
sig_name= "";
if((flag & 8) && strcmp(sig_name, "SIGABRT") == 0)
signal(i,Cleanup_handler_generic);
else if((flag & 256) && strcmp(sig_name, "SIGPIPE") == 0)
signal(i, SIG_IGN);
else
signal(i,sig_handler);
}
}
return(1);
}
#ifdef Cleanup_standalonE
struct Demo_apP {
char *msg;
};
int Demo_app_handler(struct Demo_apP *demoapp, int signum, int flag)
{
printf("Handling exit of demo application on signal %d. msg=\"%s\"\n",
signum,demoapp->msg);
return(1);
}
main()
{
struct Demo_apP demoapp;
demoapp.msg= "Good Bye";
Cleanup_set_handlers(&demoapp,(Cleanup_app_handler_T) Demo_app_handler,0);
if(1) { /* change to 0 in order to wait for external signals */
char *cpt= NULL, c= ' ';
printf("Intentionally provoking SIGSEGV ...\n");
c= *cpt;
printf("Strange: The system ignored a SIGSEGV: c= %u\n", (unsigned int) c);
} else {
printf("killme: %d\n",getpid());
sleep(3600);
}
Cleanup_set_handlers(NULL,NULL,1);
exit(0);
}
#endif /* Cleanup_standalonE */