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/* signal.c: a Hugh-approved signal handler. */
#include <signal.h>
#include <setjmp.h>
#include "rc.h"
#include "sigmsgs.h"
#include "jbwrap.h"
Jbwrap slowbuf;
volatile SIG_ATOMIC_T slow, interrupt_happened;
void (*sighandlers[NUMOFSIGNALS])(int);
static volatile SIG_ATOMIC_T sigcount, caught[NUMOFSIGNALS];
extern void catcher(int s) {
if (caught[s] == 0) {
sigcount++;
caught[s] = 1;
}
signal(s, catcher);
interrupt_happened = TRUE;
#ifndef HAVE_RESTARTABLE_SYSCALLS
if (slow)
longjmp(slowbuf.j, 1);
#endif
}
extern void sigchk() {
void (*h)(int);
int s, i;
if (sigcount == 0)
return; /* ho hum; life as usual */
if (forked)
exit(1); /* exit unconditionally on a signal in a child process */
for (i = 0, s = -1; i < NUMOFSIGNALS; i++)
if (caught[i] != 0) {
s = i;
--sigcount;
caught[s] = 0;
break;
}
if (s == -1)
panic("all-zero sig vector with nonzero sigcount");
if ((h = sighandlers[s]) == SIG_DFL)
panic("caught signal set to SIG_DFL");
if (h == SIG_IGN)
panic("caught signal set to SIG_IGN");
(*h)(s);
}
extern void (*rc_signal(int s, void (*h)(int)))(int) {
void (*old)(int);
sigchk();
old = sighandlers[s];
if (h == SIG_DFL || h == SIG_IGN) {
signal(s, h);
sighandlers[s] = h;
} else {
sighandlers[s] = h;
signal(s, catcher);
}
return old;
}
extern void initsignal() {
void (*h)(int);
int i;
for (i = 1; i < NUMOFSIGNALS; i++) {
if ((h = signal(i, SIG_DFL)) != SIG_DFL)
signal(i, h);
sighandlers[i] = h;
}
#ifdef SIGCLD
/* Ensure that SIGCLD is not SIG_IGN. Solaris's rshd does this. :-( */
h = signal(SIGCLD, SIG_DFL);
if (h != SIG_IGN)
signal(SIGCLD, h);
#endif
}
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