depot/third_party/tvl/third_party/git/sigchain.c
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GitOrigin-RevId: 3fc1143a04da49a92c3663813c6a0c1e8ccd477f
2020-09-29 23:42:59 -04:00

61 lines
1.1 KiB
C

#include "cache.h"
#include "sigchain.h"
#define SIGCHAIN_MAX_SIGNALS 32
struct sigchain_signal {
sigchain_fun *old;
int n;
int alloc;
};
static struct sigchain_signal signals[SIGCHAIN_MAX_SIGNALS];
static void check_signum(int sig)
{
if (sig < 1 || sig >= SIGCHAIN_MAX_SIGNALS)
BUG("signal out of range: %d", sig);
}
int sigchain_push(int sig, sigchain_fun f)
{
struct sigchain_signal *s = signals + sig;
check_signum(sig);
ALLOC_GROW(s->old, s->n + 1, s->alloc);
s->old[s->n] = signal(sig, f);
if (s->old[s->n] == SIG_ERR)
return -1;
s->n++;
return 0;
}
int sigchain_pop(int sig)
{
struct sigchain_signal *s = signals + sig;
check_signum(sig);
if (s->n < 1)
return 0;
if (signal(sig, s->old[s->n - 1]) == SIG_ERR)
return -1;
s->n--;
return 0;
}
void sigchain_push_common(sigchain_fun f)
{
sigchain_push(SIGINT, f);
sigchain_push(SIGHUP, f);
sigchain_push(SIGTERM, f);
sigchain_push(SIGQUIT, f);
sigchain_push(SIGPIPE, f);
}
void sigchain_pop_common(void)
{
sigchain_pop(SIGPIPE);
sigchain_pop(SIGQUIT);
sigchain_pop(SIGTERM);
sigchain_pop(SIGHUP);
sigchain_pop(SIGINT);
}