1#include "cache.h"2#include "sigchain.h"34#define SIGCHAIN_MAX_SIGNALS 3256struct sigchain_signal {7sigchain_fun *old;8int n;9int alloc;10};11static struct sigchain_signal signals[SIGCHAIN_MAX_SIGNALS];1213static void check_signum(int sig)14{15if (sig < 1 || sig >= SIGCHAIN_MAX_SIGNALS)16die("BUG: signal out of range: %d", sig);17}1819int sigchain_push(int sig, sigchain_fun f)20{21struct sigchain_signal *s = signals + sig;22check_signum(sig);2324ALLOC_GROW(s->old, s->n + 1, s->alloc);25s->old[s->n] = signal(sig, f);26if (s->old[s->n] == SIG_ERR)27return -1;28s->n++;29return 0;30}3132int sigchain_pop(int sig)33{34struct sigchain_signal *s = signals + sig;35check_signum(sig);36if (s->n < 1)37return 0;3839if (signal(sig, s->old[s->n - 1]) == SIG_ERR)40return -1;41s->n--;42return 0;43}4445void sigchain_push_common(sigchain_fun f)46{47sigchain_push(SIGINT, f);48sigchain_push(SIGHUP, f);49sigchain_push(SIGTERM, f);50sigchain_push(SIGQUIT, f);51sigchain_push(SIGPIPE, f);52}5354void sigchain_pop_common(void)55{56sigchain_pop(SIGPIPE);57sigchain_pop(SIGQUIT);58sigchain_pop(SIGTERM);59sigchain_pop(SIGHUP);60sigchain_pop(SIGINT);61}