1 #include "sigchain.h" 2 #include "cache.h" 3 4 #define SIGCHAIN_MAX_SIGNALS 32 5 6 struct sigchain_signal { 7 sigchain_fun *old; 8 int n; 9 int alloc; 10 }; 11 static struct sigchain_signal signals[SIGCHAIN_MAX_SIGNALS]; 12 13 static void check_signum(int sig) 14 { 15 if (sig < 1 || sig >= SIGCHAIN_MAX_SIGNALS) 16 die("BUG: signal out of range: %d", sig); 17 } 18 19 static int sigchain_push(int sig, sigchain_fun f) 20 { 21 struct sigchain_signal *s = signals + sig; 22 check_signum(sig); 23 24 ALLOC_GROW(s->old, s->n + 1, s->alloc); 25 s->old[s->n] = signal(sig, f); 26 if (s->old[s->n] == SIG_ERR) 27 return -1; 28 s->n++; 29 return 0; 30 } 31 32 int sigchain_pop(int sig) 33 { 34 struct sigchain_signal *s = signals + sig; 35 check_signum(sig); 36 if (s->n < 1) 37 return 0; 38 39 if (signal(sig, s->old[s->n - 1]) == SIG_ERR) 40 return -1; 41 s->n--; 42 return 0; 43 } 44 45 void sigchain_push_common(sigchain_fun f) 46 { 47 sigchain_push(SIGINT, f); 48 sigchain_push(SIGHUP, f); 49 sigchain_push(SIGTERM, f); 50 sigchain_push(SIGQUIT, f); 51 sigchain_push(SIGPIPE, f); 52 } 53
