Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame^] | 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 | } |