strbuf: add strbuf_read_once to read without blocking
[git/git.git] / sigchain.c
CommitLineData
4a16d072 1#include "cache.h"
1c4b6604 2#include "sigchain.h"
4a16d072
JK
3
4#define SIGCHAIN_MAX_SIGNALS 32
5
6struct sigchain_signal {
7 sigchain_fun *old;
8 int n;
9 int alloc;
10};
11static struct sigchain_signal signals[SIGCHAIN_MAX_SIGNALS];
12
13static 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
19int 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
32int 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}
57b235a4
JK
44
45void 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}