mirror of
https://github.com/git/git
synced 2024-08-25 02:35:46 +00:00
![Jeff King](/assets/img/avatar_default.png)
If a piece of code wanted to do some cleanup before exiting (e.g., cleaning up a lockfile or a tempfile), our usual strategy was to install a signal handler that did something like this: do_cleanup(); /* actual work */ signal(signo, SIG_DFL); /* restore previous behavior */ raise(signo); /* deliver signal, killing ourselves */ For a single handler, this works fine. However, if we want to clean up two _different_ things, we run into a problem. The most recently installed handler will run, but when it removes itself as a handler, it doesn't put back the first handler. This patch introduces sigchain, a tiny library for handling a stack of signal handlers. You sigchain_push each handler, and use sigchain_pop to restore whoever was before you in the stack. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
23 lines
340 B
C
23 lines
340 B
C
#include "sigchain.h"
|
|
#include "cache.h"
|
|
|
|
#define X(f) \
|
|
static void f(int sig) { \
|
|
puts(#f); \
|
|
fflush(stdout); \
|
|
sigchain_pop(sig); \
|
|
raise(sig); \
|
|
}
|
|
X(one)
|
|
X(two)
|
|
X(three)
|
|
#undef X
|
|
|
|
int main(int argc, char **argv) {
|
|
sigchain_push(SIGINT, one);
|
|
sigchain_push(SIGINT, two);
|
|
sigchain_push(SIGINT, three);
|
|
raise(SIGINT);
|
|
return 0;
|
|
}
|