[mirror_ubuntu-artful-kernel.git] / tools / lib / subcmd / sigchain.c

#include <signal.h>
#include "subcmd-util.h"
#include "sigchain.h"

#define SIGCHAIN_MAX_SIGNALS 32

struct sigchain_signal {
	sigchain_fun *old;
	int n;
	int alloc;
};
static struct sigchain_signal signals[SIGCHAIN_MAX_SIGNALS];

static void check_signum(int sig)
{
	if (sig < 1 || sig >= SIGCHAIN_MAX_SIGNALS)
		die("BUG: signal out of range: %d", sig);
}

static int sigchain_push(int sig, sigchain_fun f)
{
	struct sigchain_signal *s = signals + sig;
	check_signum(sig);

	ALLOC_GROW(s->old, s->n + 1, s->alloc);
	s->old[s->n] = signal(sig, f);
	if (s->old[s->n] == SIG_ERR)
		return -1;
	s->n++;
	return 0;
}

int sigchain_pop(int sig)
{
	struct sigchain_signal *s = signals + sig;
	check_signum(sig);
	if (s->n < 1)
		return 0;

	if (signal(sig, s->old[s->n - 1]) == SIG_ERR)
		return -1;
	s->n--;
	return 0;
}

void sigchain_push_common(sigchain_fun f)
{
	sigchain_push(SIGINT, f);
	sigchain_push(SIGHUP, f);
	sigchain_push(SIGTERM, f);
	sigchain_push(SIGQUIT, f);
	sigchain_push(SIGPIPE, f);
}
Commit	Line	Data
2f4ce5ec JP	1	#include <signal.h>
2f4ce5ec JP	2	#include "subcmd-util.h"
a930d2c0	3	#include "sigchain.h"
a930d2c0 IM	4
	5	#define SIGCHAIN_MAX_SIGNALS 32
	6
	7	struct sigchain_signal {
	8	sigchain_fun *old;
	9	int n;
	10	int alloc;
	11	};
	12	static struct sigchain_signal signals[SIGCHAIN_MAX_SIGNALS];
	13
	14	static void check_signum(int sig)
	15	{
	16	if (sig < 1 \|\| sig >= SIGCHAIN_MAX_SIGNALS)
	17	die("BUG: signal out of range: %d", sig);
	18	}
	19
a41794cd	20	static int sigchain_push(int sig, sigchain_fun f)
a930d2c0 IM	21	{
	22	struct sigchain_signal *s = signals + sig;
	23	check_signum(sig);
	24
	25	ALLOC_GROW(s->old, s->n + 1, s->alloc);
	26	s->old[s->n] = signal(sig, f);
	27	if (s->old[s->n] == SIG_ERR)
	28	return -1;
	29	s->n++;
	30	return 0;
	31	}
	32
	33	int sigchain_pop(int sig)
	34	{
	35	struct sigchain_signal *s = signals + sig;
	36	check_signum(sig);
	37	if (s->n < 1)
	38	return 0;
	39
	40	if (signal(sig, s->old[s->n - 1]) == SIG_ERR)
	41	return -1;
	42	s->n--;
	43	return 0;
	44	}
	45
	46	void sigchain_push_common(sigchain_fun f)
	47	{
	48	sigchain_push(SIGINT, f);
	49	sigchain_push(SIGHUP, f);
	50	sigchain_push(SIGTERM, f);
	51	sigchain_push(SIGQUIT, f);
	52	sigchain_push(SIGPIPE, f);
	53	}