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#include <stdio.h>
#include <assert.h>
#include <signal.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "mainloop-signal.h"
#include "util.h"
struct signal_info {
int sig;
struct sigaction saved_sigaction;
void (*callback) (void *id, int signal, void *userdata);
void *userdata;
struct signal_info *previous, *next;
};
static struct pa_mainloop_api *api = NULL;
static int signal_pipe[2] = { -1, -1 };
static void* mainloop_source = NULL;
static struct signal_info *signals = NULL;
static void signal_handler(int sig) {
write(signal_pipe[1], &sig, sizeof(sig));
}
static void callback(struct pa_mainloop_api*a, void *id, int fd, enum pa_mainloop_api_io_events events, void *userdata) {
assert(a && id && events == PA_MAINLOOP_API_IO_EVENT_INPUT && id == mainloop_source && fd == signal_pipe[0]);
for (;;) {
ssize_t r;
int sig;
struct signal_info*s;
if ((r = read(signal_pipe[0], &sig, sizeof(sig))) < 0) {
if (errno == EAGAIN)
return;
fprintf(stderr, "signal.c: read(): %s\n", strerror(errno));
return;
}
if (r != sizeof(sig)) {
fprintf(stderr, "signal.c: short read()\n");
return;
}
for (s = signals; s; s = s->next)
if (s->sig == sig) {
assert(s->callback);
s->callback(s, sig, s->userdata);
break;
}
}
}
int pa_signal_init(struct pa_mainloop_api *a) {
assert(a);
if (pipe(signal_pipe) < 0) {
fprintf(stderr, "pipe() failed: %s\n", strerror(errno));
return -1;
}
pa_make_nonblock_fd(signal_pipe[0]);
pa_make_nonblock_fd(signal_pipe[1]);
api = a;
mainloop_source = api->source_io(api, signal_pipe[0], PA_MAINLOOP_API_IO_EVENT_INPUT, callback, NULL);
assert(mainloop_source);
return 0;
}
void pa_signal_done(void) {
assert(api && signal_pipe[0] >= 0 && signal_pipe[1] >= 0 && mainloop_source);
api->cancel_io(api, mainloop_source);
mainloop_source = NULL;
close(signal_pipe[0]);
close(signal_pipe[1]);
signal_pipe[0] = signal_pipe[1] = -1;
while (signals)
pa_signal_unregister(signals);
api = NULL;
}
void* pa_signal_register(int sig, void (*callback) (void *id, int signal, void *userdata), void *userdata) {
struct signal_info *s = NULL;
struct sigaction sa;
assert(sig > 0 && callback);
for (s = signals; s; s = s->next)
if (s->sig == sig)
goto fail;
s = malloc(sizeof(struct signal_info));
assert(s);
s->sig = sig;
s->callback = callback;
s->userdata = userdata;
memset(&sa, 0, sizeof(sa));
sa.sa_handler = signal_handler;
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_RESTART;
if (sigaction(sig, &sa, &s->saved_sigaction) < 0)
goto fail;
s->previous = NULL;
s->next = signals;
signals = s;
return s;
fail:
if (s)
free(s);
return NULL;
}
void pa_signal_unregister(void *id) {
struct signal_info *s = id;
assert(s);
if (s->next)
s->next->previous = s->previous;
if (s->previous)
s->previous->next = s->next;
else
signals = s->next;
sigaction(s->sig, &s->saved_sigaction, NULL);
free(s);
}
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