#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>
#include <errno.h>
#include <sys/epoll.h>
#include <fcntl.h>
#include "aytype.h"
#include "aylist.h"
#include <vector>
using namespace std;
static int32_t pipe_fds[2] = {-1, -1};
static int32_t epollfd = -1;
static struct sigaction act;
static void _real_signal_to_pipe_(int signal_num, siginfo_t* si, void *context)
{
int32_t sig = signal_num;
int32_t res = 0;
if (pipe_fds[1] > 0) {
try_again:
res = write(pipe_fds[1], &sig, sizeof(int32_t));
if (res == -1 && errno == EAGAIN) {
goto try_again;
} else if (res != sizeof(int32_t)) {
fprintf(stderr, "error when write to pipe\n");
return;
}
}
}
static int32_t epoll_init()
{
epollfd = epoll_create(EPOLL_CLOEXEC);
if (epollfd < 0)
return -errno;
return 0;
}
static int32_t epoll_add(int32_t fd)
{
struct epoll_event ev;
int32_t res = 0;
ev.events = EPOLLIN;
ev.data.u64 = 0;
if (epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &ev) == -1)
res = -errno;
return res;
}
static int32_t epoll_del(int32_t fd)
{
int32_t res = 0;
if (epoll_ctl(epollfd, EPOLL_CTL_DEL, fd, NULL) == -1)
res = -errno;
return res;
}
static int32_t sys_fd_nonblock_cloexec_set(int32_t fd)
{
int32_t res = 0;
int32_t oldflags = fcntl(fd, F_GETFD, 0);
if (oldflags < 0)
oldflags = 0;
oldflags |= FD_CLOEXEC;
res = fcntl(fd, F_SETFD, oldflags);
if (res == -1) {
res = -errno;
fprintf(stderr, "could not set close-on-exit on fd:%d\n", fd);
return res;
}
res = fcntl(fd, F_SETFL, O_NONBLOCK);
if (res == -1) {
res = -errno;
return res;
}
return res;
}
static int32_t my_poll_start()
{
const int MAX_EVENTS = 12;
int32_t event_count;
int32_t res;
int32_t the_signal;
struct epoll_event events[MAX_EVENTS];
vector<int> signal_queue;
vector<int>::iterator signal_queue_ite;
while (1) {
retry_poll:
event_count = epoll_wait(epollfd, events, MAX_EVENTS, /*timeout*/10);
if (errno == EINTR && event_count == -1) {
goto retry_poll;
} else if (event_count == -1) {
return -errno;
}
/* we have only one fds to listen */
for (int i = 0; i < event_count; i++) {
if (events[i].events & EPOLLIN) {
res = read(pipe_fds[0], &the_signal, sizeof(int32_t));
if (res != sizeof(int32_t)) {
fprintf(stderr, "failed to read pipe\n");
return -1;
} else {
signal_queue.push_back(the_signal);
printf("\nsignal_queue\n");
for (signal_queue_ite = signal_queue.begin();
signal_queue_ite != signal_queue.end();
signal_queue_ite++) {
printf("|- %d\n", *signal_queue_ite);
}
printf("\n");
}
}
}
}
return 0;
}
static int my_poll_init()
{
int32_t res = 0;
res = pipe(pipe_fds);
if (res == -1) {
res = -errno;
return res;
}
sys_fd_nonblock_cloexec_set(pipe_fds[0]);
sys_fd_nonblock_cloexec_set(pipe_fds[1]);
if ((res = epoll_init()) < 0)
goto error_exit;
if ((res = epoll_add(pipe_fds[0])) < 0)
goto error_exit;
// so wired
act.sa_sigaction = _real_signal_to_pipe_;
act.sa_flags = SA_NOMASK;
return 0;
error_exit:
if (pipe_fds[0] >= 0)
close(pipe_fds[0]);
if (pipe_fds[1] >= 0)
close(pipe_fds[1]);
return res;
}
static void my_poll_add_signal(int signum)
{
sigaction(signum, &act, NULL);
}
int main()
{
my_poll_init();
my_poll_add_signal(SIGINT);
my_poll_add_signal(SIGQUIT);
my_poll_start();
return 0;
}
转载于:https://www.cnblogs.com/Anney/archive/2013/01/06/2848344.html
相关资源：Digital Signal Processing (DSP) with Python Programming
