/**
* Kill the server. This function can be called from another thread to kill the
* server, causing runServer() to return.
*/
void killServer(void) {
fprintf(stdout, "Stopping socket listener event loop.\n");
if (event_base_loopexit(evbase_accept, NULL)) {
perror("Error shutting down server");
}
fprintf(stdout, "Stopping workers.\n");
workqueue_shutdown(&workqueue);
}
/**
* Run the server. This function blocks, only returning when the server has terminated.
*/
int runServer(void) {
int sockfd;
struct sockaddr_in listen_addr;
struct event ev_accept;
int reuseaddr_on;
/* Initialize libevent. */
event_init();
/* Set signal handlers
sigset_t：信号集,其被定义为一种数据类型
struct sigaction {
void (*sa_handler)(int); //此参数和signal()的参数handler 相同, 代表新的信号处理函数
void (*sa_sigaction)(int, siginfo_t *, void *);
sigset_t sa_mask; //用来设置在处理该信号时暂时将sa_mask 指定的信号搁置
int sa_flags; //用来设置信号处理的其他相关操作, A_NOCLDSTOP: 如果参数signum 为SIGCHLD, 则当子进程暂停时并不会通知父进程;SA_RESTART: 被信号中断的系统调用会自行重启;
void (*sa_restorer)(void); //此参数没有使用
};
*/
sigset_t sigset;
sigemptyset(&sigset); //初始化信号集，信号集里面的所有信号被清空
/*struct sigaction siginfo = {
.sa_handler = sighandler,
.sa_mask = sigset,
.sa_flags = SA_RESTART,
};*/
struct sigaction siginfo;
siginfo.sa_handler = sighandler;
siginfo.sa_mask = sigset;
siginfo.sa_flags = SA_RESTART;
sigaction(SIGINT, &siginfo, NULL); //程序终止(interrupt)信号, 在用户键入INTR字符(通常是Ctrl-C)时发出
sigaction(SIGTERM, &siginfo, NULL); //程序结束(terminate)信号, 与SIGKILL不同的是该信号可以被阻塞和处理.通常用来要求程序自己正常退出.shell命令kill缺省产生这个信号.
/* Create our listening socket. */
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0) {
err(1, "listen failed");
}
memset(&listen_addr, 0, sizeof(listen_addr));
listen_addr.sin_family = AF_INET;
listen_addr.sin_addr.s_addr = INADDR_ANY;
listen_addr.sin_port = htons(SERVER_PORT);
if (bind(sockfd, (struct sockaddr *)&listen_addr, sizeof(listen_addr)) < 0) {
err(1, "bind failed");
}
if (listen(sockfd, CONNECTION_BACKLOG) < 0) {
err(1, "listen failed");
}
reuseaddr_on = 1;
setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &reuseaddr_on, sizeof(reuseaddr_on));
/* Set the socket to non-blocking, this is essential in event
* based programming with libevent. */
if (setnonblock(sockfd) < 0) {
err(1, "failed to set server socket to non-blocking");
}
evbase_accept = event_base_new();
if (NULL == evbase_accept)
{
perror("Unable to create socket accept event base");
close(sockfd);
return 1;
}
/* Initialize work queue. */
if (workqueue_init(&workqueue, NUM_THREADS)) {
perror("Failed to create work queue");
close(sockfd);
workqueue_shutdown(&workqueue);
return 1;
}
/* We now have a listening socket, we create a read event to
* be notified when a client connects. */
event_set(&ev_accept, sockfd, EV_READ | EV_PERSIST, on_accept, (void *)&workqueue);
event_base_set(evbase_accept, &ev_accept);
event_add(&ev_accept, NULL);
printf("Server is running...\n");
/* Start the event loop. */
event_base_dispatch(evbase_accept);
event_base_free(evbase_accept);
evbase_accept = NULL;
close(sockfd);
printf("Server shutdown.\n");
return 0;
}
/**
* Run the server. This function blocks, only returning when the server has terminated.
*/
int runServer(void) {
int listenfd;
struct sockaddr_in listen_addr;
struct event ev_accept;
int reuseaddr_on;
/* Initialize libevent. */
event_init();
/* Set signal handlers */
sigset_t sigset;
sigemptyset(&sigset);
struct sigaction siginfo = {
.sa_handler = sighandler,
.sa_mask = sigset,
.sa_flags = SA_RESTART,
};
sigaction(SIGINT, &siginfo, NULL);
sigaction(SIGTERM, &siginfo, NULL);
/* Create our listening socket. */
listenfd = socket(AF_INET, SOCK_STREAM, 0);
if (listenfd < 0) {
err(1, "listen failed");
}
memset(&listen_addr, 0, sizeof(listen_addr));
listen_addr.sin_family = AF_INET;
listen_addr.sin_addr.s_addr = INADDR_ANY;
listen_addr.sin_port = htons(SERVER_PORT);
if (bind(listenfd, (struct sockaddr *)&listen_addr, sizeof(listen_addr)) < 0) {
err(1, "bind failed");
}
if (listen(listenfd, CONNECTION_BACKLOG) < 0) {
err(1, "listen failed");
}
reuseaddr_on = 1;
setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &reuseaddr_on, sizeof(reuseaddr_on));
/* Set the socket to non-blocking, this is essential in event
* based programming with libevent. */
if (setnonblock(listenfd) < 0) {
err(1, "failed to set server socket to non-blocking");
}
if ((evbase_accept = event_base_new()) == NULL) {
perror("Unable to create socket accept event base");
close(listenfd);
return 1;
}
/* Initialize work queue. */
if (workqueue_init(&workqueue, NUM_THREADS)) {
perror("Failed to create work queue");
close(listenfd);
workqueue_shutdown(&workqueue);
return 1;
}
/* We now have a listening socket, we create a read event to
* be notified when a client connects. */
event_set(&ev_accept, listenfd, EV_READ|EV_PERSIST, on_accept, (void *)&workqueue);
event_base_set(evbase_accept, &ev_accept);
event_add(&ev_accept, NULL);
printf("Server running.\n");
/* Start the event loop. */
event_base_dispatch(evbase_accept);
event_base_free(evbase_accept);
evbase_accept = NULL;
close(listenfd);
printf("Server shutdown.\n");
return 0;
}
