- \n
- HTTP\u77ed\u8fde\u63a5\u670d\u52a1（\u65e9\u671fApache）<\/li>\n
- CGI\u5feb\u901f\u5904\u7406<\/li>\n
- \u7b80\u5355\u6d4b\u8bd5\u670d\u52a1\u5668<\/li>\n<\/ul>\n
3. \u7efc\u5408\u4ee3\u7801<\/h5>\n
#include <stdio.h>
\n#include <sys\/types.h> \/* See NOTES *\/
\n#include <sys\/socket.h>
\n#include <netinet\/in.h>
\n#include <netinet\/ip.h> \/* superset of previous *\/
\n#include <arpa\/inet.h>
\n#include <strings.h>
\n#include <unistd.h>
\n#include <stdlib.h>
\n#include <string.h><\/p>\nint main(int argc, const char *argv[])
\n{
\nif (argc != 3)
\n{
\nprintf("Usage: %s <port> <ip>\\\\n",argv[0]);
\nreturn -1;
\n}<\/p>\n\/\/1.socket \u521b\u5efa\u901a\u4fe1\u4e00\u7aef
\nint fd = socket(AF_INET,SOCK_STREAM,0);<\/p>\nif (fd < 0)
\n{
\nperror("socket fail\\\\n");
\nreturn -1;
\n}<\/p>\nstruct sockaddr_in seraddr;
\nbzero(&seraddr,sizeof(seraddr));<\/p>\nseraddr.sin_family = AF_INET;
\nseraddr.sin_port = htons(atoi(argv[1]));
\nseraddr.sin_addr.s_addr = inet_addr(argv[2]);
\nprintf("fd = %d\\\\n",fd);
\n \/\/2.bind — \u7ed1\u5b9a\u670d\u52a1\u5668\u7aef\u7684\u5730\u5740\u4fe1\u606f
\nif (bind(fd,(const struct sockaddr*)&seraddr,sizeof(seraddr)) < 0)
\n{
\nperror("connect fail");
\nreturn -1;
\n}<\/p>\nprintf("connect success!\\\\n");<\/p>\n
\/\/3.listen — \u8bbe\u7f6e\u76d1\u542c
\nif (listen(fd,5) < 0)
\n{
\nperror("listen fail");
\nreturn -1;
\n}<\/p>\nwhile (1)
\n{
\n\/\/4.accept
\nint connfd = accept(fd,NULL,NULL);<\/p>\nif (connfd < 0)
\n{
\nperror("accept fail");
\nreturn -1;
\n}<\/p>\nprintf("—-client — connectted\\\\n");<\/p>\n
char buf[1024];
\nchar sbuf[1024];
\nwhile (1)
\n{
\nrecv(connfd,buf,sizeof(buf),0);
\nprintf("c: %s\\\\n",buf);<\/p>\nif (strncmp(buf,"quit",4) == 0)
\n{
\nclose(connfd);
\nbreak;
\n}
\nsprintf(sbuf,"server + %s\\\\n",buf);
\nsend(connfd,sbuf,strlen(sbuf)+1,0);
\n}
\n}
\nclose(fd);<\/p>\nreturn 0;
\n}<\/p>\n4. \u4f18\u7f3a\u70b9\u5206\u6790<\/h5>\n
\n
\u4f18\u70b9\u7f3a\u70b9<\/tr>\n \n\n \u5b9e\u73b0\u7b80\u5355<\/td>\n \u65e0\u6cd5\u5904\u7406\u5e76\u53d1\u8bf7\u6c42<\/td>\n<\/tr>\n \n \u65e0\u8d44\u6e90\u7ade\u4e89\u95ee\u9898<\/td>\n \u957f\u8fde\u63a5\u4f1a\u963b\u585e\u540e\u7eed\u8bf7\u6c42<\/td>\n<\/tr>\n \n \u9002\u5408\u4f4e\u8d1f\u8f7d\u573a\u666f<\/td>\n \u541e\u5410\u91cf\u4f4e（QPS < 100）<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n\u4e8c\u3001\u591a\u8fdb\u7a0b\u5e76\u53d1\u6a21\u578b<\/h2>\n
1. \u6838\u5fc3\u5b9e\u73b0<\/h5>\n
while(1) {
\n int newfd = accept(listen_fd, …);
\n pid_t pid = fork();<\/p>\nif (pid == 0) { \/\/ \u5b50\u8fdb\u7a0b
\n close(listen_fd);
\n handle_connection(newfd);
\n close(newfd);
\n exit(0);
\n } else if (pid > 0) { \/\/ \u7236\u8fdb\u7a0b
\n close(newfd);
\n waitpid(-1, NULL, WNOHANG); \/\/ \u975e\u963b\u585e\u56de\u6536
\n }
\n}<\/p>\n2. \u8fdb\u7a0b\u7ba1\u7406\u4f18\u5316<\/h5>\n
\/\/ \u4f7f\u7528\u4fe1\u53f7\u5904\u7406\u907f\u514d\u50f5\u5c38\u8fdb\u7a0b
\nsignal(SIGCHLD, SIG_IGN); \/\/ \u5ffd\u7565\u5b50\u8fdb\u7a0b\u7ed3\u675f\u4fe1\u53f7<\/p>\n\/\/ \u6216\u4f7f\u7528waitpid\u5faa\u73af
\nwhile (waitpid(-1, NULL, WNOHANG) > 0);<\/p>\n3. \u5178\u578b\u5e94\u7528<\/h5>\n
- \n
- \u4f20\u7edfApache\u7684prefork\u6a21\u5f0f<\/li>\n
- FTP\u670d\u52a1\u5668<\/li>\n
- \u6570\u636e\u5e93\u8fde\u63a5\u6c60<\/li>\n<\/ul>\n
4. \u8d44\u6e90\u6d88\u8017\u5bf9\u6bd4<\/h5>\n
\n
\u8d44\u6e90\u7c7b\u578b\u8fdb\u7a0b\u521b\u5efa\u5f00\u9500\u793a\u4f8b\u7cfb\u7edf\u8c03\u7528<\/tr>\n \n\n \u5185\u5b58<\/td>\n \u9700\u8981\u590d\u5236\u6574\u4e2aPCB<\/td>\n fork()<\/td>\n<\/tr>\n \n CPU<\/td>\n \u4e0a\u4e0b\u6587\u5207\u6362\u6210\u672c\u9ad8<\/td>\n schedule()<\/td>\n<\/tr>\n \n \u6587\u4ef6\u63cf\u8ff0\u7b26<\/td>\n \u9700\u8981\u663e\u5f0f\u5173\u95ed\u7ee7\u627f\u7684fd<\/td>\n close()<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n 5. \u4f18\u7f3a\u70b9\u5206\u6790<\/h5>\n
\n
\u4f18\u70b9\u7f3a\u70b9<\/tr>\n \n\n \u53ef\u4ee5\u5b8c\u6210\u591a\u4e2a\u8fdb\u7a0b\u7684\u5b9e\u65f6\u4ea4\u4e92<\/td>\n \u56de\u6536\u8d44\u6e90\u4e0d\u65b9\u4fbf<\/td>\n<\/tr>\n \n \u4fe1\u606f\u7684\u5b8c\u6574\u6027\u53ef\u4ee5\u4fdd\u8bc1\u3002<\/td>\n \u6bcf\u6b21fork \u5360\u7528\u7cfb\u7edf\u8d44\u6e90\u591a<\/td>\n<\/tr>\n \n \u9002\u5408\u4f4e\u8d1f\u8f7d\u573a\u666f<\/td>\n \u53ef\u80fd\u51fa\u73b0\u50f5\u5c38\u8fdb\u7a0b<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n6. \u7efc\u5408\u4ee3\u7801<\/h4>\n
#include <stdio.h>
\n#include <sys\/types.h> \/* See NOTES *\/
\n#include <sys\/socket.h>
\n#include <netinet\/in.h>
\n#include <netinet\/ip.h> \/* superset of previous *\/
\n#include <arpa\/inet.h>
\n#include <strings.h>
\n#include <unistd.h>
\n#include <stdlib.h>
\n#include <string.h>
\n#include <signal.h>
\n#include <sys\/wait.h><\/p>\nvoid handler(int signo)
\n{
\nwait(NULL);
\n}<\/p>\nint init_server(const char *ip,unsigned short port)
\n{
\n\/\/1.socket \u521b\u5efa\u901a\u4fe1\u4e00\u7aef
\nint fd = socket(AF_INET,SOCK_STREAM,0);<\/p>\nif (fd < 0)
\n{
\nperror("socket fail\\\\n");
\nreturn -1;
\n}<\/p>\nstruct sockaddr_in seraddr;
\nbzero(&seraddr,sizeof(seraddr));<\/p>\nseraddr.sin_family = AF_INET;
\nseraddr.sin_port = htons(port);
\nseraddr.sin_addr.s_addr = inet_addr(ip);<\/p>\n\/\/2.bind — \u7ed1\u5b9a\u670d\u52a1\u5668\u7aef\u7684\u5730\u5740\u4fe1\u606f
\nif (bind(fd,(const struct sockaddr*)&seraddr,sizeof(seraddr)) < 0)
\n{
\nperror("connect fail");
\nreturn -1;
\n}<\/p>\n\/\/3.listen — \u8bbe\u7f6e\u76d1\u542c
\nif (listen(fd,5) < 0)
\n{
\nperror("listen fail");
\nreturn -1;
\n}
\nreturn fd;
\n}<\/p>\nint client_handler(int connfd)
\n{
\nchar buf[1024];
\nchar sbuf[1024];
\nint ret = 0;<\/p>\nwhile (1)
\n{
\nret = recv(connfd,buf,sizeof(buf),0);
\nif (ret < 0)
\n{
\nperror("client_handler recv fail");
\nret = -1;
\n}
\nprintf("c: %s\\\\n",buf);<\/p>\nif (strncmp(buf,"quit",4) == 0)
\n{
\nclose(connfd);
\nret = 1;
\nbreak;
\n}
\nsprintf(sbuf,"server + %s\\\\n",buf);
\nret = send(connfd,sbuf,strlen(sbuf)+1,0);
\nif (ret < 0)
\n{
\nperror("client_handler send fail");
\nret = -1;
\n}
\n}<\/p>\nreturn ret;<\/p>\n
}<\/p>\n
int main(int argc, const char *argv[])
\n{
\nif (argc != 3)
\n{
\nprintf("Usage: %s <ip> <port>\\\\n",argv[0]);
\nreturn -1;
\n}<\/p>\nsignal(SIGCHLD,handler);<\/p>\n
int fd = init_server(argv[1],atoi(argv[2]));
\nif (fd < 0)
\n{
\nprintf("init_server fail\\\\n");
\nreturn -1;
\n}<\/p>\nwhile (1)
\n{
\n\/\/4.accept
\nint connfd = accept(fd,NULL,NULL);<\/p>\nif (connfd < 0)
\n{
\nperror("accept fail");
\nreturn -1;
\n}<\/p>\npid_t pid = fork();
\nif (pid < 0)
\n{
\nperror("fork fail");
\nreturn -1;
\n}
\nif (pid == 0)
\n{<\/p>\nint ret = 0;
\nif ((ret = client_handler(connfd)) < 0)
\n{
\nprintf("client_handler fail");
\nreturn -1;
\n}
\nif (ret == 1)
\n{
\nprintf("child exit…\\\\n");
\nexit(EXIT_SUCCESS);
\n}<\/p>\n}
\n}
\nclose(fd);<\/p>\nreturn 0;
\n}<\/p>\n\u4e09\u3001\u591a\u7ebf\u7a0b\u5e76\u53d1\u6a21\u578b<\/h2>\n
1. \u6838\u5fc3\u5b9e\u73b0（POSIX\u7ebf\u7a0b）<\/h5>\n
while(1) {
\n int newfd = accept(listen_fd, …);
\n pthread_t tid;
\n pthread_create(&tid, NULL, thread_handler, (void*)newfd);
\n pthread_detach(tid); \/\/ \u5206\u79bb\u7ebf\u7a0b\u81ea\u52a8\u56de\u6536
\n}<\/p>\nvoid* thread_handler(void* arg) {
\n int fd = (int)arg;
\n \/\/ \u5904\u7406\u8bf7\u6c42
\n close(fd);
\n return NULL;
\n}<\/p>\n2. \u7ebf\u7a0b\u5b89\u5168\u63a7\u5236<\/h5>\n
\/\/ \u4f7f\u7528\u4e92\u65a5\u9501\u4fdd\u62a4\u5171\u4eab\u8d44\u6e90
\npthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;<\/p>\nvoid safe_write(int fd, const char* data) {
\n pthread_mutex_lock(&lock);
\n write(fd, data, strlen(data));
\n pthread_mutex_unlock(&lock);
\n}<\/p>\n3. \u5178\u578b\u5e94\u7528<\/h5>\n
- \n
- Java Tomcat<\/li>\n
- IIS\u5e94\u7528\u6c60<\/li>\n
- \u5b9e\u65f6\u901a\u4fe1\u670d\u52a1\u5668<\/li>\n<\/ul>\n
4. \u6027\u80fd\u6307\u6807\u5bf9\u6bd4<\/h5>\n
\n
\u6307\u6807\u8fdb\u7a0b\u6a21\u578b\u7ebf\u7a0b\u6a21\u578b<\/tr>\n \n\n \u521b\u5efa\u901f\u5ea6<\/td>\n \u6162（10-100ms）<\/td>\n \u5feb（0.1-1ms）<\/td>\n<\/tr>\n \n \u4e0a\u4e0b\u6587\u5207\u6362\u6210\u672c<\/td>\n \u9ad8（\u5207\u6362\u9875\u8868\u7b49）<\/td>\n \u4f4e（\u5171\u4eab\u5730\u5740\u7a7a\u95f4）<\/td>\n<\/tr>\n \n \u5185\u5b58\u5360\u7528<\/td>\n \u9ad8（\u72ec\u7acb\u8d44\u6e90）<\/td>\n \u4f4e（\u5171\u4eab\u8d44\u6e90）<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n 5. \u4f18\u7f3a\u70b9\u5206\u6790<\/h5>\n
\n
\u4f18\u70b9\u7f3a\u70b9<\/tr>\n \n\n \u53ef\u4ee5\u5b8c\u6210\u591a\u4e2a\u8fdb\u7a0b\u7684\u5b9e\u65f6\u4ea4\u4e92<\/td>\n \u7ebf\u7a0b\u5171\u4eab\u8fdb\u7a0b\u8d44\u6e90<\/td>\n<\/tr>\n \n \u521b\u5efa\u901f\u5ea6\u5feb，\u8c03\u5ea6\u5feb<\/td>\n \u7a33\u5b9a\u6027 \u8f83\u5dee<\/td>\n<\/tr>\n \n \u9002\u5408\u4f4e\u8d1f\u8f7d\u573a\u666f<\/td>\n \u5b89\u5168\u6027 \u8f83\u5dee\u00a0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n6. \u7efc\u5408\u4ee3\u7801<\/h4>\n
#include <stdio.h>
\n#include <pthread.h>
\n#include <sys\/types.h> \/* See NOTES *\/
\n#include <sys\/socket.h>
\n#include <netinet\/in.h>
\n#include <netinet\/ip.h> \/* superset of previous *\/
\n#include <arpa\/inet.h>
\n#include <strings.h>
\n#include <unistd.h>
\n#include <stdlib.h>
\n#include <string.h>
\n#include <signal.h>
\n#include <sys\/wait.h>
\n#include <errno.h><\/p>\nint init_server(const char *ip,unsigned short port)
\n{
\n\/\/1.socket \u521b\u5efa\u901a\u4fe1\u4e00\u7aef
\nint fd = socket(AF_INET,SOCK_STREAM,0);<\/p>\nif (fd < 0)
\n{
\nperror("socket fail\\\\n");
\nreturn -1;
\n}<\/p>\nstruct sockaddr_in seraddr;
\nbzero(&seraddr,sizeof(seraddr));<\/p>\nseraddr.sin_family = AF_INET;
\nseraddr.sin_port = htons(port);
\nseraddr.sin_addr.s_addr = inet_addr(ip);<\/p>\n\/\/2.bind — \u7ed1\u5b9a\u670d\u52a1\u5668\u7aef\u7684\u5730\u5740\u4fe1\u606f
\nif (bind(fd,(const struct sockaddr*)&seraddr,sizeof(seraddr)) < 0)
\n{
\nperror("connect fail");
\nreturn -1;
\n}<\/p>\n\/\/3.listen — \u8bbe\u7f6e\u76d1\u542c
\nif (listen(fd,5) < 0)
\n{
\nperror("listen fail");
\nreturn -1;
\n}
\nreturn fd;
\n}<\/p>\nvoid* client_handler(void *arg)
\n{
\nint connfd = *(int *)arg;
\nchar buf[1024];
\nchar sbuf[1024];
\nlong int ret = 0;<\/p>\nwhile (1)
\n{
\nret = recv(connfd,buf,sizeof(buf),0);
\nif (ret < 0)
\n{
\nperror("client_handler recv fail");
\nret = -1;
\n}
\nprintf("c: %s\\\\n",buf);<\/p>\nif (strncmp(buf,"quit",4) == 0)
\n{
\nclose(connfd);
\nret = 1;
\nbreak;
\n}
\nsprintf(sbuf,"server + %s\\\\n",buf);
\nret = send(connfd,sbuf,strlen(sbuf)+1,0);
\nif (ret < 0)
\n{
\nperror("client_handler send fail");
\nret = -1;
\n}
\n}<\/p>\nreturn (void*)ret;<\/p>\n
}<\/p>\n
int main(int argc, const char *argv[])
\n{
\nif (argc != 3)
\n{
\nprintf("Usage: %s <ip> <port>\\\\n",argv[0]);
\nreturn -1;
\n}<\/p>\nint fd = init_server(argv[1],atoi(argv[2]));
\nif (fd < 0)
\n{
\nprintf("init_server fail\\\\n");
\nreturn -1;
\n}<\/p>\nwhile (1)
\n{
\n\/\/4.accept
\nint connfd = accept(fd,NULL,NULL);<\/p>\nif (connfd < 0)
\n{
\nperror("accept fail");
\nreturn -1;
\n}<\/p>\npthread_t tid;<\/p>\n
int ret = pthread_create(&tid,NULL,client_handler,&connfd);
\nif(ret != 0)
\n{
\nerrno = ret;
\nperror("pthread_create fail");
\nreturn -1;
\n}
\npthread_detach(tid);\/\/\u8bbe\u7f6e\u5206\u79bb\u5c5e\u6027,\u7531\u7cfb\u7edf\u56de\u6536\u8d44\u6e90
\n}
\nclose(fd);
\nreturn 0;
\n}<\/p>\n
\n\u56db\u3001\u5e76\u53d1\u7684\u670d\u52a1\u5668\u6a21\u578b —\u66f4\u9ad8\u7a0b\u5ea6\u4e0a\u7684\u5e76\u53d1\u00a0<\/h2>\n
（\u4e00）fcntl\u00a0\u51fd\u6570\u4e0e I\/O \u6a21\u578b\u8be6\u89e3<\/h3>\n
1. \u51fd\u6570\u539f\u578b<\/h5>\n
#include <unistd.h>
\n#include <fcntl.h><\/p>\nint fcntl(int fd, int cmd, … \/* arg *\/ );<\/p>\n
2. \u4e3b\u8981\u64cd\u4f5c\u7c7b\u578b<\/h5>\n
\n
\u547d\u4ee4\u529f\u80fd\u63cf\u8ff0\u53c2\u6570\u8981\u6c42<\/tr>\n \n\n F_DUPFD<\/td>\n \u590d\u5236\u6587\u4ef6\u63cf\u8ff0\u7b26<\/td>\n \u6307\u5b9a\u6700\u5c0f\u53ef\u7528fd\u503c<\/td>\n<\/tr>\n \n F_GETFD\/F_SETFD<\/td>\n \u83b7\u53d6\/\u8bbe\u7f6e\u6587\u4ef6\u63cf\u8ff0\u7b26\u6807\u5fd7<\/td>\n \u6807\u5fd7\u503c<\/td>\n<\/tr>\n \n F_GETFL\/F_SETFL<\/td>\n \u83b7\u53d6\/\u8bbe\u7f6e\u6587\u4ef6\u72b6\u6001\u6807\u5fd7<\/td>\n \u65b0\u6807\u5fd7\u503c<\/td>\n<\/tr>\n \n F_GETOWN\/F_SETOWN<\/td>\n \u83b7\u53d6\/\u8bbe\u7f6e\u5f02\u6b65I\/O\u6240\u6709\u6743<\/td>\n \u8fdb\u7a0bID\u6216\u7ec4ID<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n（\u4e8c）\u975e\u963b\u585eI\/O\u8bbe\u7f6e\u793a\u4f8b<\/h3>\n
1. \u8bbe\u7f6e\u6d41\u7a0b<\/h5>\n
int flag = fcntl(connfd,F_GETFL,0);
\nflag = flag | O_NONBLOCK;
\nfcntl(connfd,F_SETFL,flag); <\/p>\n2. \u884c\u4e3a\u53d8\u5316\u5bf9\u6bd4<\/h5>\n
\n
\u64cd\u4f5c\u963b\u585e\u6a21\u5f0f\u975e\u963b\u585e\u6a21\u5f0f<\/tr>\n \n\n read()<\/td>\n \u963b\u585e\u76f4\u5230\u6570\u636e\u5230\u8fbe<\/td>\n \u7acb\u5373\u8fd4\u56de，\u65e0\u6570\u636e\u65f6\u8fd4\u56deEAGAIN<\/td>\n<\/tr>\n \n write()<\/td>\n \u963b\u585e\u76f4\u5230\u7f13\u51b2\u533a\u7a7a\u95f4\u53ef\u7528<\/td>\n \u7acb\u5373\u8fd4\u56de，\u7a7a\u95f4\u4e0d\u8db3\u8fd4\u56deEAGAIN<\/td>\n<\/tr>\n \n accept()<\/td>\n \u963b\u585e\u76f4\u5230\u6709\u65b0\u8fde\u63a5<\/td>\n \u7acb\u5373\u8fd4\u56de，\u65e0\u8fde\u63a5\u65f6\u8fd4\u56deEAGAIN<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n（\u4e09）I\/O \u6a21\u578b\u5bf9\u6bd4<\/h3>\n
1. \u963b\u585eI\/O\u6a21\u578b<\/h5>\n
![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/04\/20250418104531-68022d4bc28d2.png\")
<\/h5>\n2. \u975e\u963b\u585eI\/O\u6a21\u578b<\/h5>\n
![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/04\/20250418104531-68022d4bec860.png\")
<\/p>\n#include <stdio.h>
\n#include <sys\/types.h> \/* See NOTES *\/
\n#include <sys\/socket.h>
\n#include <netinet\/in.h>
\n#include <netinet\/ip.h> \/* superset of previous *\/
\n#include <arpa\/inet.h>
\n#include <strings.h>
\n#include <unistd.h>
\n#include <stdlib.h>
\n#include <string.h><\/p>\n#include <fcntl.h>
\nint main(int argc, const char *argv[])
\n{
\nif (argc != 3)
\n{
\nprintf("Usage: %s <port> <ip>\\\\n",argv[0]);
\nreturn -1;
\n}<\/p>\n\/\/1.socket \u521b\u5efa\u901a\u4fe1\u4e00\u7aef
\nint fd = socket(AF_INET,SOCK_STREAM,0);<\/p>\nif (fd < 0)
\n{
\nperror("socket fail\\\\n");
\nreturn -1;
\n}<\/p>\nstruct sockaddr_in seraddr;
\nbzero(&seraddr,sizeof(seraddr));<\/p>\nseraddr.sin_family = AF_INET;
\nseraddr.sin_port = htons(atoi(argv[1]));
\nseraddr.sin_addr.s_addr = inet_addr(argv[2]);
\nprintf("fd = %d\\\\n",fd);
\n \/\/2.bind — \u7ed1\u5b9a\u670d\u52a1\u5668\u7aef\u7684\u5730\u5740\u4fe1\u606f
\nif (bind(fd,(const struct sockaddr*)&seraddr,sizeof(seraddr)) < 0)
\n{
\nperror("connect fail");
\nreturn -1;
\n}<\/p>\nprintf("connect success!\\\\n");<\/p>\n
\/\/3.listen — \u8bbe\u7f6e\u76d1\u542c
\nif (listen(fd,5) < 0)
\n{
\nperror("listen fail");
\nreturn -1;
\n}<\/p>\nwhile (1)
\n{
\n\/\/4.accept
\nint connfd = accept(fd,NULL,NULL);<\/p>\nif (connfd < 0)
\n{
\nperror("accept fail");
\nreturn -1;
\n}<\/p>\nprintf("—-client — connectted\\\\n");<\/p>\n
char buf[1024];
\nchar sbuf[1024];<\/p>\nint flag = fcntl(connfd,F_GETFL,0);
\nflag = flag | O_NONBLOCK;
\nfcntl(connfd,F_SETFL,flag);<\/p>\nwhile (1)
\n{
\nrecv(connfd,buf,sizeof(buf),0);
\nprintf("c: %s\\\\n",buf);<\/p>\nif (strncmp(buf,"quit",4) == 0)
\n{
\nclose(connfd);
\nbreak;
\n}
\nsprintf(sbuf,"server + %s\\\\n",buf);
\nsend(connfd,sbuf,strlen(sbuf)+1,0);
\n}
\n}
\nclose(fd);<\/p>\nreturn 0;
\n}<\/p>\n（\u56db）\u4fe1\u53f7\u9a71\u52a8 I\/O \u8be6\u89e3<\/h3>\n
![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/04\/20250418104532-68022d4c260d7.png\")
<\/p>\n1. \u8bbe\u7f6e\u5f02\u6b65\u6807\u5fd7<\/h5>\n
\/\/ \u83b7\u53d6\u5f53\u524d\u6587\u4ef6\u72b6\u6001\u6807\u5fd7
\nint flags = fcntl(fd, F_GETFL);
\nif (flags == -1) {
\n perror("fcntl F_GETFL");
\n exit(EXIT_FAILURE);
\n}<\/p>\n\/\/ \u6dfb\u52a0\u5f02\u6b65I\/O\u6807\u5fd7
\nif (fcntl(fd, F_SETFL, flags | O_ASYNC) == -1) {
\n perror("fcntl F_SETFL");
\n exit(EXIT_FAILURE);
\n}<\/p>\n2. \u6307\u5b9a\u4fe1\u53f7\u63a5\u6536\u8005<\/h5>\n
\/\/ \u8bbe\u7f6e\u5f53\u524d\u8fdb\u7a0b\u4e3a\u4fe1\u53f7\u63a5\u6536\u8005
\nif (fcntl(fd, F_SETOWN, getpid()) == -1) {
\n perror("fcntl F_SETOWN");
\n exit(EXIT_FAILURE);
\n}<\/p>\n3. \u6ce8\u518c\u4fe1\u53f7\u5904\u7406\u51fd\u6570<\/h5>\n
\/\/ \u66f4\u5b89\u5168\u7684sigaction\u66ff\u4ee3signal
\nstruct sigaction sa;
\nsa.sa_flags = SA_RESTART;
\nsa.sa_handler = sigio_handler;
\nsigemptyset(&sa.sa_mask);<\/p>\nif (sigaction(SIGIO, &sa, NULL) == -1) {
\n perror("sigaction");
\n exit(EXIT_FAILURE);
\n}<\/p>\n4. \u57fa\u672c\u5904\u7406\u903b\u8f91<\/h5>\n
#include <stdio.h>
\n#include <sys\/types.h>
\n#include <sys\/stat.h>
\n#include <fcntl.h>
\n#include <unistd.h>
\n#include <errno.h>
\n#include <string.h>
\n#include <signal.h><\/p>\nint g_fd;<\/p>\n
void handler(int signo)
\n{
\nchar buf[1024];
\nread(g_fd,buf,sizeof(buf));<\/p>\nif (strncmp(buf,"quit",4) == 0)
\nreturn;
\nprintf("buf = %s\\\\n",buf);<\/p>\n}<\/p>\n
int main(int argc, const char *argv[])
\n{
\nif (mkfifo(argv[1],0666) < 0 && errno != EEXIST)
\n{
\nperror("mkfifo fail");
\nreturn -1;
\n}<\/p>\nprintf("mkfifo success\\\\n");<\/p>\n
int fd = open(argv[1], O_RDONLY);
\nif (fd < 0)
\n{
\nperror("open fail");
\nreturn -1;
\n}<\/p>\ng_fd = fd;
\nint flag = fcntl(fd,F_GETFL,0);
\nflag = flag | O_ASYNC;\/\/\u8bbe\u7f6e\u4e3a\u5f02\u6b65\u901a\u4fe1
\nfcntl(fd,F_SETFL,flag);<\/p>\nfcntl(fd,F_SETOWN,getpid());\/\/\u6240\u6709\u8005
\nsignal(SIGIO,handler);<\/p>\nint i = 0;
\nwhile (1)
\n{
\nprintf("i = %d\\\\n",i);
\nsleep(1);
\n++i;
\n}<\/p>\nclose(fd);
\nreturn 0;
\n}<\/p>\n
\n5.\u6838\u5fc3\u5c40\u9650\u6027\u5206\u6790<\/h5>\n
\n
\u95ee\u9898\u7c7b\u578b\u5177\u4f53\u8868\u73b0\u89e3\u51b3\u601d\u8def<\/tr>\n \n\n \u4fe1\u53f7\u5408\u5e76<\/td>\n \u5feb\u901f\u8fde\u7eed\u4fe1\u53f7\u53ef\u80fd\u88ab\u5408\u5e76<\/td>\n \u4f7f\u7528\u5b9e\u65f6\u4fe1\u53f7（SIGRTMIN+）<\/td>\n<\/tr>\n \n \u591afd\u533a\u5206\u56f0\u96be<\/td>\n \u65e0\u6cd5\u76f4\u63a5\u5224\u65ad\u54ea\u4e2afd\u89e6\u53d1\u4fe1\u53f7<\/td>\n \u6bcf\u4e2afd\u7ed1\u5b9a\u4e0d\u540c\u4fe1\u53f7（\u4e0d\u73b0\u5b9e）<\/td>\n<\/tr>\n \n \u5f02\u6b65\u5b89\u5168\u9650\u5236<\/td>\n \u4fe1\u53f7\u5904\u7406\u51fd\u6570\u4e2d\u64cd\u4f5c\u53d7\u9650<\/td>\n \u4ec5\u8bbe\u7f6e\u6807\u5fd7，\u4e3b\u5faa\u73af\u5904\u7406<\/td>\n<\/tr>\n \n \u6027\u80fd\u74f6\u9888<\/td>\n \u9ad8\u9891\u7387\u4fe1\u53f7\u5bfc\u81f4CPU\u5360\u7528\u9ad8<\/td>\n \u914d\u5408epoll\u4f7f\u7528<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n （\u4e94）select\u00a0\u51fd\u6570\u8be6\u89e3<\/h3>\n
![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/04\/20250418104532-68022d4c5171b.png\")
<\/p>\n\u4e00\u3001\u51fd\u6570\u539f\u578b\u4e0e\u53c2\u6570\u89e3\u6790<\/h4>\n
#include <sys\/select.h><\/p>\n
int select(int nfds,
\n fd_set *readfds,
\n fd_set *writefds,
\n fd_set *exceptfds,
\n struct timeval *timeout);<\/p>\n\u53c2\u6570\u8bf4\u660e<\/h5>\n
\n
\u53c2\u6570\u7c7b\u578b\u8bf4\u660e<\/tr>\n \n\n nfds<\/td>\n int<\/td>\n \u76d1\u63a7\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u6700\u5927\u503c +1（\u4f18\u5316\u5185\u6838\u68c0\u67e5\u8303\u56f4）<\/td>\n<\/tr>\n \n readfds<\/td>\n fd_set*<\/td>\n \u76d1\u63a7\u53ef\u8bfb\u4e8b\u4ef6\u7684\u63cf\u8ff0\u7b26\u96c6\u5408（\u53efNULL）<\/td>\n<\/tr>\n \n writefds<\/td>\n fd_set*<\/td>\n \u76d1\u63a7\u53ef\u5199\u4e8b\u4ef6\u7684\u63cf\u8ff0\u7b26\u96c6\u5408（\u53efNULL）<\/td>\n<\/tr>\n \n exceptfds<\/td>\n fd_set*<\/td>\n \u76d1\u63a7\u5f02\u5e38\u4e8b\u4ef6\u7684\u63cf\u8ff0\u7b26\u96c6\u5408（\u53efNULL）<\/td>\n<\/tr>\n \n timeout<\/td>\n timeval*<\/td>\n \u8d85\u65f6\u65f6\u95f4：<br>\u2022 NULL：\u963b\u585e\u7b49\u5f85<br>\u2022 0：\u7acb\u5373\u8fd4\u56de<br>\u2022 \u6b63\u6570：\u5b9a\u65f6\u7b49\u5f85<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n \u8fd4\u56de\u503c<\/h5>\n
- \n
- \u6210\u529f：\u8fd4\u56de\u5c31\u7eea\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u603b\u6570（\u53ef\u80fd\u4e3a0）<\/li>\n
- \u5931\u8d25：\u8fd4\u56de-1\u5e76\u8bbe\u7f6eerrno<\/li>\n
- \u8d85\u65f6：\u8fd4\u56de0<\/li>\n<\/ul>\n
\n\u4e8c\u3001\u6838\u5fc3\u64cd\u4f5c\u5b8f<\/h4>\n
\n
\u5b8f\u529f\u80fd\u793a\u4f8b<\/tr>\n \n\n FD_ZERO<\/td>\n \u6e05\u7a7a\u63cf\u8ff0\u7b26\u96c6\u5408<\/td>\n FD_ZERO(&read_fds);<\/td>\n<\/tr>\n \n FD_SET<\/td>\n \u6dfb\u52a0\u63cf\u8ff0\u7b26\u5230\u96c6\u5408<\/td>\n FD_SET(sockfd, &read_fds);<\/td>\n<\/tr>\n \n FD_CLR<\/td>\n \u4ece\u96c6\u5408\u4e2d\u79fb\u9664\u63cf\u8ff0\u7b26<\/td>\n FD_CLR(sockfd, &read_fds);<\/td>\n<\/tr>\n \n FD_ISSET<\/td>\n \u68c0\u6d4b\u63cf\u8ff0\u7b26\u662f\u5426\u5728\u96c6\u5408\u4e2d<\/td>\n if(FD_ISSET(sockfd, &read_fds))<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n\u4e09\u3001\u5178\u578b\u4f7f\u7528\u6d41\u7a0b<\/h4>\n
1. \u521d\u59cb\u5316\u63cf\u8ff0\u7b26\u96c6\u5408<\/h5>\n
fd_set read_fds;
\nFD_ZERO(&read_fds);
\nFD_SET(listen_fd, &read_fds);
\nint max_fd = listen_fd;<\/p>\n2. \u7b49\u5f85\u4e8b\u4ef6\u5c31\u7eea<\/h5>\n
struct timeval tv = {5, 0}; \/\/ 5\u79d2\u8d85\u65f6
\nfd_set tmp_fds = read_fds;<\/p>\nint ready = select(max_fd + 1, &tmp_fds, NULL, NULL, &tv);
\nif (ready == -1) {
\n if (errno == EINTR) continue; \/\/ \u5904\u7406\u4fe1\u53f7\u4e2d\u65ad
\n perror("select error");
\n break;
\n} else if (ready == 0) {
\n printf("Timeout\\\\n");
\n continue;
\n}<\/p>\n3. \u5904\u7406\u5c31\u7eea\u4e8b\u4ef6<\/h5>\n
for (int fd = 0; fd <= max_fd; fd++) {
\n if (FD_ISSET(fd, &tmp_fds)) {
\n if (fd == listen_fd) {
\n \/\/ \u5904\u7406\u65b0\u8fde\u63a5
\n int new_fd = accept(listen_fd, …);
\n FD_SET(new_fd, &read_fds);
\n max_fd = (new_fd > max_fd) ? new_fd : max_fd;
\n } else {
\n \/\/ \u5904\u7406\u5ba2\u6237\u7aef\u6570\u636e
\n ssize_t n = read(fd, …);
\n if (n <= 0) {
\n close(fd);
\n FD_CLR(fd, &read_fds);
\n }
\n }
\n }
\n}<\/p>\n
\n\u56db\u3001\u5173\u952e\u6ce8\u610f\u4e8b\u9879<\/h4>\n
- \n
\u96c6\u5408\u91cd\u7528\u95ee\u9898 select\u8fd4\u56de\u540e，\u96c6\u5408\u4f1a\u88ab\u4fee\u6539\u4e3a\u5c31\u7eea\u7684fd\u96c6\u5408，\u6bcf\u6b21\u8c03\u7528\u524d\u5fc5\u987b\u91cd\u65b0\u521d\u59cb\u5316：<\/p>\n
fd_set tmp_fds = read_fds; \/\/ \u4f7f\u7528\u4e34\u65f6\u96c6\u5408\n <\/li>\n
- \n
\u8d85\u65f6\u65f6\u95f4\u91cd\u7f6e timeout\u53c2\u6570\u4f1a\u88ab\u4fee\u6539\u4e3a\u5269\u4f59\u65f6\u95f4，\u5faa\u73af\u8c03\u7528\u65f6\u9700\u8981\u91cd\u65b0\u8bbe\u7f6e：<\/p>\n
struct timeval tv = {5, 0};
\nwhile(1) {
\n select(…, &tv);
\n tv.tv_sec = 5; \/\/ \u5fc5\u987b\u91cd\u7f6e
\n}\n <\/li>\n- \n
\u6700\u5927fd\u9650\u5236 \u53d7FD_SETSIZE\u9650\u5236（\u901a\u5e381024），\u8d85\u51fa\u4f1a\u5bfc\u81f4\u672a\u5b9a\u4e49\u884c\u4e3a<\/p>\n<\/li>\n
- \n
\u6027\u80fd\u95ee\u9898 \u6bcf\u6b21\u8c03\u7528\u9700\u8981\u4ece\u7528\u6237\u6001\u590d\u5236\u6574\u4e2afd_set\u5230\u5185\u6838\u6001，\u65f6\u95f4\u590d\u6742\u5ea6O(n)<\/p>\n<\/li>\n
#include <stdio.h>
\n#include <sys\/types.h>
\n#include <sys\/stat.h>
\n#include <fcntl.h>
\n#include <unistd.h>
\n#include <errno.h>
\n#include <string.h>
\nint main(int argc, const char *argv[])
\n{
\nif (mkfifo(argv[1],0666) < 0 && errno != EEXIST)
\n{
\nperror("mkfifo fail");
\nreturn -1;
\n}<\/p>\nprintf("mkfifo success\\\\n");<\/p>\n
int fd = open(argv[1], O_RDONLY);
\nif (fd < 0)
\n{
\nperror("open fail");
\nreturn -1;
\n}
\nchar buf[1024] = {0};<\/p>\n\/\/1.\u5efa\u8868
\nfd_set readfds;
\nFD_ZERO(&readfds);<\/p>\n\/\/2.\u6dfb\u52a0\u8981\u5173\u5fc3\u7684fd
\nFD_SET(0,&readfds);
\nFD_SET(fd,&readfds);<\/p>\n\/\/3.select\u51fd\u6570\u76d1\u63a7
\nfd_set backfds;<\/p>\nstruct timeval tv = {5,0};
\nwhile(1)
\n{
\nbackfds = readfds;\/\/\u6bcf\u6b21\u5faa\u73af\u56de\u6765\u62ff\u5230\u7684\u90fd\u662f\u6700\u539f\u59cb\u6570\u636e
\nint nfds = fd + 1;\/\/\u56e0\u4e3a\u53e6\u4e00\u4e2a\u662f0,\u6240\u4ee5\u6700\u5927\u4e5f\u5c31\u662fｆｄ
\nint ret = select(nfds,&backfds,NULL,NULL,&tv);
\nif(ret < 0)
\n{
\nperror("select fail");
\nreturn -1;
\n}
\nif(ret > 0)
\n{
\nfor(int i = 0;i < nfds;i++)\/\/\u4e5f\u53ef\u4ee5\u662f1024,\u4f46\u6ca1\u5fc5\u8981
\n{
\nif(FD_ISSET(i,&backfds))
\n{
\nif(i == 0)
\n{
\nfgets(buf,sizeof(buf),stdin);
\nif (strncmp(buf,"quit",4) == 0)
\nbreak;
\nprintf("buf = %s\\\\n",buf);
\n}else if(i == fd)
\n{
\nread(fd,buf,sizeof(buf));
\nif (strncmp(buf,"quit",4) == 0)
\nbreak;
\nprintf("buf = %s\\\\n",buf);
\n}
\n}
\n}
\n}
\n}<\/p>\nclose(fd);
\nreturn 0;
\n}<\/p>\n\u53ef\u4ee5\u4ece\u5ba2\u6237\u7aef\u8bfb\u53d6\u6570\u636e，\u4e5f\u53ef\u4ee5\u81ea\u8eab\u4ece\u952e\u76d8\u8f93\u5165<\/p>\n
![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/04\/20250418104532-68022d4c78ad9.png\")
<\/h3>\ntcp\u591a\u5ba2\u6237\u7aef\u8fde\u63a5\u5230\u670d\u52a1\u5668<\/p>\n
#include <stdio.h>
\n#include <sys\/types.h> \/* See NOTES *\/
\n#include <sys\/socket.h>
\n#include <netinet\/in.h>
\n#include <netinet\/ip.h> \/* superset of previous *\/
\n#include <arpa\/inet.h>
\n#include <strings.h>
\n#include <unistd.h>
\n#include <stdlib.h>
\n#include <string.h>
\n#include <sys\/select.h><\/p>\nint main(int argc, const char *argv[])
\n{
\nif (argc != 3)
\n{
\nprintf("Usage: %s <port> <ip>\\\\n",argv[0]);
\nreturn -1;
\n}<\/p>\n\/\/1.socket \u521b\u5efa\u901a\u4fe1\u4e00\u7aef
\nint fd = socket(AF_INET,SOCK_STREAM,0);<\/p>\nif (fd < 0)
\n{
\nperror("socket fail\\\\n");
\nreturn -1;
\n}<\/p>\nstruct sockaddr_in seraddr;
\nbzero(&seraddr,sizeof(seraddr));<\/p>\nseraddr.sin_family = AF_INET;
\nseraddr.sin_port = htons(atoi(argv[1]));
\nseraddr.sin_addr.s_addr = inet_addr(argv[2]);
\nprintf("fd = %d\\\\n",fd);
\n\/\/2.bind — \u7ed1\u5b9a\u670d\u52a1\u5668\u7aef\u7684\u5730\u5740\u4fe1\u606f
\nif (bind(fd,(const struct sockaddr*)&seraddr,sizeof(seraddr)) < 0)
\n{
\nperror("connect fail");
\nreturn -1;
\n}<\/p>\nprintf("connect success!\\\\n");<\/p>\n
\/\/3.listen — \u8bbe\u7f6e\u76d1\u542c
\nif (listen(fd,5) < 0)
\n{
\nperror("listen fail");
\nreturn -1;
\n}<\/p>\n\/\/1.\u51c6\u5907\u8868
\nfd_set readfds;
\nFD_ZERO(&readfds);<\/p>\n\/\/2.\u6dfb\u52a0\u8981\u76d1\u63a7\u7684fd
\nFD_SET(fd,&readfds);
\nint connfd = 0;<\/p>\nfd_set backfds;
\nint i = 0;
\nint nfds = fd + 1;
\nwhile (1)
\n{
\nbackfds = readfds;
\nint ret = select(nfds,&backfds,NULL,NULL,NULL);<\/p>\nif (ret < 0)
\n{
\nperror("select fail");
\nreturn -1;
\n}<\/p>\nif (ret > 0)
\n{
\nfor (i = 0; i < nfds; ++i)
\n{<\/p>\nif (FD_ISSET(i,&backfds))
\n{
\nif (i == fd)
\n{
\n\/\/4.accept
\nconnfd = accept(fd,NULL,NULL);<\/p>\nif (connfd < 0)
\n{
\nperror("accept fail");
\nreturn -1;
\n}<\/p>\nFD_SET(connfd,&readfds);
\nnfds = nfds > connfd + 1 ? nfds:connfd + 1;
\n}else
\n{
\nchar buf[1024];
\nchar sbuf[1024];
\nrecv(i,buf,sizeof(buf),0);
\nprintf("c: %s\\\\n",buf);<\/p>\nif (strncmp(buf,"quit",4) == 0)
\n{
\nclose(i);
\nFD_CLR(i,&readfds);
\n}
\nsprintf(sbuf,"server + %s\\\\n",buf);
\nsend(i,sbuf,strlen(sbuf)+1,0);<\/p>\n}
\n}
\n}
\n}<\/p>\n}
\nclose(fd);<\/p>\nreturn 0;
\n}<\/p>\n\u5e76\u53d1\u6a21\u578b\u5bf9\u6bd4<\/h3>\n
\n
\u6a21\u578b\u5b9e\u73b0\u65b9\u5f0f\u4f18\u70b9\u7f3a\u70b9<\/tr>\n \n\n \u591a\u8fdb\u7a0b<\/td>\n fork()<\/td>\n \u9694\u79bb\u6027\u597d<\/td>\n \u8d44\u6e90\u6d88\u8017\u5927<\/td>\n<\/tr>\n \n \u591a\u7ebf\u7a0b<\/td>\n pthread_create()<\/td>\n \u8d44\u6e90\u5171\u4eab\u9ad8\u6548<\/td>\n \u540c\u6b65\u590d\u6742\u5ea6\u9ad8<\/td>\n<\/tr>\n \n I\/O\u591a\u8def\u590d\u7528<\/td>\n select\/poll\/epoll<\/td>\n \u9ad8\u5e76\u53d1\u4f4e\u5f00\u9500<\/td>\n \u7f16\u7a0b\u590d\u6742\u5ea6\u8f83\u9ad8<\/td>\n<\/tr>\n \n \u4fe1\u53f7\u9a71\u52a8<\/td>\n SIGIO+fcntl<\/td>\n \u5b9e\u65f6\u6027\u597d<\/td>\n \u4fe1\u53f7\u5904\u7406\u590d\u6742<\/td>\n<\/tr>\n \n \u5f02\u6b65I\/O<\/td>\n aio_*\u7cfb\u5217\u51fd\u6570<\/td>\n \u771f\u6b63\u7684\u5f02\u6b65\u64cd\u4f5c<\/td>\n \u7cfb\u7edf\u652f\u6301\u4e0d\u7edf\u4e00<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n （\u516d）epoll\u00a0<\/h3>\n
![\"\"](\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/04\/20250418104532-68022d4c94e0c.png\")
<\/p>\n
\n\u4e00\u3001\u6838\u5fc3\u51fd\u6570\u89e3\u6790<\/h4>\n
1.\u00a0epoll_create：\u521b\u5efa epoll \u5b9e\u4f8b<\/h5>\n
#include <sys\/epoll.h>
\nint epoll_create(int size);<\/p>\n- \n
- \u53c2\u6570：\n
- \n
- size：\u5185\u6838\u521d\u59cb\u5206\u914d\u6570\u636e\u7ed3\u6784\u7684\u5efa\u8bae\u503c（Linux 2.6.8+ \u540e\u5ffd\u7565，\u4f46\u9700 > 0）<\/li>\n<\/ul>\n<\/li>\n
- \u8fd4\u56de\u503c：\n
- \n
- \u6210\u529f：epoll \u6587\u4ef6\u63cf\u8ff0\u7b26 (epfd)<\/li>\n
- \u5931\u8d25：-1，\u8bbe\u7f6e\u00a0errno<\/li>\n<\/ul>\n<\/li>\n
- \u6ce8\u610f：\n
- \n
- \u9700\u624b\u52a8\u8c03\u7528\u00a0close(epfd)\u00a0\u91ca\u653e\u8d44\u6e90<\/li>\n
- \u5178\u578b\u7528\u6cd5：epoll_create1(0)（\u66f4\u63a8\u8350，\u652f\u6301\u00a0EPOLL_CLOEXEC\u00a0\u6807\u5fd7）<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n
\n2.\u00a0epoll_ctl：\u7ba1\u7406\u76d1\u63a7\u5217\u8868<\/h5>\n
int epoll_ctl(int epfd, int op, int fd, struct epoll_event *event);<\/p>\n
- \n
- \n
\u64cd\u4f5c\u7c7b\u578b\u00a0(op)：<\/p>\n
\n
\u64cd\u4f5c\u8bf4\u660e<\/tr>\n \n\n EPOLL_CTL_ADD<\/td>\n \u6dfb\u52a0 fd \u5230\u76d1\u63a7\u5217\u8868（\u91cd\u590d\u6dfb\u52a0\u62a5\u00a0EEXIST\u00a0\u9519\u8bef）<\/td>\n<\/tr>\n \n EPOLL_CTL_MOD<\/td>\n \u4fee\u6539\u5df2\u6ce8\u518c fd \u7684\u4e8b\u4ef6（\u672a\u6ce8\u518c\u7684 fd \u62a5\u00a0ENOENT\u00a0\u9519\u8bef）<\/td>\n<\/tr>\n \n EPOLL_CTL_DEL<\/td>\n \u4ece\u76d1\u63a7\u5217\u8868\u5220\u9664 fd（\u5185\u6838\u4f1a\u5ffd\u7565 event \u53c2\u6570）<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/li>\n - \n
\u4e8b\u4ef6\u7ed3\u6784：<\/p>\n
struct epoll_event {
\n uint32_t events; \/\/ \u76d1\u63a7\u7684\u4e8b\u4ef6\u7c7b\u578b（\u4f4d\u63a9\u7801）
\n epoll_data_t data; \/\/ \u7528\u6237\u6570\u636e（\u53ef\u643a\u5e26 fd\u3001\u6307\u9488\u7b49）
\n};<\/p>\ntypedef union epoll_data {
\n void *ptr;
\n int fd;
\n uint32_t u32;
\n uint64_t u64;
\n} epoll_data_t;\n <\/li>\n<\/ul>\n
\n3.\u00a0epoll_wait：\u7b49\u5f85\u4e8b\u4ef6\u5c31\u7eea<\/h5>\n
int epoll_wait(int epfd, struct epoll_event *events, int maxevents, int timeout);<\/p>\n
- \n
- \u53c2\u6570：\n
- \n
- events：\u8f93\u51fa\u53c2\u6570，\u5b58\u50a8\u5c31\u7eea\u4e8b\u4ef6\u6570\u7ec4<\/li>\n
- maxevents：\u6700\u591a\u8fd4\u56de\u7684\u4e8b\u4ef6\u6570\u91cf（\u9700 \u2264 \u6570\u7ec4\u957f\u5ea6）<\/li>\n
- timeout：\u8d85\u65f6\u65f6\u95f4（ms），-1 \u8868\u793a\u963b\u585e，0 \u8868\u793a\u7acb\u5373\u8fd4\u56de<\/li>\n<\/ul>\n<\/li>\n
- \u8fd4\u56de\u503c：\n
- \n
- \u6210\u529f：\u5c31\u7eea\u4e8b\u4ef6\u6570\u91cf<\/li>\n
- \u8d85\u65f6：0<\/li>\n
- \u9519\u8bef：-1，\u8bbe\u7f6e\u00a0errno<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n
\n\u4e8c\u3001\u4e8b\u4ef6\u7c7b\u578b\u4e0e\u89e6\u53d1\u6a21\u5f0f<\/h4>\n
1.\u00a0\u57fa\u7840\u4e8b\u4ef6\u7c7b\u578b<\/h5>\n
\n
\u4e8b\u4ef6\u7c7b\u578b\u8bf4\u660e<\/tr>\n \n\n EPOLLIN<\/td>\n \u6570\u636e\u53ef\u8bfb（\u5305\u62ec\u5bf9\u7aef\u5173\u95ed）<\/td>\n<\/tr>\n \n EPOLLOUT<\/td>\n \u6570\u636e\u53ef\u5199（\u6ce8\u610f：\u53ef\u80fd\u89e6\u53d1\u865a\u5047\u5c31\u7eea）<\/td>\n<\/tr>\n \n EPOLLRDHUP<\/td>\n \u5bf9\u7aef\u5173\u95ed\u8fde\u63a5\u6216\u5173\u95ed\u5199\u65b9\u5411（\u9700\u5185\u6838 \u2265 2.6.17）<\/td>\n<\/tr>\n \n EPOLLPRI<\/td>\n \u7d27\u6025\u6570\u636e\u53ef\u8bfb（\u5982 TCP \u5e26\u5916\u6570\u636e）<\/td>\n<\/tr>\n \n EPOLLERR<\/td>\n \u9519\u8bef\u6761\u4ef6（\u81ea\u52a8\u76d1\u63a7，\u65e0\u9700\u624b\u52a8\u8bbe\u7f6e）<\/td>\n<\/tr>\n \n EPOLLHUP<\/td>\n \u6302\u8d77（\u5982\u7ba1\u9053\u5bf9\u7aef\u5173\u95ed，\u81ea\u52a8\u76d1\u63a7）<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n 2.\u00a0\u9ad8\u7ea7\u63a7\u5236\u6807\u5fd7<\/h5>\n
\n
\u6807\u5fd7\u8bf4\u660e<\/tr>\n \n\n EPOLLET<\/td>\n \u8fb9\u6cbf\u89e6\u53d1\u6a21\u5f0f（\u9ed8\u8ba4\u6c34\u5e73\u89e6\u53d1 LT）<\/td>\n<\/tr>\n \n EPOLLONESHOT<\/td>\n \u5355\u6b21\u89e6\u53d1，\u4e8b\u4ef6\u5904\u7406\u540e\u9700\u7528\u00a0EPOLL_CTL_MOD\u00a0\u91cd\u65b0\u6fc0\u6d3b<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n\u4e09\u3001\u89e6\u53d1\u6a21\u5f0f\u5bf9\u6bd4<\/h4>\n
\n
\u7279\u6027\u6c34\u5e73\u89e6\u53d1 (LT)\u8fb9\u6cbf\u89e6\u53d1 (ET)<\/tr>\n \n\n \u89e6\u53d1\u6761\u4ef6<\/td>\n \u53ea\u8981\u7f13\u51b2\u533a\u6709\u6570\u636e\/\u7a7a\u95f4\u5c31\u4f1a\u89e6\u53d1<\/td>\n \u4ec5\u5728\u7f13\u51b2\u533a\u72b6\u6001\u53d8\u5316\u65f6\u89e6\u53d1\u4e00\u6b21<\/td>\n<\/tr>\n \n \u6570\u636e\u8bfb\u53d6<\/td>\n \u53ef\u90e8\u5206\u8bfb\u53d6，\u4e0b\u6b21\u4ecd\u4f1a\u89e6\u53d1<\/td>\n \u5fc5\u987b\u4e00\u6b21\u6027\u8bfb\u53d6\u5230\u00a0EAGAIN<\/td>\n<\/tr>\n \n \u6027\u80fd<\/td>\n \u9002\u5408\u4f4e\u9891\u5927\u5757\u6570\u636e<\/td>\n \u9002\u5408\u9ad8\u9891\u9ad8\u5e76\u53d1\u573a\u666f<\/td>\n<\/tr>\n \n \u5b9e\u73b0\u590d\u6742\u5ea6<\/td>\n \u7b80\u5355<\/td>\n \u9700\u914d\u5408\u975e\u963b\u585e I\/O \u548c\u5faa\u73af\u8bfb\u5199<\/td>\n<\/tr>\n \n \u9002\u7528\u573a\u666f<\/td>\n \u7b80\u5355\u4ea4\u4e92\u3001\u6587\u4ef6\u4f20\u8f93<\/td>\n \u5b9e\u65f6\u901a\u4fe1\u3001\u9ad8\u5e76\u53d1\u670d\u52a1\u5668<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n \u5b9e\u4f8b：<\/h4>\n
\u57fa\u4e8e epoll \u7684\u7b80\u5355 TCP \u670d\u52a1\u5668，\u53ef\u4ee5\u540c\u65f6\u5904\u7406\u591a\u4e2a\u5ba2\u6237\u7aef\u8fde\u63a5<\/p>\n
#include <stdio.h>
\n#include <sys\/types.h> \/* See NOTES *\/
\n#include <sys\/socket.h>
\n#include <netinet\/in.h>
\n#include <netinet\/ip.h> \/* superset of previous *\/
\n#include <arpa\/inet.h>
\n#include <strings.h>
\n#include <unistd.h>
\n#include <stdlib.h>
\n#include <string.h>
\n#include <sys\/select.h>
\n#include <sys\/epoll.h><\/p>\n\/\/ \u5c06\u6587\u4ef6\u63cf\u8ff0\u7b26\u6dfb\u52a0\u5230 epoll \u5b9e\u4f8b\u4e2d
\nint add_fd(int epfd,int fd)
\n{
\nstruct epoll_event ev;
\nev.events = EPOLLIN;\/\/ \u76d1\u542c\u53ef\u8bfb\u4e8b\u4ef6
\nev.data.fd = fd;\/\/ \u8bbe\u7f6e\u6587\u4ef6\u63cf\u8ff0\u7b26<\/p>\nif(epoll_ctl(epfd,EPOLL_CTL_ADD,fd,&ev) < 0)
\n{
\nperror("epoll_ctl fail");
\nreturn -1;
\n}
\nreturn 0;
\n}
\n\/\/ \u4ece epoll \u5b9e\u4f8b\u4e2d\u5220\u9664\u6587\u4ef6\u63cf\u8ff0\u7b26
\nint del_fd(int epfd,int fd)
\n{
\nstruct epoll_event ev;
\nev.events = EPOLLIN;
\nev.data.fd = fd;<\/p>\nif(epoll_ctl(epfd,EPOLL_CTL_DEL,fd,&ev) < 0)
\n{
\nperror("epoll_ctl fail");
\nreturn -1;
\n}
\nreturn 0;
\n}<\/p>\nint main(int argc, const char *argv[])
\n{
\nif (argc != 3)
\n{
\nprintf("Usage: %s <port> <ip>\\\\n",argv[0]);
\nreturn -1;
\n}<\/p>\n\/\/1.socket \u521b\u5efa\u901a\u4fe1\u4e00\u7aef
\nint fd = socket(AF_INET,SOCK_STREAM,0);<\/p>\nif (fd < 0)
\n{
\nperror("socket fail\\\\n");
\nreturn -1;
\n}<\/p>\nstruct sockaddr_in seraddr;
\nbzero(&seraddr,sizeof(seraddr));<\/p>\nseraddr.sin_family = AF_INET;
\nseraddr.sin_port = htons(atoi(argv[1]));
\nseraddr.sin_addr.s_addr = inet_addr(argv[2]);
\n\/\/2.bind — \u7ed1\u5b9a\u670d\u52a1\u5668\u7aef\u7684\u5730\u5740\u4fe1\u606f
\nif (bind(fd,(const struct sockaddr*)&seraddr,sizeof(seraddr)) < 0)
\n{
\nperror("connect fail");
\nreturn -1;
\n}<\/p>\nprintf("connect success!\\\\n");<\/p>\n
\/\/3.listen — \u8bbe\u7f6e\u76d1\u542c
\nif (listen(fd,5) < 0)
\n{
\nperror("listen fail");
\nreturn -1;
\n}<\/p>\n\/\/1.\u51c6\u5907\u8868
\nint epfd = epoll_create(2);
\nif(epfd < 0)
\n{
\nperror("epoll_create fail");
\nreturn -1;
\n}<\/p>\n\/\/2.\u6dfb\u52a0\u8981\u76d1\u63a7\u7684fd
\nadd_fd(epfd,fd); \/\/ \u6dfb\u52a0\u76d1\u542c socket \u5230 epoll
\nint connfd = 0;<\/p>\nstruct epoll_event result[1024];\/\/ \u4fdd\u5b58 epoll_wait \u8fd4\u56de\u7684\u4e8b\u4ef6
\nint maxevents = 1024;\/\/\u6307\u5b9a epoll_wait \u51fd\u6570\u6700\u591a\u53ef\u4ee5\u8fd4\u56de\u7684\u4e8b\u4ef6\u6570\u91cf\u3002
\nint ret = 0;
\nint i = 0;<\/p>\nint tm = 3000;\/\/3s
\nwhile (1)
\n{\/\/ \u7b49\u5f85 epoll \u4e8b\u4ef6
\nret = epoll_wait(epfd,result,maxevents,tm);<\/p>\nif (ret < 0)
\n{
\nperror("epoll_wait fail");
\nreturn -1;
\n}else if (ret == 0) {
\nprintf("epoll_wait timeout\\\\n");\/\/\u5904\u7406\u8d85\u65f6
\n}else if(ret > 0)
\n{
\nfor (i = 0; i < ret; ++i)
\n{
\n\/\/ \u5982\u679c\u662f\u76d1\u542c socket \u6709\u4e8b\u4ef6，\u8bf4\u660e\u6709\u65b0\u8fde\u63a5
\nif (result[i].data.fd == fd)\/\/\u4f5c\u7528\u4e3a\u76d1\u542c\u7684fd
\n{
\n\/\/4.accept
\nconnfd = accept(fd,NULL,NULL);<\/p>\nif (connfd < 0)
\n{
\nperror("accept fail");
\nreturn -1;
\n}
\n\/\/ \u5c06\u65b0\u8fde\u63a5\u7684 socket \u6dfb\u52a0\u5230 epoll
\nadd_fd(epfd,connfd);
\n}else \/\/\u901a\u4fe1\u7684fd
\n{
\n\/\/ \u5904\u7406\u5ba2\u6237\u7aef\u6570\u636e
\nconnfd = result[i].data.fd;\/\/\u53d6\u89e6\u53d1\u4e8b\u4ef6\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26
\nchar buf[1024];
\nchar sbuf[1024];
\nrecv(connfd,buf,sizeof(buf),0);
\nprintf("c: %s\\\\n",buf);<\/p>\nif (strncmp(buf,"quit",4) == 0)
\n{
\ndel_fd(epfd,connfd);
\nclose(connfd);
\ncontinue;
\n}
\nsprintf(sbuf,"server + %s\\\\n",buf);
\nsend(connfd,sbuf,strlen(sbuf)+1,0);
\n}
\n}
\n}<\/p>\n}
\nclose(fd);<\/p>\nreturn 0;
\n}<\/p>\n\u57fa\u4e8e epoll \u7684\u7b80\u5355 TCP \u670d\u52a1\u5668，\u53ef\u4ee5\u540c\u65f6\u5904\u7406\u591a\u4e2a\u5ba2\u6237\u7aef\u8fde\u63a5（\u8fb9\u6cbf\u89e6\u53d1\u6a21\u5f0f）<\/p>\n
#include <stdio.h>
\n#include <sys\/types.h> \/* See NOTES *\/
\n#include <sys\/socket.h>
\n#include <netinet\/in.h>
\n#include <netinet\/ip.h> \/* superset of previous *\/
\n#include <arpa\/inet.h>
\n#include <strings.h>
\n#include <unistd.h>
\n#include <stdlib.h>
\n#include <string.h>
\n#include <sys\/select.h>
\n#include <sys\/epoll.h>
\n#include <errno.h>
\n#include <fcntl.h><\/p>\n\/\/ \u5c06\u6587\u4ef6\u63cf\u8ff0\u7b26\u6dfb\u52a0\u5230 epoll \u5b9e\u4f8b\u4e2d
\nint add_fd(int epfd,int fd)
\n{
\nstruct epoll_event ev;
\nev.events = EPOLLIN|EPOLLET;\/\/ \u76d1\u542c\u53ef\u8bfb\u4e8b\u4ef6，\u5e76\u4f7f\u7528\u8fb9\u7f18\u89e6\u53d1\u6a21\u5f0f
\nev.data.fd = fd;\/\/ \u8bbe\u7f6e\u6587\u4ef6\u63cf\u8ff0\u7b26<\/p>\nif(epoll_ctl(epfd,EPOLL_CTL_ADD,fd,&ev) < 0)
\n{
\nperror("epoll_ctl fail");
\nreturn -1;
\n}
\nreturn 0;
\n}
\n\/\/ \u4ece epoll \u5b9e\u4f8b\u4e2d\u5220\u9664\u6587\u4ef6\u63cf\u8ff0\u7b26
\nint del_fd(int epfd,int fd)
\n{
\nstruct epoll_event ev;
\nev.events = EPOLLIN;
\nev.data.fd = fd;<\/p>\nif(epoll_ctl(epfd,EPOLL_CTL_DEL,fd,&ev) < 0)
\n{
\nperror("epoll_ctl fail");
\nreturn -1;
\n}
\nreturn 0;
\n}
\n\/\/ \u8bbe\u7f6e\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e3a\u975e\u963b\u585e\u6a21\u5f0f
\nvoid set_nonblock(int fd)
\n{
\nint flag = fcntl(fd,F_GETFL,0);\/\/ \u83b7\u53d6\u5f53\u524d\u6587\u4ef6\u72b6\u6001\u6807\u5fd7
\nflag = flag|O_NONBLOCK;\/\/ \u8bbe\u7f6e\u975e\u963b\u585e\u6807\u5fd7
\nfcntl(fd,F_SETFL,flag);\/\/ \u66f4\u65b0\u6587\u4ef6\u72b6\u6001\u6807\u5fd7
\n}<\/p>\nint main(int argc, const char *argv[])
\n{
\nif (argc != 3)
\n{
\nprintf("Usage: %s <port> <ip>\\\\n",argv[0]);
\nreturn -1;
\n}<\/p>\n\/\/1.socket \u521b\u5efa\u901a\u4fe1\u4e00\u7aef
\nint fd = socket(AF_INET,SOCK_STREAM,0);<\/p>\nif (fd < 0)
\n{
\nperror("socket fail\\\\n");
\nreturn -1;
\n}<\/p>\nstruct sockaddr_in seraddr;
\nbzero(&seraddr,sizeof(seraddr));<\/p>\nseraddr.sin_family = AF_INET;
\nseraddr.sin_port = htons(atoi(argv[1]));
\nseraddr.sin_addr.s_addr = inet_addr(argv[2]);
\n\/\/2.bind — \u7ed1\u5b9a\u670d\u52a1\u5668\u7aef\u7684\u5730\u5740\u4fe1\u606f
\nif (bind(fd,(const struct sockaddr*)&seraddr,sizeof(seraddr)) < 0)
\n{
\nperror("connect fail");
\nreturn -1;
\n}<\/p>\nprintf("connect success!\\\\n");<\/p>\n
\/\/3.listen — \u8bbe\u7f6e\u76d1\u542c
\nif (listen(fd,5) < 0)
\n{
\nperror("listen fail");
\nreturn -1;
\n}<\/p>\n\/\/1.\u51c6\u5907\u8868
\nint epfd = epoll_create(2);
\nif(epfd < 0)
\n{
\nperror("epoll_create fail");
\nreturn -1;
\n}<\/p>\n\/\/2.\u6dfb\u52a0\u8981\u76d1\u63a7\u7684fd
\n\/\/ \u6dfb\u52a0\u76d1\u542c socket \u5230 epoll，\u5e76\u8bbe\u7f6e\u4e3a\u975e\u963b\u585e\u6a21\u5f0f
\nadd_fd(epfd,fd);
\nset_nonblock(fd);<\/p>\nint connfd = 0;<\/p>\n
struct epoll_event result[1024];\/\/ \u4fdd\u5b58 epoll_wait \u8fd4\u56de\u7684\u4e8b\u4ef6
\nint maxevents = 1024;\/\/\u6307\u5b9a epoll_wait \u51fd\u6570\u6700\u591a\u53ef\u4ee5\u8fd4\u56de\u7684\u4e8b\u4ef6\u6570\u91cf\u3002
\nint ret = 0;
\nint i = 0;<\/p>\nint tm = 3000;\/\/3s
\nwhile (1)
\n{\/\/ \u7b49\u5f85 epoll \u4e8b\u4ef6
\nret = epoll_wait(epfd,result,maxevents,tm);<\/p>\nif (ret < 0)
\n{
\nperror("epoll_wait fail");
\nreturn -1;
\n}else if (ret == 0) {
\nprintf("epoll_wait timeout\\\\n");\/\/\u5904\u7406\u8d85\u65f6
\n}else if(ret > 0)
\n{
\nfor (i = 0; i < ret; ++i)
\n{
\n\/\/ \u5982\u679c\u662f\u76d1\u542c socket \u6709\u4e8b\u4ef6，\u8bf4\u660e\u6709\u65b0\u8fde\u63a5
\nif (result[i].data.fd == fd)\/\/\u4f5c\u7528\u4e3a\u76d1\u542c\u7684fd
\n{
\n\/\/4.accept
\nconnfd = accept(fd,NULL,NULL);<\/p>\nif (connfd < 0)
\n{
\nperror("accept fail");
\nreturn -1;
\n}
\nset_nonblock(connfd);\/\/ \u8bbe\u7f6e\u65b0\u8fde\u63a5\u4e3a\u975e\u963b\u585e\u6a21\u5f0f
\n\/\/ \u5c06\u65b0\u8fde\u63a5\u7684 socket \u6dfb\u52a0\u5230 epoll
\nadd_fd(epfd,connfd);
\n}else \/\/\u901a\u4fe1\u7684fd
\n{
\n\/\/ \u5904\u7406\u5ba2\u6237\u7aef\u6570\u636e
\nconnfd = result[i].data.fd;\/\/\u53d6\u89e6\u53d1\u4e8b\u4ef6\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26
\nchar buf[1024];
\nchar sbuf[1024];<\/p>\nwhile(1)
\n{
\nret = recv(connfd,buf,1,0);
\nprintf("c: %s\\\\n",buf);<\/p>\nif(ret < 0)
\n{
\nif(errno == EWOULDBLOCK||errno == EAGAIN)
\nbreak;\/\/ \u975e\u963b\u585e\u6a21\u5f0f\u4e0b，\u6ca1\u6709\u66f4\u591a\u6570\u636e\u53ef\u8bfb
\n}
\nif (strncmp(buf,"quit",4) == 0)
\n{
\ndel_fd(epfd,connfd);
\nclose(connfd);
\ncontinue;
\n}
\nsprintf(sbuf,"server + %s\\\\n",buf);
\nsend(connfd,sbuf,strlen(sbuf)+1,0);
\n}
\n}
\n}
\n}<\/p>\n}
\nclose(fd);<\/p>\nreturn 0;
\n}<\/p>\n（\u4e03）select\u3001poll\u3001epoll \u7684\u6bd4\u8f83<\/h3>\n
select \u7684\u7f3a\u70b9：<\/p>\n
- \n
select \u76d1\u542c\u6587\u4ef6\u63cf\u8ff0\u7b26\u6700\u5927\u4e2a\u6570\u4e3a 1024\u3002<\/p>\n<\/li>\n
- \n
select \u76d1\u542c\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u96c6\u5408\u5728\u7528\u6237\u5c42，\u9700\u8981\u5e94\u7528\u5c42\u548c\u5185\u6838\u5c42\u4e92\u76f8\u4f20\u9012\u6570\u636e\u3002<\/p>\n<\/li>\n
- \n
select \u9700\u8981\u5faa\u73af\u904d\u5386\u4e00\u6b21\u624d\u80fd\u627e\u5230\u4ea7\u751f\u7684\u4e8b\u4ef6\u3002<\/p>\n<\/li>\n
- \n
select \u53ea\u80fd\u5de5\u4f5c\u5728\u6c34\u5e73\u89e6\u53d1\u6a21\u5f0f（\u4f4e\u901f\u6a21\u5f0f），\u65e0\u6cd5\u5de5\u4f5c\u5728\u8fb9\u6cbf\u89e6\u53d1\u6a21\u5f0f（\u9ad8\u901f\u6a21\u5f0f）\u3002<\/p>\n<\/li>\n
poll \u7684\u7f3a\u70b9：<\/p>\n
- \n
poll \u76d1\u542c\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e0d\u53d7\u4e0a\u9650\u9650\u5236\u3002<\/p>\n<\/li>\n
- \n
poll \u76d1\u542c\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u96c6\u5408\u5728\u7528\u6237\u5c42，\u9700\u8981\u5185\u6838\u5c42\u5411\u7528\u6237\u5c42\u4f20\u9012\u6570\u636e\u3002<\/p>\n<\/li>\n
- \n
poll \u9700\u8981\u5faa\u73af\u904d\u5386\u4e00\u6b21\u624d\u80fd\u627e\u5230\u4ea7\u751f\u7684\u4e8b\u4ef6\u3002<\/p>\n<\/li>\n
- \n
poll \u53ea\u80fd\u5de5\u4f5c\u5728\u6c34\u5e73\u89e6\u53d1\u6a21\u5f0f（\u4f4e\u901f\u6a21\u5f0f），\u65e0\u6cd5\u5de5\u4f5c\u5728\u8fb9\u6cbf\u89e6\u53d1\u6a21\u5f0f（\u9ad8\u901f\u6a21\u5f0f）\u3002<\/p>\n<\/li>\n
epoll \u7684\u4f18\u70b9：<\/p>\n
- \n
epoll \u521b\u5efa\u5185\u6838\u4e8b\u4ef6\u8868，\u4e0d\u53d7\u5230\u6587\u4ef6\u63cf\u8ff0\u7b26\u4e0a\u9650\u9650\u5236\u3002<\/p>\n<\/li>\n
- \n
epoll \u76d1\u542c\u7684\u4e8b\u4ef6\u8868\u5728\u5185\u6838\u4e2d，\u76f4\u63a5\u5728\u5185\u6838\u4e2d\u76d1\u6d4b\u4e8b\u4ef6\u6548\u7387\u9ad8\u3002<\/p>\n<\/li>\n
- \n
epoll \u4f1a\u76f4\u63a5\u83b7\u5f97\u4ea7\u751f\u4e8b\u4ef6\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\u7684\u4fe1\u606f，\u800c\u4e0d\u9700\u8981\u904d\u5386\u68c0\u6d4b\u3002<\/p>\n<\/li>\n
- \n
epoll \u65e2\u80fd\u5de5\u4f5c\u5728\u6c34\u5e73\u89e6\u53d1\u6a21\u5f0f，\u4e5f\u80fd\u5de5\u4f5c\u5728\u8fb9\u6cbf\u89e6\u53d1\u6a21\u5f0f\u3002<\/p>\n<\/li>\n","protected":false},"excerpt":{"rendered":"
\u6587\u7ae0\u6d4f\u89c8\u9605\u8bfb1.3k\u6b21\uff0c\u70b9\u8d5e34\u6b21\uff0c\u6536\u85cf30\u6b21\u3002\u6bcf\u6b21\u8c03\u7528\u9700\u8981\u4ece\u7528\u6237\u6001\u590d\u5236\u6574\u4e2afd_set\u5230\u5185\u6838\u6001\uff0c\u65f6\u95f4\u590d\u6742\u5ea6O(n)\u9650\u5236\uff08\u901a\u5e381024\uff09\uff0c\u8d85\u51fa\u4f1a\u5bfc\u81f4\u672a\u5b9a\u4e49\u884c\u4e3a\u3002\u53ef\u4ee5\u4ece\u5ba2\u6237\u7aef\u8bfb\u53d6\u6570\u636e\uff0c\u4e5f\u53ef\u4ee5\u81ea\u8eab\u4ece\u952e\u76d8\u8f93\u5165\u3002<\/p>\n","protected":false},"author":2,"featured_media":11525,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[205,43,78],"topic":[],"class_list":["post-11531","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-server","tag-tcp-ip","tag-43","tag-78"],"yoast_head":"\n
\u7f51\u7edc\u7f16\u7a0b-\u670d\u52a1\u5668\uff08\u591a\u8def\u590d\u7528IO \u548c TCP\u5e76\u53d1\u6a21\u578b\uff09 - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.wsisp.com\/helps\/11531.html\" \/>\n<meta property=\"og:locale\" content=\"zh_CN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"\u7f51\u7edc\u7f16\u7a0b-\u670d\u52a1\u5668\uff08\u591a\u8def\u590d\u7528IO \u548c TCP\u5e76\u53d1\u6a21\u578b\uff09 - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3\" \/>\n<meta property=\"og:description\" content=\"\u6587\u7ae0\u6d4f\u89c8\u9605\u8bfb1.3k\u6b21\uff0c\u70b9\u8d5e34\u6b21\uff0c\u6536\u85cf30\u6b21\u3002\u6bcf\u6b21\u8c03\u7528\u9700\u8981\u4ece\u7528\u6237\u6001\u590d\u5236\u6574\u4e2afd_set\u5230\u5185\u6838\u6001\uff0c\u65f6\u95f4\u590d\u6742\u5ea6O(n)\u9650\u5236\uff08\u901a\u5e381024\uff09\uff0c\u8d85\u51fa\u4f1a\u5bfc\u81f4\u672a\u5b9a\u4e49\u884c\u4e3a\u3002\u53ef\u4ee5\u4ece\u5ba2\u6237\u7aef\u8bfb\u53d6\u6570\u636e\uff0c\u4e5f\u53ef\u4ee5\u81ea\u8eab\u4ece\u952e\u76d8\u8f93\u5165\u3002\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.wsisp.com\/helps\/11531.html\" \/>\n<meta property=\"og:site_name\" content=\"\u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3\" \/>\n<meta property=\"article:published_time\" content=\"2025-04-18T10:45:33+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/04\/20250418104531-68022d4bc28d2.png\" \/>\n<meta name=\"author\" content=\"admin\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"\u4f5c\u8005\" \/>\n\t<meta name=\"twitter:data1\" content=\"admin\" \/>\n\t<meta name=\"twitter:label2\" content=\"\u9884\u8ba1\u9605\u8bfb\u65f6\u95f4\" \/>\n\t<meta name=\"twitter:data2\" content=\"17 \u5206\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.wsisp.com\/helps\/11531.html\",\"url\":\"https:\/\/www.wsisp.com\/helps\/11531.html\",\"name\":\"\u7f51\u7edc\u7f16\u7a0b-\u670d\u52a1\u5668\uff08\u591a\u8def\u590d\u7528IO \u548c TCP\u5e76\u53d1\u6a21\u578b\uff09 - 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