# 10.2 基于事件服務器 ##服務端 ```cpp #include <event2/event-config.h> #include <sys/types.h> #include <sys/stat.h> #include <sys/queue.h> #include <unistd.h> #include <sys/time.h> #include <fcntl.h> #include <stdlib.h> #include <stdio.h> #include <string.h> #include <errno.h> #include <event.h> static void fifo_read(evutil_socket_t fd, short event, void *arg) { char buf[255]; int len; struct event *ev = arg; /* Reschedule this event */ event_add(ev, NULL); fprintf(stderr, "fifo_read called with fd: %d, event: %d, arg: %p\n", (int)fd, event, arg); len = read(fd, buf, sizeof(buf) - 1); if (len == -1) { perror("read"); return; } else if (len == 0) { fprintf(stderr, "Connection closed\n"); return; } buf[len] = '\0'; fprintf(stdout, "Read: %s\n", buf); } int main(int argc, char **argv) { struct event evfifo; struct stat st; const char *fifo = "event.fifo"; int socket; if (lstat(fifo, &st) == 0) { if ((st.st_mode & S_IFMT) == S_IFREG) { errno = EEXIST; perror("lstat"); exit(1); } } unlink(fifo); if (mkfifo(fifo, 0600) == -1) { perror("mkfifo"); exit(1); } /* Linux pipes are broken, we need O_RDWR instead of O_RDONLY */ socket = open(fifo, O_RDONLY | O_NONBLOCK, 0); if (socket == -1) { perror("open"); exit(1); } fprintf(stderr, "Write data to %s\n", fifo); /* Initalize the event library */ event_init(); /* Initalize one event */ event_set(&evfifo, socket, EV_READ, fifo_read, &evfifo); /* Add it to the active events, without a timeout */ event_add(&evfifo, NULL); event_dispatch(); return (0); } ``` ##客戶端 ```cpp #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <fcntl.h> #include <pthread.h> int main(int argc, char *argv[]) { int fd = 0; char *str = "hello libevent!"; fd = open("event.fifo", O_RDWR); if (fd < 0) { perror("open error"); exit(1); } while (1) { write(fd, str, strlen(str)); sleep(1); } close(fd); return 0; } ```