Using recv with nonblocking flag

Grzegorz Jabłoński
1 parent 0354f793
Showing 1 changed file with 3 additions and 19 deletions
epoll4.c
@@ -62,20 +62,6 @@ static void set_sockaddr(struct sockaddr_in *addr) {
   addr->sin_port = htons(DEFAULT_PORT);
 }
-static int setnonblocking(int sockfd) {
-  int prev = fcntl(sockfd, F_GETFL, 0);
-  if (prev == -1) {
-    perror("fcntl");
-    exit(1);
-  }
-
-  if (fcntl(sockfd, F_SETFL, fcntl(sockfd, F_GETFL, 0) | O_NONBLOCK) == -1) {
-    perror("fcntl");
-    exit(1);
-  }
-  return 0;
-}
-
 /*
  * epoll echo server
  */
@@ -113,7 +99,6 @@ void server_run() {
     exit(1);
   }
-  setnonblocking(listen_sock);
   if (listen(listen_sock, MAX_CONN) < 0) {
     perror("listen");
     exit(1);
@@ -145,13 +130,12 @@ void server_run() {
         inet_ntop(AF_INET, (char *)&(cli_addr.sin_addr), buf, sizeof(buf));
         printf("[+] connected with %s:%d\n", buf, ntohs(cli_addr.sin_port));
-        setnonblocking(conn_sock);
         epoll_ctl_add(epfd, conn_sock,
                       EPOLLIN | EPOLLET | EPOLLRDHUP | EPOLLHUP);
       } else if (events[i].events & EPOLLIN) {
         /* handle EPOLLIN event */
         for (;;) {
-          n = read(events[i].data.fd, buf, sizeof(buf) - 1);
+          n = recv(events[i].data.fd, buf, sizeof(buf) - 1, MSG_DONTWAIT);
           if (n == -1 && ((errno == EAGAIN) || (errno == EWOULDBLOCK))) {
             break;
           } else if (n == 0) {
@@ -163,8 +147,8 @@ void server_run() {
             while (n != strlen(buf)) {
               int rv = send(events[i].data.fd, buf + n, strlen(buf) - n,
                             MSG_NOSIGNAL);
-              if (rv == -1 && (errno == EAGAIN || errno == EWOULDBLOCK))
-                continue; // FIXME: busy waiting - should wait using epoll
+              if (rv == -1 && (errno == EINTR))
+                continue; // FIXME: might lock up due to client not receiving - should wait using epoll
               if (rv == -1)
                 break;
               n += rv;