From b28f9e46e5e618b71925417fbd797cb03c203ffc Mon Sep 17 00:00:00 2001
From: "flyingscorpio@clevo" <tfranken@protonmail.com>
Date: Fri, 28 Oct 2022 10:12:17 +0200
Subject: [PATCH] Make client_sockid non blocking and handle the reading loops

---
 src/server.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/src/server.c b/src/server.c
index 6e8e4dd..41fff8b 100644
--- a/src/server.c
+++ b/src/server.c
@@ -2,6 +2,8 @@
 #include <stdlib.h>
 #include <string.h>
 #include <pthread.h>
+#include <fcntl.h>
+#include <errno.h>
 #include <unistd.h>
 #include <sys/wait.h>
 
@@ -99,6 +101,8 @@ int main(int argc, char *argv[]) {
         } else {
             printf("received connection from %s\n", ip4tostring(ntohl(client_socket.sin_addr.s_addr)));
 
+            fcntl(client_sockid, F_SETFL, O_NONBLOCK);
+
             /* Get client id to make sure we can handle him */
             if ((client_id = get_next_free_client_id()) == -1) {
                 /* Client array is full, refuse connection */
@@ -292,13 +296,11 @@ void *ClientListener(void *arg) {
     int n = 0;
 
     while (1) {
-        /* Loop for as long as there is nothing to read */
-        while ((n = read(details.sockid, buf, BUF_LEN)) == 0);
-        if (n == -1) {
-            perror("read");
+        /* Loop for as long as there is nothing to read (or there is an error) */
+        while ((n = read(details.sockid, buf, BUF_LEN)) == -1) {
+            if (errno != EAGAIN) perror("read");
             continue;
         }
-
         /* TODO: Get mutex */
 
         /* Write client_id for Dispatcher */
@@ -308,11 +310,8 @@ void *ClientListener(void *arg) {
         /* Write what we've read as long as there is something to read */
         do {
             write(message_buffer[1], buf, n);
-        } while ((n = read(details.sockid, buf, BUF_LEN)) > 0); // TODO: we are blocking here, change socket details to make it non blocking?
-        if (n == -1) {
-            perror("read");
-            continue;
-        }
+        } while ((n = read(details.sockid, buf, BUF_LEN)) > 0);
+        if ((n == -1) && (errno != EAGAIN)) perror("read");
 
         /* TODO: Free mutex */
     }