Implemented hearbeat

client.c

@@ -1,16 +1,28 @@
-#include "commands.h"
 #include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>
-#include <stdlib.h>
 #include <string.h>
 #include <sys/msg.h>
 #include <sys/stat.h>
 #include <unistd.h>
 
+#include "commands.h"
+
 #define send(queue_id, msgbuf_ptr)                                             \
   msgsnd(queue_id, msgbuf_ptr, sizeof(*(msgbuf_ptr)) - sizeof(long), 0)
 
+static void heartbeat_loop(int server_queue_id, const char *client_id) {
+  msgbuf_t msg = {.mtype = Hearbeat, .sender = ""};
+  strncpy(msg.sender, client_id, COMMAND_LENGTH - 1);
+  while (1) {
+    if (send(server_queue_id, &msg) == -1) {
+      perror("msgsnd(heartbeat) failed");
+      break;
+    }
+    sleep(HEARTBEAT_INTERVAL);
+  }
+}
+
 static void cleanup_queue(int qid) {
   if (qid != -1) {
     msgctl(qid, IPC_RMID, NULL);
@@ -33,21 +45,22 @@ int main(int argc, char *argv[]) {
 
   int server_queue_id = -1;
   const char *id_path = "/home/piotr/server_queue_id";
-  FILE *f = fopen(id_path, "rb");
+  int fd = open(id_path, O_RDONLY);
+  if (fd == -1) {
+    perror("Failed to open server queue id file");
+    cleanup_queue(client_queue_id);
+    return 1;
+  }
 
-  if (fread(&server_queue_id, sizeof(int), 1, f) != 1) {
+  if (read(fd, &server_queue_id, sizeof(int)) == -1) {
     fprintf(stderr, "Failed to read server queue id from %s\n", id_path);
     server_queue_id = -1;
   }
-  fclose(f);
+  close(fd);
 
-  msgbuf_t msg;
-  memset(&msg, 0, sizeof(msgbuf_t));
-  msg.mtype = Login;
-  /* command field holds client id for login */
-  strncpy(msg.command, client_id, COMMAND_LENGTH - 1);
-  /* message field holds the client's queue id as string */
-  snprintf(msg.message, MESSAGE_LENGTH, "%d", client_queue_id);
+  msgbuf_t msg = {.mtype = Login, .sender = ""};
+  strncpy(msg.sender, client_id, COMMAND_LENGTH - 1);
+  snprintf(msg.command, COMMAND_LENGTH, "%d", client_queue_id);
 
   if (msgsnd(server_queue_id, &msg, sizeof(msg) - sizeof(long), 0) == -1) {
     perror("msgsnd(login) failed");
@@ -73,11 +86,14 @@ int main(int argc, char *argv[]) {
 
   printf("Login accepted for id '%s'\n", client_id);
 
+  if (fork() == 0) {
+    heartbeat_loop(server_queue_id, client_id);
+    return 0;
+  }
+
   /* Send a test message to the server */
-  msgbuf_t test = {
-      .mtype = Message,
-      .sender = "the_only_one",
-  };
+  msgbuf_t test = {.mtype = Message, .sender = ""};
+  strncpy(test.sender, client_id, COMMAND_LENGTH - 1);
   snprintf(test.message, MESSAGE_LENGTH, "Hello from %s", client_id);
 
   if (msgsnd(server_queue_id, &test, sizeof(test) - sizeof(long), 0) == -1) {
@@ -90,7 +106,8 @@ int main(int argc, char *argv[]) {
   printf("Sent test message to server: \"%s\"\n", test.message);
 
   /* Now wait for server forwarded message(s) and a signal ack.
-     We'll wait until we've seen both a Message and a Signal ack or timeout. */
+     We'll wait until we've seen both a Message and a Signal ack or timeout.
+   */
   int seen_message = 0;
   int seen_ack = 0;
   const int MAX_ITER = 10;
@@ -102,7 +119,7 @@ int main(int argc, char *argv[]) {
                          sizeof(incoming) - sizeof(long), 0, 0);
     perror("Got a message damn");
     if (got == -1) {
-        perror("msgrcv(incoming) failed");
+      perror("msgrcv(incoming) failed");
 
       if (errno == EINTR) {
         continue;