Added comments and removed unnecessary code

list.txt

@@ -0,0 +1,17 @@
+/* threading stuff */
+LIST *receivelist, *sendlist;
+pthread_t input_thread, send_thread, receive_thread, output_thread;
+pthread_mutex_t sendmut, receivemut, sendcvmut, receivecvmut, rendermut;
+pthread_cond_t sendcv, receivecv;
+char closed[] = "Connection closed.";
+
+/* networking stuff */
+int confd, sockfd;
+char s[INET6_ADDRSTRLEN];
+
+/* notcurses stuff */
+struct notcurses *nc;
+struct ncplane *chatlog, *prompt, *stdn;
+unsigned int rows, cols;
+
+

list_removers.c

@@ -31,7 +31,6 @@ int ListRemove(LIST *list) {
     list->current = list->current->next;
   }
   
-  unused->data = NULL;
   free(unused->data);
   free(unused);
   list->size--;

main.c

@@ -32,32 +32,35 @@ void *input(void *arg) {
   int i;
   CONTEXT *context = (CONTEXT *)arg; 
   
-  while (1) {
+	while (1) {
     /* Get a message from the user */
     msg = malloc(512);
     memset(msg, 0, 512);
     i = 0;
-    ncplane_printf_yx(context->plane_prompt, 0, 0, "Type a message: ");
     
-    pthread_mutex_lock(&context->mut_render);
+    pthread_mutex_lock(context->mut_render);
+    ncplane_printf_yx(context->plane_prompt, 0, 0, "Type a message: ");
     notcurses_render(context->ctx_nc);
-    pthread_mutex_unlock(&context->mut_render);
+    pthread_mutex_unlock(context->mut_render);
    
     /* Loop to get input */
     while (1) {
-      character = notcurses_get(context->ctx_nc, NULL, &ni);  
-      if (character == NCKEY_ENTER) {
+     character = notcurses_get(context->ctx_nc, NULL, &ni);
+
+     if (character == NCKEY_ENTER) {
         /* Add to sendlist when user presses enter */
-        pthread_mutex_lock(&context->mut_send);
+        pthread_mutex_lock(context->mut_send);
         ListAppend(context->ctx_sendlist, msg);
-        pthread_mutex_unlock(&context->mut_send);
+        pthread_mutex_unlock(context->mut_send);
 
+        pthread_mutex_lock(context->mut_render);
         ncplane_erase_region(context->plane_prompt, 0, 16, 1, 
-        context->ctx_cols);
+            context->ctx_cols);
+        pthread_mutex_unlock(context->mut_render);
         
-        pthread_mutex_lock(&context->mut_render);
+        pthread_mutex_lock(context->mut_render);
         notcurses_render(context->ctx_nc);
-        pthread_mutex_unlock(&context->mut_render);
+        pthread_mutex_unlock(context->mut_render);
    
         break;
       }
@@ -71,18 +74,23 @@ void *input(void *arg) {
       }
 
       /* Print the message as the user types it */
+      pthread_mutex_lock(context->mut_render);
       ncplane_erase_region(context->plane_prompt, 0, 0, 1, context->ctx_cols);
       ncplane_printf_yx(context->plane_prompt, 0, 0, "Type a message: %s", msg);
-      
-      pthread_mutex_lock(&context->mut_render);
       notcurses_render(context->ctx_nc);
-      pthread_mutex_unlock(&context->mut_render);
+      pthread_mutex_unlock(context->mut_render);
+    
     } 
     
     /* Wake up thread if it was waiting to have a msg to send */
+    pthread_mutex_lock(context->mut_sendcv);
     if (ListCount(context->ctx_sendlist) == 1) {
-      pthread_cond_signal(&context->cv_send);
+      pthread_cond_signal(context->cv_send);    
     }
+    pthread_mutex_unlock(context->mut_sendcv);
+    /* s = pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
+           if (s != 0)
+               handle_error_en(s, "pthread_setcancelstate");*/
   }
 	return 0;
 }
@@ -94,13 +102,18 @@ void *sender(void *arg) {
   CONTEXT *context = (CONTEXT *)arg; 
   
   while (1) {
+    /* 
+    s = pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
+    if (s != 0)
+      handle_error_en(s, "pthread_setcancelstate");
+    */
     /* Check if the list has any content to send 
      * If not, wait for some to arrive */
+    pthread_mutex_lock(context->mut_sendcv);
     if (ListCount(context->ctx_sendlist) == 0) {
-      pthread_mutex_lock(&context->mut_sendcv);
-      pthread_cond_wait(&context->cv_send, &context->mut_sendcv);
-      pthread_mutex_unlock(&context->mut_sendcv);
+      pthread_cond_wait(context->cv_send, context->mut_sendcv);
     }
+    pthread_mutex_unlock(context->mut_sendcv);
     
     msg = malloc(512);
     header = malloc(519);
@@ -110,11 +123,11 @@ void *sender(void *arg) {
     /* Obtain mutex, get and then remove message 
      * from the list, unlock mutex,
      * send message. */
-    pthread_mutex_unlock(&context->mut_send);
+    pthread_mutex_lock(context->mut_send);
     ListFirst(context->ctx_sendlist);
     strcpy(msg, (char*)ListCurr(context->ctx_sendlist));
     ListRemove(context->ctx_sendlist);
-    pthread_mutex_unlock(&context->mut_send);
+    pthread_mutex_unlock(context->mut_send);
     
     bytes = send(context->ctx_confd, msg, 512, 0);
     
@@ -123,21 +136,28 @@ void *sender(void *arg) {
       pthread_cancel(*context->thread_in);
       pthread_cancel(*context->thread_out);
       pthread_cancel(*context->thread_recv);
-      pthread_exit(&context->ctx_closed);
+      pthread_exit(context->ctx_closed);
     }
     
     /* Append message to header and add to print list */
     strcpy(header, "You: ");
     strncat(header, msg, strlen(msg));
    
-    pthread_mutex_lock(&context->mut_recv);
+    /* Add to receive list. This is done to print the received and
+     * sent messages in order */
+    pthread_mutex_lock(context->mut_recv);
     ListAppend(context->ctx_recvlist, header);
-    pthread_mutex_unlock(&context->mut_recv);
+    pthread_mutex_unlock(context->mut_recv);
     
     /* Wake thread waiting for message to print */
-    if (ListCount(context->ctx_recvlist) == 1) {
-      pthread_cond_signal(&context->cv_recv);
-    }
+    pthread_cond_signal(context->cv_recv);
+    
+    free(msg);
+/*
+    s = pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
+    if (s != 0)
+      handle_error_en(s, "pthread_setcancelstate");
+  */
   }
   return 0;	
 }
@@ -150,9 +170,9 @@ void *receiver(void *arg) {
 
   while (1) {
     msg = malloc(512);
-    header = malloc(strlen(context->ip) + 514);
+    header = malloc(strlen(context->ip) + 515);
     memset(msg, 0, 512);
-    memset(header, 0, strlen(context->ip) + 514);
+    memset(header, 0, strlen(context->ip) + 515); 
     
     bytes = recv(context->ctx_confd, msg, 512, 0);
     
@@ -161,7 +181,7 @@ void *receiver(void *arg) {
       pthread_cancel(*context->thread_send);
       pthread_cancel(*context->thread_in);
       pthread_cancel(*context->thread_out);
-      pthread_exit(&context->ctx_closed);    
+      pthread_exit(context->ctx_closed);    
     }
     
     strncpy(header, context->ip, strlen(context->ip));
@@ -170,14 +190,14 @@ void *receiver(void *arg) {
     
     /* Add message to list for other thread to print */
     if (bytes != -1) {
-      pthread_mutex_lock(&context->mut_recv);
+      pthread_mutex_lock(context->mut_recv);
       ListAppend(context->ctx_recvlist, header);
-      pthread_mutex_unlock(&context->mut_recv);
+      pthread_mutex_unlock(context->mut_recv);
     }
     
     /* Signal output thread, if it was waiting for something to print */
     if (ListCount(context->ctx_recvlist) == 1) {
-      pthread_cond_signal(&context->cv_recv);
+      pthread_cond_signal(context->cv_recv);
     }
   }
   return 0;
@@ -189,27 +209,28 @@ void *output(void *arg) {
   CONTEXT *context = (CONTEXT *)arg;  
   
   while (1) {
-    msg = malloc(512 + strlen(context->ip));
 
     /* Block if there's nothing to output */
     if (ListCount(context->ctx_recvlist) == 0) {
-      pthread_mutex_lock(&context->mut_recvcv);
-      pthread_cond_wait(&context->cv_recv, &context->mut_recvcv);
-      pthread_mutex_unlock(&context->mut_recvcv);
+      pthread_mutex_lock(context->mut_recvcv);
+      pthread_cond_wait(context->cv_recv, context->mut_recvcv);
+      pthread_mutex_unlock(context->mut_recvcv);
     }
     
+    msg = malloc(515 + strlen(context->ip));
     /* Remove a message from the list and print it to chatlog */
-    pthread_mutex_lock(&context->mut_recv);
+    pthread_mutex_lock(context->mut_recv);
     ListFirst(context->ctx_recvlist);
     strcpy(msg, (char*)ListCurr(context->ctx_recvlist));
     ListRemove(context->ctx_recvlist);
-    pthread_mutex_unlock(&context->mut_recv);
+    pthread_mutex_unlock(context->mut_recv);
     
+    pthread_mutex_lock(context->mut_render);
     ncplane_printf(context->plane_log, "%s\n", msg);
-    
-    pthread_mutex_lock(&context->mut_render);
     notcurses_render(context->ctx_nc);
-    pthread_mutex_unlock(&context->mut_render);
+    pthread_mutex_unlock(context->mut_render);
+    
+    free(msg); 
   }
   return 0;
 }
@@ -236,9 +257,15 @@ int main(int argc, char* argv[]) {
 	int yes = 1;
 
   /* threading stuff */
+  CONTEXT *context = malloc(sizeof(CONTEXT));
   LIST *receivelist, *sendlist;
   pthread_t input_thread, send_thread, receive_thread, output_thread;
-  pthread_mutex_t sendmut, receivemut, sendcvmut, receivecvmut, rendermut;
+  pthread_mutex_t sendmut, 
+                  receivemut,
+                  sendcvmut,
+                  receivecvmut,
+                  rendermut,
+                  savedmut;
   pthread_cond_t sendcv, receivecv;
   char closed[] = "Connection closed.";
 
@@ -389,6 +416,10 @@ int main(int argc, char* argv[]) {
     fprintf(stderr, "Error: render mutex init failed\n");
     return -1;
   }
+  if (pthread_mutex_init(&savedmut, NULL) != 0) {
+    fprintf(stderr, "Error: saved mutex init failed\n");
+    return -1;
+  }
   if (pthread_cond_init(&sendcv, NULL) != 0) {
     fprintf(stderr, "Error: send CV init failed\n");
     return -1;
@@ -428,39 +459,43 @@ int main(int argc, char* argv[]) {
   }
   ncplane_set_scrolling(chatlog, true);
  
-  CONTEXT context = {
-    .ctx_recvlist = receivelist,
-    .ctx_sendlist = sendlist,
+  /* Lists to store messages */
+  context->ctx_recvlist = receivelist;
+  context->ctx_sendlist = sendlist;
   
-    .thread_in = &input_thread,
-    .thread_out = &output_thread,
-    .thread_recv = &receive_thread,
-    .thread_send = &send_thread,
+  /* Threads */
+  context->thread_in = &input_thread; 
+  context->thread_out = &output_thread;
+  context->thread_recv = &receive_thread;
+  context->thread_send = &send_thread;
   
-    .mut_send = sendmut,
-    .mut_recv = receivemut,
-    .mut_sendcv = sendcvmut,
-    .mut_recvcv = receivecvmut,
-    .mut_render = rendermut,
+  /* Mutexes */
+  context->mut_send = &sendmut;
+  context->mut_recv = &receivemut;
+  context->mut_sendcv = &sendcvmut;
+  context->mut_recvcv = &receivecvmut;
+  context->mut_render = &rendermut;
 
-    .cv_send = sendcv,
-    .cv_recv = receivecv,
+  /* Condition variables */
+  context->cv_send = &sendcv;
+  context->cv_recv = &receivecv;
 
-    .ip = s,
-    .ctx_confd = confd,
+  /* Networking stuff */
+  context->ip = s;
+  context->ctx_confd = confd;
 
-    .ctx_nc = nc,
-    .plane_log = chatlog,
-    .plane_prompt = prompt,
-    .ctx_rows = rows,
-    .ctx_cols = cols,
-    .ctx_closed = closed,
-  };
+  /* Notcurses rendering stuff */
+  context->ctx_nc = nc;
+  context->plane_log = chatlog;
+  context->plane_prompt = prompt;
+  context->ctx_rows = rows;
+  context->ctx_cols = cols;
+  context->ctx_closed = closed;
   
-  pthread_create(&input_thread, NULL, input, &context);
-  pthread_create(&send_thread, NULL, sender, &context);
-	pthread_create(&output_thread, NULL, output, &context);
-  pthread_create(&receive_thread, NULL, receiver,  &context);
+  pthread_create(&input_thread, NULL, input, context);
+  pthread_create(&send_thread, NULL, sender, context);
+	pthread_create(&output_thread, NULL, output, context);
+  pthread_create(&receive_thread, NULL, receiver,  context);
   
   pthread_join(input_thread, NULL);
   pthread_join(output_thread, NULL);