check rvalues from pthread_mutex_ operations in examples

src/examples/websocket_chatserver_example.c

@@ -188,7 +188,8 @@
   "  {\n" \
   " /* Determine the base url (for http:/" "/ this is ws:/" "/ for https:/" \
   "/ this must be wss:/" "/) */\n" \
-  "    baseUrl = 'ws' + (window.location.protocol === 'https:' ? 's' : '') + ':/" "/' + window.location.host + '/ChatServerWebSocket';\n" \
+  "    baseUrl = 'ws' + (window.location.protocol === 'https:' ? 's' : '') + ':/" \
+  "/' + window.location.host + '/ChatServerWebSocket';\n" \
   "    chat_generate();\n" \
   "    chat_connect();\n" \
   "  }\n" \
@@ -737,8 +738,8 @@ send_all (struct ConnectedUser *cu,
   ssize_t ret;
   size_t off;
 
-  if (0 == pthread_mutex_lock (&cu->send_mutex))
+  if (0 != pthread_mutex_lock (&cu->send_mutex))
-  {
+    abort ();
   for (off = 0; off < len; off += ret)
   {
     ret = send (cu->fd,
@@ -757,8 +758,8 @@ send_all (struct ConnectedUser *cu,
     if (0 == ret)
       break;
   }
-    pthread_mutex_unlock (&cu->send_mutex);
+  if (0 != pthread_mutex_unlock (&cu->send_mutex))
-  }
+    abort ();
 }
 
 
@@ -806,7 +807,7 @@ chat_addmessage (size_t from_user_id,
   if (0 != needs_lock)
   {
     if (0 != pthread_mutex_lock (&chat_mutex))
-      return 1;
+      abort ();
   }
 
   /* add the new message to the global message list */
@@ -819,7 +820,8 @@ chat_addmessage (size_t from_user_id,
   {
     free (message);
     if (0 != needs_lock)
-      pthread_mutex_unlock (&chat_mutex);
+      if (0 != pthread_mutex_unlock (&chat_mutex))
+        abort ();
     return 1;
   }
   messages_[message_count] = message;
@@ -834,7 +836,8 @@ chat_addmessage (size_t from_user_id,
   if (0 != needs_lock)
   {
     if (0 != needs_lock)
-      pthread_mutex_unlock (&chat_mutex);
+      if (0 != pthread_mutex_unlock (&chat_mutex))
+        abort ();
   }
   return 0;
 }
@@ -854,7 +857,7 @@ chat_clearmessages (int needs_lock)
   if (0 != needs_lock)
   {
     if (0 != pthread_mutex_lock (&chat_mutex))
-      return 1;
+      abort ();
   }
 
   /* update the clean counter and check whether we need cleaning */
@@ -864,7 +867,8 @@ chat_clearmessages (int needs_lock)
     /* no cleanup required */
     if (0 != needs_lock)
     {
-      pthread_mutex_unlock (&chat_mutex);
+      if (0 != pthread_mutex_unlock (&chat_mutex))
+        abort ();
     }
     return 0;
   }
@@ -916,7 +920,8 @@ chat_clearmessages (int needs_lock)
   /* unlock the global mutex if needed */
   if (0 != needs_lock)
   {
-    pthread_mutex_unlock (&chat_mutex);
+    if (0 != pthread_mutex_unlock (&chat_mutex))
+      abort ();
   }
   return 0;
 }
@@ -947,10 +952,7 @@ chat_adduser (struct ConnectedUser *cu)
 
   /* lock the mutex */
   if (0 != pthread_mutex_lock (&chat_mutex))
-  {
+    abort ();
-    free (data);
-    return 1;
-  }
   /* inform the other chat users about the new user */
   if (0 != chat_addmessage (0,
                             0,
@@ -960,7 +962,8 @@ chat_adduser (struct ConnectedUser *cu)
                             0))
   {
     free (data);
-    pthread_mutex_unlock (&chat_mutex);
+    if (0 != pthread_mutex_unlock (&chat_mutex))
+      abort ();
     return 1;
   }
   free (data);
@@ -973,7 +976,8 @@ chat_adduser (struct ConnectedUser *cu)
   if (NULL == users_)
   {
     /* realloc failed */
-    pthread_mutex_unlock (&chat_mutex);
+    if (0 != pthread_mutex_unlock (&chat_mutex))
+      abort ();
     return 1;
   }
   users_[user_count] = cu;
@@ -985,7 +989,8 @@ chat_adduser (struct ConnectedUser *cu)
   cu->next_message_index = message_count;
 
   /* unlock the mutex */
-  pthread_mutex_unlock (&chat_mutex);
+  if (0 != pthread_mutex_unlock (&chat_mutex))
+    abort ();
   return 0;
 }
 
@@ -1014,10 +1019,7 @@ chat_removeuser (struct ConnectedUser *cu)
 
   /* lock the mutex */
   if (0 != pthread_mutex_lock (&chat_mutex))
-  {
+    abort ();
-    free (data);
-    return 1;
-  }
   /* inform the other chat users that the user is gone */
   int got_error = 0;
   if (0 != chat_addmessage (0, 0, data, data_len, 0, 0))
@@ -1045,7 +1047,8 @@ chat_removeuser (struct ConnectedUser *cu)
     got_error = 1;
 
   /* unlock the mutex */
-  pthread_mutex_unlock (&chat_mutex);
+  if (0 != pthread_mutex_unlock (&chat_mutex))
+    abort ();
 
   return got_error;
 }
@@ -1066,9 +1069,7 @@ chat_renameuser (struct ConnectedUser *cu,
 {
   /* lock the mutex */
   if (0 != pthread_mutex_lock (&chat_mutex))
-  {
+    abort ();
-    return 1;
-  }
 
   /* check whether the name is already in use */
   for (size_t i = 0; i < user_count; ++i)
@@ -1078,7 +1079,8 @@ chat_renameuser (struct ConnectedUser *cu,
       if ((users[i]->user_name_len == new_name_len) &&
           (0 == strcasecmp (users[i]->user_name, new_name)))
       {
-        pthread_mutex_unlock (&chat_mutex);
+        if (0 != pthread_mutex_unlock (&chat_mutex))
+          abort ();
         return 2;
       }
     }
@@ -1101,7 +1103,8 @@ chat_renameuser (struct ConnectedUser *cu,
   if (0 != chat_addmessage (0, 0, data, data_len, 0, 0))
   {
     free (data);
-    pthread_mutex_unlock (&chat_mutex);
+    if (0 != pthread_mutex_unlock (&chat_mutex))
+      abort ();
     return 1;
   }
   free (data);
@@ -1112,7 +1115,8 @@ chat_renameuser (struct ConnectedUser *cu,
   cu->user_name_len = new_name_len;
 
   /* unlock the mutex */
-  pthread_mutex_unlock (&chat_mutex);
+  if (0 != pthread_mutex_unlock (&chat_mutex))
+    abort ();
 
   return 0;
 }
@@ -1411,8 +1415,8 @@ connecteduser_parse_received_websocket_stream (struct ConnectedUser *cu,
               case 3:
                 /* ping */
                 {
-                  if (0 == pthread_mutex_lock (&chat_mutex))
+                  if (0 != pthread_mutex_lock (&chat_mutex))
-                  {
+                    abort ();
                   /* check whether the to_user exists */
                   struct ConnectedUser *ping_user = NULL;
                   for (size_t k = 0; k < user_count; ++k)
@@ -1442,17 +1446,8 @@ connecteduser_parse_received_websocket_stream (struct ConnectedUser *cu,
                       pthread_cond_signal (&ping_user->wake_up_sender);
                     }
                   }
-                    pthread_mutex_unlock (&chat_mutex);
+                  if (0 != pthread_mutex_unlock (&chat_mutex))
-                  }
+                    abort ();
-                  else
-                  {
-                    chat_addmessage (0,
-                                     from_user_id,
-                                     "error||Error while pinging.",
-                                     27,
-                                     0,
-                                     1);
-                  }
                 }
                 break;
 
@@ -1591,8 +1586,8 @@ connecteduser_send_messages (void *cls)
   struct ConnectedUser *cu = cls;
 
   /* the main loop of sending messages requires to lock the mutex */
-  if (0 == pthread_mutex_lock (&chat_mutex))
+  if (0 != pthread_mutex_lock (&chat_mutex))
-  {
+    abort ();
   for (;;)
   {
     /* loop while not all messages processed */
@@ -1611,14 +1606,16 @@ connecteduser_send_messages (void *cls)
           MHD_upgrade_action (urh,
                               MHD_UPGRADE_ACTION_CLOSE);
         }
-          pthread_mutex_unlock (&chat_mutex);
+        if (0 != pthread_mutex_unlock (&chat_mutex))
+          abort ();
         return NULL;
       }
       else if (1 == cu->disconnect)
       {
         /* The sender thread shall close. */
         /* This is only requested by the receive thread, so we can just leave. */
-          pthread_mutex_unlock (&chat_mutex);
+        if (0 != pthread_mutex_unlock (&chat_mutex))
+          abort ();
         return NULL;
       }
       else if (1 == cu->ping_status)
@@ -1643,14 +1640,13 @@ connecteduser_send_messages (void *cls)
 
           /* send the data via the TCP/IP socket and */
           /* unlock the mutex while sending */
-            pthread_mutex_unlock (&chat_mutex);
+          if (0 != pthread_mutex_unlock (&chat_mutex))
+            abort ();
           send_all (cu,
                     frame_data,
                     frame_len);
           if (0 != pthread_mutex_lock (&chat_mutex))
-            {
+            abort ();
-              return NULL;
-            }
         }
         MHD_websocket_free (cu->ws, frame_data);
       }
@@ -1691,7 +1687,8 @@ connecteduser_send_messages (void *cls)
 
         /* send the data via the TCP/IP socket and */
         /* unlock the mutex while sending */
-          pthread_mutex_unlock (&chat_mutex);
+        if (0 != pthread_mutex_unlock (&chat_mutex))
+          abort ();
         if (MHD_WEBSOCKET_STATUS_OK == er)
         {
           send_all (cu,
@@ -1701,9 +1698,7 @@ connecteduser_send_messages (void *cls)
         MHD_websocket_free (cu->ws,
                             frame_data);
         if (0 != pthread_mutex_lock (&chat_mutex))
-          {
+          abort ();
-            return NULL;
-          }
         /* check whether there are still pending messages */
         all_messages_read = (cu->next_message_index < message_count) ? 0 : 1;
       }
@@ -1720,7 +1715,6 @@ connecteduser_send_messages (void *cls)
     /* lock the mutex after waiting */
     pthread_cond_wait (&cu->wake_up_sender, &chat_mutex);
   }
-  }
 
   return NULL;
 }
@@ -1817,8 +1811,8 @@ connecteduser_receive_messages (void *cls)
     size_t init_users_len = 0;
 
     /* first collect all users without sending (so the mutex isn't locked too long) */
-    if (0 == pthread_mutex_lock (&chat_mutex))
+    if (0 != pthread_mutex_lock (&chat_mutex))
-    {
+      abort ();
     if (0 < user_count)
     {
       init_users = (struct UserInit *) malloc (user_count * sizeof (struct
@@ -1846,8 +1840,8 @@ connecteduser_receive_messages (void *cls)
         }
       }
     }
-      pthread_mutex_unlock (&chat_mutex);
+    if (0 != pthread_mutex_unlock (&chat_mutex))
-    }
+      abort ();
 
     /* then send all users to the connected client */
     for (size_t i = 0; i < init_users_len; ++i)
@@ -1922,13 +1916,14 @@ connecteduser_receive_messages (void *cls)
                                                             cu->extra_in_size))
     {
       chat_removeuser (cu);
-      if (0 == pthread_mutex_lock (&chat_mutex))
+      if (0 != pthread_mutex_lock (&chat_mutex))
-      {
+        abort ();
       cu->disconnect = 1;
       pthread_cond_signal (&cu->wake_up_sender);
-        pthread_mutex_unlock (&chat_mutex);
+      if (0 != pthread_mutex_unlock (&chat_mutex))
+        abort ();
       pthread_join (pt, NULL);
-      }
+
       struct MHD_UpgradeResponseHandle *urh = cu->urh;
       if (NULL != urh)
       {
@@ -1967,13 +1962,13 @@ connecteduser_receive_messages (void *cls)
       {
         /* A websocket protocol error occurred */
         chat_removeuser (cu);
-        if (0 == pthread_mutex_lock (&chat_mutex))
+        if (0 != pthread_mutex_lock (&chat_mutex))
-        {
+          abort ();
         cu->disconnect = 1;
         pthread_cond_signal (&cu->wake_up_sender);
-          pthread_mutex_unlock (&chat_mutex);
+        if (0 != pthread_mutex_unlock (&chat_mutex))
+          abort ();
         pthread_join (pt, NULL);
-        }
         struct MHD_UpgradeResponseHandle *urh = cu->urh;
         if (NULL != urh)
         {
@@ -1993,13 +1988,13 @@ connecteduser_receive_messages (void *cls)
 
   /* cleanup */
   chat_removeuser (cu);
-  if (0 == pthread_mutex_lock (&chat_mutex))
+  if (0 != pthread_mutex_lock (&chat_mutex))
-  {
+    abort ();
   cu->disconnect = 1;
   pthread_cond_signal (&cu->wake_up_sender);
-    pthread_mutex_unlock (&chat_mutex);
+  if (0 != pthread_mutex_unlock (&chat_mutex))
+    abort ();
   pthread_join (pt, NULL);
-  }
   struct MHD_UpgradeResponseHandle *urh = cu->urh;
   if (NULL != urh)
   {
@@ -2322,16 +2317,16 @@ main (int argc,
     return 1;
   (void) getc (stdin);
 
-  if (0 == pthread_mutex_lock (&chat_mutex))
+  if (0 != pthread_mutex_lock (&chat_mutex))
-  {
+    abort ();
   disconnect_all = 1;
   for (size_t i = 0; i < user_count; ++i)
     pthread_cond_signal (&users[i]->wake_up_sender);
-    pthread_mutex_unlock (&chat_mutex);
+  if (0 != pthread_mutex_unlock (&chat_mutex))
-  }
+    abort ();
   sleep (2);
-  if (0 == pthread_mutex_lock (&chat_mutex))
+  if (0 != pthread_mutex_lock (&chat_mutex))
-  {
+    abort ();
   for (size_t i = 0; i < user_count; ++i)
   {
     struct MHD_UpgradeResponseHandle *urh = users[i]->urh;
@@ -2342,8 +2337,8 @@ main (int argc,
                           MHD_UPGRADE_ACTION_CLOSE);
     }
   }
-    pthread_mutex_unlock (&chat_mutex);
+  if (0 != pthread_mutex_unlock (&chat_mutex))
-  }
+    abort ();
   sleep (2);
 
   /* usually we should wait here in a safe way for all threads to disconnect, */

src/examples/websocket_threaded_example.c

@@ -625,7 +625,8 @@ ws_send_frame (MHD_socket sock, const char *msg, size_t length)
   }
   response[idx_response] = '\0';
   output = 0;
-  pthread_mutex_lock (&MUTEX);
+  if (0 != pthread_mutex_lock (&MUTEX))
+    abort ();
   for (i = 0; i < MAX_CLIENTS; i++)
   {
     isock = CLIENT_SOCKS[i];
@@ -634,7 +635,8 @@ ws_send_frame (MHD_socket sock, const char *msg, size_t length)
       output += send_all (isock, response, idx_response);
     }
   }
-  pthread_mutex_unlock (&MUTEX);
+  if (0 != pthread_mutex_unlock (&MUTEX))
+    abort ();
   free (response);
   return (ssize_t) output;
 }
@@ -759,7 +761,8 @@ run_usock (void *cls)
       }
     }
   }
-  pthread_mutex_lock (&MUTEX);
+  if (0 != pthread_mutex_lock (&MUTEX))
+    abort ();
   for (i = 0; i < MAX_CLIENTS; i++)
   {
     if (CLIENT_SOCKS[i] == ws->sock)
@@ -768,7 +771,8 @@ run_usock (void *cls)
       break;
     }
   }
-  pthread_mutex_unlock (&MUTEX);
+  if (0 != pthread_mutex_unlock (&MUTEX))
+    abort ();
   free (ws);
   MHD_upgrade_action (urh, MHD_UPGRADE_ACTION_CLOSE);
   return NULL;
@@ -798,7 +802,8 @@ uh_cb (void *cls, struct MHD_Connection *con, void *req_cls,
   ws->sock = sock;
   ws->urh = urh;
   sock_overflow = MHD_YES;
-  pthread_mutex_lock (&MUTEX);
+  if (0 != pthread_mutex_lock (&MUTEX))
+    abort ();
   for (i = 0; i < MAX_CLIENTS; i++)
   {
     if (MHD_INVALID_SOCKET == CLIENT_SOCKS[i])
@@ -808,7 +813,8 @@ uh_cb (void *cls, struct MHD_Connection *con, void *req_cls,
       break;
     }
   }
-  pthread_mutex_unlock (&MUTEX);
+  if (0 != pthread_mutex_unlock (&MUTEX))
+    abort ();
   if (sock_overflow)
   {
     free (ws);