Fix calling schedule task cause deadlock (#1586)

MinecraftClient/McClient.cs

@@ -701,13 +701,38 @@ namespace MinecraftClient
         /// <param name="task">Task to run</param>
         public object ScheduleTask(Delegate task)
         {
-            var taskAndResult = new TaskWithResult(task);
+            if (!InvokeRequired())
-            lock (threadTasksLock)
             {
-                threadTasks.Enqueue(taskAndResult);
+                return task.DynamicInvoke();
+            }
+            else
+            {
+                var taskAndResult = new TaskWithResult(task);
+                lock (threadTasksLock)
+                {
+                    threadTasks.Enqueue(taskAndResult);
+                }
+                taskAndResult.Block();
+                return taskAndResult.Result;
+            }
+        }
+
+        /// <summary>
+        /// Check if calling thread is main thread or other thread
+        /// </summary>
+        /// <returns>True if calling thread is other thread</returns>
+        public bool InvokeRequired()
+        {
+            int callingThreadId = Thread.CurrentThread.ManagedThreadId;
+            if (handler != null)
+            {
+                return handler.GetNetReadThreadId() != callingThreadId;
+            }
+            else
+            {
+                // net read thread (main thread) not yet ready
+                return false;
             }
-            taskAndResult.Block();
-            return taskAndResult.Result;
         }
 
         #region Management: Load/Unload ChatBots and Enable/Disable settings

MinecraftClient/Protocol/Handlers/Protocol16.cs

@@ -201,6 +201,15 @@ namespace MinecraftClient.Protocol.Handlers
             netRead.Start();
         }
 
+        /// <summary>
+        /// Get net read thread (main thread) ID
+        /// </summary>
+        /// <returns>Net read thread ID</returns>
+        public int GetNetReadThreadId()
+        {
+            return netRead != null ? netRead.ManagedThreadId : -1;
+        }
+
         public void Dispose()
         {
             try

MinecraftClient/Protocol/Handlers/Protocol18.cs

@@ -67,7 +67,7 @@ namespace MinecraftClient.Protocol.Handlers
         PacketTypePalette packetPalette;
         SocketWrapper socketWrapper;
         DataTypes dataTypes;
-        Thread netRead;
+        Thread netRead; // main thread
         ILogger log;
 
         public Protocol18Handler(TcpClient Client, int protocolVersion, IMinecraftComHandler handler, ForgeInfo forgeInfo)
@@ -1112,6 +1112,15 @@ namespace MinecraftClient.Protocol.Handlers
             netRead.Start();
         }
 
+        /// <summary>
+        /// Get net read thread (main thread) ID
+        /// </summary>
+        /// <returns>Net read thread ID</returns>
+        public int GetNetReadThreadId()
+        {
+            return netRead != null ? netRead.ManagedThreadId : -1;
+        }
+
         /// <summary>
         /// Disconnect from the server, cancel network reading.
         /// </summary>

MinecraftClient/Protocol/IMinecraftCom.cs

@@ -235,5 +235,11 @@ namespace MinecraftClient.Protocol
         /// </summary>
         /// <param name="selectedSlot">The slot of the trade, starts at 0.</param>
         bool SelectTrade(int selectedSlot);
+
+        /// <summary>
+        /// Get net read thread (main thread) ID
+        /// </summary>
+        /// <returns>Net read thread ID</returns>
+        int GetNetReadThreadId();
     }
 }