github issue: The user can create infinite loops #6. Fix: add a maxim…

…um loop limitation and report 'infinite loop'.

Source/Script/CodeDB/CSharp/CSharpInterpreter.cs

@@ -83,12 +83,24 @@ public override void Stop()
             }
         }
 
+        public override void Error(string msg)
+        {
+            if (mRunningProcess != null)
+            {
+                mRunner.StopProcess(mRunningProcess);
+                mRunningProcess = null;
+                CSharp.Interpreter.FireUpdate(new InterpreterUpdateState(InterpreterUpdateState.Error, msg));
+            }
+        }
+
         /// <summary>
         /// coroutine run code for workspace
         /// todo: execute topblocks in order or synchronously
         /// </summary>
         IEnumerator RunWorkspace(Workspace workspace)
         {
+            yield return null;
+
             //traverse all blocks in the workspace and run code for the blocks
             List<Block> blocks = workspace.GetTopBlocks(true);
             foreach (Block block in blocks)
@@ -109,6 +121,12 @@ IEnumerator RunWorkspace(Workspace workspace)
         /// </summary>
         IEnumerator RunBlock(Block block)
         {
+            //check if stopped
+            if (mRunningProcess == null)
+            {
+                yield break;
+            }
+
             //check flow 
             if (ControlCmdtor.SkipRunByControlFlow(block))
             {

Source/Script/CodeDB/CSharp/Interpreters/Loop_CSharp.cs

@@ -27,7 +27,7 @@ namespace UBlockly
     public abstract class ControlCmdtor : EnumeratorCmdtor
     {
         protected ControlFlowType mFlowState;
-
+    
         public bool NeedBreak
         {
             get { return mFlowState == ControlFlowType.Break; }
@@ -48,6 +48,19 @@ public void ResetFlowState()
             mFlowState = ControlFlowType.None;
         }
 
+        private int mLoopCount = 0;
+
+        protected bool CheckInfiniteLoop()
+        {
+            if (++mLoopCount == Int16.MaxValue)
+            {
+                CSharp.Interpreter.Error("Infinite loop!");
+                mLoopCount = 0;
+                return true;
+            }
+            return false;
+        }
+
         /// <summary>
         /// find the parent loop block of the flow block
         /// </summary>
@@ -99,6 +112,7 @@ protected override IEnumerator Execute(Block block)
                 //reset flow control
                 if (NeedBreak) break;
                 if (NeedContinue) ResetFlowState();
+                if (CheckInfiniteLoop()) break;
             }
         }
     }
@@ -124,6 +138,7 @@ protected override IEnumerator Execute(Block block)
                 //reset flow control
                 if (NeedBreak) break;
                 if (NeedContinue) ResetFlowState();
+                if (CheckInfiniteLoop()) break;
             }
         }
     }
@@ -157,6 +172,7 @@ protected override IEnumerator Execute(Block block)
                 //reset flow control
                 if (NeedBreak) break;
                 if (NeedContinue) ResetFlowState();
+                if (CheckInfiniteLoop()) break;
             }
         }
     }
@@ -190,6 +206,7 @@ protected override IEnumerator Execute(Block block)
                 //reset flow control
                 if (NeedBreak) break;
                 if (NeedContinue) ResetFlowState();
+                if (CheckInfiniteLoop()) break;
             }
         }
     }
@@ -226,6 +243,7 @@ protected override IEnumerator Execute(Block block)
                 //reset flow control
                 if (NeedBreak) break;
                 if (NeedContinue) ResetFlowState();
+                if (CheckInfiniteLoop()) break;
             }
         }
     }

Source/Script/Core/Code/CoroutineRunner.cs

@@ -84,6 +84,7 @@ public bool StopProcess(IEnumerator itorFunc)
             CoroutineStruct value;
             if (mCoroutineDict.TryGetValue(itorFunc, out value))
             {
+                value.paused = true;
                 StopCoroutine(value.coroutine);
                 mCoroutineDict.Remove(itorFunc);
 
@@ -144,6 +145,9 @@ public bool ResumeProcess(IEnumerator itorFunc)
         /// <returns></returns>
         IEnumerator SimulateCoroutine(IEnumerator itorFunc)
         {
+            //wait for one frame to get the coroutine returned, for dictionary check.
+            yield return null;
+
             Debug.LogFormat("<color=green>[CodeRunner]SimulateCoroutine: begin - time: {0}.</color>", Time.time);
 
             Stack<IEnumerator> stack = new Stack<IEnumerator>();

Source/Script/Core/Code/Interpreter.cs

@@ -77,6 +77,11 @@ public virtual void Resume() {}
         /// stop the current running interpreting process 
         /// </summary>
         public virtual void Stop() {}
+
+        /// <summary>
+        /// process overflows
+        /// </summary>
+        public virtual void Error(string msg) {}
     }
 
     public class InterpreterUpdateState
@@ -86,9 +91,11 @@ public class InterpreterUpdateState
         public const int Pause = 3;
         public const int Resume = 4;
         public const int Stop = 5;
+        public const int Error = 6;
 
         public readonly int Type;
         public readonly Block RunningBlock;
+        public readonly string Msg;
 
         public InterpreterUpdateState(int type)
         {
@@ -99,5 +106,10 @@ public InterpreterUpdateState(int type, Block runBlock) : this(type)
         {
             RunningBlock = runBlock;
         }
+
+        public InterpreterUpdateState(int type, string msg) : this(type)
+        {
+            Msg = msg;
+        }
     }
 }

Source/Script/UGUIView/BlockStatusView.cs

@@ -92,6 +92,18 @@ public void UpdateStatus(InterpreterUpdateState args)
                     mRunBlockView = null;
                     break;
                 }
+                case InterpreterUpdateState.Error:
+                {
+                    if (!string.IsNullOrEmpty(args.Msg))
+                    {
+                        MsgDialog dialog = DialogFactory.CreateDialog("message") as MsgDialog;
+                        dialog.SetMsg(args.Msg);    
+                    }
+                    enabled = false;
+                    mRunningBlocks.Clear();
+                    mRunBlockView = null;
+                    break;
+                }
             }
         }
 

Source/Script/UGUIView/Dialogs/MsgDialog.cs

@@ -0,0 +1,33 @@
+/****************************************************************************
+
+Copyright 2016 [email protected]
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+****************************************************************************/
+
+using UnityEngine;
+using UnityEngine.UI;
+
+namespace UBlockly.UGUI
+{
+    public class MsgDialog : BaseDialog
+    {
+        [SerializeField] private Text m_MsgText;
+
+        public void SetMsg(string msg)
+        {
+            m_MsgText.text = msg;
+        }
+    }
+}