Avoid sending JobData back to the main thread.

The main thread can easily look these up by ID, and in HTML5, sending the full `JobData` can cause errors.

src/lime/app/Future.hx

@@ -416,17 +416,11 @@ import lime.utils.Log;
 			var result = bundle.work.dispatch(bundle.state);
 			if (result != null || bundle.legacyCode)
 			{
-				#if (lime_threads && html5)
-				bundle.work.makePortable();
-				#end
 				output.sendComplete(result);
 			}
 		}
 		catch (e:Dynamic)
 		{
-			#if (lime_threads && html5)
-			bundle.work.makePortable();
-			#end
 			output.sendError(e);
 		}
 	}

src/lime/system/ThreadPool.hx

@@ -245,12 +245,12 @@ class ThreadPool extends WorkOutput
 				var thread:Thread = __activeThreads[job.id];
 				if (idleThreads < minThreads)
 				{
-					thread.sendMessage(new ThreadEvent(WORK, null, null));
+					thread.sendMessage({event: CANCEL});
 					__idleThreads.push(thread);
 				}
 				else
 				{
-					thread.sendMessage(new ThreadEvent(EXIT, null, null));
+					thread.sendMessage({event: EXIT});
 				}
 			}
 			#end
@@ -270,10 +270,10 @@ class ThreadPool extends WorkOutput
 		__activeJobs.clear();
 
 		#if lime_threads
-		// Cancel idle threads if there are more than the minimum.
+		// Exit idle threads if there are more than the minimum.
 		while (idleThreads > minThreads)
 		{
-			__idleThreads.pop().sendMessage(new ThreadEvent(EXIT, null, null));
+			__idleThreads.pop().sendMessage({event: EXIT});
 		}
 		#end
 
@@ -310,7 +310,7 @@ class ThreadPool extends WorkOutput
 			var thread:Thread = __activeThreads[data.id];
 			if (thread != null)
 			{
-				thread.sendMessage(new ThreadEvent(WORK, null, null));
+				thread.sendMessage({event: CANCEL});
 				__activeThreads.remove(data.id);
 				__idleThreads.push(thread);
 			}
@@ -395,7 +395,7 @@ class ThreadPool extends WorkOutput
 					{
 						event = Thread.readMessage(true);
 					}
-					while (!#if (haxe_ver >= 4.2) Std.isOfType #else Std.is #end (event, ThreadEvent));
+					while (event == null || !Reflect.hasField(event, "event"));
 
 					output.resetJobProgress();
 				}
@@ -409,7 +409,7 @@ class ThreadPool extends WorkOutput
 					return;
 				}
 
-				if (event.event != WORK || event.job == null)
+				if (event.event != WORK || !#if (haxe_ver >= 4.2) Std.isOfType #else Std.is #end (event.job, JobData))
 				{
 					// Go idle.
 					event = null;
@@ -440,7 +440,7 @@ class ThreadPool extends WorkOutput
 					// Work is done; wait for more.
 					event = interruption;
 				}
-				else if(#if (haxe_ver >= 4.2) Std.isOfType #else Std.is #end (interruption, ThreadEvent))
+				else if(Reflect.hasField(interruption, "event"))
 				{
 					// Work on the new job.
 					event = interruption;
@@ -494,7 +494,7 @@ class ThreadPool extends WorkOutput
 
 				var thread:Thread = __idleThreads.isEmpty() ? createThread(__executeThread) : __idleThreads.pop();
 				__activeThreads[job.id] = thread;
-				thread.sendMessage(new ThreadEvent(WORK, null, job));
+				thread.sendMessage({event: WORK, job: job});
 			}
 			#end
 		}
@@ -539,15 +539,19 @@ class ThreadPool extends WorkOutput
 		var threadEvent:ThreadEvent;
 		while ((threadEvent = __jobOutput.pop(false)) != null)
 		{
-			if (!__activeJobs.exists(threadEvent.job))
+			if (threadEvent.jobID != null)
 			{
-				// Ignore events from canceled jobs.
+				activeJob = __activeJobs.getByID(threadEvent.jobID);
-				continue;
+			}
+			else
+			{
+				activeJob = threadEvent.job;
 			}
 
-			// Get by ID because in HTML5, the object will have been cloned,
+			if (activeJob == null || !__activeJobs.exists(activeJob))
-			// which will interfere with attempts to test equality.
+			{
-			activeJob = __activeJobs.getByID(threadEvent.job.id);
+				continue;
+			}
 
 			if (mode == MULTI_THREADED)
 			{
@@ -582,7 +586,7 @@ class ThreadPool extends WorkOutput
 
 						if (currentThreads > maxThreads || __jobQueue.length == 0 && currentThreads > minThreads)
 						{
-							thread.sendMessage(new ThreadEvent(EXIT, null, null));
+							thread.sendMessage({event: EXIT});
 						}
 						else
 						{

src/lime/system/WorkOutput.hx

@@ -105,12 +105,11 @@ class WorkOutput
 			#if (lime_threads && html5)
 			if (mode == MULTI_THREADED)
 			{
-				activeJob.doWork.makePortable();
+				Thread.returnMessage({event: COMPLETE, message: message, jobID: activeJob.id}, transferList);
-				Thread.returnMessage(new ThreadEvent(COMPLETE, message, activeJob), transferList);
 			}
 			else
 			#end
-			__jobOutput.add(new ThreadEvent(COMPLETE, message, activeJob));
+			__jobOutput.add({event: COMPLETE, message: message, jobID: activeJob.id});
 		}
 	}
 
@@ -130,12 +129,11 @@ class WorkOutput
 			#if (lime_threads && html5)
 			if (mode == MULTI_THREADED)
 			{
-				activeJob.doWork.makePortable();
+				Thread.returnMessage({event: ERROR, message: message, jobID: activeJob.id}, transferList);
-				Thread.returnMessage(new ThreadEvent(ERROR, message, activeJob), transferList);
 			}
 			else
 			#end
-			__jobOutput.add(new ThreadEvent(ERROR, message, activeJob));
+			__jobOutput.add({event: ERROR, message: message, jobID: activeJob.id});
 		}
 	}
 
@@ -153,12 +151,11 @@ class WorkOutput
 			#if (lime_threads && html5)
 			if (mode == MULTI_THREADED)
 			{
-				activeJob.doWork.makePortable();
+				Thread.returnMessage({event: PROGRESS, message: message, jobID: activeJob.id}, transferList);
-				Thread.returnMessage(new ThreadEvent(PROGRESS, message, activeJob), transferList);
 			}
 			else
 			#end
-			__jobOutput.add(new ThreadEvent(PROGRESS, message, activeJob));
+			__jobOutput.add({event: PROGRESS, message: message, jobID: activeJob.id});
 		}
 	}
 
@@ -343,43 +340,22 @@ class JobData
 
 #if haxe4 enum #else @:enum #end abstract ThreadEventType(String)
 {
-	/**
+	// Events sent from a worker thread to the main thread
-		Sent by the background thread, indicating completion.
-	**/
 	var COMPLETE = "COMPLETE";
-	/**
-		Sent by the background thread, indicating failure.
-	**/
 	var ERROR = "ERROR";
-	/**
-		Sent by the background thread.
-	**/
 	var PROGRESS = "PROGRESS";
-	/**
+
-		Sent by the main thread, indicating that the provided job should begin
+	// Commands sent from the main thread to a worker thread
-		in place of any ongoing job. If `state == null`, the existing job will
-		stop and the thread will go idle. (To run a job with no argument, set
-		`state = {}` instead.)
-	**/
 	var WORK = "WORK";
-	/**
+	var CANCEL = "CANCEL";
-		Sent by the main thread to shut down a thread.
-	**/
 	var EXIT = "EXIT";
 }
 
-class ThreadEvent
+typedef ThreadEvent = {
-{
+	var event:ThreadEventType;
-	public var event(default, null):ThreadEventType;
+	@:optional var message:Dynamic;
-	public var message(default, null):State;
+	@:optional var job:JobData;
-	public var job(default, null):JobData;
+	@:optional var jobID:Int;
-
-	public inline function new(event:ThreadEventType, message:State, job:JobData)
-	{
-		this.event = event;
-		this.message = message;
-		this.job = job;
-	}
 }
 
 class JSAsync