resolved joins from main thread as illegal

src/main/java/carpet/script/value/ThreadValue.java

@@ -12,36 +12,24 @@ import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ThreadPoolExecutor;
-import java.util.function.Supplier;
 
 public class ThreadValue extends Value
 {
     private CompletableFuture<Value> taskFuture;
     private long id;
     private final Object lock;
-    private final boolean[] started;
-    private Supplier<Value>task;
     private static long sequence = 0L;
-
     private static final Map<Value,ThreadPoolExecutor> executorServices = new HashMap<>();
 
     public ThreadValue(Value pool, FunctionValue function, Expression expr, Tokenizer.Token token, Context ctx)
     {
         id = sequence++;
         lock = new Object();
-        started = new boolean[]{false};
-        task = () ->
-        {
-            if (!started[0])
-            {
-                started[0] = true;
-                return function.lazyEval(ctx, Context.NONE, expr, token, Collections.emptyList()).evalValue(ctx);
-            }
-            return null;
-        };
         taskFuture = CompletableFuture.supplyAsync(
-                () -> { synchronized (lock) { return task.get(); } },
-                executorServices.computeIfAbsent(pool, (v) -> (ThreadPoolExecutor)Executors.newCachedThreadPool())
+            () -> { synchronized (lock) {
+                return function.lazyEval(ctx, Context.NONE, expr, token, Collections.emptyList()).evalValue(ctx);
+            } },
+            executorServices.computeIfAbsent(pool, (v) -> (ThreadPoolExecutor)Executors.newCachedThreadPool())
         );
         Thread.yield();
     }
@@ -60,18 +48,6 @@ public class ThreadValue extends Value
 
     public Value join()
     {
-        if (!started[0])
-        {
-            synchronized (lock)
-            {
-                if (!started[0])
-                {
-                    Value res = task.get();
-                    taskFuture.complete(res);
-                    return res;
-                }
-            }
-        }
         try
         {
             return taskFuture.get();
@@ -93,7 +69,6 @@ public class ThreadValue extends Value
         {
             if (!taskFuture.isDone())
             {
-                started[0] = true;
                 taskFuture.complete(Value.NULL);
             }
         }