Actually fix kill threads

src/Forking/Fork.php

@@ -68,6 +68,11 @@ class Fork implements ContextInterface
         $this->channel = null;
     }
 
+    public function __destruct()
+    {
+        $this->kill(); // Will only terminate if the process is still running.
+    }
+
     /**
      * Checks if the context is running.
      *

src/Threading/Internal/Thread.php

@@ -83,7 +83,7 @@ class Thread extends \Thread
         $coroutine = new Coroutine($this->execute($channel));
         $coroutine->done();
 
-        $timer = $loop->timer(self::KILL_CHECK_FREQUENCY, true, function () use ($loop, $coroutine, $channel) {
+        $timer = $loop->timer(self::KILL_CHECK_FREQUENCY, true, function () use ($loop) {
             if ($this->killed) {
                 $loop->stop();
             }
@@ -99,7 +99,7 @@ class Thread extends \Thread
     public function kill()
     {
         $this->killed = true;
-        parent::kill();
+        return parent::kill();
     }
 
     /**

src/Threading/Thread.php

@@ -138,13 +138,23 @@ class Thread implements ContextInterface
      */
     public function kill()
     {
-        if (null === $this->thread) {
-            throw new StatusError('The thread has not been started.');
-        }
-
+        if (null !== $this->thread) {
             $this->close();
 
-        $this->thread->kill();
+            if ($this->thread->isRunning() && !$this->thread->kill()) {
+                throw new ThreadException('Could not kill thread.');
+            }
+        }
+    }
+
+    /**
+     * Kills the thread if it is still running.
+     *
+     * @throws \Icicle\Concurrent\Exception\ThreadException
+     */
+    public function __destruct()
+    {
+        $this->kill();
     }
 
     /**

src/Worker/Worker.php

@@ -4,7 +4,6 @@ namespace Icicle\Concurrent\Worker;
 use Icicle\Concurrent\ContextInterface;
 use Icicle\Concurrent\Exception\StatusError;
 use Icicle\Concurrent\Worker\Internal\TaskFailure;
-use Icicle\Coroutine\Coroutine;
 
 class Worker implements WorkerInterface
 {
@@ -95,14 +94,4 @@ class Worker implements WorkerInterface
     {
         $this->context->kill();
     }
-
-    /**
-     * Kills the worker when it is destroyed.
-     */
-    public function __destruct()
-    {
-        if ($this->context->isRunning()) {
-            $this->context->kill();
-        }
-    }
 }