From 88c6a79f7e17abbf61a1cc290cab2d8dc1290882 Mon Sep 17 00:00:00 2001
From: Aaron Piotrowski <aaron@trowski.com>
Date: Tue, 8 Sep 2015 12:55:29 -0500
Subject: [PATCH] Null thread reference at shutdown

---
 src/Threading/Thread.php | 33 ++++++++++++++++++++++-----------
 1 file changed, 22 insertions(+), 11 deletions(-)

diff --git a/src/Threading/Thread.php b/src/Threading/Thread.php
index 83564cc..92602c6 100644
--- a/src/Threading/Thread.php
+++ b/src/Threading/Thread.php
@@ -48,6 +48,11 @@ class Thread implements ContextInterface
      */
     private $args;
 
+    /**
+     * @var bool
+     */
+    private $started = false;
+
     /**
      * Spawns a new thread and runs it.
      *
@@ -116,10 +121,12 @@ class Thread implements ContextInterface
      */
     public function start()
     {
-        if (null !== $this->thread) {
+        if ($this->started) {
             throw new StatusError('The thread has already been started.');
         }
 
+        $this->started = true;
+
         list($channel, $this->socket) = Socket\pair();
 
         $this->thread = new Internal\Thread($this->socket, $this->function, $this->args);
@@ -139,10 +146,12 @@ class Thread implements ContextInterface
     public function kill()
     {
         if (null !== $this->thread) {
-            $this->close();
-
-            if ($this->thread->isRunning() && !$this->thread->kill()) {
-                throw new ThreadException('Could not kill thread.');
+            try {
+                if ($this->thread->isRunning() && !$this->thread->kill()) {
+                    throw new ThreadException('Could not kill thread.');
+                }
+            } finally {
+                $this->close();
             }
         }
     }
@@ -169,6 +178,8 @@ class Thread implements ContextInterface
         if (is_resource($this->socket)) {
             fclose($this->socket);
         }
+
+        $this->thread = null;
     }
 
     /**
@@ -186,8 +197,8 @@ class Thread implements ContextInterface
      */
     public function join()
     {
-        if (null === $this->thread) {
-            throw new StatusError('The thread has not been started.');
+        if (null === $this->channel || null === $this->thread) {
+            throw new StatusError('The thread has not been started or has already finished.');
         }
 
         try {
@@ -213,8 +224,8 @@ class Thread implements ContextInterface
      */
     public function receive()
     {
-        if (null === $this->thread) {
-            throw new StatusError('The thread has not been started.');
+        if (null === $this->channel) {
+            throw new StatusError('The thread has not been started or has already finished.');
         }
 
         $data = (yield $this->channel->receive());
@@ -236,8 +247,8 @@ class Thread implements ContextInterface
      */
     public function send($data)
     {
-        if (null === $this->thread) {
-            throw new StatusError('The thread has not been started.');
+        if (null === $this->channel) {
+            throw new StatusError('The thread has not been started or has already finished.');
         }
 
         if ($data instanceof ExitStatusInterface) {