From 4e862941cb9307ebbcfb88c1a14e463c62a854c4 Mon Sep 17 00:00:00 2001
From: Seth Alves <seth.alves@gmail.com>
Date: Thu, 19 May 2016 14:51:56 -0700
Subject: [PATCH] fix a race when restarting scripts -- avoid the old
 not-yet-stopped script from being considered the restart script

---
 libraries/script-engine/src/ScriptEngine.h    | 3 +++
 libraries/script-engine/src/ScriptEngines.cpp | 4 +++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/libraries/script-engine/src/ScriptEngine.h b/libraries/script-engine/src/ScriptEngine.h
index 80978e4527..b576e2a37f 100644
--- a/libraries/script-engine/src/ScriptEngine.h
+++ b/libraries/script-engine/src/ScriptEngine.h
@@ -146,6 +146,8 @@ public:
 
     bool isFinished() const { return _isFinished; } // used by Application and ScriptWidget
     bool isRunning() const { return _isRunning; } // used by ScriptWidget
+    bool isStopping() const { return _isStopping; }
+    void flagAsStopping() { _isStopping = true; }
 
     bool isDebuggable() const { return _debuggable; }
 
@@ -189,6 +191,7 @@ protected:
     QString _parentURL;
     std::atomic<bool> _isFinished { false };
     std::atomic<bool> _isRunning { false };
+    std::atomic<bool> _isStopping { false };
     int _evaluatesPending { 0 };
     bool _isInitialized { false };
     QHash<QTimer*, CallbackData> _timerFunctionMap;
diff --git a/libraries/script-engine/src/ScriptEngines.cpp b/libraries/script-engine/src/ScriptEngines.cpp
index 70eb055d22..5a2beb901d 100644
--- a/libraries/script-engine/src/ScriptEngines.cpp
+++ b/libraries/script-engine/src/ScriptEngines.cpp
@@ -351,6 +351,7 @@ void ScriptEngines::stopAllScripts(bool restart) {
                 reloadScript(scriptName);
             });
         }
+        it.value()->flagAsStopping();
         QMetaObject::invokeMethod(it.value(), "stop");
         //it.value()->stop();
         qCDebug(scriptengine) << "stopping script..." << it.key();
@@ -369,6 +370,7 @@ bool ScriptEngines::stopScript(const QString& rawScriptURL, bool restart) {
         if (_scriptEnginesHash.contains(scriptURL)) {
             ScriptEngine* scriptEngine = _scriptEnginesHash[scriptURL];
             if (restart) {
+                scriptEngine->flagAsStopping();
                 auto scriptCache = DependencyManager::get<ScriptCache>();
                 scriptCache->deleteScript(scriptURL);
                 connect(scriptEngine, &ScriptEngine::finished, this, [this](QString scriptName, ScriptEngine* engine) {
@@ -454,7 +456,7 @@ ScriptEngine* ScriptEngines::getScriptEngine(const QUrl& rawScriptURL) {
         QReadLocker lock(&_scriptEnginesHashLock);
         const QUrl scriptURL = normalizeScriptURL(rawScriptURL);
         auto it = _scriptEnginesHash.find(scriptURL);
-        if (it != _scriptEnginesHash.end()) {
+        if (it != _scriptEnginesHash.end() && !it.value()->isStopping()) {
             result = it.value();
         }
     }