Properly shut down SpiderMonkey using JS_ShutDown.

This also adds some validation to ensure the correct order of JS_Init,
JS_NewRuntime, JS_DestroyRuntime and JS_ShutDown calls.

Refs #3708

This was SVN commit r18584.

source/scriptinterface/ScriptEngine.h

@@ -0,0 +1,55 @@
+/* Copyright (C) 2016 Wildfire Games.
+ * This file is part of 0 A.D.
+ *
+ * 0 A.D. is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 0 A.D. is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef INCLUDED_SCRIPTENGINE
+#define INCLUDED_SCRIPTENGINE
+
+#include "ScriptTypes.h"
+#include "ps/Singleton.h"
+
+/**
+ * A class using the RAII (Resource Acquisition Is Initialization) idiom to manage initialization
+ * and shutdown of the SpiderMonkey script engine. It also keeps a count of active script runtimes
+ * in order to validate the following constraints:
+ *  1. JS_Init must be called before any ScriptRuntimes are initialized
+ *  2. JS_Shutdown must be called after all ScriptRuntimes have been destroyed
+ */
+
+class ScriptEngine : public Singleton<ScriptEngine>
+{
+public:
+	ScriptEngine()
+	{
+		ENSURE(m_Runtimes.size() == 0 && "JS_Init must be called before any runtimes are created!");
+		JS_Init();
+	}
+
+	~ScriptEngine()
+	{
+		ENSURE(m_Runtimes.size() == 0 && "All runtimes must be destroyed before calling JS_ShutDown!");
+		JS_ShutDown();
+	}
+
+	void RegisterRuntime(const JSRuntime* rt) { m_Runtimes.push_back(rt); }
+	void UnRegisterRuntime(const JSRuntime* rt) { m_Runtimes.remove(rt); }
+
+private:
+
+	std::list<const JSRuntime*> m_Runtimes;
+};
+
+#endif // INCLUDED_SCRIPTENGINE

source/scriptinterface/ScriptInterface.cpp

@@ -433,11 +433,6 @@ ScriptInterface::~ScriptInterface()
 	}
 }
 
-void ScriptInterface::ShutDown()
-{
-	JS_ShutDown();
-}
-
 void ScriptInterface::SetCallbackData(void* pCBData)
 {
 	m_CxPrivate.pCBData = pCBData;

source/scriptinterface/ScriptInterface.h

@@ -97,12 +97,6 @@ public:
 
 	~ScriptInterface();
 
-	/**
-	 * Shut down the JS system to clean up memory. Must only be called when there
-	 * are no ScriptInterfaces alive.
-	 */
-	static void ShutDown();
-
 	struct CxPrivate
 	{
 		ScriptInterface* pScriptInterface; // the ScriptInterface object the current context belongs to

source/scriptinterface/ScriptRuntime.cpp

@@ -21,6 +21,7 @@
 
 #include "ps/GameSetup/Config.h"
 #include "ps/Profile.h"
+#include "scriptinterface/ScriptEngine.h"
 
 
 void GCSliceCallbackHook(JSRuntime* UNUSED(rt), JS::GCProgress progress, const JS::GCDescription& UNUSED(desc))
@@ -104,19 +105,13 @@ void ScriptRuntime::AddDeferredFinalizationObject(const std::shared_ptr<void>& o
 	m_FinalizationListObjectIdCache.push_back(obj);
 }
 
-bool ScriptRuntime::m_Initialized = false;
-
 ScriptRuntime::ScriptRuntime(shared_ptr<ScriptRuntime> parentRuntime, int runtimeSize, int heapGrowthBytesGCTrigger):
 	m_LastGCBytes(0),
 	m_LastGCCheck(0.0f),
 	m_HeapGrowthBytesGCTrigger(heapGrowthBytesGCTrigger),
 	m_RuntimeSize(runtimeSize)
 {
-	if (!m_Initialized)
-	{
-		ENSURE(JS_Init());
-		m_Initialized = true;
-	}
+	ENSURE(ScriptEngine::IsInitialised() && "The ScriptEngine must be initialized before constructing any ScriptRuntimes!");
 
 	JSRuntime* parentJSRuntime = parentRuntime ? parentRuntime->m_rt : nullptr;
 	m_rt = JS_NewRuntime(runtimeSize, JS_USE_HELPER_THREADS, parentJSRuntime);
@@ -135,6 +130,8 @@ ScriptRuntime::ScriptRuntime(shared_ptr<ScriptRuntime> parentRuntime, int runtim
 	
 	m_dummyContext = JS_NewContext(m_rt, STACK_CHUNK_SIZE);
 	ENSURE(m_dummyContext);
+
+	ScriptEngine::GetSingleton().RegisterRuntime(m_rt);
 }
 
 ScriptRuntime::~ScriptRuntime()
@@ -143,6 +140,9 @@ ScriptRuntime::~ScriptRuntime()
 	JS_SetGCCallback(m_rt, nullptr, nullptr);
 	JS_DestroyRuntime(m_rt);
 	ENSURE(m_FinalizationListObjectIdCache.empty() && "Leak: Removing callback while some objects still aren't finalized!");
+
+	ENSURE(ScriptEngine::IsInitialised() && "The ScriptEngine must be active (initialized and not yet shut down) when destroying a ScriptRuntime!");
+	ScriptEngine::GetSingleton().UnRegisterRuntime(m_rt);
 }
 
 void ScriptRuntime::RegisterContext(JSContext* cx)

source/scriptinterface/ScriptRuntime.h

@@ -79,7 +79,6 @@ private:
 	
 	std::list<JSContext*> m_Contexts;
 	std::vector<std::shared_ptr<void> > m_FinalizationListObjectIdCache;
-	static bool m_Initialized;
 
 	int m_RuntimeSize;
 	int m_HeapGrowthBytesGCTrigger;