Line data    Source code

       1             : /* Copyright (C) 2020 Wildfire Games.
       2             :  * This file is part of 0 A.D.
       3             :  *
       4             :  * 0 A.D. is free software: you can redistribute it and/or modify
       5             :  * it under the terms of the GNU General Public License as published by
       6             :  * the Free Software Foundation, either version 2 of the License, or
       7             :  * (at your option) any later version.
       8             :  *
       9             :  * 0 A.D. is distributed in the hope that it will be useful,
      10             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      11             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      12             :  * GNU General Public License for more details.
      13             :  *
      14             :  * You should have received a copy of the GNU General Public License
      15             :  * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
      16             :  */
      17             : 
      18             : #ifndef INCLUDED_SCRIPTENGINE
      19             : #define INCLUDED_SCRIPTENGINE
      20             : 
      21             : #include "ScriptTypes.h"
      22             : #include "ps/Singleton.h"
      23             : 
      24             : #include "js/Initialization.h"
      25             : 
      26             : #include <list>
      27             : 
      28             : /**
      29             :  * A class using the RAII (Resource Acquisition Is Initialization) idiom to manage initialization
      30             :  * and shutdown of the SpiderMonkey script engine. It also keeps a count of active script contexts
      31             :  * in order to validate the following constraints:
      32             :  *  1. JS_Init must be called before any ScriptContexts are initialized
      33             :  *  2. JS_Shutdown must be called after all ScriptContexts have been destroyed
      34             :  */
      35             : 
      36             : class ScriptEngine : public Singleton<ScriptEngine>
      37             : {
      38             : public:
      39           1 :     ScriptEngine()
      40           1 :     {
      41           1 :         ENSURE(m_Contexts.empty() && "JS_Init must be called before any contexts are created!");
      42           1 :         JS_Init();
      43           1 :     }
      44             : 
      45           1 :     ~ScriptEngine()
      46           1 :     {
      47           1 :         ENSURE(m_Contexts.empty() && "All contexts must be destroyed before calling JS_ShutDown!");
      48           1 :         JS_ShutDown();
      49           1 :     }
      50             : 
      51           1 :     void RegisterContext(const JSContext* cx) { m_Contexts.push_back(cx); }
      52           1 :     void UnRegisterContext(const JSContext* cx) { m_Contexts.remove(cx); }
      53             : 
      54             : private:
      55             :     std::list<const JSContext*> m_Contexts;
      56             : };
      57             : 
      58             : #endif // INCLUDED_SCRIPTENGINE