text: /**
   * Appcelerator Titanium License
   * This source code and all modifications done by Appcelerator
   * are licensed under the Apache Public License (version 2) and
   * are Copyright (c) 2009-2012 by Appcelerator, Inc.
   */
  
  /*
   * Copyright (C) 2008 Apple Inc. All Rights Reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
   * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
   * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
   *
   */
  
  #ifndef WTFThreadData_h
  #define WTFThreadData_h
  
  #include <wtf/HashMap.h>
  #include <wtf/HashSet.h>
  #include <wtf/Noncopyable.h>
  #include <wtf/StackBounds.h>
  #include <wtf/text/StringHash.h>
  
  // This was ENABLE(WORKERS) in WebCore, but this is not defined when compiling JSC.
  // However this check was not correct anyway, re this comment:
  //    // FIXME: Workers are not necessarily the only feature that make per-thread global data necessary.
  //    // We need to check for e.g. database objects manipulating strings on secondary threads.
  // Always enabling this is safe, and should be a better option until we can come up
  // with a better define.
  #define WTFTHREADDATA_MULTITHREADED 1
  
  #if WTFTHREADDATA_MULTITHREADED
  #include <wtf/ThreadSpecific.h>
  #include <wtf/Threading.h>
  #endif
  
  #if USE(JSC)
  // FIXME: This is a temporary layering violation while we move more string code to WTF.
  namespace TI {
  
  typedef HashMap<const char*, RefPtr<StringImpl>, PtrHash<const char*> > LiteralIdentifierTable;
  
  class IdentifierTable {
      WTF_MAKE_FAST_ALLOCATED;
  public:
      ~IdentifierTable();
  
      std::pair<HashSet<StringImpl*>::iterator, bool> add(StringImpl* value);
      template<typename U, typename V>
      std::pair<HashSet<StringImpl*>::iterator, bool> add(U value);
  
      bool remove(StringImpl* r)
      {
          HashSet<StringImpl*>::iterator iter = m_table.find(r);
          if (iter == m_table.end())
              return false;
          m_table.remove(iter);
          return true;
      }
  
      LiteralIdentifierTable& literalTable() { return m_literalTable; }
  
  private:
      HashSet<StringImpl*> m_table;
      LiteralIdentifierTable m_literalTable;
  };
  
  }
  #endif
  
  namespace WTI {
  
  class AtomicStringTable;
  
  typedef void (*AtomicStringTableDestructor)(AtomicStringTable*);
  
  class WTFThreadData {
      WTF_MAKE_NONCOPYABLE(WTFThreadData);
  public:
      WTFThreadData();
      ~WTFThreadData();
  
      AtomicStringTable* atomicStringTable()
      {
          return m_atomicStringTable;
      }
  
  #if USE(JSC)
      TI::IdentifierTable* currentIdentifierTable()
      {
          return m_currentIdentifierTable;
      }
  
      TI::IdentifierTable* setCurrentIdentifierTable(TI::IdentifierTable* identifierTable)
      {
          TI::IdentifierTable* oldIdentifierTable = m_currentIdentifierTable;
          m_currentIdentifierTable = identifierTable;
          return oldIdentifierTable;
      }
  
      void resetCurrentIdentifierTable()
      {
          m_currentIdentifierTable = m_defaultIdentifierTable;
      }
  
      const StackBounds& stack() const
      {
          return m_stackBounds;
      }
  #endif
  
  private:
      AtomicStringTable* m_atomicStringTable;
      AtomicStringTableDestructor m_atomicStringTableDestructor;
  
  #if USE(JSC)
      TI::IdentifierTable* m_defaultIdentifierTable;
      TI::IdentifierTable* m_currentIdentifierTable;
      StackBounds m_stackBounds;
  #endif
  
  #if WTFTHREADDATA_MULTITHREADED
      static JS_EXPORTDATA ThreadSpecific<WTFThreadData>* staticData;
  #else
      static JS_EXPORTDATA WTFThreadData* staticData;
  #endif
      friend WTFThreadData& wtfThreadData();
      friend class AtomicStringTable;
  };
  
  inline WTFThreadData& wtfThreadData()
  {
  #if WTFTHREADDATA_MULTITHREADED
      // WRT WebCore:
      //    WTFThreadData is used on main thread before it could possibly be used
      //    on secondary ones, so there is no need for synchronization here.
      // WRT TiCore:
      //    wtfThreadData() is initially called from initializeThreading(), ensuring
      //    this is initially called in a pthread_once locked context.
      if (!WTFThreadData::staticData)
          WTFThreadData::staticData = new ThreadSpecific<WTFThreadData>;
      return **WTFThreadData::staticData;
  #else
      if (!WTFThreadData::staticData) {
          WTFThreadData::staticData = static_cast<WTFThreadData*>(fastMalloc(sizeof(WTFThreadData)));
          // WTFThreadData constructor indirectly uses staticData, so we need to set up the memory before invoking it.
          new (WTFThreadData::staticData) WTFThreadData;
      }
      return *WTFThreadData::staticData;
  #endif
  }
  
  } // namespace WTI
  
  using WTI::WTFThreadData;
  using WTI::wtfThreadData;
  
  #endif // WTFThreadData_h
  