macosmutex.cpp

"More for C++" is a class library that provides some features that are usually common for object ori

//
//  This file is part of the "More for C++" library
//
//  Copyright (c) 1999-2003 by Thorsten Goertz ([e-mail])
//
//  The "More for C++" library is free software; you can redistribute it and/or
//  modify it under the terms of the license that comes with this package.
//
//  Read "license.txt" for more details.
//
//  THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
//  WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES
//  OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.

////////////////////////////////////////////////////////////////////////////////

#include <MacHeadersPPC>
#include "macosmutex.hpp"

using namespace more::macos;

////////////////////////////////////////////////////////////////////////////////

MacOSMutex::MacOSMutex( ) : m_nBlockingThread( kNoThreadID )
{
}

////////////////////////////////////////////////////////////////////////////////

void MacOSMutex::lock( )
{
  ThreadID  nCurrentThread;
  OSErr    nErrorCode = GetCurrentThread( &nCurrentThread );

  if( nErrorCode == noErr )
  {
    if( m_nBlockingThread != kNoThreadID )
    {
      m_waitingThreads.push_back( nCurrentThread );

      if( m_nBlockingThread != nCurrentThread )
      {
        SetThreadState( nCurrentThread, kStoppedThreadState, m_nBlockingThread );
      }
    }

    m_nBlockingThread = nCurrentThread;
  }
  else
  {
    m_nBlockingThread = kNoThreadID;
  }
}

////////////////////////////////////////////////////////////////////////////////

void MacOSMutex::unlock( )
{
  if( m_waitingThreads.size( ) > 0 )
  {
    ThreadID nFirstWaitingThread = m_waitingThreads.front( );

    if( nFirstWaitingThread != m_nBlockingThread )
    {
      SetThreadState( nFirstWaitingThread, kReadyThreadState, m_nBlockingThread );
    }

    m_waitingThreads.pop_front( );
  }
  else
  {
    m_nBlockingThread = kNoThreadID;
  }
}

////////////////////////////////////////////////////////////////////////////////

void MacOSMutex::finalize( )
{
  m_waitingThreads.clear( );
}

////////////////////////////////////////////////////////////////////////////////