/*------------------------------------------------------------------------
* (The MIT License)
* 
* Copyright (c) 2008-2011 Rhomobile, Inc.
* 
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
* 
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
* 
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
* 
* http://rhomobile.com
*------------------------------------------------------------------------*/

#ifndef _RHOSYSTEM_H_
#define _RHOSYSTEM_H_

#include "RhoPort.h"

#if defined OS_LINUX || defined OS_FREEBSD || defined OS_MACOSX
#include <sys/syscall.h>
#endif

namespace rho{
namespace common{

class CSystem{
public:
    CSystem(){}

    static unsigned int getThreadID();
};

inline unsigned int CSystem::getThreadID(){ 
  // On Linux and FreeBSD, we try to use gettid().
#if defined OS_LINUX || defined OS_FREEBSD || defined OS_MACOSX
#ifndef __NR_gettid
#ifdef OS_MACOSX
#define __NR_gettid SYS_gettid
#elif ! defined __i386__
#error "Must define __NR_gettid for non-x86 platforms"
#else
#define __NR_gettid 224
#endif
#endif
  static bool lacks_gettid = false;
  if (!lacks_gettid) {
    pid_t tid = syscall(__NR_gettid);
    if (tid != -1) {
      return tid;
    }
    // Technically, this variable has to be volatile, but there is a small
    // performance penalty in accessing volatile variables and there should
    // not be any serious adverse effect if a thread does not immediately see
    // the value change to "true".
    lacks_gettid = true;
  }
#endif  // OS_LINUX || OS_FREEBSD

  // If gettid() could not be used, we use one of the following.
#if defined OS_LINUX
  return getpid();  // Linux:  getpid returns thread ID when gettid is absent
#elif defined(WINDOWS_PLATFORM) || defined(OS_CYGWIN)
  return GetCurrentThreadId();
#else
  // If none of the techniques above worked, we use pthread_self().
    return (pid_t)(int64)pthread_self();
#endif
    }

}
}

#endif //_RHOFILEPATH_H_