file.cpp

ACE自适配通信环境（ADAPTIVE Communication Environment）是可以自由使用、开放源码的面向对象（OO）框架（Framework）

// FILE.cpp,v 1.3 2004/01/04 21:17:14 bala Exp

#include "ace/config-all.h"
#include "ace/Guard_T.h"
#include "ace/Synch_Traits.h"
#include "ace/Thread_Mutex.h"

#ifndef JAWS_BUILD_DLL
#define JAWS_BUILD_DLL
#endif 

#include "jaws3/FILE.h"


JAWS_FILE::JAWS_FILE (void)
  : map_ (0)
  , can_map_ (0)
{
}

JAWS_FILE::~JAWS_FILE (void)
{
  delete this->map_;
  this->map_ = 0;
}

ACE_Mem_Map *
JAWS_FILE::mem_map (int length,
                    int prot,
                    int share,
                    void *addr,
                    off_t offset,
                    LPSECURITY_ATTRIBUTES sa) const
{
  if (this->can_map_ == 0)
    return 0;

  JAWS_FILE *mutable_this = (JAWS_FILE *) this;
  return mutable_this->mem_map (length, prot, share, addr, offset, sa);
}

ACE_Mem_Map *
JAWS_FILE::mem_map (int length,
                    int prot,
                    int share,
                    void *addr,
                    off_t offset,
                    LPSECURITY_ATTRIBUTES sa)
{
  if (this->can_map_ == 0)
    return 0;

  if (this->map_ == 0)
    {
      ACE_Guard<ACE_SYNCH_MUTEX> g (this->lock_);

      if (this->map_ == 0)
        {
          this->map_ = new ACE_Mem_Map;
          if (this->map_ != 0)
            {
              int r = this->map_->map (this->get_handle (),
                                       length, prot, share, addr, offset, sa);
              if (r < 0)
                {
                  delete this->map_;
                  this->map_ = 0;
                }
            }
        }
    }

  return this->map_;

}


ACE_Mem_Map *
JAWS_FILE::map (void) const
{
  return this->map_;
}

void
JAWS_FILE::can_map (int flag)
{
  this->can_map_ = (flag != 0);
}