isolistener.cpp

VHPD1394 V1.15驅動程序源碼

/************************************************************************
 *  THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY
 *  KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
 *  IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR
 *  PURPOSE.
 ************************************************************************/

/************************************************************************
 *
 *  Module:       IsoListener.cpp
 *  Long name:    Isochronous Listener class implementation
 *  Description:  Simple class which handles reception of data over an 
 *                isochronous channel.
 *                Optionally, data may be written to a file.
 *
 *  Runtime Env.: Win32
 *  Author(s):    Frank Senf
 *  Company:      Thesycon GmbH, Ilmenau
 ************************************************************************/

#include "IsoListener.h"


// constructor implementation
CIsoListener::CIsoListener()
{
  // init members
  m_BufferError = 0;
  m_LastError = VHPD_STATUS_SUCCESS;

  m_ThreadExited = false;

  m_File = NULL;

} // ctor

// destructor implementation
CIsoListener::~CIsoListener()
{
  // ensure all resources are released
  CloseFile();

} // dtor


// open the destination file
unsigned long
CIsoListener::OpenFile(const char* Filename)
{
  unsigned long retval;

  if ( m_File == NULL ) {
    // open the file, if it already exists it will be overwritten
    m_File = ::CreateFile(
                  Filename,       // name of file
                  GENERIC_WRITE,  // access mode
                  FILE_SHARE_READ,  // share mode (0=not shared)
                  NULL,           // security descriptor
                  CREATE_ALWAYS,  // how to create
                  FILE_FLAG_WRITE_THROUGH,  // file flags and attributes
                  NULL            // handle to template file
                  );
    if ( m_File == INVALID_HANDLE_VALUE ) {
      // opening output file failed
      retval = ::GetLastError();
      m_File = NULL;
    } else {
      // file successfully opened
      retval = 0;
    }
  } else {
    // an output file was already opened
    retval = 1;
  }
  
  return retval;

} // OpenFile


// close the destination file
void CIsoListener::CloseFile()
{
  if ( m_File!=NULL ) {
    ::CloseHandle(m_File);
    m_File = NULL;
  }

} // CloseFile


// overloaded CVhpdThread::TerminateThread() function
// NOTE 1: called in the context of the main thread
// NOTE 2: TerminateThread() is overloaded to ensure that the
// thread will exit. This is done by trying to terminate the
// thread until it really terminates. For future version of VHPDLib
// this will be implemented by the base class
void CIsoListener::TerminateThread()
{
  // cancel all pending notification buffers, this forces the worker thread
  // to resume from a wait state and check for termination
  AbortIoBuffers();

  // now wait for the thread to terminate
  if ( mThreadHandle != NULL ) {
    // loop until thread has terminated
    for (;;) {
      // wait on thread handle, 40 ms timeout
      DWORD err = WaitForSingleObject(mThreadHandle,40);
      if ( err==WAIT_OBJECT_0 ) {
        // handle is signaled, done
        break;
      }
      if ( err==WAIT_TIMEOUT ) {
        // wait timed out
        // cancel all pending notification buffers again, should force the worker thread
        // to resume from the wait state and check for termination
        AbortIoBuffers();
        // loop and wait again
        continue;
      }
      // neither WAIT_OBJECT_0 nor WAIT_TIMEOUT returned -> error during wait
      break;
    } // for()
  }
} // TerminateThread


// overloaded CVhpdThread::OnThreadExit() function
// NOTE: It is called in the context of the worker thread.
void CIsoListener::OnThreadExit()
{
  // store new thread state
  m_ThreadExited = true;  

} // OnThreadExit


// function is called with each buffer before it is submitted to the driver
// may be used to initialize the buffer and to set special parameters within
// the associated VHPD_ISOCH_SUBMIT_BUFFER structure
void
CIsoListener::PreProcessBuffer(
  CVhpdBuf* Buf,
  VHPD_ISOCH_SUBMIT_BUFFER* Submit)
{
  // delete any buffer contents
  memset(Buf->Buffer(),0x0,Buf->Size());

  // *** TODO: add code to modify Submit structure here ***

  // e.g. to receive data from a DV camcorder uncomment the following
  //Submit->Flags |= VHPD_FLAG_ISOCH_SYNCH_ON_TAG;
  //Submit->TagField = 1;

} // PreProcessBuffer


// function is called after a buffer is completed by the driver
// function may return FALSE to stop buffer processing, TRUE to continue
BOOL
CIsoListener::PostProcessBuffer(
  CVhpdBuf* Buf,
  VHPD_ISOCH_SUBMIT_BUFFER* Submit)
{
  if ( Buf->mStatus == VHPD_STATUS_SUCCESS ) {
    // test for an output file
    if ( m_File != NULL ) {
      // output file is available
      // write buffer data to output file
      unsigned long bytecount = 0;
      BOOL succ = ::WriteFile(m_File, Buf->Buffer(), Buf->mBytesTransferred, &bytecount, NULL);
      if ( (!succ) || (bytecount != Buf->mBytesTransferred) ) {
        // serious error, stop reception
        return FALSE;
      }
    } else {
      // no output file, just discard buffer data
    }

  } else {
    // completed with error, count it
    m_BufferError++;
    m_LastError = Buf->mStatus;

  }

  // always continue
  return TRUE;

} // PostProcessBuffer

/*************************** EOF **************************************/