DVC 서버 모듈 예제
다음 C++ 코드 샘플에서는 서버 쪽 DVC(동적 가상 채널) 모듈을 만드는 방법의 예를 제공합니다.
#include <windows.h>
#include <wtsapi32.h>
#include <pchannel.h>
#include <crtdbg.h>
#pragma comment(lib, "wtsapi32.lib")
#define _MAX_WAIT 60000
#define MAX_MSG_SIZE 0x20000
#define START_MSG_SIZE 4
#define STEP_MSG_SIZE 113
DWORD OpenDynamicChannel(LPCSTR szChannelName, HANDLE *phFile);
DWORD WINAPI WriteThread(PVOID param);
DWORD WINAPI ReadThread(PVOID param);
INT _cdecl wmain(INT argc, __in_ecount( argc ) WCHAR **argv)
{
DWORD rc;
HANDLE hFile;
rc = OpenDynamicChannel ( "DVC_Sample", &hFile );
if ( ERROR_SUCCESS != rc )
{
return 0;
}
DWORD dwThreadId;
HANDLE hReadThread = CreateThread(
NULL,
0,
ReadThread,
hFile,
0,
&dwThreadId );
HANDLE hWriteThread = CreateThread(
NULL,
0,
WriteThread,
hFile,
0,
&dwThreadId );
HANDLE ah[] = {hReadThread, hWriteThread};
WaitForMultipleObjects(2, ah, TRUE, INFINITE );
CloseHandle( hReadThread );
CloseHandle( hWriteThread );
CloseHandle( hFile );
return 1;
}
/*
* Open a dynamic channel with the name given in szChannelName.
* The output file handle can be used in ReadFile/WriteFile calls.
*/
DWORD OpenDynamicChannel(
LPCSTR szChannelName,
HANDLE *phFile )
{
HANDLE hWTSHandle = NULL;
HANDLE hWTSFileHandle;
PVOID vcFileHandlePtr = NULL;
DWORD len;
DWORD rc = ERROR_SUCCESS;
hWTSHandle = WTSVirtualChannelOpenEx(
WTS_CURRENT_SESSION,
(LPSTR)szChannelName,
WTS_CHANNEL_OPTION_DYNAMIC );
if ( NULL == hWTSHandle )
{
rc = GetLastError();
goto exitpt;
}
BOOL fSucc = WTSVirtualChannelQuery(
hWTSHandle,
WTSVirtualFileHandle,
&vcFileHandlePtr,
&len );
if ( !fSucc )
{
rc = GetLastError();
goto exitpt;
}
if ( len != sizeof( HANDLE ))
{
rc = ERROR_INVALID_PARAMETER;
goto exitpt;
}
hWTSFileHandle = *(HANDLE *)vcFileHandlePtr;
fSucc = DuplicateHandle(
GetCurrentProcess(),
hWTSFileHandle,
GetCurrentProcess(),
phFile,
0,
FALSE,
DUPLICATE_SAME_ACCESS );
if ( !fSucc )
{
rc = GetLastError();
goto exitpt;
}
rc = ERROR_SUCCESS;
exitpt:
if ( vcFileHandlePtr )
{
WTSFreeMemory( vcFileHandlePtr );
}
if ( hWTSHandle )
{
WTSVirtualChannelClose( hWTSHandle );
}
return rc;
}
/*
* Write a series of random messages into the dynamic virtual channel.
*/
DWORD WINAPI WriteThread(PVOID param)
{
HANDLE hFile;
BYTE WriteBuffer[MAX_MSG_SIZE];
DWORD dwWritten;
BOOL fSucc;
BYTE b = 0;
HANDLE hEvent;
hFile = (HANDLE)param;
hEvent = CreateEvent( NULL, FALSE, FALSE, NULL );
for( ULONG msgSize = START_MSG_SIZE;
msgSize < MAX_MSG_SIZE;
msgSize += STEP_MSG_SIZE )
{
OVERLAPPED Overlapped = {0};
Overlapped.hEvent = hEvent;
for( ULONG i = 0; i < msgSize; i++, b++ )
{
WriteBuffer[i] = b;
}
fSucc = WriteFile(
hFile,
WriteBuffer,
msgSize,
&dwWritten,
&Overlapped );
if ( !fSucc )
{
if ( GetLastError() == ERROR_IO_PENDING )
{
DWORD dw = WaitForSingleObject( Overlapped.hEvent, _MAX_WAIT );
_ASSERT( WAIT_OBJECT_0 == dw );
fSucc = GetOverlappedResult(
hFile,
&Overlapped,
&dwWritten,
FALSE );
}
}
if ( !fSucc )
{
DWORD error = GetLastError();
return error;
}
_ASSERT( dwWritten == msgSize );
}
return 0;
}
/*
* Read the data from the dynamic virtual channel reconstruct the original
* message and verify its content.
*/
DWORD WINAPI ReadThread(PVOID param)
{
HANDLE hFile;
BYTE ReadBuffer[CHANNEL_PDU_LENGTH];
DWORD dwRead;
BYTE b = 0;
CHANNEL_PDU_HEADER *pHdr;
BOOL fSucc;
HANDLE hEvent;
hFile = (HANDLE)param;
pHdr = (CHANNEL_PDU_HEADER*)ReadBuffer;
hEvent = CreateEvent( NULL, FALSE, FALSE, NULL );
for( ULONG msgSize = START_MSG_SIZE;
msgSize < MAX_MSG_SIZE;
msgSize += STEP_MSG_SIZE )
{
OVERLAPPED Overlapped = {0};
DWORD TotalRead = 0;
do {
Overlapped.hEvent = hEvent;
// Read the entire message.
fSucc = ReadFile(
hFile,
ReadBuffer,
sizeof( ReadBuffer ),
&dwRead,
&Overlapped );
if ( !fSucc )
{
if ( GetLastError() == ERROR_IO_PENDING )
{
DWORD dw = WaitForSingleObject( Overlapped.hEvent, INFINITE );
_ASSERT( WAIT_OBJECT_0 == dw );
fSucc = GetOverlappedResult(
hFile,
&Overlapped,
&dwRead,
FALSE );
}
}
if ( !fSucc )
{
DWORD error = GetLastError();
return error;
}
ULONG packetSize = dwRead - sizeof( *pHdr );
TotalRead += packetSize;
PBYTE pData = (PBYTE)( pHdr + 1 );
for ( ULONG i = 0; i < packetSize; pData++, i++, b++ )
{
_ASSERT( *pData == b );
}
_ASSERT( msgSize == pHdr->length );
} while( 0 == ( pHdr->flags & CHANNEL_FLAG_LAST ));
_ASSERT( TotalRead == msgSize );
}
return 0;
}