Windows2003-3790/enduser/netmeeting/av/nac/bufpool.cpp
2020-09-30 16:53:55 +02:00

153 lines
2.2 KiB
C++

#include "precomp.h"
///////////////////////////////////////////////////////
//
// Public methods
//
BufferPool::BufferPool ( void )
{
InitializeCriticalSection (&m_CritSect);
_Construct ();
}
BufferPool::~BufferPool ( void )
{
_Destruct ();
DeleteCriticalSection (&m_CritSect);
}
HRESULT BufferPool::Initialize ( UINT uBuf, ULONG cbSizeBuf )
{
HRESULT hr = DPR_SUCCESS;
PBYTE *ppb;
DEBUGMSG (ZONE_VERBOSE, ("BufPool::Initialize: enter.\r\n"));
EnterCriticalSection (&m_CritSect);
if (m_fInitialized)
{
hr = DPR_CANT_INITIALIZE_AGAIN;
goto MyExit;
}
m_cBufFree = uBuf;
m_cbSizeBuf = (cbSizeBuf + 3) & (~3); // round up to 4
m_pAlloc = m_pBufFree = LocalAlloc (LMEM_FIXED, m_cBufFree * m_cbSizeBuf);
if (m_pAlloc == NULL)
{
hr = DPR_OUT_OF_MEMORY;
goto MyExit;
}
ppb = (PBYTE *) m_pBufFree;
while (-- uBuf)
{
ppb = (PBYTE *) (*ppb = (PBYTE) ppb + m_cbSizeBuf);
}
*ppb = NULL;
MyExit:
if (hr == DPR_SUCCESS) m_fInitialized = TRUE;
LeaveCriticalSection (&m_CritSect);
DEBUGMSG (ZONE_VERBOSE, ("BufPool::Initialize: exit, hr=0x%lX\r\n", hr));
return hr;
}
PVOID BufferPool::GetBuffer ( void )
{
PVOID p = NULL;
EnterCriticalSection (&m_CritSect);
if (m_fInitialized)
{
p = m_pBufFree;
if (m_pBufFree)
{
m_pBufFree = (PVOID) *((PBYTE *) m_pBufFree);
}
}
LeaveCriticalSection (&m_CritSect);
return p;
}
void BufferPool::ReturnBuffer ( PVOID p )
{
EnterCriticalSection (&m_CritSect);
if (m_fInitialized)
{
*((PVOID *) p) = m_pBufFree;
m_pBufFree = p;
}
LeaveCriticalSection (&m_CritSect);
}
ULONG BufferPool::GetMaxBufferSize ( void )
{
return m_fInitialized ? m_cbSizeBuf : 0;
}
void BufferPool::Release ( void )
{
_Destruct ();
}
///////////////////////////////////////////////////////
//
// Private methods
//
void BufferPool::_Construct ( void )
{
m_fInitialized = FALSE;
m_cbSizeBuf = 0;
m_cBufAlloc = 0;
m_cBufFree = 0;
m_pAlloc = NULL;
m_pBufFree = NULL;
}
void BufferPool::_Destruct ( void )
{
if (m_fInitialized)
{
if (m_pAlloc)
{
LocalFree (m_pAlloc);
m_pAlloc = NULL;
}
m_fInitialized = FALSE;
}
}