Leaked source code of windows server 2003
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/*++
Copyright (c) 1996 Microsoft Corporation
Module Name:
refcnt.c
Abstract:
This module exports Reference Counting support functions. By
including a Reference Count Control Block (REF_CNT) in a
dynamic type, and using this API, a Reference scheme can be
implemented for that type.
Author:
Edward Buchwalter (v-edbuc) 14-Aug-1996
Revision History:
Shreedhar Madhavapeddi (ShreeM) 16-April-1999
Adapted for NT and GPC by ShreeM\MBert.
--*/
//
// Include Files
//
#include "gpcpre.h"
#define EXPAND_TAG(t) ((CHAR *)(&Tag))[0],((CHAR *)(&Tag))[1],((CHAR *)(&Tag))[2],((CHAR *)(&Tag))[3]
VOID
ReferenceInit
(
IN PREF_CNT pRefCnt,
PVOID InstanceHandle,
VOID (*DeleteHandler)( PVOID )
)
/*++
Routine Description:
ReferenceInit initializes and adds one reference to the
supplied Reference Control Block. If provided, an instance
handle and delete handler are saved for use by the ReferenceRemove
function when all references to the instance are removed.
Arguments:
pRefCnt - pointer to uninitialized Reference Control Block
InstanceHandle - handle to the managed instance.
DeleteHandler - pointer to delete function, NULL is OK.
Return Value:
The function's value is VOID.
--*/
{
TRACE(REFCOUNT, pRefCnt, InstanceHandle, "ReferenceInit( 0x%x, 0x%x )\n");
ASSERT( pRefCnt );
// Set the reference to 1 and save the instance
// handle and the delete handler.
pRefCnt->Count = 0;
pRefCnt->Instance = InstanceHandle;
pRefCnt->DeleteHandler = DeleteHandler;
#if DBG
pRefCnt->Sig = REF_SIG;
RtlZeroMemory(pRefCnt->Tags, sizeof(REF_TAG) * TAG_CNT);
pRefCnt->Tags[0].Tag = 'LTOT';
CTEInitLock(&pRefCnt->Lock);
#endif
}
VOID
ReferenceAdd
(
IN PREF_CNT pRefCnt
)
/*++
Routine Description:
Arguments:
Return Value:
--*/
{
ASSERT( pRefCnt );
InterlockedIncrement(&pRefCnt->Count);
TRACE(REFCOUNT, pRefCnt->Count, 0, "R+%d\n");
}
VOID
ReferenceAddCount
(
IN PREF_CNT pRefCnt,
IN UINT Count
)
/*++
Routine Description:
Arguments:
Return Value:
--*/
{
ASSERT( pRefCnt->Count > 0 );
CTEInterlockedExchangeAdd(&pRefCnt->Count, Count);
}
PVOID
ReferenceRemove
(
IN PREF_CNT pRefCnt
)
/*++
Routine Description:
Arguments:
Return Value:
--*/
{
ASSERT( pRefCnt );
// Trap remove reference on a zero count
ASSERT( pRefCnt->Count > 0 );
// If the decremented count is non zero return the instance handle
if (InterlockedDecrement(&pRefCnt->Count) > 0 )
{
TRACE(REFCOUNT, pRefCnt->Count, 0, "R-%d\n");
TRACE(REFCOUNT, pRefCnt->Count, 0, "ReferenceRemove:remaining: %d\n");
return( pRefCnt->Instance );
}
// Delete this instance if a delete handler is available
if( pRefCnt->DeleteHandler )
{
TRACE(REFCOUNT, 0, 0, "Executing DeleteHandler\n");
(pRefCnt->DeleteHandler)( pRefCnt->Instance );
}
// Indicate no active references to this instance
return( NULL );
}
//
// API Test Support
//
#if DBG
VOID
ReferenceApiTest( VOID )
{
REF_CNT RefCnt;
TRACE(REFCOUNT, 0, 0, "\nReferenceApiTest\n");
TRACE(REFCOUNT, 0, 0, "\nTest #1: NULL delete handler\n");
ReferenceInit( &RefCnt, &RefCnt, NULL );
ReferenceAdd( &RefCnt );
ReferenceAdd( &RefCnt );
ReferenceAdd( &RefCnt );
while( ReferenceRemove( &RefCnt ) )
{
;
}
TRACE( REFCOUNT, 0, 0, "\nTest #2: Delete Handler - TBD\n");
}
VOID
ReferenceAddDbg(PREF_CNT pRefCnt, ULONG Tag)
{
int i;
CTELockHandle hLock;
int TotalPerArray = 0;
ASSERT(pRefCnt->Sig == REF_SIG);
TRACE(REFCOUNT, EXPAND_TAG(Tag), pRefCnt->Count, ("GPC REF: add (%c%c%c%c) %d\n"));
CTEGetLock(&pRefCnt->Lock, &hLock);
for (i = 1; i < TAG_CNT; i++)
{
if (pRefCnt->Tags[i].Tag == 0 || pRefCnt->Tags[i].Tag == Tag)
{
pRefCnt->Tags[i].Tag = Tag;
InterlockedIncrement(&pRefCnt->Tags[i].Count);
break;
}
}
ASSERT(i < TAG_CNT);
InterlockedIncrement(&pRefCnt->Tags[0].Count);
InterlockedIncrement(&pRefCnt->Count);
ASSERT(pRefCnt->Tags[0].Count == pRefCnt->Count);
// sanity check
/*
for (i = 1; i < TAG_CNT; i++)
{
if (pRefCnt->Tags[i].Tag != 0)
{
TotalPerArray += pRefCnt->Tags[i].Count;
continue;
}
}
ASSERT(TotalPerArray == pRefCnt->Tags[0].Count);
if (TotalPerArray != pRefCnt->Tags[0].Count)
{
DbgBreakPoint();
}
*/
CTEFreeLock(&pRefCnt->Lock, hLock);
}
VOID
ReferenceRemoveDbg(PREF_CNT pRefCnt, ULONG Tag)
{
int i;
CTELockHandle hLock;
int TotalPerArray = 0;
BOOLEAN FoundIt = FALSE;
ASSERT(pRefCnt->Sig == REF_SIG);
TRACE(REFCOUNT, EXPAND_TAG(Tag), pRefCnt->Count, "GPC REF: remove (%c%c%c%c) %d\n");
CTEGetLock(&pRefCnt->Lock, &hLock);
for (i = 1; i < TAG_CNT; i++)
{
if (pRefCnt->Tags[i].Tag == Tag)
{
FoundIt = TRUE;
ASSERT(pRefCnt->Tags[i].Count > 0);
InterlockedDecrement(&pRefCnt->Tags[i].Count);
if (pRefCnt->Tags[i].Count == 0)
pRefCnt->Tags[i].Tag = Tag;
break;
}
}
ASSERT(FoundIt);
ASSERT(pRefCnt->Tags[0].Count > 0);
ASSERT(pRefCnt->Tags[0].Count == pRefCnt->Count);
InterlockedDecrement(&pRefCnt->Tags[0].Count);
if (InterlockedDecrement(&pRefCnt->Count) > 0 )
{
CTEFreeLock(&pRefCnt->Lock, hLock);
}
else if (pRefCnt->DeleteHandler)
{
TRACE(REFCOUNT, 0 , 0, "Executing DeleteHandler\n");
CTEFreeLock(&pRefCnt->Lock, hLock);
(pRefCnt->DeleteHandler)( pRefCnt->Instance );
}
else
{
CTEFreeLock(&pRefCnt->Lock, hLock);
}
/*
// sanity check
for (i = 1; i < TAG_CNT; i++)
{
if (pRefCnt->Tags[i].Tag != 0)
{
TotalPerArray += pRefCnt->Tags[i].Count;
continue;
}
}
ASSERT(TotalPerArray == pRefCnt->Tags[0].Count);
if (TotalPerArray != pRefCnt->Tags[0].Count)
{
DbgPrint(TEXT("Tag %X, RefCnt %X, perArray %d, total %d\n"), Tag, pRefCnt,
TotalPerArray, pRefCnt->Tags[0].Count);
DbgBreakPoint();
}
*/
}
VOID
ReferenceCheckForZeroRef(PREF_CNT pRefCnt, ULONG Tag)
{
int i;
CTELockHandle hLock;
int TotalPerArray = 0;
BOOLEAN FoundIt = FALSE;
ASSERT(pRefCnt->Sig == REF_SIG);
CTEGetLock(&pRefCnt->Lock, &hLock);
for (i = 1; i < TAG_CNT; i++)
{
if (pRefCnt->Tags[i].Tag == Tag)
{
FoundIt = TRUE;
ASSERT(pRefCnt->Tags[i].Count == 0);
break;
}
}
ASSERT(FoundIt);
CTEFreeLock(&pRefCnt->Lock, hLock);
}
#endif