www.pudn.com > PCIConf.rar > RemoveLock.cpp

// RemoveLock.cpp -- Portable implementation for remove-lock functions 
// Copyright (C) 1999 by Walter Oney 
// All rights reserved 
 
#include "stddcls.h" 
 
/////////////////////////////////////////////////////////////////////////////// 
 
#pragma PAGEDCODE 
 
VOID InitializeRemoveLock(PREMOVE_LOCK lock, ULONG tag, ULONG minutes, ULONG maxcount) 
	{							// InitializeRemoveLock 
	PAGED_CODE(); 
	KeInitializeEvent(&lock->evRemove, NotificationEvent, FALSE); 
	lock->usage = 1; 
	lock->removing = FALSE; 
	}							// InitializeRemoveLock 
 
/////////////////////////////////////////////////////////////////////////////// 
 
#pragma LOCKEDCODE 
 
NTSTATUS AcquireRemoveLock(PREMOVE_LOCK lock, PVOID tag) 
	{							// AcquireRemoveLock 
	LONG usage = InterlockedIncrement(&lock->usage); 
	if (lock->removing) 
		{						// removal in progress 
		if (InterlockedDecrement(&lock->usage) == 0) 
			KeSetEvent(&lock->evRemove, 0, FALSE); 
		return STATUS_DELETE_PENDING; 
		}						// removal in progress 
	return STATUS_SUCCESS; 
	}							// AcquireRemoveLock 
 
/////////////////////////////////////////////////////////////////////////////// 
 
VOID ReleaseRemoveLock(PREMOVE_LOCK lock, PVOID tag) 
	{							// ReleaseRemoveLock 
	if (InterlockedDecrement(&lock->usage) == 0) 
		KeSetEvent(&lock->evRemove, 0, FALSE); 
	}							// ReleaseRemoveLock 
 
/////////////////////////////////////////////////////////////////////////////// 
 
#pragma PAGEDCODE 
 
VOID ReleaseRemoveLockAndWait(PREMOVE_LOCK lock, PVOID tag) 
	{							// ReleaseRemoveLockAndWait 
	PAGED_CODE(); 
	lock->removing = TRUE; 
	ReleaseRemoveLock(lock, tag); 
	ReleaseRemoveLock(lock, NULL); 
	KeWaitForSingleObject(&lock->evRemove, Executive, KernelMode, FALSE, NULL); 
	}							// ReleaseRemoveLockAndWait