readwrite.cpp

来自「一本在讲述USB驱动程式的书 及其范例原码」· C++ 代码 · 共 72 行

// Read/Write request processors for evwait driver
// Copyright (C) 1999 by Walter Oney
// All rights reserved

#include "stddcls.h"
#include "driver.h"

///////////////////////////////////////////////////////////////////////////////

#pragma PAGEDCODE

NTSTATUS DispatchCreate(PDEVICE_OBJECT fdo, PIRP Irp)
	{							// DispatchCreate
	PAGED_CODE();
	KdPrint((DRIVERNAME " - IRP_MJ_CREATE\n"));
	PDEVICE_EXTENSION pdx = (PDEVICE_EXTENSION) fdo->DeviceExtension;

	PIO_STACK_LOCATION stack = IoGetCurrentIrpStackLocation(Irp);

	NTSTATUS status = STATUS_SUCCESS;
	if (InterlockedIncrement(&pdx->handles) > 1)
		{
		InterlockedDecrement(&pdx->handles);
		status = STATUS_ACCESS_DENIED;
		}

	return CompleteRequest(Irp, status, 0);
	}							// DispatchCreate

///////////////////////////////////////////////////////////////////////////////

#pragma LOCKEDCODE

NTSTATUS DispatchClose(PDEVICE_OBJECT fdo, PIRP Irp)
	{							// DispatchClose
	PAGED_CODE();
	KdPrint((DRIVERNAME " - IRP_MJ_CLOSE\n"));
	PDEVICE_EXTENSION pdx = (PDEVICE_EXTENSION) fdo->DeviceExtension;
	PIO_STACK_LOCATION stack = IoGetCurrentIrpStackLocation(Irp);

	// Make sure any registered event gets released now

	KIRQL oldirql;
	KeAcquireSpinLock(&pdx->eventlock, &oldirql);
	if (pdx->event)
		ObDereferenceObject(pdx->event);
	pdx->event = NULL;
	KeReleaseSpinLock(&pdx->eventlock, oldirql);

	InterlockedDecrement(&pdx->handles);
	
	return CompleteRequest(Irp, STATUS_SUCCESS, 0);
	}							// DispatchClose

///////////////////////////////////////////////////////////////////////////////

#pragma PAGEDCODE

NTSTATUS StartDevice(PDEVICE_OBJECT fdo, PCM_PARTIAL_RESOURCE_LIST raw, PCM_PARTIAL_RESOURCE_LIST translated)
	{							// StartDevice
	return STATUS_SUCCESS;
	}							// StartDevice

///////////////////////////////////////////////////////////////////////////////

#pragma PAGEDCODE

VOID StopDevice(IN PDEVICE_OBJECT fdo, BOOLEAN oktouch /* = FALSE */)
	{							// StopDevice
	PDEVICE_EXTENSION pdx = (PDEVICE_EXTENSION) fdo->DeviceExtension;
	}							// StopDevice