csqueueroutines.c

老外写的一个相当不错的虚拟显示器驱动

#include "Driver.h"


/*************************************************************************************************/
VOID CSReadInsertIrp(IN PIO_CSQ Csq, IN PIRP Irp)
{
	PFDO_DATA deviceExtension = CONTAINING_RECORD(Csq, FDO_DATA, CSReadQueue);
    InsertTailList(&deviceExtension->ReadIrpQueue, &Irp->Tail.Overlay.ListEntry);
}


/*************************************************************************************************/
VOID CSReadRemoveIrp(IN PIO_CSQ Csq, IN PIRP Irp)
{
	PFDO_DATA deviceExtension = CONTAINING_RECORD(Csq, FDO_DATA, CSReadQueue);
    RemoveEntryList(&Irp->Tail.Overlay.ListEntry);
}


/*************************************************************************************************/
PIRP CSReadPeekNextIrp(IN PIO_CSQ Csq, IN PIRP Irp, IN PVOID PeekContext)
{
	PFDO_DATA deviceExtension = CONTAINING_RECORD(Csq, FDO_DATA, CSReadQueue);
    PIRP nextIrp = NULL;
    PLIST_ENTRY nextEntry;
    PLIST_ENTRY listHead;
    PIO_STACK_LOCATION irpStack;

    listHead = &deviceExtension->ReadIrpQueue;

    // If the IRP is NULL, we will start peeking from the listhead, else
    // we will start from that IRP onwards. This is done under the
    // assumption that new IRPs are always inserted at the tail.
    if (Irp == NULL)
        nextEntry = listHead->Flink;
	else
        nextEntry = Irp->Tail.Overlay.ListEntry.Flink;
    
    while (nextEntry != listHead)
	{
        nextIrp = CONTAINING_RECORD(nextEntry, IRP, Tail.Overlay.ListEntry);

        if (PeekContext)
		{
			irpStack = IoGetCurrentIrpStackLocation(nextIrp);
            
			if (irpStack->FileObject == (PFILE_OBJECT)PeekContext)
                break;
        }
		else
            break;

        nextIrp = NULL;
        nextEntry = nextEntry->Flink;
    }

    return nextIrp;
}


/*************************************************************************************************/
VOID CSReadAcquireLock(IN PIO_CSQ Csq, OUT PKIRQL Irql)
{
	PFDO_DATA deviceExtension = CONTAINING_RECORD(Csq, FDO_DATA, CSReadQueue);
    KeAcquireSpinLock(&deviceExtension->ReadQueueLock, Irql);
}


/*************************************************************************************************/
VOID CSReadReleaseLock(IN PIO_CSQ Csq, IN KIRQL Irql)
{
	PFDO_DATA deviceExtension = CONTAINING_RECORD(Csq, FDO_DATA, CSReadQueue);
    KeReleaseSpinLock(&deviceExtension->ReadQueueLock, Irql);
}


/*************************************************************************************************/
VOID CSReadCompleteCanceledIrp(IN PIO_CSQ Csq, IN PIRP Irp)
{
	Irp->IoStatus.Status = STATUS_CANCELLED;
    Irp->IoStatus.Information = 0;
    IoCompleteRequest(Irp, IO_NO_INCREMENT);
}