IoCsqInitializeEx function

Description

The IoCsqInitializeEx routine initializes the dispatch table for a cancel-safe IRP queue.

Parameters

Csq [out]

Pointer to the IO_CSQ structure to be initialized by IoCsqInitializeEx.

CsqInsertIrp [in]

Pointer to the driver-defined CsqInsertIrpEx function for the driver's cancel-safe IRP queue.

CsqRemoveIrp [in]

Pointer to the driver-defined CsqRemoveIrp function for the driver's cancel-safe IRP queue.

CsqPeekNextIrp [in]

Pointer to the driver-defined CsqPeekNextIrp function for the driver's cancel-safe IRP queue.

CsqAcquireLock [in]

Pointer to the driver-defined CsqAcquireLock function for the driver's cancel-safe IRP queue.

CsqReleaseLock [in]

Pointer to the driver-defined CsqReleaseLock function for the driver's cancel-safe IRP queue.

CsqCompleteCanceledIrp [in]

Pointer to the driver-defined CsqCompleteCanceledIrp function for the driver's cancel-safe IRP queue.

Return value

IoCsqInitializeEx returns STATUS_SUCCESS on success, or the appropriate error code on failure.

Remarks

The IoCsqInitialize and IoCsqInitializeEx routines initialize an IO_CSQ structure that describes a driver's cancel-safe IRP queue. You can use IoCsqInitializeEx to specify an IRP queue with extended capabilities instead of one specified by IoCsqInitialize:

• The driver implements a CsqInsertIrpEx routine rather than a CsqInsertIrp routine. CsqInsertIrpEx takes an additional parameter, InsertContext. When the driver calls IoCsqInsertIrpEx to insert the IRP, it specifies the value that is passed as InsertContext.
• IoCsqInsertIrpEx returns the return value of CsqInsertIrpEx. Drivers can use the return value to indicate whether an insert operation succeeded or failed.

Otherwise, the effect of IoCsqInitializeEx is identical to that of IoCsqInitialize. For more information, see Cancel-Safe IRP Queues.

Note that IoCsq*Xxx* routines use the DriverContext[3] member of the IRP to hold IRP context information. Drivers that use these routines to queue IRPs must leave that member unused.

See also

CsqAcquireLock

CsqCompleteCanceledIrp

CsqInsertIrp

CsqInsertIrpEx

CsqPeekNextIrp

CsqReleaseLock

CsqRemoveIrp

IO_CSQ

IO_CSQ_IRP_CONTEXT

IoCsqInitializeEx

IoCsqInsertIrp

IoCsqInsertIrpEx

IoCsqRemoveIrp

IoCsqRemoveNextIrp