IoCsqInitializeEx function (wdm.h)

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

Syntax

NTSTATUS IoCsqInitializeEx(
  [out] PIO_CSQ                       Csq,
  [in]  PIO_CSQ_INSERT_IRP_EX         CsqInsertIrp,
  [in]  PIO_CSQ_REMOVE_IRP            CsqRemoveIrp,
  [in]  PIO_CSQ_PEEK_NEXT_IRP         CsqPeekNextIrp,
  [in]  PIO_CSQ_ACQUIRE_LOCK          CsqAcquireLock,
  [in]  PIO_CSQ_RELEASE_LOCK          CsqReleaseLock,
  [in]  PIO_CSQ_COMPLETE_CANCELED_IRP CsqCompleteCanceledIrp
);

Parameters

[out] Csq

Pointer to the IO_CSQ structure to be initialized by IoCsqInitializeEx.

[in] CsqInsertIrp

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

[in] CsqRemoveIrp

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

[in] CsqPeekNextIrp

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

[in] CsqAcquireLock

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

[in] CsqReleaseLock

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

[in] CsqCompleteCanceledIrp

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 IoCsqXxx 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.

Requirements

Requirement Value
Minimum supported client Available in Windows Server 2003 and later versions of the Windows operating system. The routine is also available in the Csq.lib library that ships with the Windows Driver Kit (WDK) and the Driver Development Kit (DDK) for Windows Server 2003. Drivers that must also work on Windows XP, Windows 2000, and Windows 98/Me can instead link to Csq.lib to use the routine.
Target Platform Universal
Header wdm.h (include Wdm.h, Ntddk.h, Ntifs.h)
Library NtosKrnl.lib
DLL NtosKrnl.exe
IRQL Any level

See also

CsqAcquireLock

CsqCompleteCanceledIrp

CsqInsertIrp

CsqInsertIrpEx

CsqPeekNextIrp

CsqReleaseLock

CsqRemoveIrp

IO_CSQ

IO_CSQ_IRP_CONTEXT

IoCsqInitializeEx

IoCsqInsertIrp

IoCsqInsertIrpEx

IoCsqRemoveIrp

IoCsqRemoveNextIrp