AVCSTRM_ABORT_STREAMING

The AVCSTRM_ABORT_STREAMING function code cancels all the pending data requests and frees the resources used.

I/O Status Block

If successful, avcstrm.sys sets Irp->IoStatus.Status to STATUS_SUCCESS.

Possible error return values include:

Error Status	Description
STATUS_DEVICE_REMOVED	The device corresponding to the AVCSTRM_READ operation no longer exists.
STATUS_CANCELLED	The request was unable to be completed.
STATUS_INVALID_PARAMETER	A parameter specified in the IRP is incorrect,
STATUS_INSUFFICIENT_RESOURCES	There were not sufficient system resources to complete the request.
STATUS_PENDING	The request has been received but requires further processing. The I/O completion routine will handle the final response.

AVC_STREAM_REQUEST_BLOCK Input

SizeOfThisBlock, Version and Function
Use the INIT_AVCSTRM_HEADER macro to initialize these members. Pass AVCSTRM_ABORT_STREAMING in the Request argument of the macro.

AVCStreamContext
Specifies the stream context (handle) returned by an earlier AVCSTRM_OPEN call that is the target for the data write operation.

A subunit driver must first allocate an IRP and an AVC_STREAM_REQUEST_BLOCK structure.

Next, it should use the INIT_AVCSTRM_HEADER macro to initialize the AVC_STREAM_REQUEST_BLOCK structure, passing AVCSTRM_READ as the Request argument to the macro.

Next, the subunit driver sets the AVCStreamContext member to the stream context (handle) of the stream to abort streaming.

To send this request, a subunit submits an IRP_MJ_INTERNAL_DEVICE_CONTROL IRP with the IoControlCode member of the IRP set to IOCTL_AVCSTRM_CLASS and the Argument1 member of the IRP set to the AVC_STREAM_REQUEST_BLOCK structure that describes the abort streaming operation to take place.

This function code must be called at PASSIVE_LEVEL. When a data IRP is being canceled, it can be executed at DISPATCH_LEVEL. In this case, a subunit should start a work item and call this function in its work item routine, which is executing at the PASSIVE_LEVEL.

Comments

Note, this functionality cancels all streaming IRPs. To cancel an individual IRP, use IoCancelIrp.

A subunit should call this when its target device is removed or the original data IRP is canceled to stop stream operation.

This function does not use any member of the CommandData union in the AVC_STREAM_REQUEST_BLOCK structure.

typedef struct _AVC_STREAM_REQUEST_BLOCK {
  ULONG  SizeOfThisBlock;
  ULONG  Version;
  AVCSTRM_FUNCTION  Function;
  .
  .
  PVOID AVCStreamContext;
  .
  .
} AVC_STREAM_REQUEST_BLOCK, *PAVC_STREAM_REQUEST_BLOCK;

Requirements

Headers: Declared in avcstrm.h. Include avcstrm.h.

See Also

INIT_AVCSTRM_HEADER

IRP_MJ_INTERNAL_DEVICE_CONTROL

IOCTL_AVCSTRM_CLASS

AVCSTRM_FUNCTION