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.