EVT_SERCX2_PIO_RECEIVE_CANCEL_READY_NOTIFICATION callback function (sercx.h)

Article
10/21/2021

The EvtSerCx2PioReceiveCancelReadyNotification event callback function is called by version 2 of the serial framework extension (SerCx2) to cancel a ready notification that SerCx2 enabled in a previous call to the EvtSerCx2PioReceiveEnableReadyNotification event callback function.

Syntax

EVT_SERCX2_PIO_RECEIVE_CANCEL_READY_NOTIFICATION EvtSercx2PioReceiveCancelReadyNotification;

BOOLEAN EvtSercx2PioReceiveCancelReadyNotification(
  [in] SERCX2PIORECEIVE PioReceive
)
{...}

Parameters

[in] PioReceive

A SERCX2PIORECEIVE handle to a PIO-receive object. The serial controller driver previously called the SerCx2PioReceiveCreate method to create this object.

Return value

The EvtSerCx2PioReceiveCancelReadyNotification function returns TRUE if the ready notification was successfully disabled and the serial controller driver can guarantee that this notification will not cause the SerCx2PioReceiveReady method to be called. The function returns FALSE if the driver has already called SerCx2PioReceiveReady, or is about to call this method.

Remarks

Your serial controller driver must implement this function. The driver registers the function in the SerCx2PioReceiveCreate call that creates the PIO-receive object.

If the associated read request times out or is canceled while a ready notification is enabled, SerCx2 calls the EvtSerCx2PioReceiveCancelReadyNotification function to cancel the pending notification. If this call returns FALSE, SerCx2 expects the serial controller driver to call SerCx2PioReceiveReady; only after this call does SerCx2 call the EvtSerCx2PioReceiveCleanupTransaction event callback function, if it is implemented, and complete the request.

To cancel the ready notification, the EvtSerCx2PioReceiveCancelReadyNotification function typically disables the interrupt in the serial controller that indicates that more data is available to be read from the receive FIFO. This interrupt was enabled by a previous call to the EvtSerCx2PioReceiveEnableReadyNotification function.

For more information, see SerCx2 PIO-Receive Transactions.

Examples

To define an EvtSerCx2PioReceiveCancelReadyNotification callback function, you must first provide a function declaration that identifies the type of callback function you're defining. Windows provides a set of callback function types for drivers. Declaring a function using the callback function types helps Code Analysis for Drivers, Static Driver Verifier (SDV), and other verification tools find errors, and it's a requirement for writing drivers for the Windows operating system.

For example, to define an EvtSerCx2PioReceiveCancelReadyNotification callback function that is named MyPioReceiveCancelReadyNotification, use the EVT_SERCX2_PIO_RECEIVE_CANCEL_READY_NOTIFICATION function type, as shown in this code example:

EVT_SERCX2_PIO_RECEIVE_CANCEL_READY_NOTIFICATION  MyPioReceiveCancelReadyNotification;

Then, implement your callback function as follows:

_Use_decl_annotations_
BOOLEAN
  MyPioReceiveCancelReadyNotification(
    SERCX2PIORECEIVE  PioReceive
    )
  {...}

The EVT_SERCX2_PIO_RECEIVE_CANCEL_READY_NOTIFICATION function type is defined in the Sercx.h header file. To more accurately identify errors when you run the code analysis tools, be sure to add the Use_decl_annotations annotation to your function definition. The Use_decl_annotations annotation ensures that the annotations that are applied to the EVT_SERCX2_PIO_RECEIVE_CANCEL_READY_NOTIFICATION function type in the header file are used. For more information about the requirements for function declarations, see Declaring Functions by Using Function Role Types for KMDF Drivers. For more information about Use_decl_annotations, see Annotating Function Behavior.

Requirements

Requirement	Value
Minimum supported client	Available starting with Windows 8.1.
Target Platform	Desktop
Header	sercx.h
IRQL	Called at IRQL <= DISPATCH_LEVEL.