SERCX_ACTIVITY structure

The SERCX_ACTIVITY structure contains a summary of work items that are ready for the serial controller driver to process.

Syntax


typedef struct _SERCX_ACTIVITY {
  ULONG   Size;
  BOOLEAN Transmitting;
  BOOLEAN Receiving;
} SERCX_ACTIVITY, *PSERCX_ACTIVITY;

Members

Size

The size, in bytes, of this structure. The SerCxGetActivity method uses this member to determine which version of the structure the caller is using. The size of this structure might change in future versions of the Sercx.h header file.

Transmitting

Whether a transmit (write) operation is in progress. This member is TRUE if a transmit operation is in progress. Otherwise, it is FALSE.

Receiving

Whether a receive (read) operation is in progress. This member is TRUE if a receive operation is in progress. Otherwise, it is FALSE.

Remarks

This structure must be initialized by the SERCX_ACTIVITY_INIT function before its initial use. Thereafter, calls to the SerCxGetActivity method update the contents of this structure to indicate the work that is currently pending.

The SERCX_ACTIVITY structure summarizes the pending work that the serial framework extension (SerCx) assigns to the serial controller driver. This work is driven by I/O requests from clients, but an I/O request does not necessarily spawn a work item. For example, if SerCx has a sufficient amount of received data in its memory buffer to complete a pending read request, this request does not cause the Receiving member of the SERCX_ACTIVITY structure to be set to TRUE.

Typically, SerCxGetActivity is called from the main loop of the transmit/receive DPC function in the serial controller driver. This function calls SerCxGetActivity, processes a complete transmit or receive operation, and then calls SerCxGetActivity again to determine whether an operation of another type requires work. If more work is available, the DPC function might perform this work before it returns.

Requirements

Version

Supported starting with Windows 8.

Header

1.0\Sercx.h

See also

SERCX_ACTIVITY_INIT
SerCxCompleteWait
SerCxGetActivity
SerCxProgressReceive
SerCxProgressTransmit

 

 

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