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IOCTL_SERIAL_SET_QUEUE_SIZE (Compact 2013)

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3/26/2014

This I/O control message requests that the queue sizes of a communications device are set. Send this message with DeviceIoControl.

Syntax

BOOL DeviceIoControl(
    HANDLE hDevice,           // handle to device
    DWORD dwIoControlCode     // use IOCTL_SERIAL_SET_QUEUE_SIZE
    LPVOID lpInBuffer,        // pointer to input buffer
    DWORD nInBufferSize,      // input buffer size
    LPVOID lpOutBuffer,       // pointer to output buffer
    DWORD nOutBufferSize,     // output buffer size
    LPDWORD lpBytesReturned,  // number of bytes returned
    OVERLAPPED lpOverlapped   // pointer to OVERLAPPED structure
);

Parameters

  • hDevice
    [in] Handle to the device.
  • dwIoControlCode
    [in] The control code for the operation. Use IOCTL_SERIAL_SET_QUEUE_SIZE for this operation.
  • nInBufferSize
    [in] sizeof(SERIAL_QUEUE_SIZES). Set to 0 (zero).
  • lpOutBuffer
    [in][out] Ignored; set to NULL.
  • nOutBufferSize
    [in] Ignored; set to 0 (zero).
  • lpBytesReturned
    [out] Ignored; set to 0 (zero).
  • lpOverlapped
    [in] Set to NULL.

Return Values

Returns TRUE if the message is sent successfully; otherwise, returns FALSE. To get extended error information, call GetLastError. Returning TRUE does not indicate that the parameters were actually set, merely that the request was made.

Remarks

This message is optional. Depending on the driver implementation, sending this message may not change the queue size. Queue size values are set at the platform dependent driver (PDD) level during initialization, and in most PDDs cannot be changed.

Requirements

Header

pegdser.h

See Also

Reference

Serial Port Driver IOCTLs
COM_IOControl
COM_Open
DeviceIoControl
SERIAL_QUEUE_SIZES