FreeRTOS_ReleaseUDPPayloadBuffer()

[FreeRTOS+TCP API Reference]

FreeRTOS_sockets.h

void FreeRTOS_ReleaseUDPPayloadBuffer( void *pvBuffer );
		

FreeRTOS_ReleaseUDPPayloadBuffer() is used to return to the TCP/IP stack a buffer that was used with the zero copy interface.

The zero copy interface for transmitting data is described on the FreeRTOS_sendto() documentation page.

The zero copy interface for receiving data is described on the FreeRTOS_recvfrom() documentation page.

A buffer needs to be returned to the stack if:

1. It is obtained from a call to FreeRTOS_recvfrom() and the data it contains is no longer required, or

2. It was obtained from a call to FreeRTOS_GetUDPPayloadBuffer() but the buffer could not be passed into the TCP/IP stack (the call to FreeRTOS_sendto() in which the buffer was used failed).

A buffer can also be re-used rather than returned to the TCP/IP stack.

Parameters:

pvBuffer

The buffer that is being returned to the TCP/IP stack.

Example usage:

The FreeRTOS_sendto() documentation page includes an example zero copy send operation that demonstrates how to use FreeRTOS_ReleaseUDPPayloadBuffer() when the send operation fails.

the FreeRTOS_recvfrom() documentation page includes an example that demonstrates how to use FreeRTOS_ReleaseUDPPayloadBuffer() to release a buffer obtained from a call to FreeRTOS_recvfrom().