[FreeRTOS+TCP API Reference]
BaseType_t FreeRTOS_closesocket( Socket_t xSocket );
Close a socket.
The function is named FreeRTOS_closesocket() rather than simply FreeRTOS_close() to avoid potential name space collisions with functions in FreeRTOS+IO.
A socket should be shutdown gracefully before it is closed, and cannot be used after it has been closed.
The handle of the socket being closed. The socket
must have already been created (see
and cannot be used after it has been closed.
0 is always returned.
Although FreeRTOS+TCP does not [currently] use the return value in a meaningful way, the return value is included in the function prototype to ensure consistency with the expected standard Berkeley sockets API, and to ensure compatibility with future versions of FreeRTOS+TCP.
/* FreeRTOS+TCP sockets include. */
void aFunction( void )
/* Create a socket. */
xSocket = FreeRTOS_socket( FREERTOS_AF_INET, FREERTOS_SOCK_DGRAM, FREERTOS_IPPROTO_UDP );
if( xSocket != FREERTOS_INVALID_SOCKET )
* The socket can now be used…
/* . . . */
/* Initialise a shutdown before closing the socket. */
FreeRTOS_shutdown( xSocket );
/* Wait for the socket to disconnect gracefully (indicated by FreeRTOS_recv()
returning a FREERTOS_EINVAL error) before closing the socket. */
while( FreeRTOS_recv( xSocket, pcBufferToTransmit, xTotalLengthToSend, 0 ) >= 0 )
/* Wait for shutdown to complete. If a receive block time is used then
this delay will not be necessary as FreeRTOS_recv() will place the RTOS task
into the Blocked state anyway. */
vTaskDelay( pdTICKS_TO_MS( 250 ) );
/* Note – real applications should implement a timeout here, not just
loop forever. */
/* Close the socket again. */
FreeRTOS_closesocket( xSocket );
Example use of the FreeRTOS_closesocket() API function