FreeRTOS_closesocket()

[FreeRTOS+TCP API Reference]

FreeRTOS_sockets.h
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.

Parameters:

xSocket   The handle of the socket being closed. The socket must have already been created (see FreeRTOS_socket()), and cannot be used after it has been closed.

Returns:

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.

Example usage:


/* FreeRTOS+TCP sockets include. */
#define “FreeRTOS_sockets.h”

void aFunction( void )
{
Socket_t xSocket;

/* 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