[FreeRTOS Embedded IP Stack API]
xSocketSet_t FreeRTOS_CreateSocketSet( unsigned BaseType_t uxEventQueueLength );
Create a socket set for use with the FreeRTOS_select() function.
Socket Sets allow an application task to block when reading from multiple sockets at the same time. Instead of blocking on an individual socket, a task instead blocks on the set.
To use a socket set:
Create a socket set by calling FreeRTOS_CreateSocketSet().
A socket set is equivalent to the Berkeley sockets fd_set type.
Add one or more sockets to the set using calls to FreeRTOS_FD_SET().
FreeRTOS_FD_SET() is equivalent to the Berkeley sockets FD_SET() macro.
Call FreeRTOS_Select() to test the sockets in the set to see if any contain data that is
waiting to be read.
- Read from the socket returned by FreeRTOS_select() (if any) using a call to FreeRTOS_recvfrom() as normal.
FreeRTOS_FD_CLR() removes a socket from a set.
A receive event is generated each time a socket in the
socket set receives data. uxEventQueueLength sets the
maximum number of receive events that can be stored by
the socket set at any one time.
If a packet is received by a socket that is a member of a socket set, and the socket set’s event queue is full, then the packet will be dropped.
If the socket set was created then a handle to the created socket set is returned. If the socket set was not created (because there was insufficient FreeRTOS heap memory available) then NULL is returned.
See the example on the FreeRTOS_select() documentation page.