FreeRTOS+TCP sockets in multiple threads.

captainjerk wrote on Thursday, July 14, 2016:

Hello.
What I want to achieve is to have multiple threads, each responsible for its own protocol. I am starting two threads and initialize two queues (Q1, Q2) (to pass the messages through them). Upon receiveing the message from queue, thread is supposed to open a socket, dump the message and eventually close the connection. What actually happens is, when I post messages like this:
xQueueSend(Q1, msg1, 0)
delay
xQueueSend(Q2, msg2, 0)
Everything works and both remote servers receive messages, but if no delay inserted, then one thread (I guess the one that calls FreeRTOS_connect later) fails to connect (connect() always returns ERRNO_TIMEOUT). What could be wrong? Does not sockets supposed to work simultaneous?

rtel wrote on Thursday, July 14, 2016:

I’m afraid there is not enough information in your post to fully
understand your usage scenario, or how you are using the sockets, to be
able to provide a full answer.

As far as using sockets from multiple threads go:

Any number of threads (tasks) can use FreeRTOS+TCP at any time, however
there is a restriction on how tasks can share a single socket as
follows: If you use the SAME socket from more than one thread then only
one of the threads can write to the socket and only one of the threads
can read from the socket - you can not have more than one thread both
reading to and writing from the SAME socket.