RTCSERR_SOCK_ESHUTDOWN from select()

[emanueletrapani]

Hi, i use MQX 4.2, CW 10.6 and frdmk64f.

in my application, i stay in select() function waiting activity on the socket. i created this stream socket and i connect it to a remote server that is always running. sometimes the select() function return a error unexpected: 0x1719. it is unexpected because the server is always running and it not send any closing request. the freedom board is connected on a router that is connected on the network where the server stay.

i read the documentation of RTCS. In the chapter of select() function i see that it is explained that this error is returned from select() when happens "Abort request (remote host sends RST or unexpected SYN to us)".

My question is: what is the cause of this error? what means "unexpected SYN to us"?

[Martin_]

When you get this error code it means the stack has already closed the TCB (whatever reason). Most typical is RST received from connected peer, but it can also be a received SYN when a connection is already established.

As the TCB does not exists, your software has to closesocket(). It can also open a new connection to the server.