detect client disconnect about ws HOT 3 CLOSED

thanks! i'm try to integrate ping/pong

from ws.

Hello!

So, am I understand it right, that conn is a tcp socket?
Thus, it depends on how client closes its connections – if it does just tcpconn.Close() (say, linux close() syscall), then you will receive error on your further Write() call. If client closes its connection gracefully with tcpconn.CloseWrite() (say, linux shutdown() syscall), then your Write() will still receive no error. Furthermore, if you doing your Write() calls not so frequently, even if client did close(), your socket and the main i/o loop will be active until you prepare next Write() call.

So my suggestion is to use additional goroutine that reads, say, 1 byte from client connection and when it returns io.EOF it means that client gone somehow. After that you could stop reading from ptmx (for example by killing spawned cmd) and return from the main loop.

Advanced solution may be to use epoll instance to handle events on multiple clients in one goroutine handler and close theirs cmd instances on io.EOF.

Other way to solve this issue is to implement simple ping/pong messaging at WebSocket layer or your application layer. WebSocket protocol provides ping/pong mechanism, which is also helpful when client disappeared due to network problems. When network down, that Read() approach will not work until tcp keepalive is used. So you may use WebSocket ping/pong messaging instead of tcp keepalive to solve both problem with client shutdown and with the network consistency.

from ws.

if that closes automatically by receiving 1005 from ws. should i still prepare to make ping pong message too?

1005 | No Status Recvd | Reserved.  Indicates that no status code was provided even though one was expected.
-- | -- | --

https://developer.mozilla.org/en-US/docs/Web/API/CloseEvent

from ws.