Arvados

The only concern is that is is possible the same port number can be returned by the following code if two different clients tried to get an available port before the passenger start is executed by one of those clients to use up that port. May be it is so rare and unlikely that we can live with it?

s = TCPServer.new('0.0.0.0', 0)
WEBSOCKET_PORT = s.addr[1]
s.close
SERVER_PID_PATH = "tmp/pids/passenger.#{WEBSOCKET_PORT}.pid" 

Other than that, LGTM.

Radhika Chippada wrote:

The only concern is that is is possible the same port number can be returned by the following code if two different clients tried to get an available port before the passenger start is executed by one of those clients to use up that port. May be it is so rare and unlikely that we can live with it?

Yes, I think we just have to live with this possibility. The "select available port" implementation (in linux at least) is randomized, so even in a race it's unlikely two processes will choose the same one.

We might be able to tell passenger to use port zero, and figure out which one it used by reading its logs or something, but it doesn't seem worth the effort at this point...

Sounds good to live with it. Thanks.