Description:
------------
stream_set_timeout($udp, 0,300); 
just like 
stream_set_timeout($udp, 0);
it ignore the third parameter
strace the process:
poll([{fd=3, events=POLLIN|POLLERR|POLLHUP, revents=POLLERR}], 1, 0) = 1

Reproduce code:
---------------
<?php
$udp = stream_socket_client("udp://127.0.0.1:3434");
fwrite($udp,'xx');
stream_set_timeout($udp, 0,300);
$time = microtime(true);
fread($udp,1500);
echo microtime(true) - $time;

Expected result:
----------------
0.30182409286499

Actual result:
--------------
3.3140182495117E-5