persistant socket differs in behavior from php

pfsockopen on the same port in php allows file descriptor reuse.
hhvm does not reuse sockets

http://pastebin.com/e5jhmGUT test case. Requires a memcached server locally to test with.

expected results:
int(X) _repeated 5 times_
int(Y) _repeated 5 times_

php --version
PHP 5.5.21-1~dotdeb.1 (cli) (built: Feb 1 2015 19:51:51)
Results:
int(X) _repeated 5 times_
int(Y) _repeated 5 times_

hhvm --version
HipHop VM 3.6.0 (rel)
Compiler: tags/HHVM-3.6.0-0-g6ef13f20da20993dc8bab9eb103f73568618d3e8
Repo schema: 3ab6576af394a33abbb29796c652f06b1c7640ce

int(5 different numbers)
int(5 different numbers)