I should also note that this doesn't appear to be due to HHVM's lack of garbage collection, these objects arn't destroyed at the right time in php5 when forcing garbage collection pre-fork either.

Oh fun. Forking is a huge pain. Maybe it makes sense to use hhvm's work api thing. I forget what it is called and don't know if it'd be better. Maybe we just ignore these.

hhvm has a couple different methods for that: xbox server, pagelet server, and rpc server. All of them only work when in server mode, not cli, so probably not worth the effort.

Actually it looks like pagelet server is available from CLI, but would have to be enabled either in the global config file, or via some extra commandline options:

hhvm -vServer.SourceRoot=$PWD -vPageletServer.ThreadCount=5 foo.php

<?php

if(empty($_GET['pagelet'])) {
        $task = pagelet_server_task_start("foo.php?pagelet=1", array(), '');
        var_dump( pagelet_server_task_result( $task, $headers, $code, 1000) );
} else {
        echo "Hello from pagelet!";
}

I could poke at this and turn it into something similar to the ForkController, but i wonder if the requirements for extra CLI options is going to make it more trouble than its worth for most installations.

seems i spoke too soon, xbox server works too :)

hhvm -vXbox.ServerInfo.RequestInitDocument=$PWD/foo.php foo.php

if(empty($_SERVER['THREAD_TYPE'])) {
        $t = xbox_task_start('1');
        xbox_task_result($t, 0, $r);
        var_dump($r);
} else {
        function xbox_process_message($msg) {
                return "In xbox: $msg";
        }
}

I'm ok with saying that multi-process reindexing is an hhvm only thing so
long as that actually makes it simpler.

Change 257059 had a related patch set uploaded (by Aaron Schulz):
Make ForkController destroy redis instances too

https://gerrit.wikimedia.org/r/257059

Change 257059 merged by jenkins-bot:
Make ForkController destroy redis instances too

https://gerrit.wikimedia.org/r/257059