Excerpts from Yuya Nishihara's message of 2017-02-28 01:02:23 +0900:
> On Wed, 22 Feb 2017 18:16:10 -0800, Jun Wu wrote:
> > # HG changeset patch
> > # User Jun Wu <qu...@fb.com>
> > # Date 1487813979 28800
> > # Wed Feb 22 17:39:39 2017 -0800
> > # Node ID 28571825744fb4f4b424385f55afa9484532ef43
> > # Parent 630457e88fa0485bce7822345ea640b5cdcb9b8e
> > # Available At https://bitbucket.org/quark-zju/hg-draft
> > # hg pull https://bitbucket.org/quark-zju/hg-draft -r
> > 28571825744f
> > chgcache: implement the background preloading thread
> >
> > The background preloading thread is meant to used by chg master, and it sets
> > up the IPC channel.
> >
> > diff --git a/mercurial/chgcache.py b/mercurial/chgcache.py
> > --- a/mercurial/chgcache.py
> > +++ b/mercurial/chgcache.py
> > @@ -13,4 +13,5 @@ import select
> > import socket
> > import termios
> > +import threading
> > import time
> >
> > @@ -87,2 +88,51 @@ def reportrepopaths():
> > for path in _localrepopaths:
> > _ipc.send('%s %s' % (now, path))
> > +
> > +# -- only used by the master
> > --------------------------------------------------
> > +
> > +def _initipc():
> > + """initialize and return the global IPC object"""
> > + global _ipc
> > + if _ipc is None:
> > + _ipc = socketipc()
> > + return _ipc
> > +
> > +class preloader(object):
> > + """background thread doing the actual preloading work"""
> > +
> > + def __init__(self):
> > + self._ipc = _initipc()
> > + self._shouldexit = threading.Event()
> > + self._thread = None
> > +
> > + def start(self):
> > + if self._thread is not None:
> > + self.stop()
> > + self._thread = threading.Thread(target=self._preloadloop,
> > + name='chgcache.preloader')
> > + self._thread.daemon = True
> > + self._thread.start()
>
> If start() designed to be called more than once, _shouldexit should be
> cleared.
Practically, it's probably not called more than once.
> > + def stop(self):
> > + if self._thread is None:
> > + return
> > + self._shouldexit.set()
> > + self._ipc.send('') # unblock (possibly blocking) recv()
>
> Ok, that will work though I'm not a fan of it.
>
> Perhaps a cleaner way is to move recv() to the main loop of the server,
> and deliver received messages via thread-safe queue + event. But that will
> need more codes.
That sounds over complicated. Maybe shm is a better approach (no atime
needed, no blocking / close issues, need extra code to write "atomically"
but that's not hard)
> > + def _preloadloop(self, interval=0.5):
> > + while not self._shouldexit.is_set():
> > + try:
> > + atimestr, path = self._ipc.recv().split(' ', 1)
> > + atime = float(atimestr)
>
> recv() will block the thread with no timeout, so the interval is useless?
Sorry - interval was left from the shm code. It should be removed.
_______________________________________________
Mercurial-devel mailing list
Mercurial-devel@mercurial-scm.org
https://www.mercurial-scm.org/mailman/listinfo/mercurial-devel
