Re: [PATCH] mirrorlist_client.wsgi use select() waiting for server

[Mike McGrath]

On Wed, 12 May 2010, Ricky Zhou wrote:

>  On 2010-05-12 09:07:35 AM, Matt Domsch wrote:
>  > >From 7cd05b296ab426c386e99c3ff6f7143fbf6ed052 Mon Sep 17 00:00:00 2001
>  > From: Matt Domsch <Matt_Domsch(a)dell.com&gt;
>  > Date: Wed, 12 May 2010 08:59:16 -0500
>  > Subject: [PATCH] mirrorlist_client: use select() waiting on the response from
> mirrorlist_server
>  >
>  > Client was spinning waiting for read() to complete, during the time
>  > the server was doing its thinking.  Instead, use select() to sleep
>  > until the server has data to return.  This should reduce CPU time
>  > spent in the client considerably.
>  > ---
>  >  mirrorlist-server/mirrorlist_client.wsgi |   15 ++++++++++-----
>  >  1 files changed, 10 insertions(+), 5 deletions(-)
>  >
>  > diff --git a/mirrorlist-server/mirrorlist_client.wsgi
> b/mirrorlist-server/mirrorlist_client.wsgi
>  > index cc4416c..15b3a15 100755
>  > --- a/mirrorlist-server/mirrorlist_client.wsgi
>  > +++ b/mirrorlist-server/mirrorlist_client.wsgi
>  > @@ -4,7 +4,7 @@
>  >  #  by Matt Domsch <Matt_Domsch(a)dell.com&gt;
>  >  # Licensed under the MIT/X11 license
>  >
>  > -import socket
>  > +import socket, select
>  >  import cPickle as pickle
>  >  from string import zfill, atoi, strip, replace
>  >  from paste.wsgiwrappers import *
>  > @@ -32,24 +32,29 @@ def get_mirrorlist(d):
>  >      s.shutdown(socket.SHUT_WR)
>  >      del p
>  >
>  > +    # wait for other end to start writing
>  > +    expiry = datetime.utcnow() + timedelta(seconds=request_timeout)
>  > +    rlist, wlist, xlist = select.select([s],[],[],request_timeout)
>  > +    if len(rlist) == 0:
>  > +        s.shutdown(socket.SHUT_RD)
>  > +        raise socket.timeout
>  > +
>  >      readlen = 0
>  >      resultsize = ''
>  >      while readlen < 10:
>  >          resultsize += s.recv(10 - readlen)
>  >          readlen = len(resultsize)
>  >      resultsize = atoi(resultsize)
>  > -
>  > -    expiry = datetime.utcnow() + timedelta(seconds=request_timeout)
>  > +
>  >      readlen = 0
>  >      p = ''
>  >      while readlen < resultsize and datetime.utcnow() < expiry:
>  >          p += s.recv(resultsize - readlen)
>  >          readlen = len(p)
>  > -
>  > -    s.shutdown(socket.SHUT_RD)
>  >      results = pickle.loads(p)
>  >      del p
>  >
>  > +    s.shutdown(socket.SHUT_RD)
>  >      return results
>  >
>  >  def real_client_ip(xforwardedfor):
>  > --
>  > 1.7.0.1
>  +1
>  
+1

	-Mike