Return-Path: william@bourbon.usc.edu
Delivery-Date: Fri Sep 19 22:23:09 2008
X-Spam-Checker-Version: SpamAssassin 3.2.3 (2007-08-08) on merlot.usc.edu
X-Spam-Level: 
X-Spam-Status: No, score=-2.3 required=5.0 tests=AWL,BAYES_00 autolearn=ham
	version=3.2.3
Received: from bourbon.usc.edu (bourbon.usc.edu [128.125.9.75])
	by merlot.usc.edu (8.14.1/8.14.1) with ESMTP id m8K5N9N3018996
	for <cs551@merlot.usc.edu>; Fri, 19 Sep 2008 22:23:09 -0700
Received: from bourbon.usc.edu (localhost.localdomain [127.0.0.1])
	by bourbon.usc.edu (8.14.2/8.14.1) with ESMTP id m8K5OwCD023034
	for <cs551@merlot>; Fri, 19 Sep 2008 22:24:58 -0700
Message-Id: <200809200524.m8K5OwCD023034@bourbon.usc.edu>
To: cs551@merlot.usc.edu
Subject: Re: CSC551
Date: Fri, 19 Sep 2008 22:24:58 -0700
From: Bill Cheng <william@bourbon.usc.edu>

Someone wrote:

  > The timeout for the select() and pthread_cond_timewait() is the
  > value returned by the getinterval() call. This value is converted
  > to the right units and the simulation works fine with expected
  > results( i.e. close to calculated values) but consumes too much
  > CPU cycle.

If these threads are sleeping and your process is eating up
CPU time, it must be other threads in your process that's
eating up CPU time!  What are your other threads doing?
--
Bill Cheng // bill.cheng@usc.edu <URL:http://merlot.usc.edu/william/usc/>




  ----- Original Message ----
  From: Bill Cheng <william@bourbon.usc.edu>
  To: cs551@merlot.usc.edu
  Sent: Friday, September 19, 2008 8:42:42 PM
  Subject: Re: CSC551
  
  Someone wrote:
  
    > I have tried using  select() and  pthread_cond_timedwait() to
    > wait but my process still consumes a lot of CPU cycles. I
  always
    > broadcast the condition mutex before calling any of these
    > functions.Every thread goes into a while loop which loops
  until
    > all arrivals have taken place and are serviced except if
    > interrupted with a cntrl+C. Is there anything else I can do
  to
    > reduce the CPU usage?
  
  What's the timeout for your select() and pthread_cond_timewait()?
  --
  Bill Cheng // bill.cheng@usc.edu
  <URL:http://merlot.usc.edu/william/usc/>