Path: csiph.com!x330-a1.tempe.blueboxinc.net!newsfeed.hal-mli.net!feeder3.hal-mli.net!nx02.iad01.newshosting.com!newshosting.com!69.16.185.11.MISMATCH!npeer01.iad.highwinds-media.com!news.highwinds-media.com!feed-me.highwinds-media.com!postnews.google.com!h25g2000prf.googlegroups.com!not-for-mail
From: Robert Stark <panxiaozhong@gmail.com>
Newsgroups: comp.lang.java.programmer
Subject: A quota based lock
Followup-To: comp.lang.java.programmer
Date: Mon, 8 Aug 2011 00:13:10 -0700 (PDT)
Organization: http://groups.google.com
Lines: 45
Message-ID: <83f81158-8aee-486d-a51b-c0f7dfdbb0da@h25g2000prf.googlegroups.com>
NNTP-Posting-Host: 205.177.226.156
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
X-Trace: posting.google.com 1312787590 12225 127.0.0.1 (8 Aug 2011 07:13:10 GMT)
X-Complaints-To: groups-abuse@google.com
NNTP-Posting-Date: Mon, 8 Aug 2011 07:13:10 +0000 (UTC)
Complaints-To: groups-abuse@google.com
Injection-Info: h25g2000prf.googlegroups.com; posting-host=205.177.226.156; posting-account=XnCmRgoAAABeRfo7PVUBJGDgHa3ZBNu6
User-Agent: G2/1.0
X-HTTP-Via: 1.1 SZXISA11-IN, 1.1 HKGOPR01-IN
X-Google-Web-Client: true
X-Google-Header-Order: VECRUHALSNK
X-HTTP-UserAgent: Mozilla/5.0 (Windows NT 5.1; rv:5.0) Gecko/20100101 Firefox/5.0,gzip(gfe)
Xref: x330-a1.tempe.blueboxinc.net comp.lang.java.programmer:6862

I want to write a lock to control access to a resource, there are
different kind of jobs using this resource, say job A,B,C, at the
beginning, i use Lock api from jdk concurrent package, but i suffered
from serious job starvation, so i want to do something like this:

class T LockManager<T extends Enum>{
      //the input is like this, A=>20, B=>70, C=>10, assign quota to
different jobs
      public LockManager(Map<T,Integer> quota){

       }

       private void lock(T type){......}

       private void unlock(T type){........}

       public Lock getLock(T type){
            return new QutaLock(type);
       }

       public class QutaLock implements Lock{
             public QutaLock(T type){
                    .....
              }

              public void lock(){.....}
              public void unlock(){.........}
             ......
       }

}

My idea is input a map of percentages you want to assign for each job,
and provide a simple lock api.

Input  A=>20, B=>70, C=>10 means A=>20%, B=>70%, C=>10%
If there's no A jobs pending on the lock, then its quota would be
divided evenly to other pending jobs that is B=>80%, C=>20%.(This rule
apply to other type of jobs as well).

Then i got stuck, the only way i can think about is to introduce an
extra dispatch thread and several queues, can someone give me some
hint?