Re: Multithreading one-at-a-time-problem

From:

Lew <lew@lewscanon.com>

Newsgroups:

comp.lang.java.programmer

Date:

Tue, 09 Oct 2007 18:40:51 -0400

Message-ID:

<BvednXca0O3unpHanZ2dnUVZ_smnnZ2d@comcast.com>

Morty wrote:

public void run() {
  while (this.countValue < this.maxValue) {
  System.out.println(this.getName()+" value "+this.countValue);
  this.countValue++;
  yield();
}
}
}

Lew wrote:

'yield()' is a static method. To avoid confusion, always invoke static
entities through their class, thus:

Thread.yield();

And that might not even help you, since yield() is not guaranteed to cause a
thread to yield its timeslice.

Thread.yield is a purely heuristic hint advising the JVM that
if there are any other runnable but non-running threads, the
scheduler should run one or more of these threads rather than
the current thread.
The JVM may interpret this hint in any way it likes.

<http://g.oswego.edu/dl/cpj/mechanics.html>
excerpted from Doug Lea's excellent /Concurrent Programming in Java/, which
goes on to say,

On JVM implementations that employ pre-emptive scheduling
policies, especially those on multiprocessors, it is possible
and even desirable that
the scheduler will simply ignore this hint provided by yield.

--
Lew