Re: How to acquire object's monitor optionally?

From:
Knute Johnson <nospam@rabbitbrush.frazmtn.com>
Newsgroups:
comp.lang.java.programmer
Date:
Sun, 28 Sep 2008 20:41:03 -0700
Message-ID:
<48e04e4a$0$28845$b9f67a60@news.newsdemon.com>
Chris wrote:

I've got a method that should run in a single-threaded manner. Many
threads need to execute this method, so I mark it synchronized. So far,
so good.

The trouble is, sometimes I want a thread to skip running the method if
another thread owns it already. If I attempt to execute the synchronized
method, the thread will just hang instead of continuing. Basically, I
want to do something like a tryLock().

I've tried implementing some complex locking schemes, including one
based on ReentrantLock, and another using a roll-your-own scheme with
AtomicBoolean. Each has failed for its own reasons. (I've got a lot of
hours in this).

What I really need is some simple way to try to acquire an object's
monitor and fail immediately if it can't. Possible?


Sounds like the perfect application for a semaphore.

--

Knute Johnson
email s/nospam/knute2008/

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