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POHow to demonstrate java multithreading visibility problems?
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2010-05-07T08:08:12.503
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Body
If variables in Java are accessed from multiple threads, one must ensure that they are safely published. This usually means using <code>synchronized</code>or <code>volatile</code>. I have got the impression, that some of my colleagues do not take this issue seriously, since they "never heard of <code>volatile</code> before and their programs have worked for years". So my question is: Can someone provide an example Java program/snippet, that reliably shows data visibility problems. I think running a program and seeing the unexpected NPE or stale variable value would help more, than just theoretic explanations, that cannot be demonstrated. Thanks a lot for your help! Update: Just to emphasis the point again. I have read Java Concurreny in Practice and know examples that theoretically have visibility issues. What I am looking for is a way to actually demonstrate them. I am not sure, that this is actually possible, but maybe there is a jvm configuration or something similar that allows it. 
Tags
<java><multithreading><visibility>
Title
How to demonstrate java multithreading visibility problems?
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