[NETBEANS-6458] A bogus Cyclic Reference issue is resolved by marking fields as volatile. #3635
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JaroslavTulach
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I am usually ashamed when I look back at my old multithreaded code after all those years. This is the case as well. The code using FolderInstance was randomly failing for many years, should your change fix that, then you deserve tons of kudos, Martine!
Making as much fields final is the best option. Some of the fields however have to be mutable. There is some synchronize(this) guard for some and the question is whether more appropriate to guard more fields by this or make more fields volatile?
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In the GraalVM debugging tests (
java/debugger.jpda.truffle) there was often a Cyclic reference issue fromFolderInstance.It turned out, that there was not really any cyclic reference, but as the field
waitForwas not marked as volatile, the code sometimes did not see the new value updated by the creation task.By marking the fields as
volatilewe assure that their updated values are seen by other threads.