Ivan, Can you elaborate on the issue with the thread local cleanup you've faced?
вт, 11 сент. 2018 г. в 9:13, Павлухин Иван <vololo...@gmail.com>: > Guys, > > As we know ThreadLocal is an instrument which should be used with great > care. And I recently faced with problems related to proper cleanup of > ThreadLocal which is not needed anymore. In my opinion the best thing (in > ideal world) is to get rid of ThreadLocal where possible, but I guess that > it is quite hard (in real world). > > Also, a question comes to my mind. As ThreadLocal is so common in our code, > could you suggest some guidance or code fragments which address proper > ThreadLocal > lifecycle control and especially cleanup? > > 2018-09-10 12:46 GMT+03:00 Alexey Goncharuk <alexey.goncha...@gmail.com>: > > > Maxim, > > > > Ignite supports starting multiple instances of Ignite in the same VM, so > > having static thread locals for the fields you mentioned does not work. > > > > Generally, I think thread-local should be bound to the lifespan of the > > component it describes. Static thread-locals are hard to clean-up and > they > > often lead to leaks, so I would rather changed existing static > > thread-locals to be non-static. > > > > --AG > > > > пн, 10 сент. 2018 г. в 11:54, Maxim Muzafarov <maxmu...@gmail.com>: > > > > > Igniters, > > > > > > According to javadoc [1] class ThreadLocal: > > > `ThreadLocal instances are typically private *static* fields in classes > > > that wish to associate state with a thread (e.g., a user ID or > > Transaction > > > ID).` > > > > > > So, AFAIK non-static ThreadLocal usage means as `per thread - per class > > > instance`. What the real cases of using non-static ThreadLocal class > > fields > > > in Ignite code project? When we need it? > > > > > > In Ignite code project I've found ThreadLocal usage as: > > > - non-static - 67 > > > - static - 68 > > > > > > Back to my example, I've checked FileWriteAheadLogManager. It has: > > > 1) private final ThreadLocal<Boolean> interrupted [2] > > > 2) private final ThreadLocal<WALPointer> lastWALPtr [3] > > > I think both of these fields should be set and used as `static`. Can > > anyone > > > confirm it? > > > > > > > > > [1] > https://docs.oracle.com/javase/8/docs/api/java/lang/ThreadLocal.html > > > [2] > > > > > > https://github.com/apache/ignite/blob/master/modules/ > > core/src/main/java/org/apache/ignite/internal/processors/ > > cache/persistence/wal/FileWriteAheadLogManager.java#L253 > > > [3] > > > > > > https://github.com/apache/ignite/blob/master/modules/ > > core/src/main/java/org/apache/ignite/internal/processors/ > > cache/persistence/wal/FileWriteAheadLogManager.java#L340 > > > -- > > > -- > > > Maxim Muzafarov > > > > > > > > > -- > Best regards, > Ivan Pavlukhin >
