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Andrey Kuznetsov commented on IGNITE-6736: ------------------------------------------ Choosing ReentrantLock approach. See [1]. [1] http://apache-ignite-developers.2346864.n4.nabble.com/Separate-code-paths-for-Java-8-and-Java-9-tp25289p25291.html > Java 9: rework GridCacheMapEntry synchronization logic to avoid > Unsafe.monitor* methods > --------------------------------------------------------------------------------------- > > Key: IGNITE-6736 > URL: https://issues.apache.org/jira/browse/IGNITE-6736 > Project: Ignite > Issue Type: Task > Components: cache > Reporter: Vladimir Ozerov > Fix For: 2.4 > > > {{GridCacheMapEntry}} class rely on {{synchronized}} on itself heavily. In > {{ATOMIC}} caches we lock multiple entries at once using > {{Unsafe.monitorEnter/Exit}} methods. Unfortunately these methods were > removed in Java 9. Recursion is not an option, as it would cause stack > overflow for {{putAll}} operations with multiple entries. > Possible fixes: > 1) Rework {{synchronized}} to {{ReentrantLock}}. Easy, but may cause > additional memory pressure. > 2) Have different implementations for Java 8 ({{synchronzied}}) and Java 9 > ({{ReentrantLock}}) - much more complex solution, because we will require > separate module for Java 8 and Java 9. > 3) Rework {{ATOMIC}} caches, so that {{putAll}} operation updates entries > one-by-one. As a side effect it will eliminate deadlocks. -- This message was sent by Atlassian JIRA (v6.4.14#64029)