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https://issues.apache.org/jira/browse/IGNITE-1615?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Vladimir Ozerov resolved IGNITE-1615.
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Resolution: Won't Fix
This cannot be done because another node might update the value. So any local
optimizations do not work by default.
> .Net: Perform AtomicLong.get() without JNI if possible.
> -------------------------------------------------------
>
> Key: IGNITE-1615
> URL: https://issues.apache.org/jira/browse/IGNITE-1615
> Project: Ignite
> Issue Type: Task
> Components: interop
> Affects Versions: ignite-1.4
> Reporter: Vladimir Ozerov
> Fix For: ignite-1.5
>
>
> Variables with atomic/interlocked semantics are frequently used in
> mostly-read scenarios. E.g. in spin-loops, non-blocking alogrithms, as
> regular volatiles, etc..
> With current implementation we perform JNI call on every read which is too
> expensive, especially with poor Java performance when performing (native ->
> JVM) transition.
> We can optimize it with the following non-blocking algorithm:
> 1) Add atomic "stamp" field.
> 2) Add atomic "cached" field.
> 3) On any update:
> - Do the update;
> - Atomically increment the stamp;
> 4) On any read:
> - Read stamp (oldStamp);
> - Read cached value;
> - Read stamp again (newStamp);
> - if (oldStamp == newStamp == cache.stamp()), return cached value.
> - Otherwise perform real read through JNI and update cached value with a pair
> of (readValue + oldStamp);
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