JEP Draft: Deprecate Memory-Access Methods in Sun.misc.Unsafe for Removal

• gc_less

  1 5 8.8 Java

  Experiments with JVM zero-allocation approaches

Nice.

Once I did some experiments at programming in Java using only sun.misc.Unsafe for a memory access: https://github.com/xonixx/gc_less. I was able to implement this way basic data structures (array, array list, hash table). I even explicitely set a very small heap and used Epsilon GC to make sure I don't allocate in heap.

Just recently I decided to check if it still works in the latest Java (23) and to my surprise it appears - it is. Now, apparently, this is going to change.

• 1brc

  28 5,077 9.9 Java

  1️⃣🐝🏎️ The One Billion Row Challenge -- A fun exploration of how quickly 1B rows from a text file can be aggregated with Java

In terms of performance: I realize that this is a somewhat "toy" issue, and it's a sample size of 1, but for the currently ongoing "One Billion Row Challenge"[1] (an ongoing Java performance competition related to parsing and aggregating a 13 GB file), all of the current top-performers are using Unsafe. More specifically, the use of Unsafe appears to have been the change for a few entries that allowed getting below the 3-second barrier in the test.

1. https://github.com/gunnarmorling/1brc

• WorkOS

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• Disruptor

  30 17,020 5.4 Java

  High Performance Inter-Thread Messaging Library

  

"Why we chose Java for our High-Frequency Trading application"

https://medium.com/@jadsarmo/why-we-chose-java-for-our-high-...

LMAX Disruptor customers

https://lmax-exchange.github.io/disruptor/

Among many other examples.

Suggest a related project