[GitHub] [flink] azagrebin opened a new pull request #9747: [FLINK-13985] Use native memory for managed memory

[GitBox <gi...@apache.org>]

azagrebin opened a new pull request #9747: [FLINK-13985] Use native memory for managed memory
URL: https://github.com/apache/flink/pull/9747
 
 
   ## What is the purpose of the change
   
   This PR introduces allocation of off-heap memory independent of direct buffers and limiting option `-XX:MaxDirectMemorySize`. This implementation uses `sun.misc.Unsafe` for that purpose.
   
   ## Brief change log
   
    - Make tests use `MemorySegmentFactory` to create `MemorySegment` and remove shorthand constructors of `HybridMemorySegment` in favour of `MemorySegmentFactory` methods.
    - Add allocate/release unsafe memory methods to `MemoryUtils`
     - Add a `MemoryUtils#createMemoryGcCleaner` to release memory in phantom reference queue upon GC of the memory owning object (based on `sun.misc.Cleaner` similar to `java.nio.DirectByteBuffer(int cap)`).
     - Add `MemoryUtils#wrapUnsafeMemoryWithByteBuffer` which uses the private constructor `java.nio.DirectByteBuffer(long address, int cap)` to wrap unsafe memory but w/o checking `-XX:MaxDirectMemorySize`.
    - Add an optional custom action to call in `HybridMemorySegment#free` for memory cleanup
    - Change `MemorySegmentFactory#allocateUnpooledOffHeapMemory` to allocate unsafe memory, wrap it with ByteBuffer with `MemoryUtils#wrapUnsafeMemoryWithByteBuffer`, hook a phantom reference queue cleaner upon the buffer GC and create `HybridMemorySegment` with this buffer and its custom cleaner.
   
   ## Verifying this change
   
   Units tests.
   
   ## Does this pull request potentially affect one of the following parts:
   
     - Dependencies (does it add or upgrade a dependency): (no)
     - The public API, i.e., is any changed class annotated with `@Public(Evolving)`: (no)
     - The serializers: (no)
     - The runtime per-record code paths (performance sensitive): (no)
     - Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Yarn/Mesos, ZooKeeper: (no)
     - The S3 file system connector: (no)
   
   ## Documentation
   
     - Does this pull request introduce a new feature? (no)
     - If yes, how is the feature documented? (not applicable)
   

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