DirectByteBuf implementations should not force free memory #893
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Motivation: ServiceTalk doesn't expose reference counting and relies upon GC for memory reclamation. Buffer objects are resizable an in the event a buffer is resized (e.g. a write operation needs to expand the buffer) this will result in allocating new memory and Netty will attempt to deallocate the old memory. Applications may be multi-threaded and it is possible another thread will still have a reference to this old memory location due to visibility constraints. We should prevent Netty from force-freeing this old memory and instead rely upon GC to avoid undefined behavior. Modifications: - ServiceTalk DirectByteBuf implementations to override freeDirect(ByteBuffer) and do nothing. Result: Less risk for resize operation resulting in referencing freed memory.
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this change is mostly reverted by #894 after discussion on netty/netty#9850 |
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Motivation:
ServiceTalk doesn't expose reference counting and relies upon GC for memory
reclamation. Buffer objects are resizable an in the event a buffer is resized
(e.g. a write operation needs to expand the buffer) this will result in
allocating new memory and Netty will attempt to deallocate the old memory.
Applications may be multi-threaded and it is possible another thread will still
have a reference to this old memory location due to visibility constraints. We
should prevent Netty from force-freeing this old memory and instead rely upon GC
to avoid undefined behavior.
Modifications:
and do nothing.
Result:
Less risk for resize operation resulting in referencing freed memory.