[AVRO-1283] remove static caches from GenericData, SpecificData and ReflectData

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: java
• Assignee: Unassigned
• Reporter: Doug Cutting
• Created: 22/Mar/13 23:13
• Updated: 30/Dec/18 04:17

Description

Currently GenericData, ReflectData and SpecificData are often treated as singletons, through an instance returned by a static get() method. Because of this, the caches they have must be thread-safe and are also memory leaks.

Increasingly of late, new instances of these are allocated for use by a given DatumReader or DatumWriter. This issue explores whether we can:

• Change the static get() methods to always return new instances, so that each DatumReader and DatumWriter has its own instance. Since DatumReader and DatumWriter are not thread-safe, the thread safety requirement could then be removed from caches, increasing their performance; and
• Change caches to be non-static, to remove potential memory leaks.

Issue Links

• is related to: AVRO-1277 Improve performance of reflection-based serializers
• is related to: AVRO-1282 Make use of the sun.misc.Unsafe class during serialization if a JDK supports it