Bug ID: JDK-8048248 [Backed out] G1 Class Unloading after completing a concurrent mark cycle

JDK-8048248 : [Backed out] G1 Class Unloading after completing a concurrent mark cycle

Type: Enhancement
Component: hotspot
Sub-Component: gc
Affected Version: 9

Priority: P2
Status: Resolved
Resolution: Fixed

Submitted: 2014-06-26
Updated: 2014-08-29
Resolved: 2014-07-07

Versions (Unresolved/Resolved/Fixed)

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Resolved: Release in which this issue/RFE has been resolved.
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JDK 9
9 b24Fixed

Related Reports

Cloners :	JDK-8049421 - G1 Class Unloading after completing a concurrent mark cycle
Relates :	JDK-8049420 - Backout 8048248 to correct attribution
Relates :	JDK-8048268 - G1 Code Root Migration performs poorly
Relates :	JDK-8015332 - G1: Interned strings with no references only garbage collected upon full GC.
Relates :	JDK-8048269 - Add flag to turn off class unloading after G1 concurrent mark

Description

[This bug was backed out and pushed as JDK-8049421 instead]

Currently G1 treats all classes as live except for during full gcs.

Modify the concurrent marking code to keep track of liveness of classes in order to be able to unload unreachable classes at the remark pause.
This involves reusing the infrastructure used by CMS to follow the object headers to find live classes.

Comments

This bug (JDK-8048248) was pushed with a missing Contributed-by line and was therefore backed out as JDK-8049420. JDK-8049421 is a resubmit with the correct attribution.

07-07-2014