JDK-8026977 : NPG: Remove ConstantPool::lock
  • Type: Bug
  • Component: hotspot
  • Sub-Component: runtime
  • Priority: P3
  • Status: Closed
  • Resolution: Fixed
  • Submitted: 2013-10-21
  • Updated: 2014-07-17
  • Resolved: 2014-06-19
The Version table provides details related to the release that this issue/RFE will be addressed.

Unresolved : Release in which this issue/RFE will be addressed.
Resolved: Release in which this issue/RFE has been resolved.
Fixed : Release in which this issue/RFE has been fixed. The release containing this fix may be available for download as an Early Access Release or a General Availability Release.

To download the current JDK release, click here.
JDK 9
9 b23Fixed
Related Reports
Relates :  
JDK-8047290 - Make Mutex::_no_safepoint_check_flag locks verify that this lock never checks for safepoint
Relates :  
JDK-8008962 - NPG: Memory regression: One extra Monitor per ConstantPool
Description
The use of locks of constant pool could raise memory usage (see JDK-8014910) or cause deadlock (see JDK-8008962).

Let's try to remove the lock altogether. Much of the existing operation (see CPSlot class) is already lock free.
Comments
Why is this changed from Bug to RFE? This is still a regression in JDK8 that we have not fixed. The affects version should include 8.
12-02-2014
Release team: Approved for deferral to 8-pool
25-10-2013
SQE: Agrees this change is too risky given proximity to the final release
21-10-2013