JDK-8147844 : new method j.l.Thread.onSpinWait() and the corresponding x86 hotspot instrinsic
  • Type: Sub-task
  • Component: hotspot
  • Sub-Component: compiler
  • Priority: P4
  • Status: Resolved
  • Resolution: Fixed
  • Submitted: 2016-01-20
  • Updated: 2017-05-17
  • Resolved: 2016-04-06
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 b120Fixed
Related Reports
Relates :  
JDK-8159532 - Investigate SPARC intrinsic for Thread.onSpinWait
Description
For details on the java.lang.Thread.onSpinWait() methods refer to the parent task.

This subtask adds a new method onSpinWait() to java.lang.Thread class with a legitimate implementation that is empty. A corresponding x86 hotspot intrinsic allows to actually benefit from this spin loop hint by injecting a 'pause' instruction into the c2 compiled code.
Comments
I still don't see the changeset a7aa11177232 promoted to the main hotspot repository. What kind of valhalla captured this changeset?
26-04-2016
The webrevs in Comment #1 were reflecting the proposal of onSpinWint method for the java.lang.Runtime class. The current proposal is to place this method in the Thread class.
24-02-2016
This Webrev passed the code review with core-libs team: http://cr.openjdk.java.net/~ikrylov/8147844.jdk.02 and this webrev passed the code review with the Hotspot team: http://cr.openjdk.java.net/~ikrylov/8147844.hs.03
22-02-2016