JDK-8246477 : add whitebox support for deflating idle monitors
  • Type: Sub-task
  • Component: hotspot
  • Sub-Component: runtime
  • Affected Version: 15
  • Priority: P4
  • Status: Resolved
  • Resolution: Fixed
  • OS: generic
  • CPU: generic
  • Submitted: 2020-06-03
  • Updated: 2024-11-13
  • Resolved: 2020-06-24
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JDK 16
16 b04Fixed
Related Reports
Relates :  
JDK-8249638 - Re-instate idle monitor deflation as part of System.gc()
Relates :  
JDK-8153224 - Monitor deflation prolong safepoints
Description
The fix for JDK-8153224 Monitor deflation prolong safepoints
includes several workarounds for invoking the safepoint
based deflation mechanism via a "special deflation request".
These workarounds are necessary for several tests that
expect certain operations, e.g., System.gc() or the whitebox
equivalents, to deflate idle monitors.

In order to remove the safepoint based deflation mechanism,
we have to provide an alternative whitebox APIs for those
tests that "know too much" about how things work.
Comments
Changeset: 3e4ad5d8 Author: Daniel D. Daugherty <dcubed@openjdk.org> Date: 2020-06-24 17:48:53 +0000 URL: https://git.openjdk.java.net/panama-foreign/commit/3e4ad5d8
02-07-2020
Changeset: 3e4ad5d8 Author: Daniel D. Daugherty <dcubed@openjdk.org> Date: 2020-06-24 17:48:53 +0000 URL: https://git.openjdk.java.net/amber/commit/3e4ad5d8
02-07-2020
Changeset: 3e4ad5d8 Author: Daniel D. Daugherty <dcubed@openjdk.org> Date: 2020-06-24 17:48:53 +0000 URL: https://git.openjdk.java.net/mobile/commit/3e4ad5d8
02-07-2020
URL: https://hg.openjdk.java.net/jdk/jdk/rev/6d462945718b User: dcubed Date: 2020-06-24 21:53:32 +0000
24-06-2020
Adding whitebox support for deflating idle monitors will allow the "special deflation request" mechanism to be removed. Early testing of my prototype has been promising and I haven't seen a single missed deflation related failure (so far).
15-06-2020