RFR: 8324174: assert(m->is_entered(current)) failed: invariant

Vladimir Kozlov kvn at openjdk.org
Fri Jan 26 22:15:49 UTC 2024


When we fail re-allocate scalarized object during deoptimization we unlock all monitors in affected frames and throw OOM exception [JDK-6898462](https://bugs.openjdk.org/browse/JDK-6898462).
The unlocking was done in incorrect order starting from outermost monitor which cause this assert when we unlock following nested monitor (the same object) - it sees that it was already unlocked.

The fix is to start unlocking from most nested/inner monitor.
I also noticed that we have incorrect order of frames for re-locking during deoptimization. We should start from outermost frame. Inside frame re-locking order is correct - from outermost monitor.

Added regression test with deep nested locks.
Ran tier1-5, Xcomp, stress testing.

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Commit messages:
 - 8324174: assert(m->is_entered(current)) failed: invariant

Changes: https://git.openjdk.org/jdk/pull/17600/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17600&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8324174
  Stats: 150 lines in 2 files changed: 148 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/17600.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17600/head:pull/17600

PR: https://git.openjdk.org/jdk/pull/17600


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