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  1. JDK
  2. JDK-6666698

EnableBiasedLocking with BiasedLockingStartupDelay can block Watcher thread

    Details

    • Type: Bug
    • Status: Closed
    • Priority: P3
    • Resolution: Fixed
    • Affects Version/s: 7
    • Fix Version/s: hs12
    • Component/s: hotspot
    • Labels:
      None
    • Subcomponent:
    • Resolved In Build:
      b02
    • CPU:
      generic
    • OS:
      generic
    • Verification:
      Not verified

      Backports

        Description

        When run with -XX:+CacheTimeMillis the attached testcase appears to lose time because the cached time is not getting updated after ~4 seconds into the run.

        It is caused by the following. The EnableBiasedLocking PeriodicTask runs on the Watcher thread when BiasedLockingStartupDelay > 0. It attempts to synchronously reach a safepoint, blocking the watcher thread, after the delay. If a safepoint cannot be reached relatively quickly, since CacheTimeMillis relies on a responsive watcher thread, the cached time may not get updated promptly.

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                • Assignee:
                  sbohne Steve Bohne (Inactive)
                  Reporter:
                  sbohne Steve Bohne (Inactive)
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