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  1. JDK
  2. JDK-8256382

Use try_lock for hs_err EventLog printing

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    Details

    • Type: Enhancement
    • Status: Resolved
    • Priority: P4
    • Resolution: Fixed
    • Affects Version/s: 16
    • Fix Version/s: 16
    • Component/s: hotspot
    • Labels:
      None
    • Subcomponent:
      gc
    • Resolved In Build:
      b27

      Description

      The EventLog locks are taken when the hs_err files are generated. Since crashes and asserts can occur when other locks are held, this can cause lock reordering problems if the held locks also are low-rank locks. There's no way to solve this if blocking locks are taken.

      I hit this problem when investigating making the GCLogPrecious lock use the lowest lock rank (same as EventLog).

      Both GCLogPrecious and EventLog are considered "leaf" locks. No other locks should be taken when those locks are taken. However, if we crash in either of these sub-systems, there will be a lock-reordering error message in the hs_err file, and the rest of the logged info is skipped in the currently logged section.

      The proposal is to use try_lock_without_range_check and only log information if the lock could be acquired without blocking. This relies on the new try_lock_without_range_check function from JDK-8255678.

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              Assignee:
              stefank Stefan Karlsson
              Reporter:
              stefank Stefan Karlsson
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                Created:
                Updated:
                Resolved: