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  1. JDK
  2. JDK-8209139

globalCounter bootstrap issue

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: P3
    • Resolution: Fixed
    • Affects Version/s: 12
    • Fix Version/s: 12
    • Component/s: hotspot
    • Labels:
    • Subcomponent:
    • Resolved In Build:
      b20

      Description

      Followup to JDK-8195100 from Kim Barrett's feedback:

      src/hotspot/share/utilities/globalCounter.cpp
      64 // Handle bootstrap
      65 if (Threads::number_of_threads() == 0) {
      66 return;
      67 }

      What is this about? number_of_threads only refers to Java threads,
      but the iteration should deal with there being none, right? Or does
      this get called so early (because of SymbolTable changes) that even
      that iteration setup doesn't work?

      If not that, then maybe we're calling before the VMThread exists, and
      that's the real problem? In which case a different test, differently
      located, seems necessary.

      We needed it when I was bringing up the code and I tried removing it to see whether we still need it and it seems that we do (details on the crash in the bug itself). Maybe Robbin can shed more light here?

      The problem here is that we're using the StringTable (and therefore
      GlobalCounter) before the main thread has been registered. That
      registration happens in create_vm() (Threads::add(main_thread), line
      3729), which follows the call to init_globals() (where the symbol
      table usage is occurring) in create_vm().

      Maybe moving the Threads::add earlier would fix the problem? But this
      initialization code is very ordering sensitive, so I don't know if
      that would work.

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              • Assignee:
                rehn Robbin Ehn
                Reporter:
                gziemski Gerard Ziemski
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                • Created:
                  Updated:
                  Resolved: