uDIG

Double-checked locking is broken

Details

  • Type: Bug Bug
  • Status: Open Open
  • Priority: Minor Minor
  • Resolution: Unresolved
  • Affects Version/s: UDIG 1.1-RC14
  • Fix Version/s: UDIG 1.4.1
  • Component/s: framework
  • Labels:
    None

Description

The double checked locking idiom used in some tutorial classes is broken (see http://www.javaworld.com/jw-02-2001/jw-0209-double.html). This pattern must not be used anymore in any Java program, thus using it in tutorial code is misleading.

The attached patch fixes the code.

Activity

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Jesse Eichar added a comment -
you are correct. A simpler patch would be to make the resource and info objects volatile. In that case the double checked locking pattern does work (On Java 5+ virtual machines)... Although I tend to agree that it is a tricky pattern and shouldn't be commonly used
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Jesse Eichar added a comment - you are correct. A simpler patch would be to make the resource and info objects volatile. In that case the double checked locking pattern does work (On Java 5+ virtual machines)... Although I tend to agree that it is a tricky pattern and shouldn't be commonly used
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Jody Garnett added a comment -
With Java 5 including the concurrency packages can we make some progress on this one?
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Jody Garnett added a comment - With Java 5 including the concurrency packages can we make some progress on this one?

People

  • Assignee:
    Unassigned
    Reporter:
    Dirk Starke
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Dates

  • Created:
    Updated: