castor

Improve synchronization/locking at TimeLimited cache

Details

  • Type: Sub-task Sub-task
  • Status: Resolved Resolved
  • Priority: Minor Minor
  • Resolution: Fixed
  • Affects Version/s: 1.3.2
  • Fix Version/s: 1.3.3rc1
  • Component/s: JDO
  • Labels:
    None
  • Number of attachments :
    3
  1. Text File
    patch-C3155-20110724.txt
    23/Jul/11 10:26 PM
    9 kB
    Wensheng Dou
  2. Text File
    patch-C3155-20110725.txt
    25/Jul/11 12:39 PM
    10 kB
    Ralf Joachim
  3. Text File
    patch-C3155-20110727.txt
    27/Jul/11 4:46 AM
    9 kB
    Ralf Joachim

Activity

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Wensheng Dou added a comment -

In this patch, use ConcurrentHashMap to improve the performance.

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Wensheng Dou added a comment - In this patch, use ConcurrentHashMap to improve the performance.
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Ralf Joachim added a comment -

Slightly improved patch.

At TimeLimited.put() the internal map has been accessed twice. This prevented some construction of QueueItem instances and therefore reduced garbage collection. While this was good idea when put method has been synchronized it could have produced unpredictable results without the synchronization. At least its difficult to understand what may happen.

This change also allowed some other improvements to QueueItemand tick() method.

What's your opinion on these changes?

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Ralf Joachim added a comment - Slightly improved patch. At TimeLimited.put() the internal map has been accessed twice. This prevented some construction of QueueItem instances and therefore reduced garbage collection. While this was good idea when put method has been synchronized it could have produced unpredictable results without the synchronization. At least its difficult to understand what may happen. This change also allowed some other improvements to QueueItemand tick() method. What's your opinion on these changes?
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Wensheng Dou added a comment -

Yes, very good improvement, thanks.
My patch made the code more difficult to understand, especially for the twice access and volitable value. Your improvement simplifies the code, and make it more understandable.

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Wensheng Dou added a comment - Yes, very good improvement, thanks. My patch made the code more difficult to understand, especially for the twice access and volitable value. Your improvement simplifies the code, and make it more understandable.
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Ralf Joachim added a comment -

Last patch has some problems if put() gets called during tick() method. New patch should solve this problem.

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Ralf Joachim added a comment - Last patch has some problems if put() gets called during tick() method. New patch should solve this problem.
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Wensheng Dou added a comment -

Yes, the new patch will work well. And the usage of putIfAbsent is very clever Thanks.

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Wensheng Dou added a comment - Yes, the new patch will work well. And the usage of putIfAbsent is very clever Thanks.

People

  • Assignee:
    Wensheng Dou
    Reporter:
    Ralf Joachim
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Dates

  • Created:
    Updated:
    Resolved: