[jira] [Work logged] (CXF-8149) Reduce synchronization in AbstractJAXBProvider

["ASF GitHub Bot (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/CXF-8149?focusedWorklogId=340991&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-340991 ]

ASF GitHub Bot logged work on CXF-8149:
---------------------------------------

                Author: ASF GitHub Bot
            Created on: 10/Nov/19 01:06
            Start Date: 10/Nov/19 01:06
    Worklog Time Spent: 10m 
      Work Description: scsosna99 commented on pull request #596: CXF-8149 - Reduce synchronization in AbstractJXBProvider
URL: https://github.com/apache/cxf/pull/596
 
 
   Previous version did what I would consider a lot of gratuitous synchronization which can be reduced in a number of ways.
   
   First, use ConcurrentHashMap instead of straight HashMap for managing for tracking the contexts created for classes and packages.  At that point, we only need to do serialization when the collections don't already contain a context for the class or package.
   
   Second, move to a "ConcurrentHashSet" for collectionContextClasses.  Underlying this is a ConcurrentHashMap and is used by ConcurrentHashMap as the KeySet, so we can create one of these for the collectionContextClasses.  At that point, can again reduce synchronizations required.
   
   These changes were made locally at my company to address these synchronizations substantially slowing down some of our web services, and reducing synchronizations substantially improved throughput by - in most cases - reducing synchronizations and letting threads not block each other.
 
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Issue Time Tracking
-------------------

            Worklog Id:     (was: 340991)
    Remaining Estimate: 0h
            Time Spent: 10m

> Reduce synchronization in AbstractJAXBProvider 
> -----------------------------------------------
>
>                 Key: CXF-8149
>                 URL: https://issues.apache.org/jira/browse/CXF-8149
>             Project: CXF
>          Issue Type: Improvement
>          Components: JAX-RS
>    Affects Versions: 3.3.4
>            Reporter: Scott Sosna
>            Priority: Major
>          Time Spent: 10m
>  Remaining Estimate: 0h
>
> My company discovered that there was excessive blocking occurring which was tracked down to AbstractJAXBProvider doing synchronizations when checking various collections.  Instead, using ConcurrentHashMaps and other techniques, those synchronizations are only necessary when the collection in fact needs modifications, i.e., the first time a specific type is used.  After that, synchronizations are no longer required and multiple concurrent calls don't start blocking each other.



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