RFR(S): 8193933: Export ClassLoaderData claim state to support interleaved object traversal

[coleen.phillimore at oracle.com]

This bug is marked for JDK 10.  It is not appropriate to do this level 
of cleanup for JDK 10.

I have only looked through the classLoaderData.hpp changes and I don't 
agree with the gratuituous moving functions around.  I do like removing 
header files and adding forward declarations, when possible, but that's 
a smaller change.  Also a cleanup that should be done in JDK 11, not 10.

Thanks,
Coleen

On 12/21/17 9:14 AM, Markus Gronlund wrote:
> Greetings,
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> Kindly asking for reviews for the following changes:
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> Bug: https://bugs.openjdk.java.net/browse/JDK-8193933
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> Webrev: http://cr.openjdk.java.net/~mgronlun/8193933/webrev01/
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> Additional information about the changes:
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> The only semantically relevant change here is moving the following member functions from private to public:
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> .         bool clear_claimed();
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> .         bool claimed() const;
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> .         bool claim();
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> In addition, I took the opportunity to include a few cleanups that have accumulated over time:
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> For GC folks, removing unused headers from ClassLoaderData.hpp revealed some .cpp's having missing includes for "memory/metaspaceCounters.hpp".
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> .         genCollectedHeap.cpp
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> .         parallelScavengeHeap.cpp
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> .         g1MonitoringSupport.cpp
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> .         universe.cpp
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> Each have now received an #include "memory/metaspaceCounters.hpp"
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> Summary changes to ClassLoaderData.hpp:
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> .         Removed unused header includes
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> .         Removed tracing components (moved to classLoaderData.cpp)
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> .         Removed unused member functions
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> .         Migrated private member functions to classLoaderData.cpp where possible
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> .         Reduced to a single private section and a single public section
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> .         Removed unused static variables ReadOnly and ReadWrite metaspaces
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> .         Removed/introduced a few forward declarations
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> .         Some updated member functions now wrapped in Debug/Non-product declarations
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> .         A very short attempt to group declared functionality (iterators, handles, statics)
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> Summary changes ClassLoaderData.cpp:
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> I realize it is pretty hopeless to view the changes to ClassLoaderData.cpp via the webrev.
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> Basically the changes attempts to reduce the amount of interleaving regarding the member function definitions for ClassLoaderDataGraph vs ClassLoaderData vs Iterators.
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> Here is the updated class layout:
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> ClassLoaderData::Dependendencies;
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> ClassLoaderData::ChunkedHandleList;
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> ClassLoaderData
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> ClassLoaderDataGraph
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> Iterators
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> In addition, the member function definition order reflects (although not completely) the groupings in ClassLoaderData.hpp.
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> Thank you
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> Markus
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