Please review
http://cr.openjdk.java.net/~iklam/jdk9/8150607_cleanup_compact_hashtable.v01/
Bug: Clean up CompactHashtable
https://bugs.openjdk.java.net/browse/JDK-8150607
Summary of fix:
[1] Instead of reading/writing the table bit-by-bit, which is tedious and
error prone, use SimpleCompactHashtable::serialize(), which is more
structural.
[2] Split up the _buckets and _entries into two separate arrays, so the
dumping and walking code is easier to understand
(see comments above SimpleCompactHashtable declaration)
These 2 arrays are now allocated from the RO region (used to be in RW)
[3] Renamed a few things
COMPACT_BUCKET_TYPE -> TINY_BUCKET_TYPE
(having something called "compact" in CompactHashtable is
confusing)
The old names "dump_table" (actually dumping the buckets) and
"dump_buckets" (actually dumping the entries) were conflicting with
terminology used elsewhere. Now the terminology is unified:
"buckets" = the main index, "entries" = the second level.
lookup_entry -> decode_entry (it wasn't doing any lookup)
[4] Changed all "*p++" to "array->at_put", so out-of-bounds can be
checked with assert.
[5] Replaced all juint to u4 (suggested by Coleen)
[6] templatize the iterator (see CompactHashtable::symbols_do ->
SimpleCompactHashtable::iterate)
[7] I also added a test case using Serviceability Agent -- due to the
lack of
a regression test, the walking of the compact hashtable in SA had been
broken for a while before it was fixed in JDK-8151368, so having a test
case would make the code more maintainable.
Tests:
Hotspot JTREG tests
Thanks
- Ioi
