RFR 8209387: Follow ups to JDK-8195100 Use a low latency hashtable for SymbolTable

[Gerard Ziemski]

Hi all,

Please review these couple small “cleanup” tasks as a followup to JDK-8195100 (Use a low latency hashtable for SymbolTable)

The first 2 of these affect both Symbol and String hashtables:

#1 We replace macros with constant constructs.

#2 We use “size_t" for counters, instead of “int”, to reduce the need of castings.

#3 I expanded on the comment for “mark_item_clean_count"

Please notice that:

A) “_alt_hash” is handled separately by https://bugs.openjdk.java.net/browse/JDK-8214449

B) I don’t personally agree with the 2nd point raised in this issue (i.e. placement of "assert that sym->refcount() == 0” in “delete_symbol”), so I’d like to leave the code as is.

Issue:   https://bugs.openjdk.java.net/browse/JDK-8209387
Webrev:  http://cr.openjdk.java.net/~gziemski/8209387_rev1
Testing: Mach5 hs_tier1,2,3,4,5


Cheers