RFR: [6904367]: (coll) IdentityHashMap is resized before exceeding the expected maximum size

[Jeff Hain]

>Here is the updated webrev:
>http://cr.openjdk.java.net/~igerasim/6904367/2/webrev/

There is another bug with the initial implementation:
if put throws, the element is still put (and the size incremented accordingly),
and if putting a new mapping after the throwing one, the table gets full
and get()/put()/remove() become subject to infinite loop.
(and my idea that size was not supposed to go past MAX_CAPACITY was false in that case :-)

With the new implementation, if put throws, the map is not modified
(not even modCount) so it doesn't get broken.

For performance, maybe isolating the code in the "if" in a
"int resizeAndPut(Object k, Object item, int len, int i) {...}"
method would help, reducing put() bytecode size.

Having put() find the last free slots in an almost-full table
would most often require a lot of time, so I wonder if
anyone would have hit any of these infinite loops in practice.


-Jeff