ConcurrentHashMap/ConcurrentMap/Map.compute (original) (raw)

Doug Lea dl at cs.oswego.edu
Fri Dec 14 10:20:41 PST 2012

On 12/14/12 13:02, Brian Goetz wrote:

We do not have explicit parallel versions of forEach for anything yet. Existing forEach methods are inherently sequential.

But does any spec promise this? If you want parallel forEach you can do: coll.parallel().forEach()

But what's up with Maps?

But given computeIfAbsent, the name computeIfPresent seems forced, and then computeIfAbsentOrPresent==compute seems forced. And if you see the scheme laid out in this way, looks OK. Which is presumably why all the CHMV8 users seem to like it. What about recompute for compute, and recomputeIfPresent for computeIfPresent?

I forget what c-i list feedback led me to change the initial CHMV8 recompute() to computeIfPresent() but I can scan archives/replies if anyone cares.

(The former has a slight weirdness about the first time, since you can't recompute something that isn't yet computed,

Sounds like it a product of the Department of Redundancy Department :-)

Sorry to resist all these suggestions, I'd list some of my own, but then I would be forced to reply to myself about why just living with "compute" is good enough :-)

-Doug

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