RFR  Speedup construction of CopyOnWriteArraySet in special cases
ivan.gerasimov at oracle.com
Tue Apr 30 11:49:48 UTC 2013
On 30.04.2013 15:45, David Holmes wrote:
> Hi Ivan,
> On 30/04/2013 9:41 PM, Ivan Gerasimov wrote:
>> Hello everybody!
>> Would you please review my proposal to change constructor of
> Has this been run past Doug Lea and JSR-166 (ex)EG yet? All
> java.util.concurrent updates have to be coordinated through Doug.
I cc'ed the message to Doug Lea (just checked the sent box to make sure
For some reasons I do not see his address in the message received
through the list.
>> Currently, the body of the constructor is like this:
>> al = new CopyOnWriteArrayList<E>();
>> The addAllAbsent() function has O(c.length^2) complexity, so
>> construction time quickly grows with the input size.
>> However, if we knew that c is a Set, we could construct the COWAS in
>> linear time.
>> And if the c was known to be another COWAS, we could simply clone the
>> underlying CopyOnWriteArrayList.
>> The webrew also includes a test I used to make sure nothing is broken.
>> Sincerely yours,
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