Re: RFR: 8258804: Collection.toArray() should use empty array

2020-12-22 Thread Xue-Lei Andrew Fan 
On Tue, 22 Dec 2020 12:39:23 GMT, David M. Lloyd 
 wrote:

>> Comparing to Collection.toArray(new T[size)), the Collection.toArray(new 
>> T[0]) seems faster, safer and contractually cleaner.  In the update, the use 
>> of Collection.toArray(new T[size)) in the SunJSSE provider implementation is 
>> replaced with Collection.toArray(new T[0]).
>> 
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8258804
>
> src/java.base/share/classes/sun/security/ssl/SSLContextImpl.java line 854:
> 
>> 852: // Use the customized TLS protocols.
>> 853: candidates =
>> 854: refactored.toArray(new ProtocolVersion[0]);
> 
> If this level of performance improvement is justified, then would it not be 
> better to use a constant empty array instead of constructing a new one each 
> time?

I think empty array construction could be optimized in the compiler layer.

-

PR: https://git.openjdk.java.net/jdk/pull/1861

Re: RFR: 8258804: Collection.toArray() should use empty array

2020-12-22 Thread David M . Lloyd 
On Mon, 21 Dec 2020 23:58:03 GMT, Xue-Lei Andrew Fan  wrote:

> Comparing to Collection.toArray(new T[size)), he Collection.toArray(new T[0]) 
> seems faster, safer and contractually cleaner.  In the update, the use of 
> Collection.toArray(new T[size)) in the SunJSSE provider implementation is 
> replaced with Collection.toArray(new T[0]).
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8258804

src/java.base/share/classes/sun/security/ssl/SSLContextImpl.java line 854:

> 852: // Use the customized TLS protocols.
> 853: candidates =
> 854: refactored.toArray(new ProtocolVersion[0]);

If this level of performance improvement is justified, then would it not be 
better to use a constant empty array instead of constructing a new one each 
time?

-

PR: https://git.openjdk.java.net/jdk/pull/1861

Re: RFR: 8258804: Collection.toArray() should use empty array

2020-12-22 Thread Sean Mullan 
On Mon, 21 Dec 2020 23:58:03 GMT, Xue-Lei Andrew Fan  wrote:

> Comparing to Collection.toArray(new T[size)), he Collection.toArray(new T[0]) 
> seems faster, safer and contractually cleaner.  In the update, the use of 
> Collection.toArray(new T[size)) in the SunJSSE provider implementation is 
> replaced with Collection.toArray(new T[0]).
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8258804

Looks fine to me.

-

Marked as reviewed by mullan (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/1861