Re: One more round… Re: RFA 8056248: Improve ForkJoin thread throttling

[Chris Hegarty]

On 25 Sep 2014, at 14:55, Paul Sandoz <paul.sandoz at oracle.com> wrote:

> Hi Sean,
> 
> On Sep 25, 2014, at 11:47 AM, Seán Coffey <sean.coffey at oracle.com> wrote:
> 
>> Paul,
>> 
>> After further conversations with Joe Darcy it looks like the safest thing to do here is remove the new system property code completely for the jdk8u backport.
>> 
>> Consider this request approved if you can pull out the code. Please have someone review the changes also.
>> 
> 
> Thanks, below is the patch (on top of the change set pushed to 9) removing the system property.

Reviewed.

-Chris.

> Paul.
> 
> diff -r ac4184297775 src/share/classes/java/util/concurrent/ForkJoinPool.java
> --- a/src/share/classes/java/util/concurrent/ForkJoinPool.java	Fri Sep 05 10:54:28 2014 +0200
> +++ b/src/share/classes/java/util/concurrent/ForkJoinPool.java	Thu Sep 25 14:52:44 2014 -0700
> @@ -143,9 +143,6 @@
>  * - the class name of a {@link ForkJoinWorkerThreadFactory}
>  * <li>{@code java.util.concurrent.ForkJoinPool.common.exceptionHandler}
>  * - the class name of a {@link UncaughtExceptionHandler}
> - * <li>{@code java.util.concurrent.ForkJoinPool.common.maximumSpares}
> - * - the maximum number of allowed extra threads to maintain target
> - * parallelism (default 256).
>  * </ul>
>  * If a {@link SecurityManager} is present and no factory is
>  * specified, then the default pool uses a factory supplying
> @@ -1316,12 +1313,10 @@
> 
>     /**
>      * The initial value for commonMaxSpares during static
> -     * initialization unless overridden using System property
> -     * "java.util.concurrent.ForkJoinPool.common.maximumSpares".  The
> -     * default value is far in excess of normal requirements, but also
> -     * far short of MAX_CAP and typical OS thread limits, so allows
> -     * JVMs to catch misuse/abuse before running out of resources
> -     * needed to do so.
> +     * initialization. The value is far in excess of normal
> +     * requirements, but also far short of MAX_CAP and typical
> +     * OS thread limits, so allows JVMs to catch misuse/abuse
> +     * before running out of resources needed to do so.
>      */
>     private static final int DEFAULT_COMMON_MAX_SPARES = 256;
> 
> @@ -3417,8 +3412,6 @@
>                 ("java.util.concurrent.ForkJoinPool.common.threadFactory");
>             String hp = System.getProperty
>                 ("java.util.concurrent.ForkJoinPool.common.exceptionHandler");
> -            String mp = System.getProperty
> -                ("java.util.concurrent.ForkJoinPool.common.maximumSpares");
>             if (pp != null)
>                 parallelism = Integer.parseInt(pp);
>             if (fp != null)
> @@ -3427,8 +3420,6 @@
>             if (hp != null)
>                 handler = ((UncaughtExceptionHandler)ClassLoader.
>                            getSystemClassLoader().loadClass(hp).newInstance());
> -            if (mp != null)
> -                commonMaxSpares = Integer.parseInt(mp);
>         } catch (Exception ignore) {
>         }
>         if (factory == null) {