[jira] Updated: (HARMONY-3836) [drlvm][init] Performance patch for VM properties

["Gregory Shimansky (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HARMONY-3836?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Gregory Shimansky updated HARMONY-3836:
---------------------------------------

    Summary: [drlvm][init] Performance patch for VM properties  (was: [drlvm] Performance patch for VM properties)

> [drlvm][init] Performance patch for VM properties
> -------------------------------------------------
>
>                 Key: HARMONY-3836
>                 URL: https://issues.apache.org/jira/browse/HARMONY-3836
>             Project: Harmony
>          Issue Type: Improvement
>          Components: DRLVM
>            Reporter: Ilya Berezhniuk
>         Assigned To: Gregory Shimansky
>         Attachments: prop4.diff
>
>
> There are hundreds places where VM or user code access VM properties.
> Every time when property value is returned, it's returned as a copy of original string; then this copy is freed afted use. But I've found only 4 places where such copying is actually required in code (i.e. returned string is modified).
> Looks like string copying is used to ensure that returned string will not be freed, when another thread changes property value. This way can be replaced with storing property values in String_Pool.
> I've prepared patch changing properties behaviour in the following way:
> - property value is returned as 'const char*' instead of 'char*';
> - property hash contains String* instead of PropValue*;
> - String*s are allocated in loader_env->string_pool.
> Performance gain with this patch was measured with SpecJBB2005 on Windows XP (HT machine), with 2 consequent run for every mode.
> Average gain is 2.16% for default mode and 2.41% for server mode.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.