RFR: 8177845: Need a mechanism to load Graal
doug.simon at oracle.com
Wed Apr 19 09:25:54 UTC 2017
All of your suggestions look good. I've updated http://cr.openjdk.java.net/~dnsimon/8177845/jdk/src/java.base/share/classes/jdk/internal/misc/VM.java.udiff.html to include them (please check I didn't make any copy errors in the process).
I was not aware of the new Map.ofEntries method. Nice to see more space efficient map implementations being added to the JDK.
> On 19 Apr 2017, at 10:12, Peter Levart <peter.levart at gmail.com> wrote:
> On 04/19/2017 09:42 AM, Peter Levart wrote:
>> On 04/19/2017 09:37 AM, Peter Levart wrote:
>> Also, while we are at it, the following javadocs in the getSavedProperty() do not apply any more:
>> 138 * It accesses a private copy of the system properties so
>> 139 * that user's locking of the system properties object will not
>> 140 * cause the library to deadlock.
>> In JDK 9, Properties class does not use locking any more on the Properties instance for get()/getProperty() methods...
>> Regards, Peter
> I also noticed the following comment:
> // TODO: the Property Management needs to be refactored and
> // the appropriate prop keys need to be accessible to the
> // calling classes to avoid duplication of keys.
> private static Map<String, String> savedProps;
> ...which is not entirely true. Neither keys nor values are duplicated (they are just referenced in the new copy of the Properties/Map object). What is duplicated is an excessive amount of internal objects, such as array slots and Map.Entry objects. If this is a concern, then we could use the new immutable Map implementation that is available in JDK 9, so the following lines in my webrev:
> 181 @SuppressWarnings("unchecked")
> 182 Map<String, String> sp = new HashMap<>((Map)props);
> 183 // only main thread is running at this time, so savedProps and
> 184 // its content will be correctly published to threads started later
> 185 savedProps = Collections.unmodifiableMap(sp);
> Could be changed into:
> Map<String, String> sp =
> Map.ofEntries(props.entrySet().toArray(new Map.Entry));
> // only main thread is running at this time, so savedProps
> // will be correctly published to threads started later
> savedProps = sp;
> ...to save some excessive space (the implementation is a linear-probe hashtable which keeps keys and values directly in an array without wrapping them with Map.Entry objects).
> Regards, Peter
More information about the hotspot-dev