[SLING-10969] Remove synchronized & rest of accessible flag during injection

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: Models Implementation 1.4.16
• Fix Version/s: Models Implementation 1.5.0
• Component/s: Sling Models
• Assignee: Konrad Windszus
• Reporter: Paul Bjorkstrand
• Created: 06/Dec/21 15:26
• Updated: 10/Dec/21 09:26
• Resolved: 06/Dec/21 16:07

Description

To improve multithreaded performance of Sling Models, the synchronized blocks, along with the "reset" of the setAccessible using its original value should be removed.

Context:
The synchronized blocks were added to resolve a race condition [1]. After looking into another large project that uses reflection to access members of classes (Felix [2]), nowhere in that project is something similar being done. Every reflective access is just doing setAccessible(true).

Results from a JMH test allude to a significant performance improvement during multithreaded threaded access by removing the synchronized (JMH results [3]).

[1]: SLING-6584
[2]: https://github.com/apache/felix-dev/search?q=setAccessible
[3]: https://gist.github.com/paul-bjorkstrand/f3bb154665e7d2168b4656eb7b794496
[4]: https://www.mail-archive.com/[e-mail]/msg113123.html
[5]: https://github.com/apache/sling-org-apache-sling-models-impl/pull/11

Issue Links

• relates to: SLING-6584 Race condition in ModelAdapterFactory