[OpenJDK 2D-Dev] RFR: 6986863: ProfileDeferralMgr throwing ConcurrentModificationException

[Sergey Bylokhov]

On Thu, 3 Dec 2020 23:52:25 GMT, Sergey Bylokhov <serb at openjdk.org> wrote:

> This change intended to enhance the lazy initialization of the standard color profiles concurrently by different threads.
> 
> We defer standard profiles loading because most of UI application uses a small amount of data from the profile like numComponents and colorSpaceType, and this data is known in advance. But any other profile-related activity (like a color conversion, profile data accesses, etc.) triggers profile activation when we load all profile data to the memory.
> 
> Before the fix for JDK-6793818, we defer only one sRGB color profile, see: https://github.com/openjdk/jdk/commit/2726f2a3621dd2562d4fb660b4c3d376c65027aa
> 
> Notes about the link above:
> - The code in the ProfileDeferralMgr, which contain the Vector of profiles for activation does not use any synchronization
> - The `activateDeferredProfile` and `activate` methods are implemented to throw `ProfileDataException`, but this exception is ignored during activation process: 
>     https://github.com/openjdk/jdk/commit/2726f2a3621dd2562d4fb660b4c3d376c65027aa#diff-0839c25a6c999452be28b431c54d5daa91364d302cfda6efa5c56421c2f2bdcbR96
> 
> The fix:
>  - Drops the usage of ProfileDeferralMgr (which contained the Vector of profiles for activation) and ProfileActivator machinery. Instead, we will have just one `ICC_Profile.activate()` method which will activate and initialize the `ICC_Profile.cmmProfile` if it is null
>  - The `activate` method implementation mimics the old behavior when the CMMException and IOException were wrapped by the ProfileDataException, and the ProfileDataException itself was ignored during activation - > so an exception will not be thrown in the method itself, but only when the null profile will be used.
> 
> See some comments inline.

Any volunteers for a review?

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PR: https://git.openjdk.java.net/jdk/pull/1613