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

Sergey Bylokhov serb at openjdk.java.net
Fri Dec 4 02:30:12 UTC 2020

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: 

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.


Commit messages:
 - Merge branch 'master' into JDK-6986863
 - Merge branch 'master' into JDK-6986863
 - Merge branch 'master' into JDK-6986863
 - Delete the DeferralMgr machinery
 - Update ICC_Profile.java
 - Wrong spec in ProfileDeferralInfo
 - Update ICC_Profile.java
 - Race on access ICC_Profile#deferralInfo
 - Implementation of thread-safe per profile activation
 - ProfileDeferralInfo is not a InputStream

Changes: https://git.openjdk.java.net/jdk/pull/1613/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1613&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-6986863
  Stats: 520 lines in 9 files changed: 183 ins; 265 del; 72 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1613.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1613/head:pull/1613

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

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