[HARMONY-6612] Implement own instance for each ThreadGroup for class IIORegistry

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Component/s: Classlib
• Patch Info: Patch Available
• Assignee: Mark Hindess
• Reporter: Lang Yang
• Created: 09/Aug/10 00:08
• Updated: 18/Aug/10 02:45
• Resolved: 17/Aug/10 07:30

Description

Spec - http://download.oracle.com/javase/1.4.2/docs/api/javax/imageio/spi/IIORegistry.html#getDefaultInstance()

The method getDefaultInstance() should return the IIORegistry instance for the current ThreadGroup.

This implementation maintains a synchronized hash map to store instances for each ThreadGroup, use ThreadGroup as the key, IIORegistry instance as the value. When the getDefaultInstance() method is being called, we will looks up in the hashmap see if there is exist record, if there is not then a new instance will be created and pushed to the hashmap.