Slow performance on millions of objects during VirtualUniverse.removeAllLocales or release resource.

[morris821028]

Scenario

1. Load millions of TransformGroup objects into specific Locales in two-level hierarchy.

- Locale
    -  TransformGroupRetained X
        -  GroupRetained
           -   TransformGroupRetained A... (millions of object in this level)
           -   TransformGroupRetained B... (millions of object in this level)

2. Call VirtualUniverse.removeAllLocales. We will find the $O(N^2)$ time during release resource.

Reason

java3d-core/src/javax/media/j3d/TransformGroupRetained.java

Line 664 in baff3df

obj.remove(this);

TransformGroupRetained.removeNodeData will call parent TransformGroupRetained X childTransformLinks.remove step by step.

Possible Solution

Predict the live state from parent class NodeRetained.

java3d-core/src/javax/media/j3d/NodeRetained.java

Line 720 in baff3df

void clearLive(SetLiveState s) {

java3d-core/src/javax/media/j3d/TransformGroupRetained.java

Line 745 in baff3df

void clearLive(SetLiveState s) {

// in TransformGroupRetained.
    @Override
    void clearLive(SetLiveState s) {

        Targets[] savedTransformTargets = null;

        savedTransformTargets = s.transformTargets;
	// no need to gather targets from tg in clear live
        s.transformTargets = null;
        
        if (refCount - s.refCount <= 0) { // predict live to prevent children update.
            childTransformLinks.clear();
        }

	super.clearLive(s);
        ...