[
https://issues.apache.org/jira/browse/NETBEANS-3196?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Eirik Bakke resolved NETBEANS-3196.
-----------------------------------
Resolution: Fixed
PR was merged; marking resolved.
> Calling Children.LEAF.getNodesCount() changes lazy loading behavior globally
> ----------------------------------------------------------------------------
>
> Key: NETBEANS-3196
> URL: https://issues.apache.org/jira/browse/NETBEANS-3196
> Project: NetBeans
> Issue Type: Improvement
> Components: platform - Nodes
> Affects Versions: 11.0
> Reporter: Eirik Bakke
> Priority: Minor
> Labels: pull-request-available
> Time Spent: 1h 50m
> Remaining Estimate: 0h
>
> There's a small bug in org.openide.nodes.Node.setChildren(Children). The
> logic goes something like this:
> {code:java}
> protected final void setChildren(final Children ch) {
> boolean wasInited = hierarchy.isInitialized();
> boolean wasLeaf = hierarchy == Children.LEAF;
> // ...
> hierarchy = ch;
> // ...
> if (wasInited && hierarchy != Children.LEAF) {
> // init new children if old was inited
> hierarchy.getNodesCount();
> {code}
> If a Node's children was originally Children.LEAF, and is then changed to a
> different instance, the resulting behavior now becomes dependent on the
> result of Children.LEAF.isInitialized(). The latter is a global piece of
> state which may return false for a long time until _any_ module anywhere in
> the IDE or in a platform application calls Children.LEAF.getNodesCount(),
> after which Children.LEAF.isInitialized() will forever after return true.
> Once Children.LEAF.getNodesCount() has been called, from any module, Node
> implementations that switch from Children.LEAF to another Children
> implementation will no longer get lazy loading behavior.
> The fix is simple; the condition should be "wasInited && !wasLeaf &&
> hierarchy != Children.LEAF)".
> It might be good to ensure that Children.LEAF is always initialized as well,
> to prevent accidentally sharing mutable global state. (Actually, I tried
> calling Children.LEAF.getNodesCount() on LEAF's initial construction, but
> this caused a failure on startup. So don't bother.)
> (This bug was found in a NetBeans Platform application that relies heavily on
> lazy loading of nodes.)
--
This message was sent by Atlassian Jira
(v8.20.1#820001)
---------------------------------------------------------------------
To unsubscribe, e-mail: commits-unsubscr...@netbeans.apache.org
For additional commands, e-mail: commits-h...@netbeans.apache.org
For further information about the NetBeans mailing lists, visit:
https://cwiki.apache.org/confluence/display/NETBEANS/Mailing+lists
