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Bug 361541

Summary:	Critical code in Graph.dispose() may lead to deadlock and frozen eclipse
Product:	[Tools] GEF	Reporter:	Jan Mauersberger <mauersberger>
Component:	GEF-Legacy Zest	Assignee:	gef-inbox <gef-inbox>
Status:	RESOLVED FIXED	QA Contact:
Severity:	critical
Priority:	P3	CC:	nyssen, steeg
Version:	unspecified
Target Milestone:	---
Hardware:	PC
OS:	Windows XP
Whiteboard:

Description Jan Mauersberger

2011-10-20 09:30:25 EDT

Build Identifier: 

The code in Graph.dispose() starts with:

while (nodes.size() > 0) {
  GraphNode node = (GraphNode) nodes.get(0);
  if (node != null && !node.isDisposed()) {
    node.dispose();
  }
}

Disposed nodes are not removed in the code but only implicitly by a call to node.dispose(). Hence in case a node is in the graph that is already disposed for some reason an infinite loop is entered.

Don't ask me how I managed to get a disposed node in there but I did and the whole eclipse did freeze. It might be that the disposed node crept in due to another bug (with exception) and essential code did not get executed. Anyway, I think we could make this code more robust since there is no reason why we should check for disposed nodes because any disposed one causes an inifite loop

Reproducible: Always

Comment 1 Fabian Steeg

2011-10-21 17:16:35 EDT

Thanks, that's a nasty freeze indeed - fixed in 1.x head and 2.x master, see GraphTests#testDisposeGraphWithDisposedNode and ...WithDisposedConnection.

http://git.eclipse.org/c/gef/org.eclipse.zest.git/commit/?id=e071b4d85594311