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Build Identifier: 20110615-0604 I was profiling and noticed that the OutlineWithEditorLinker keeps a reference to an outlinePage. I didn't look deeply into it but I suspect that, when de-activating, the outlinePage can be nulled? That outlinePage indirectly retains a reference to a couple of MBs of TokenInfos that would be released then. Reproducible: Always
Scheduled for 2.1
Created attachment 201975 [details] Root analysis of one of the leaked objects
Created attachment 201976 [details] Difference between first build and repeating step 3 four times It seems we underestimated the impact of this bug. The memory leak gets progressively worse. Steps to reproduce: 1) Open a project with big (~10000 loc) files. 2) Perform a clean. (check the amount of used memory) 3) Open/close multiple files in the editor and perform a clean again, do this several times. 4) Close all editors. You should notice a substantial increase in memory usage In my case, in this test project I go from 90MB memory usage to 130MB memory usage. If I keep repeating step 3 I can make the leak progressively bigger until I eventually run out of heapspace. The leaked memory is held by the listeners of in the ChainedPreferenceStore, specifically the OutlineWithEditorLinker listeners. Most of the leaked memory is made out of Strings and TokenInfos. I've attached a number of screenshots from yourkit to help your analysis. I think the bug importance should be bumped up to 'major'.
Created attachment 201978 [details] The leaked objects and their size
Now nulling the reference on dispose(). Does that fix your issue?
Created attachment 202995 [details] patch The issue was almost fixed, treeViewer and textViewer should be made null aswell.
Thanks. I pushed the fix to MASTER.
Is the fix of this problem only involves nulling out OutlinePage, textViewer and treeViewer? I tried to implement this fix in my own code since I cannot update to the latest Xtext but need to address the memory leak. However, I got the following NPE in this scenario: 1) open the two editors 2) close one of the editor 3) switch to the remaining editor 4) click on link with editor action. Got NPE at OutlineWithEditorLinker:100 @ OutlineWithEditorLinker.setLinkingEnabled(...) I am wondering if I am missing something or if there is another fix that I need to pick up. Please note that in my case, the OutlineWithEditorLinker.register does not get called when I switch editor. i.e. the treeViewer is never initialized after we null out the treeViewer when closing an editor.
Looking at this a bit more, looks like it's leaking OutlineWithEditorLinker as preference store's property listener. Even after the linker has been de-registered, it is still being notified about property change and resulted in NPE. Are you seeing this same problem?
We used getPreferenceStoreAccess().getPreferenceStore().addPropertyChangeListener and getPreferenceStoreAccess().getPreferenceStore().removePropertyChangeListener Unfortunately getPreferenceStoreAccess().getPreferenceStore() returns a new instance of ChainedPreferenceStore each time it is called. So that was a memory leak. I fixed it in Xtext 2.1 sream, i.e. master. For earlier version you need to override LinkWithEditorOutlineContribution with the following: private IPreferenceStore preferenceStore; @Override public void register(OutlinePage outlinePage) { IToolBarManager toolBarManager = outlinePage.getSite().getActionBars().getToolBarManager(); toolBarManager.add(getAction()); addPropertyChangeListener(); OutlineWithEditorLinker outlineWithEditorLinker = outlineWithEditorLinkerProvider.get(); outlineWithEditorLinker.activate(outlinePage); outlineWithEditorLinker.setLinkingEnabled(isPropertySet()); preferenceStore = getPreferenceStoreAccess().getPreferenceStore(); preferenceStore.addPropertyChangeListener(outlineWithEditorLinker); page2linker.put(outlinePage, outlineWithEditorLinker); } @Override public void deregister(OutlinePage outlinePage) { removePropertyChangeListener(); OutlineWithEditorLinker outlineWithEditorLinker = page2linker.remove(outlinePage); if (outlineWithEditorLinker != null) { outlineWithEditorLinker.deactivate(); preferenceStore.removePropertyChangeListener(outlineWithEditorLinker); } }
Closing all bugs that were set to RESOLVED before Neon.0
