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Bug 317226

Summary: Disassembly view throws NPE when debugging with CDI
Product: [Tools] CDT Reporter: Andy Jin <ajin>
Component: cdt-debug-cdiAssignee: Project Inbox <cdt-debug-cdi-inbox>
Status: RESOLVED FIXED QA Contact: John Cortell <john.cortell>
Severity: normal    
Priority: P3 CC: aleherb+eclipse, eran, jamesblackburn+eclipse, pawel.1.piech, teodor.madan
Version: 7.0Flags: aleherb+eclipse: review+
Target Milestone: 7.0.1   
Hardware: PC   
OS: Linux   
Whiteboard:
Attachments:
Description Flags
Fix
john.cortell: iplog-
Fix for NPE when getting frame address teodor.madan: iplog-

Description Andy Jin CLA 2010-06-17 13:45:33 EDT 
Build Identifier: I20100608-0911

When debugging a program with a large share library linked over a remote
target, the program takes some time to be load the share library. During
this loading period if I have the Disassembly view opened it will throw
NPE with below trace:

java.lang.NullPointerException
at
org.eclipse.cdt.debug.internal.ui.disassembly.dsf.DisassemblyBackendCdi.setDebugContext(DisassemblyBackendCdi.java:132)
at
org.eclipse.cdt.dsf.debug.internal.ui.disassembly.DisassemblyPart.updateDebugContext(DisassemblyPart.java:1798)
at org.eclipse.cdt.dsf.debug.internal.ui.disassembly.DisassemblyView
$1.selectionChanged(DisassemblyView.java:66)
at org.eclipse.ui.internal.AbstractPartSelectionTracker
$1.run(AbstractPartSelectionTracker.java:119)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.core.runtime.Platform.run(Platform.java:888)
at
org.eclipse.ui.internal.AbstractPartSelectionTracker.fireSelection(AbstractPartSelectionTracker.java:117)
at org.eclipse.ui.internal.PagePartSelectionTracker
$1.selectionChanged(PagePartSelectionTracker.java:49)
......................................

Looking at
org.eclipse.cdt.debug.internal.ui.disassembly.dsf.DisassemblyBackendCdi.setDebugContext(DisassemblyBackendCdi.java:132), it does a "fTargetContext.getTopStackFrame()". This function can return Null if the thread is not in suspended mode thus the stack frame is an empty list.

In our case the program is in the process of loading the share library
so its thread is not suspended.

It's pretty re-producible with CDI. I haven't seen this problem with
DSF.

Reproducible: Sometimes

Steps to Reproduce:
1. Create a program linking with a large shared library
2. Debug this program with CDI remote debug
3. Make sure the disassembly view is opened before you run the debug.
Comment 1 John Cortell CLA 2010-06-17 17:20:42 EDT 
Created attachment 172162 [details]
Fix

Andy, please try this patch with your reproducible scenario. It occurred to me that the code can't really rely on the thread being suspended. All we know is that at some point in time, we had a suspended thread and one of its frames was set as the active debug context. The thread may have since been resumed, died, whatever. We can use whatever static information we can get from the frame context, but we can't assume anything else. We simply have to be more guarded in that logic.
Comment 2 Teodor Madan CLA 2010-06-18 04:05:14 EDT 
Created attachment 172194 [details]
Fix for NPE when getting frame address

Another NPE caused by thread going into run mode is when getting frame address.
Comment 3 John Cortell CLA 2010-06-18 11:37:40 EDT 
Toni, please review these patches. I've committed my patch to HEAD and cdt_7_0. Teo, I'll leave the commit if your patch to you since you now have commit rights! :-) I reviewed it and it looks good to me.
Comment 5 CDT Genie CLA 2010-06-18 12:38:20 EDT 
*** cdt cvs genie on behalf of tmadan ***
Bug 317226: Disassembly view throws NPE when debugging with CDI. Fix also NPE when getting frame address

[*] CDIDisassemblyRetrieval.java 1.4 http://dev.eclipse.org/viewcvs/index.cgi/org.eclipse.cdt/all/org.eclipse.cdt.debug.ui/src/org/eclipse/cdt/debug/internal/ui/disassembly/dsf/CDIDisassemblyRetrieval.java?root=Tools_Project&r1=1.3&r2=1.4
Comment 6 Teodor Madan CLA 2010-06-19 03:47:58 EDT 
commited my patch to HEAD and cdt_7_0. And marked as rezolved
Comment 7 CDT Genie CLA 2010-06-19 04:23:03 EDT 
*** cdt cvs genie on behalf of tmadan ***
Bug 317226: Disassembly view throws NPE when debugging with CDI. Fix also NPE when getting frame address

[*] CDIDisassemblyRetrieval.java 1.3.2.1 http://dev.eclipse.org/viewcvs/index.cgi/org.eclipse.cdt/all/org.eclipse.cdt.debug.ui/src/org/eclipse/cdt/debug/internal/ui/disassembly/dsf/CDIDisassemblyRetrieval.java?root=Tools_Project&r1=1.3&r2=1.3.2.1
Comment 8 James Blackburn CLA 2010-06-24 12:31:11 EDT 
*** Bug 314268 has been marked as a duplicate of this bug. ***
Comment 9 Andy Jin CLA 2010-07-08 14:43:47 EDT 
- Sorry for the delay, John. Yes I re-tested using my custom test case this problem is now fixed.

Thanks for taking it.
Comment 10 Anton Leherbauer CLA 2010-07-16 01:50:37 EDT 
*** Bug 320018 has been marked as a duplicate of this bug. ***
Comment 11 Anton Leherbauer CLA 2010-07-19 10:16:42 EDT 
Reviewed.