Re: [Pharo-dev] [Pharo-fuel] Corrupt BlockClosure
I can now reprocuce corrupt sessions. The trick is to debug DFSession>>numberOfMethodCalls: 1. start new session 2. debug "DFSession uniqueInstance printString" 3. step into #numberOfMehthodCalls 4. proceed 5. stop the session 5. right click on the new session in the session browser and click "Export session" 6. boom! The reason is of course, that now the compiled method of #numberOfMethodCalls is referenced by the session and will be serialized by Fuel and when Fuel gets to the corrupt BlockClosure, serialization fails. So the real question still is: how did that BlockClosure obtain a wrong start PC? What I find particularly interesting, is that even changing the method does not fix the BlockClosure. I added the line "Transcript show: 'foo'." before the block (so the block should get a new start PC). Then running the procedure detailed above still produced an open debugger. To illustrate that the block did indeed not get fixed I ran "BlockClosure allInstances select: [ :e | e startpc = 59 ]", with 59 being the new startPC ("55 <8F 01 00 03> closureNumCopied: 0 numArgs: 1 bytes 59 to 61"). The result does not include the block. Any ideas? Max On 24.05.2013, at 08:10, roberto.minelli@usi.ch wrote:
Hi,
Thanks all of you for interest ;)
On May 24, 2013, at 7:15 AM, Max Leske <maxleske@gmail.com> wrote:
I played around with reverting the method and serializing but that doesn't change anything (the existing BlockClosure is obviously not modified). Then I thought that maybe the method was changed during a running DFSession but still couldn't reproduce.
Me neither!!
@Roberto Can you tell us anything about what you did befor / during / after running your session?
Nope. Unfortunately I've a couple of "broken sessions" I cannot serialize because of that bug.. But all of them refers sooner or later to the DFSession>>#numberOfMethodCalls method. Dunno why.
@Roberto Is it possible to reproduce the stack with a new session? Or did this only happen once?
I have no clue how to reproduce, but it did not happen only once. As I said, there are 3/4 sessions I couldn't export due to this SubscriptOutOfBounds.
Cheers, Roby
On 24.05.2013, at 06:44, Max Leske <maxleske@gmail.com> wrote:
On 23.05.2013, at 22:58, Camille Teruel <camille.teruel@gmail.com> wrote:
Hi,
This is indeed strange, the BlockClosure has an incorrect startpc (31 instead of 43). You can fix it with: theBlock instVar: 2 put: 43. The wrong startpc corresponds to the beginning of the block in the previous version of the method (DFSession>>#numberOfMethodCalls), but I don't know why.
Would it help to recompile the method?
I don't know fuel enough but could it be because the method of the block changed between serialization and materialization?
No, there was never a materialization of that session.
Camille
On 23 mai 2013, at 21:02, Max Leske wrote:
Hi Marcus
Roberto sent this mail to the Fuel-dev list. When we looked at the problem we noticed that serialization fails because of a corrupt BlockClosure. Since that's not really our territorry Mariano suggested to forward this to you.
The image with the corrupt BlockClosure is available here: https://dl.dropboxusercontent.com/u/6281855/DFlow-SubscriptOutOfBounds.zip. To see the stack, right click on the only entry in the right window and click "export session". You'll find the corrupt BlockClosure at BlockClosure>>fuelAccept:
@Roberto Is it possible to reproduce the stack with a new session? Or did this only happen once?
Cheers, Max
Begin forwarded message:
From: Mariano Martinez Peck <marianopeck@gmail.com> Subject: Re: [Pharo-fuel] [Fuel] SubscriptOutOfBounds: 27 Date: 23. Mai 2013 14:23:45 MESZ To: The Fuel Project <pharo-fuel@lists.gforge.inria.fr> Reply-To: The Fuel Project <pharo-fuel@lists.gforge.inria.fr>
Indeed, it would be nice if you can known which CompiledMethod and blockclosure are having the problem. Not only the source code but the real bytecodes. Also, can you isolate and just try to serialize them alone and reproduce the problem? In other words, a reproducible test case? :) Thanks!
On Thu, May 23, 2013 at 8:41 AM, Max Leske <maxleske@gmail.com> wrote: What's the compiled method? Is it a special one? Which selector in which class?
Max
On 23.05.2013, at 12:45, "roberto.minelli@usi.ch" <roberto.minelli@usi.ch> wrote:
Hi,
While using Fuel in a 2.0 image to serialize some objects (including CompiledMethods) I'm getting this error: SubscriptOutOfBounds: 27.
I spent hours in the debugger before writing this email, but I'm not able to figure out why this is happening. I attach the full stack of the error (STACK#1).
I understood that it has something to do with a particular CompiledMethod in my image and/or a BlockClosure which for some reason cannot be printed (i.e., the printString returns <error in printString: evaluate "self printString" to debug>) and when I try to printString to debug I got the STACK#2 which in turn does not bring me to any possible solution.
Hope some of you will have an intuition on that or at least tell me where to look or how to script a possible workaround.
Thanks in advance, Roby
############################################################################################ ######################################### STACK#1 ########################################### ########################################################################################### CompiledMethod(Object)>>errorSubscriptBounds: CompiledMethod(Object)>>at: InstructionStream>>interpretNextInstructionFor: CompiledMethod>>abstractBytecodeMessageAt: in Block: [(InstructionStream new method: self pc: pc)... BlockClosure>>on:do: CompiledMethod>>abstractBytecodeMessageAt: BlockClosure>>blockCreationBytecodeMessage BlockClosure>>endPC BlockClosure>>abstractBytecodeMessagesDo: BlockClosure>>isClean BlockClosure>>shouldBeSubstitutedByCleanCopy BlockClosure>>fuelAccept: FLFullGeneralMapper(FLLightGeneralMapper)>>mapAndTrace: FLFullGlobalMapper>>mapAndTrace: in Block: [(anObject class == CompiledMethod... FLLargeIdentityDictionary>>at:ifAbsent: FLFullGlobalMapper>>mapAndTrace: FLPluggableSubstitutionMapper>>mapAndTrace: FLPluggableSubstitutionMapper>>mapAndTrace: FLAnalysis>>mapAndTrace: FLAnalysis>>run FLAnalyzer>>setDefaultAnalysis in Block: [:anObject | (FLAnalysis... FLAnalyzer>>analysisFor: FLSerialization>>analysisStep FLSerialization>>run DFSerializer(FLSerializer)>>setDefaultSerialization in Block: [:anObject :anEncoder | (FLSerialization... DFSerializer(FLSerializer)>>serialize:on: in Block: [:anEncoder | ... FLEncoder class>>on:globalEnvironment:do: in Block: [aBlock value: anEncoder] BlockClosure>>ensure: FLEncoder class>>on:globalEnvironment:do: DFSerializer(FLSerializer)>>serialize:on:
############################################################################################ ######################################### STACK#2 ########################################### ############################################################################################ Decompiler(Object)>>error: Decompiler>>decompileBlock: BlockClosure>>decompile BlockClosure>>printOn: BlockClosure(Object)>>printStringLimitedTo: in Block: [:s | self printOn: s] String class(SequenceableCollection class)>>streamContents:limitedTo: BlockClosure(Object)>>printStringLimitedTo: BlockClosure(Object)>>printString BlockClosure>>DoIt Compiler>>evaluate:in:to:notifying:ifFail:logged: SmalltalkEditor>>evaluateSelectionAndDo: in Block: [rcvr class evaluatorClass new... BlockClosure>>on:do: SmalltalkEditor>>evaluateSelectionAndDo: SmalltalkEditor>>evaluateSelection PluggableTextMorph>>doIt in Block: [textMorph editor evaluateSelection] PluggableTextMorph>>handleEdit: in Block: [result := editBlock value] TextMorphForEditView(TextMorph)>>handleEdit: PluggableTextMorph>>handleEdit: PluggableTextMorph>>doIt SmalltalkEditor class>>buildSmalltalkEditorKeymappingsOn: in Block: [:morph | morph doIt] BlockClosure>>cull: BlockClosure>>cull:cull: BlockClosure>>cull:cull:cull: KMCategoryTarget>>completeMatch:buffer: KMKeymap>>notifyCompleteMatchTo:buffer: in Block: [:l | l completeMatch: self buffer: aBuffer] Array(SequenceableCollection)>>do: KMKeymap>>notifyCompleteMatchTo:buffer: KMKeymap>>onMatchWith:notify:andDo: KMCategory>>onMatchWith:notify:andDo: in Block: [:entry | entry... Set>>do:
_______________________________________________ Pharo-fuel mailing list Pharo-fuel@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-fuel
_______________________________________________ Pharo-fuel mailing list Pharo-fuel@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-fuel
-- Mariano http://marianopeck.wordpress.com _______________________________________________ Pharo-fuel mailing list Pharo-fuel@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-fuel
_______________________________________________ Pharo-fuel mailing list Pharo-fuel@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-fuel
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Bump. Doesn't anybody feel that corrupt blocks are a problem? IMHO that's something that should *never* happen. Max On 25.05.2013, at 17:56, Max Leske <maxleske@gmail.com> wrote:
I can now reprocuce corrupt sessions. The trick is to debug DFSession>>numberOfMethodCalls: 1. start new session 2. debug "DFSession uniqueInstance printString" 3. step into #numberOfMehthodCalls 4. proceed 5. stop the session 5. right click on the new session in the session browser and click "Export session" 6. boom!
The reason is of course, that now the compiled method of #numberOfMethodCalls is referenced by the session and will be serialized by Fuel and when Fuel gets to the corrupt BlockClosure, serialization fails.
So the real question still is: how did that BlockClosure obtain a wrong start PC? What I find particularly interesting, is that even changing the method does not fix the BlockClosure. I added the line "Transcript show: 'foo'." before the block (so the block should get a new start PC). Then running the procedure detailed above still produced an open debugger. To illustrate that the block did indeed not get fixed I ran "BlockClosure allInstances select: [ :e | e startpc = 59 ]", with 59 being the new startPC ("55 <8F 01 00 03> closureNumCopied: 0 numArgs: 1 bytes 59 to 61"). The result does not include the block.
Any ideas?
Max
On 24.05.2013, at 08:10, roberto.minelli@usi.ch wrote:
Hi,
Thanks all of you for interest ;)
On May 24, 2013, at 7:15 AM, Max Leske <maxleske@gmail.com> wrote:
I played around with reverting the method and serializing but that doesn't change anything (the existing BlockClosure is obviously not modified). Then I thought that maybe the method was changed during a running DFSession but still couldn't reproduce.
Me neither!!
@Roberto Can you tell us anything about what you did befor / during / after running your session?
Nope. Unfortunately I've a couple of "broken sessions" I cannot serialize because of that bug.. But all of them refers sooner or later to the DFSession>>#numberOfMethodCalls method. Dunno why.
@Roberto Is it possible to reproduce the stack with a new session? Or did this only happen once?
I have no clue how to reproduce, but it did not happen only once. As I said, there are 3/4 sessions I couldn't export due to this SubscriptOutOfBounds.
Cheers, Roby
On 24.05.2013, at 06:44, Max Leske <maxleske@gmail.com> wrote:
On 23.05.2013, at 22:58, Camille Teruel <camille.teruel@gmail.com> wrote:
Hi,
This is indeed strange, the BlockClosure has an incorrect startpc (31 instead of 43). You can fix it with: theBlock instVar: 2 put: 43. The wrong startpc corresponds to the beginning of the block in the previous version of the method (DFSession>>#numberOfMethodCalls), but I don't know why.
Would it help to recompile the method?
I don't know fuel enough but could it be because the method of the block changed between serialization and materialization?
No, there was never a materialization of that session.
Camille
On 23 mai 2013, at 21:02, Max Leske wrote:
Hi Marcus
Roberto sent this mail to the Fuel-dev list. When we looked at the problem we noticed that serialization fails because of a corrupt BlockClosure. Since that's not really our territorry Mariano suggested to forward this to you.
The image with the corrupt BlockClosure is available here: https://dl.dropboxusercontent.com/u/6281855/DFlow-SubscriptOutOfBounds.zip. To see the stack, right click on the only entry in the right window and click "export session". You'll find the corrupt BlockClosure at BlockClosure>>fuelAccept:
@Roberto Is it possible to reproduce the stack with a new session? Or did this only happen once?
Cheers, Max
Begin forwarded message:
From: Mariano Martinez Peck <marianopeck@gmail.com> Subject: Re: [Pharo-fuel] [Fuel] SubscriptOutOfBounds: 27 Date: 23. Mai 2013 14:23:45 MESZ To: The Fuel Project <pharo-fuel@lists.gforge.inria.fr> Reply-To: The Fuel Project <pharo-fuel@lists.gforge.inria.fr>
Indeed, it would be nice if you can known which CompiledMethod and blockclosure are having the problem. Not only the source code but the real bytecodes. Also, can you isolate and just try to serialize them alone and reproduce the problem? In other words, a reproducible test case? :) Thanks!
On Thu, May 23, 2013 at 8:41 AM, Max Leske <maxleske@gmail.com> wrote: What's the compiled method? Is it a special one? Which selector in which class?
Max
On 23.05.2013, at 12:45, "roberto.minelli@usi.ch" <roberto.minelli@usi.ch> wrote:
Hi,
While using Fuel in a 2.0 image to serialize some objects (including CompiledMethods) I'm getting this error: SubscriptOutOfBounds: 27.
I spent hours in the debugger before writing this email, but I'm not able to figure out why this is happening. I attach the full stack of the error (STACK#1).
I understood that it has something to do with a particular CompiledMethod in my image and/or a BlockClosure which for some reason cannot be printed (i.e., the printString returns <error in printString: evaluate "self printString" to debug>) and when I try to printString to debug I got the STACK#2 which in turn does not bring me to any possible solution.
Hope some of you will have an intuition on that or at least tell me where to look or how to script a possible workaround.
Thanks in advance, Roby
############################################################################################ ######################################### STACK#1 ########################################### ########################################################################################### CompiledMethod(Object)>>errorSubscriptBounds: CompiledMethod(Object)>>at: InstructionStream>>interpretNextInstructionFor: CompiledMethod>>abstractBytecodeMessageAt: in Block: [(InstructionStream new method: self pc: pc)... BlockClosure>>on:do: CompiledMethod>>abstractBytecodeMessageAt: BlockClosure>>blockCreationBytecodeMessage BlockClosure>>endPC BlockClosure>>abstractBytecodeMessagesDo: BlockClosure>>isClean BlockClosure>>shouldBeSubstitutedByCleanCopy BlockClosure>>fuelAccept: FLFullGeneralMapper(FLLightGeneralMapper)>>mapAndTrace: FLFullGlobalMapper>>mapAndTrace: in Block: [(anObject class == CompiledMethod... FLLargeIdentityDictionary>>at:ifAbsent: FLFullGlobalMapper>>mapAndTrace: FLPluggableSubstitutionMapper>>mapAndTrace: FLPluggableSubstitutionMapper>>mapAndTrace: FLAnalysis>>mapAndTrace: FLAnalysis>>run FLAnalyzer>>setDefaultAnalysis in Block: [:anObject | (FLAnalysis... FLAnalyzer>>analysisFor: FLSerialization>>analysisStep FLSerialization>>run DFSerializer(FLSerializer)>>setDefaultSerialization in Block: [:anObject :anEncoder | (FLSerialization... DFSerializer(FLSerializer)>>serialize:on: in Block: [:anEncoder | ... FLEncoder class>>on:globalEnvironment:do: in Block: [aBlock value: anEncoder] BlockClosure>>ensure: FLEncoder class>>on:globalEnvironment:do: DFSerializer(FLSerializer)>>serialize:on:
############################################################################################ ######################################### STACK#2 ########################################### ############################################################################################ Decompiler(Object)>>error: Decompiler>>decompileBlock: BlockClosure>>decompile BlockClosure>>printOn: BlockClosure(Object)>>printStringLimitedTo: in Block: [:s | self printOn: s] String class(SequenceableCollection class)>>streamContents:limitedTo: BlockClosure(Object)>>printStringLimitedTo: BlockClosure(Object)>>printString BlockClosure>>DoIt Compiler>>evaluate:in:to:notifying:ifFail:logged: SmalltalkEditor>>evaluateSelectionAndDo: in Block: [rcvr class evaluatorClass new... BlockClosure>>on:do: SmalltalkEditor>>evaluateSelectionAndDo: SmalltalkEditor>>evaluateSelection PluggableTextMorph>>doIt in Block: [textMorph editor evaluateSelection] PluggableTextMorph>>handleEdit: in Block: [result := editBlock value] TextMorphForEditView(TextMorph)>>handleEdit: PluggableTextMorph>>handleEdit: PluggableTextMorph>>doIt SmalltalkEditor class>>buildSmalltalkEditorKeymappingsOn: in Block: [:morph | morph doIt] BlockClosure>>cull: BlockClosure>>cull:cull: BlockClosure>>cull:cull:cull: KMCategoryTarget>>completeMatch:buffer: KMKeymap>>notifyCompleteMatchTo:buffer: in Block: [:l | l completeMatch: self buffer: aBuffer] Array(SequenceableCollection)>>do: KMKeymap>>notifyCompleteMatchTo:buffer: KMKeymap>>onMatchWith:notify:andDo: KMCategory>>onMatchWith:notify:andDo: in Block: [:entry | entry... Set>>do:
_______________________________________________ Pharo-fuel mailing list Pharo-fuel@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-fuel
_______________________________________________ Pharo-fuel mailing list Pharo-fuel@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-fuel
-- Mariano http://marianopeck.wordpress.com _______________________________________________ Pharo-fuel mailing list Pharo-fuel@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-fuel
_______________________________________________ Pharo-fuel mailing list Pharo-fuel@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-fuel
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Max Leske