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Recursive not understood error encountered

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Mariano Martinez Peck

Recursive not understood error encountered

Hi. I am still playing with Objects as methods, and I am having yet another kind of crash :(
This time, the image crash with the message "Recursive not understood error encountered".
I am completly sure that I am not putting ANY proxy for any method of DNU, so I don't understand why I get this error.

I copy the stacktrace. You can see 2 important things:

1) AbstractCompiledMethodProxy>run:with:in:
2) mareaHandleRun:with:in:forProxy:

1) is the proxy object and 2) is the handler.

AbstractCompiledMethodProxy >> run: aSelector with: arguments in: aReceiver
    ^ CompiledMethodProxyHandler mareaHandleRun: aSelector with: arguments in: aReceiver forProxy: self

CompiledMethodProxyHandler >> mareaHandleRun: aSelector with: arguments in: aReceiver forProxy: aProxy
    | aResult oldMethod |
    self mareaCheckLoop.
    self mareaLog: 'The method ', aSelector, ' is being executed with a receiver instance of ', aReceiver mareaClass name.
    oldMethod := self mareaUninstallForProxy: aProxy.
    aResult := oldMethod valueWithReceiver: aReceiver arguments: arguments.
    self mareaLog: 'The method ', aSelector, ' was executed with a receiver instance of ', aReceiver mareaClass name.
    ^aResult


Does anyone has an idea of what can be happening?

Thanks in advance,

Recursive not understood error encountered

591830388 Rectangle>translateBy:
591830296 ECMenuMorph>prepareRectForNextRow:
591830116 CompiledMethod>valueWithReceiver:arguments:
591799776 >mareaHandleRun:with:in:forProxy:
591799684 AbstractCompiledMethodProxy>run:with:in:
591678220 OMenuMorph>drawOn:
591678128 CompiledMethod>valueWithReceiver:arguments:
591677672 >mareaHandleRun:with:in:forProxy:
591677580 AbstractCompiledMethodProxy>run:with:in:
591677488 Canvas>draw:
591677396 Canvas>drawMorph:
591677304 Morph>fullDrawOn:
591677192 FormCanvas>roundCornersOf:in:during:
591677100 Canvas>roundCornersOf:during:
591676972 Morph>fullDrawOn:
591676792 Canvas>fullDraw:
591676700 Canvas>fullDrawMorph:
591676204 WorldState>drawWorld:submorphs:invalidAreasOn:
591675472 Rectangle>allAreasOutsideList:startingAt:do:
591675380 Rectangle>allAreasOutsideList:do:
591675908 WorldState>drawWorld:submorphs:invalidAreasOn:
591675288 SequenceableCollection>do:
591675020 WorldState>drawWorld:submorphs:invalidAreasOn:
591674900 WorldState>displayWorld:submorphs:
591674808 FormCanvas>roundCornersOf:in:during:
591674716 Canvas>roundCornersOf:during:
591674612 WorldState>displayWorld:submorphs:
591674520 PasteUpMorph>privateOuterDisplayWorld
591674428 PasteUpMorph>displayWorld
591674336 WorldState>displayWorldSafely:
591674188 BlockClosure>on:do:
591674096 BlockClosure>ifError:
591674004 WorldState>displayWorldSafely:
591643764 WorldState>doOneCycleNowFor:
591643672 WorldState>doOneCycleFor:
591643580 PasteUpMorph>doOneCycle
560519040 >spawnNewProcess
560518912 BlockClosure>newProcess

Debugger stopped.
Program exited with status value:255.(gdb)

Colin Putney-3

Re: Recursive not understood error encountered

On Fri, Dec 3, 2010 at 12:52 PM, Mariano Martinez Peck
<[hidden email]> wrote:
>
> Hi. I am still playing with Objects as methods, and I am having yet another kind of crash :(
> This time, the image crash with the message "Recursive not understood error encountered".
> I am completly sure that I am not putting ANY proxy for any method of DNU, so I don't understand why I get this error.

Without understanding the details of what you're doing, let me offer
this: try looking for objects that don't inherit from Object. Even if
you aren't proxying #doesNotUnderstand:, you can get a recursive DNU
if an object that doesn't understand #doesNotUnderstand: gets
*another* message it doesn't understand.

Hope this helps.

Colin

Mariano Martinez Peck

Re: Recursive not understood error encountered

On Sun, Dec 5, 2010 at 8:53 AM, Colin Putney <[hidden email]> wrote:

On Fri, Dec 3, 2010 at 12:52 PM, Mariano Martinez Peck
<[hidden email]> wrote:
>
> Hi. I am still playing with Objects as methods, and I am having yet another kind of crash :(
> This time, the image crash with the message "Recursive not understood error encountered".
> I am completly sure that I am not putting ANY proxy for any method of DNU, so I don't understand why I get this error.

Without understanding the details of what you're doing, let me offer
this:

thanks Colin for the help.

try looking for objects that don't inherit from Object.

Ok, there are objects that doesn't inherit from Object, and even my proxies don't do that. But.....ProtoObject DOES understands the message #doesNotUnderstand:

Even if
you aren't proxying #doesNotUnderstand:, you can get a recursive DNU
if an object that doesn't understand #doesNotUnderstand:

there cannot be objects that don't understand #doesNotUnderstand: since it is implemented in ProtoObject.

gets
*another* message it doesn't understand.

Anyway, I will think if there can be a situation that happens what you said...maybe there is.

Thanks a lot !

mariano

Hope this helps.

Colin

johnmci

Re: Recursive not understood error encountered

Mariano, knowing that ProtoObject does understand doesnotunderstand via is not enough. There are a dozen or two other methods needed

in order for a debugger to come up, even to invoke an inspector on ProtoObject subclasses.

You should look at the Objective-C bridge I wrote , the Objective-C proxy object that is based on ProtoObject and contains the

required methods to ensure a debugger will come up. It *does* override does not understand so it can transform the unknown

message into a primitive call.

On 2010-12-05, at 5:57 AM, Mariano Martinez Peck wrote:

On Sun, Dec 5, 2010 at 8:53 AM, Colin Putney <[hidden email]> wrote:

On Fri, Dec 3, 2010 at 12:52 PM, Mariano Martinez Peck
<[hidden email]> wrote:
>
> Hi. I am still playing with Objects as methods, and I am having yet another kind of crash :(
> This time, the image crash with the message "Recursive not understood error encountered".
> I am completly sure that I am not putting ANY proxy for any method of DNU, so I don't understand why I get this error.

Without understanding the details of what you're doing, let me offer
this:

thanks Colin for the help.

try looking for objects that don't inherit from Object.

Ok, there are objects that doesn't inherit from Object, and even my proxies don't do that. But.....ProtoObject DOES understands the message #doesNotUnderstand:

Even if
you aren't proxying #doesNotUnderstand:, you can get a recursive DNU
if an object that doesn't understand #doesNotUnderstand:

there cannot be objects that don't understand #doesNotUnderstand: since it is implemented in ProtoObject.

gets
*another* message it doesn't understand.

Anyway, I will think if there can be a situation that happens what you said...maybe there is.

Thanks a lot !

mariano

Hope this helps.

Colin

===========================================================================

John M. McIntosh <[hidden email]> Twitter: squeaker68882

Corporate Smalltalk Consulting Ltd. http://www.smalltalkconsulting.com

===========================================================================

Mariano Martinez Peck

Re: Recursive not understood error encountered

On Sun, Dec 5, 2010 at 9:07 PM, John M McIntosh <[hidden email]> wrote:

Mariano, knowing that ProtoObject does understand doesnotunderstand via is not enough. There are a dozen or two other methods needed
in order for a debugger to come up, even to invoke an inspector on ProtoObject subclasses.

Yes, I know that. I even had to implement few extra methods on ProtoObject in order to bring up a debugger. What how is this related to the "Recursive not understood error encountered" crash ? or this is just extra help information ? ;)

You should look at the Objective-C bridge I wrote , the Objective-C proxy object that is based on ProtoObject and contains the

required methods to ensure a debugger will come up. It *does* override does not understand so it can transform the unknown
message into a primitive call.

Excellent!! How can I load such code? (squeaksource is down now and I cannot search)

Thanks John!

Mariano

On 2010-12-05, at 5:57 AM, Mariano Martinez Peck wrote:

On Sun, Dec 5, 2010 at 8:53 AM, Colin Putney <[hidden email]> wrote:

On Fri, Dec 3, 2010 at 12:52 PM, Mariano Martinez Peck
<[hidden email]> wrote:
>
> Hi. I am still playing with Objects as methods, and I am having yet another kind of crash :(
> This time, the image crash with the message "Recursive not understood error encountered".
> I am completly sure that I am not putting ANY proxy for any method of DNU, so I don't understand why I get this error.

Without understanding the details of what you're doing, let me offer
this:

thanks Colin for the help.

try looking for objects that don't inherit from Object.

Ok, there are objects that doesn't inherit from Object, and even my proxies don't do that. But.....ProtoObject DOES understands the message #doesNotUnderstand:

Even if
you aren't proxying #doesNotUnderstand:, you can get a recursive DNU
if an object that doesn't understand #doesNotUnderstand:

there cannot be objects that don't understand #doesNotUnderstand: since it is implemented in ProtoObject.

gets
*another* message it doesn't understand.

Anyway, I will think if there can be a situation that happens what you said...maybe there is.

Thanks a lot !

mariano

Hope this helps.

Colin

--
===========================================================================

John M. McIntosh <[hidden email]> Twitter: squeaker68882

Corporate Smalltalk Consulting Ltd. http://www.smalltalkconsulting.com
===========================================================================

johnmci

Re: Recursive not understood error encountered

On 2010-12-06, at 12:38 AM, Mariano Martinez Peck wrote:

You should look at the Objective-C bridge I wrote , the Objective-C proxy object that is based on ProtoObject and contains the

required methods to ensure a debugger will come up. It *does* override does not understand so it can transform the unknown
message into a primitive call.

Excellent!! How can I load such code? (squeaksource is down now and I cannot search)

Thanks John!

Mariano

http://www.squeaksource.com/ObjectiveCBridge2.html

===========================================================================

John M. McIntosh <[hidden email]> Twitter: squeaker68882

Corporate Smalltalk Consulting Ltd. http://www.smalltalkconsulting.com

===========================================================================

Mariano Martinez Peck

Re: Recursive not understood error encountered

On Mon, Dec 6, 2010 at 8:34 PM, John M McIntosh <[hidden email]> wrote:

On 2010-12-06, at 12:38 AM, Mariano Martinez Peck wrote:

You should look at the Objective-C bridge I wrote , the Objective-C proxy object that is based on ProtoObject and contains the

required methods to ensure a debugger will come up. It *does* override does not understand so it can transform the unknown
message into a primitive call.

Excellent!! How can I load such code? (squeaksource is down now and I cannot search)

Thanks John!

Mariano

http://www.squeaksource.com/ObjectiveCBridge2.html

Thanks John, I found it once SqueakSource came back. Now, I still don't understand how is this (adding some methods to ProtoObject for debugging, inspecting, printing) related to the "Recursive not understood error encountered" crash ? or this is just extra help information ? ;)

Cheers

Mariano

--
===========================================================================

John M. McIntosh <[hidden email]> Twitter: squeaker68882

Corporate Smalltalk Consulting Ltd. http://www.smalltalkconsulting.com
===========================================================================

Mariano Martinez Peck

Re: Recursive not understood error encountered

In my case, the proxy class is CompiledMethodProxy and it is a subclass of AbstractCompiledMethodProxy which is a subclass of ProtoObject.

In AbstractCompiledMethodProxy I have:

AbstractCompiledMethodProxy >> doesNotUnderstand: aMessage
    self mareaIsProxyInstalled
        ifTrue: [ ^ CompiledMethodProxyHandler mareaHandleDoesNotUnderstand: aMessage forProxy: self]
        ifFalse: [ ^ super doesNotUnderstand: aMessage ].


CompiledMethodProxy >> mareaIsProxyInstalled
    ^ fileName isNil not

Now....I was checking in VM side, method Interpreter >> lookupMethodInClass: class
and still cannot understand how can I get a 'Recursive not understood error encountered' error, because in the previous loop, it MUST find the method dnu, since it is implemented in ProtoObject. I am confused :(

Thanks in advance for any help

Mariano

On Mon, Dec 6, 2010 at 10:09 PM, Mariano Martinez Peck <[hidden email]> wrote:

On Mon, Dec 6, 2010 at 8:34 PM, John M McIntosh <[hidden email]> wrote:

On 2010-12-06, at 12:38 AM, Mariano Martinez Peck wrote:

You should look at the Objective-C bridge I wrote , the Objective-C proxy object that is based on ProtoObject and contains the

required methods to ensure a debugger will come up. It *does* override does not understand so it can transform the unknown
message into a primitive call.

Excellent!! How can I load such code? (squeaksource is down now and I cannot search)

Thanks John!

Mariano

http://www.squeaksource.com/ObjectiveCBridge2.html

Thanks John, I found it once SqueakSource came back. Now, I still don't understand how is this (adding some methods to ProtoObject for debugging, inspecting, printing) related to the "Recursive not understood error encountered" crash ? or this is just extra help information ? ;)

Cheers

Mariano

--
===========================================================================

John M. McIntosh <[hidden email]> Twitter: squeaker68882

Corporate Smalltalk Consulting Ltd. http://www.smalltalkconsulting.com
===========================================================================

Mariano Martinez Peck

Re: Recursive not understood error encountered

Ok....I found the problem....it was what you said, but it was difficult for me.

I had this:

AbstractCompiledMethodProxy >> doesNotUnderstand: aMessage
    self mareaIsProxyInstalled
        ifTrue: [ ^ CompiledMethodProxyHandler mareaHandleDoesNotUnderstand: aMessage forProxy: self]
        ifFalse: [ ^ super doesNotUnderstand: aMessage ].

and I thought that ALL classes extend from ProtoObject, and not from nil (I thought the only subclass from nil was ProtoObject). But I was wrong, nil has another subclass: PseudoContext.
So...I was trying to swap out/in a CompiledMethod of PseudoContext, which of course, crashed the VM, because the #doesNotUnderstand: was not found in PseudoContext.

Funny, I learnt :)

Cheers

Mariano

On Tue, Dec 7, 2010 at 1:52 PM, Mariano Martinez Peck <[hidden email]> wrote:

In my case, the proxy class is CompiledMethodProxy and it is a subclass of AbstractCompiledMethodProxy which is a subclass of ProtoObject.

In AbstractCompiledMethodProxy I have:

AbstractCompiledMethodProxy >> doesNotUnderstand: aMessage
    self mareaIsProxyInstalled
        ifTrue: [ ^ CompiledMethodProxyHandler mareaHandleDoesNotUnderstand: aMessage forProxy: self]
        ifFalse: [ ^ super doesNotUnderstand: aMessage ].


CompiledMethodProxy >> mareaIsProxyInstalled
    ^ fileName isNil not

Now....I was checking in VM side, method Interpreter >> lookupMethodInClass: class
and still cannot understand how can I get a 'Recursive not understood error encountered' error, because in the previous loop, it MUST find the method dnu, since it is implemented in ProtoObject. I am confused :(

Thanks in advance for any help

Mariano

On Mon, Dec 6, 2010 at 10:09 PM, Mariano Martinez Peck <[hidden email]> wrote:

On Mon, Dec 6, 2010 at 8:34 PM, John M McIntosh <[hidden email]> wrote:

On 2010-12-06, at 12:38 AM, Mariano Martinez Peck wrote:

You should look at the Objective-C bridge I wrote , the Objective-C proxy object that is based on ProtoObject and contains the

required methods to ensure a debugger will come up. It *does* override does not understand so it can transform the unknown
message into a primitive call.

Excellent!! How can I load such code? (squeaksource is down now and I cannot search)

Thanks John!

Mariano

http://www.squeaksource.com/ObjectiveCBridge2.html

Thanks John, I found it once SqueakSource came back. Now, I still don't understand how is this (adding some methods to ProtoObject for debugging, inspecting, printing) related to the "Recursive not understood error encountered" crash ? or this is just extra help information ? ;)

Cheers

Mariano

--
===========================================================================

John M. McIntosh <[hidden email]> Twitter: squeaker68882

Corporate Smalltalk Consulting Ltd.  http://www.smalltalkconsulting.com
===========================================================================