I don't think it's a good idea to change any code to work around a temporary VM bug. I have seen this error in other cases as well (sockets) and I decided to revert the VM to 3397. I haven't reported the bug yet, because I don't have a reproducible case. The only symptom I saw is that the instance variables get mixed with temporaries (including method arguments).
Levente
On Tue, 20 Oct 2015, commits@source.squeak.org wrote:
Marcel Taeumel uploaded a new version of Graphics to project Squeak 4.6: http://source.squeak.org/squeak46/Graphics-mt.316.mcz
==================== Summary ====================
Name: Graphics-mt.316 Author: mt Time: 20 October 2015, 11:40:19.755 am UUID: 41cf59e1-6149-7e4b-9d40-485a1f4798ef Ancestors: Graphics-mt.313
Fixes loading of PNG files for recent (> #3397) v3 CogVMs.
There seems to be a bug in the VM that, at some point, manifests itself by replacing z, which is the current ZLib stream, with self, which is the PNGReadWriter. Any indirection with a BlockClosure will do. I chose to create an interval and then calling #do: on that interval. Another way would be to wrap the body/argument of #to:do: into another block like this:
0 to: height-1 do: [:y | [ ... ] value ].
This fix might affect performance a tiny little bit and might be removed as soon as the VM bug gets fixed.
Note that there might be other places in the code affected by this bug.
=============== Diff against Graphics-mt.313 ===============
Item was changed: ----- Method: PNGReadWriter>>processNonInterlaced (in category 'chunks') ----- processNonInterlaced | z filter temp copyMethod debug | debug := self debugging. copyMethod := #(copyPixelsGray: nil copyPixelsRGB: copyPixelsIndexed: copyPixelsGrayAlpha: nil copyPixelsRGBA:) at: colorType+1. debug ifTrue: [ Transcript cr; nextPutAll: 'NI chunk size='; print: idatChunkStream position ]. z := ZLibReadStream on: idatChunkStream originalContents from: 1 to: idatChunkStream position. prevScanline := ByteArray new: bytesPerScanline. thisScanline := ByteArray new: bytesPerScanline.
- (0 to: height-1) do: [ :y |
- 0 to: height-1 do: [ :y | filter := z next. debug ifTrue:[filtersSeen add: filter]. thisScanline := z next: bytesPerScanline into: thisScanline startingAt: 1. (debug and: [ thisScanline size < bytesPerScanline ]) ifTrue: [ Transcript nextPutAll: ('wanted {1} but only got {2}' format: { bytesPerScanline. thisScanline size }); cr ]. filter = 0 ifFalse:[self filterScanline: filter count: bytesPerScanline]. self perform: copyMethod with: y. temp := prevScanline. prevScanline := thisScanline. thisScanline := temp. ]. z atEnd ifFalse:[self error:'Unexpected data']. debug ifTrue: [Transcript nextPutAll: ' compressed size='; print: z position ].
!
Usually, I would agree. But we did already release Squeak 4.6 and thus have to react quickly if it does not messes things up, which this fix does not. :)
Best, Marcel
-- View this message in context: http://forum.world.st/Squeak-4-6-Graphics-mt-316-mcz-tp4856712p4856721.html Sent from the Squeak - Dev mailing list archive at Nabble.com.
The release comes with the 3397 VM, which works fine. Your fix works the bug around in a single method, but I'm sure there are hundreds of places where the issue can occur.
Levente
On Tue, 20 Oct 2015, marcel.taeumel wrote:
Usually, I would agree. But we did already release Squeak 4.6 and thus have to react quickly if it does not messes things up, which this fix does not. :)
Best, Marcel
-- View this message in context: http://forum.world.st/Squeak-4-6-Graphics-mt-316-mcz-tp4856712p4856721.html Sent from the Squeak - Dev mailing list archive at Nabble.com.
It works OK with stack VM, so I confirm it's a JIT thing So far I saw it only in cog v3, but not in cog spur
2015-10-20 11:58 GMT+02:00 Levente Uzonyi leves@elte.hu:
The release comes with the 3397 VM, which works fine. Your fix works the bug around in a single method, but I'm sure there are hundreds of places where the issue can occur.
Levente
On Tue, 20 Oct 2015, marcel.taeumel wrote:
Usually, I would agree. But we did already release Squeak 4.6 and thus have
to react quickly if it does not messes things up, which this fix does not. :)
Best, Marcel
-- View this message in context: http://forum.world.st/Squeak-4-6-Graphics-mt-316-mcz-tp4856712p4856721.html Sent from the Squeak - Dev mailing list archive at Nabble.com.
And if you update the VM, it will break. And if you update the image, now, it will work again. ;-)
Well, here is the thing: I am not able to fix that VM/JIT bug although I would rather like to. If you can fix it, please go ahead. If Eliot finds time for it -- well, it works in Spur and Stack versions -- he will surely do it.
Until then, we should fix it if possible to improve user experience. If you find any other of those hundreds of places, please consider fixing them as well. Not into trunk, but Squeak46 branch.
This VM bug has been known since mid of September at least: http://forum.world.st/Non-Spur-CogVM-3427-and-3410-cannot-load-PNG-files-any...
Nothing has happened yet.
Best, Marcel
-- View this message in context: http://forum.world.st/Squeak-4-6-Graphics-mt-316-mcz-tp4856712p4856747.html Sent from the Squeak - Dev mailing list archive at Nabble.com.
BTW, I had a fairly reproducible case, didn't I send it to this list? Ah no, it was pharo...
ScaledDecimalTests>>testCoercion
https://www.mail-archive.com/pharo-dev@lists.pharo.org/msg31997.html
2015-10-20 15:26 GMT+02:00 marcel.taeumel Marcel.Taeumel@hpi.de:
And if you update the VM, it will break. And if you update the image, now, it will work again. ;-)
Well, here is the thing: I am not able to fix that VM/JIT bug although I would rather like to. If you can fix it, please go ahead. If Eliot finds time for it -- well, it works in Spur and Stack versions -- he will surely do it.
Until then, we should fix it if possible to improve user experience. If you find any other of those hundreds of places, please consider fixing them as well. Not into trunk, but Squeak46 branch.
This VM bug has been known since mid of September at least:
http://forum.world.st/Non-Spur-CogVM-3427-and-3410-cannot-load-PNG-files-any...
Nothing has happened yet.
Best, Marcel
-- View this message in context: http://forum.world.st/Squeak-4-6-Graphics-mt-316-mcz-tp4856712p4856747.html Sent from the Squeak - Dev mailing list archive at Nabble.com.
Nicolas,
what's (where's) the reproducible case?
On Tue, Oct 20, 2015 at 8:52 AM, Nicolas Cellier < nicolas.cellier.aka.nice@gmail.com> wrote:
BTW, I had a fairly reproducible case, didn't I send it to this list? Ah no, it was pharo...
ScaledDecimalTests>>testCoercion
https://www.mail-archive.com/pharo-dev@lists.pharo.org/msg31997.html
2015-10-20 15:26 GMT+02:00 marcel.taeumel Marcel.Taeumel@hpi.de:
And if you update the VM, it will break. And if you update the image, now, it will work again. ;-)
Well, here is the thing: I am not able to fix that VM/JIT bug although I would rather like to. If you can fix it, please go ahead. If Eliot finds time for it -- well, it works in Spur and Stack versions -- he will surely do it.
Until then, we should fix it if possible to improve user experience. If you find any other of those hundreds of places, please consider fixing them as well. Not into trunk, but Squeak46 branch.
This VM bug has been known since mid of September at least:
http://forum.world.st/Non-Spur-CogVM-3427-and-3410-cannot-load-PNG-files-any...
Nothing has happened yet.
Best, Marcel
-- View this message in context: http://forum.world.st/Squeak-4-6-Graphics-mt-316-mcz-tp4856712p4856747.html Sent from the Squeak - Dev mailing list archive at Nabble.com.
Running that test case on the latest V3 CogVM (3427) should give you a debugger where the receiver got mixed up with some other variable.
Levente
On Fri, 23 Oct 2015, Eliot Miranda wrote:
Nicolas, what's (where's) the reproducible case?
On Tue, Oct 20, 2015 at 8:52 AM, Nicolas Cellier nicolas.cellier.aka.nice@gmail.com wrote: BTW, I had a fairly reproducible case, didn't I send it to this list? Ah no, it was pharo...
ScaledDecimalTests>>testCoercion
https://www.mail-archive.com/pharo-dev@lists.pharo.org/msg31997.html2015-10-20 15:26 GMT+02:00 marcel.taeumel Marcel.Taeumel@hpi.de: And if you update the VM, it will break. And if you update the image, now, it will work again. ;-)
Well, here is the thing: I am not able to fix that VM/JIT bug although I would rather like to. If you can fix it, please go ahead. If Eliot finds time for it -- well, it works in Spur and Stack versions -- he will surely do it. Until then, we should fix it if possible to improve user experience. If you find any other of those hundreds of places, please consider fixing them as well. Not into trunk, but Squeak46 branch. This VM bug has been known since mid of September at least: http://forum.world.st/Non-Spur-CogVM-3427-and-3410-cannot-load-PNG-files-anymore-td4850308.html Nothing has happened yet. Best, Marcel -- View this message in context: http://forum.world.st/Squeak-4-6-Graphics-mt-316-mcz-tp4856712p4856747.html Sent from the Squeak - Dev mailing list archive at Nabble.com.-- _,,,^..^,,,_ best, Eliot
Hi Eliot, the test case is :
ScaledDecimalTest new testCoercion
2015-10-24 15:54 GMT+02:00 Levente Uzonyi leves@elte.hu:
Running that test case on the latest V3 CogVM (3427) should give you a debugger where the receiver got mixed up with some other variable.
Levente
On Fri, 23 Oct 2015, Eliot Miranda wrote:
Nicolas,
what's (where's) the reproducible case?
On Tue, Oct 20, 2015 at 8:52 AM, Nicolas Cellier < nicolas.cellier.aka.nice@gmail.com> wrote: BTW, I had a fairly reproducible case, didn't I send it to this list? Ah no, it was pharo...
ScaledDecimalTests>>testCoercion
https://www.mail-archive.com/pharo-dev@lists.pharo.org/msg31997.html
2015-10-20 15:26 GMT+02:00 marcel.taeumel Marcel.Taeumel@hpi.de: And if you update the VM, it will break. And if you update the image, now, it will work again. ;-)
Well, here is the thing: I am not able to fix that VM/JIT bugalthough I would rather like to. If you can fix it, please go ahead. If Eliot finds time for it -- well, it works in Spur and Stack versions -- he will surely do it.
Until then, we should fix it if possible to improve userexperience. If you find any other of those hundreds of places, please consider fixing them as well. Not into trunk, but Squeak46 branch.
This VM bug has been known since mid of September at least:http://forum.world.st/Non-Spur-CogVM-3427-and-3410-cannot-load-PNG-files-any...
Nothing has happened yet. Best, Marcel -- View this message in context:http://forum.world.st/Squeak-4-6-Graphics-mt-316-mcz-tp4856712p4856747.html Sent from the Squeak - Dev mailing list archive at Nabble.com.
-- _,,,^..^,,,_ best, Eliot
Wouldn't it be better to just warn the users if they're using a VM with broken JIT? For example adding the following to one of the #startUp: method:
(Smalltalk vm isRunningCogit and: [ Smalltalk vm platformSourceVersion asInteger > 3397 ]) ifTrue: [ Warning signal: 'The VM you''re currently using has a bug which may cause unexpected errors in some cases.\Please consider downgrading to version 3397.' withCRs ].
Levente
On Tue, 20 Oct 2015, marcel.taeumel wrote:
And if you update the VM, it will break. And if you update the image, now, it will work again. ;-)
Well, here is the thing: I am not able to fix that VM/JIT bug although I would rather like to. If you can fix it, please go ahead. If Eliot finds time for it -- well, it works in Spur and Stack versions -- he will surely do it.
Until then, we should fix it if possible to improve user experience. If you find any other of those hundreds of places, please consider fixing them as well. Not into trunk, but Squeak46 branch.
This VM bug has been known since mid of September at least: http://forum.world.st/Non-Spur-CogVM-3427-and-3410-cannot-load-PNG-files-any...
Nothing has happened yet.
Best, Marcel
-- View this message in context: http://forum.world.st/Squeak-4-6-Graphics-mt-316-mcz-tp4856712p4856747.html Sent from the Squeak - Dev mailing list archive at Nabble.com.
Sounds reasonable. :)
Best, Marcel
-- View this message in context: http://forum.world.st/Squeak-4-6-Graphics-mt-316-mcz-tp4856712p4857649.html Sent from the Squeak - Dev mailing list archive at Nabble.com.
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