On 1 March 2017 at 05:42, Alexander Samoylovich <samoylov...@gmail.com> wrote:
> Thanks everybody for the explanation. > > I tried to apply Igor's suggestion. I allocate an offscreen surface 1 row > larger than needed > and when converting discard one row. > > The code looks more stable now. The test was up for about 30 minutes > before crashing instead of 1 minute before the fix. > Is it the right code change or just a coincidence? > > > AthensCairoSurface>>asForm > > > "create a form and copy an image data there" > > self checkSession. > > self flush. > > ^ Form extent: (self width@self height) - (0@1) depth: 32 bits: id > > no, it isn't . This is how it supposed to be there. But the problem is when you using surfaces for bitmaps in Cairo itself, you're screwed since AthensCairoSurface purposedly makes it 1 row taller, while for texture you want it to contain exact height, else you'll obviously have artifacts. :( So, the point is: if you creating a surface that will be used by bitblt (asForm), then you should allocate 1 extra row, else you shouldn't.. And there's no workaround to match such behavior in single class, since it doesn't knows what it will be used for :( > > On Mon, Feb 27, 2017 at 2:39 PM, Stephane Ducasse <stepharo.s...@gmail.com > > wrote: > >> Tx igor I added >> >> https://pharo.fogbugz.com/f/cases/19764/Improve-comment-of- >> AthensCairoSurfaceForm >> >> On Mon, Feb 27, 2017 at 7:35 PM, Igor Stasenko <siguc...@gmail.com> >> wrote: >> >>> and i was dealing with it by adding 1 extra line to cairo surface, >>> but reporting 1 less to Form. Like so, bitblt still reads past the >>> allowed size, but it is safe, because there are unused bit(s). >>> >>> On 27 February 2017 at 20:31, Igor Stasenko <siguc...@gmail.com> wrote: >>> >>>> >>>> >>>> On 27 February 2017 at 12:29, Esteban Lorenzano <esteba...@gmail.com> >>>> wrote: >>>> >>>>> Hi, >>>>> >>>>> the problem wit Ronie’s fix is that (as he says) you are copying >>>>> another time the surface, before passing it to the VM (who makes >>>>> yet-another-copy) so this is not optimal… and you can see it when running >>>>> the Tiger demo: there are a lot of pauses. >>>>> So I would prefer the other approach he suggests: >>>>> >>>>> Form subclass: #AthensCairoSurfaceForm >>>>> instanceVariableNames: 'surface' >>>>> classVariableNames: '' >>>>> package: 'Athens-Cairo' >>>>> >>>>> AthensCairoSurfaceForm>>surface >>>>> ^ surface >>>>> >>>>> AthensCairoSurfaceForm>>surface: anObject >>>>> surface := anObject >>>>> >>>>> AthensCairoSurface>>asForm >>>>> "create a form and copy an image data there" >>>>> self checkSession. >>>>> self flush. >>>>> ^ (AthensCairoSurfaceForm extent: (self width@self height) >>>>> depth: 32 bits: id) >>>>> surface: self; >>>>> yourself >>>>> >>>>> that seems to work. Can you try and see? >>>>> >>>>> >>>> Btw, remember the culprit there , that you must have extra word in >>>> trailing buffer space, >>>> this is because bit-blt using read-ahead . Which is OK for objects >>>> located in object memory, >>>> since there are always something past the last object (unallocated >>>> space), >>>> but not so ok for buffers allocated by malloc (such as cairo surface >>>> bitmap), and so, >>>> if you read even a single byte past it, you get protection fault. >>>> >>>> >>>>> Esteban >>>>> >>>>> > On 24 Feb 2017, at 15:47, stepharong <stephar...@free.fr> wrote: >>>>> > >>>>> > Hi alex >>>>> > >>>>> > can you try the fix of ronie and let us know if it makes roassal >>>>> more stable? >>>>> > >>>>> > Stef >>>>> > >>>>> >> Dear Alexander, >>>>> >> >>>>> >> Sine the new FFI of Pharo, using Athens has become unreliable. This >>>>> is a pity, but fixing this is not trivial at all (we have been trying for >>>>> years). >>>>> >> >>>>> >> What exactly are you doing with Athens? >>>>> >> >>>>> >> Alexandre >>>>> >> >>>>> >> >>>>> >>> On Feb 22, 2017, at 12:55 AM, Alexander Samoylovich < >>>>> samoylov...@gmail.com> wrote: >>>>> >>> >>>>> >>> Hello >>>>> >>> >>>>> >>> I am writing graphic demo programs using Athens on Mac Sierra. >>>>> >>> Time by time Pharo VM crashes. Programs not using Athens work >>>>> reliably. >>>>> >>> I believe the behavior is reproducible. >>>>> >>> How should I report a bug? >>>>> >>> >>>>> >>> Alex >>>>> >> >>>>> > >>>>> > >>>>> > -- >>>>> > Using Opera's mail client: http://www.opera.com/mail/ >>>>> > >>>>> >>>>> >>>>> >>>> >>>> >>>> -- >>>> Best regards, >>>> Igor Stasenko. >>>> >>> >>> >>> >>> -- >>> Best regards, >>> Igor Stasenko. >>> >> >> > -- Best regards, Igor Stasenko.
