Re: [Pharo-users] question about FFI
> On 26 Nov 2018, at 11:14, Henrik Sperre Johansen via Pharo-users > wrote: > > > From: Henrik Sperre Johansen > Subject: Re: question about FFI > Date: 26 November 2018 at 11:14:26 CET > To: pharo-users@lists.pharo.org > > > Yuriy Babah wrote >> in Playground i'm doing: > * >> #(2 3) doWithIndex: [:each :i | xm at: i put: each]. >> #(3 4) doWithIndex: [:each :i | ym at: i put: each]. > * >> >> whot i'm doing wrong? > > So, you're putting 2 at index 2 of xm, and then writing 3 past end of array, > and in ym you're putting 3 and 4 at offsets past the end of array? > > It's a wonder your image didn't crash, rather than return interpolation of > the uninitialized values… He is not doing that. He is using #doWithIndex: So he is passing 2 at index 1 and 3 at index 2, then 3 at index 1 and 4 at index 2. Esteban > > Cheers, > Henry > > > > -- > Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html > > >
Re: [Pharo-users] question about FFI
> FFIExamples > interpolationFunc_xm: xm getHandle > ym: ym getHandle > size: 2 > x: 2.5 . > cool! it worked !! Thank Esteban Lorenzano and everyone else )
Re: [Pharo-users] question about FFI
Hi, > On 26 Nov 2018, at 09:28, Yuriy Babah wrote: > > Hi ! > > I'm trying to call a very simple function from C ++ lib, writed for the test. > function with prototype: > > extern "C" float interpolationFunc(float* xm, float* ym, int size, float x). > > In Pharo7 wrote: > FFIExamples class >> interpolationFunc_xm: xM ym: yM size: size x: x > ^ self ffiCall: #(float interpolationFunc #(float * xM , float * yM , int > size , float x)) module: 'libinterpolationLib.so' > > in Playground i'm doing: > xm := FFIExternalArray externalNewType: 'float' size: 2. > ym := xm clone. > #(2 3) doWithIndex: [:each :i | xm at: i put: each]. > #(3 4) doWithIndex: [:each :i | ym at: i put: each]. > FFIExamples interpolationFunc_xm: xm pointer ym: ym pointer size: 2 x: 2.5 . This is incorrect. “xm” and “ym” are already pointers (references) When you pass "xm pointer” you are actually passing a pointer to a pointer (a float** in this case) This looks better: FFIExamples interpolationFunc_xm: xm getHandle ym: ym getHandle size: 2 x: 2.5 . Still, you need to do something with those arrays after using them, since you are creating them with externalNewType:… (which mean it allocates the memory space). You will need to send #free to them. Other solution would be to not use #externalNewType:size: but plain #newType:size: Cheers, Esteban > > last expression returninп me 0.0, but right is 3.5. > > I'm dit the same in Python3 ctypes, and there work's fine. > > In UnifiedFFI booklet is absent chapter "Arrays", anybody may help with whot > i'm doing wrong?
Re: [Pharo-users] question about FFI
--- Begin Message --- Nevermind me, hadn't had my coffee yet, for some reason I didn't see it was doWithIndex: you were using :/ Still a bit scary that FFIExternalArray at:put: doesn't perform bounds checks... Cheers, Henry -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html --- End Message ---
Re: [Pharo-users] question about FFI
just in case, and https://www.virustotal.com/ru/file/738460bb6be71b4615581dad1a787cbb80b188e52fe3480ef54b7bfce500f3dd/analysis/1543226071/ пн, 26 нояб. 2018 г. в 12:50, Yuriy Babah : > Thank, i'm trued do this, and i'm got > aBoxedFloat64 4.5879913020458836e-41 , > which is still a very strange value > > пн, 26 нояб. 2018 г. в 12:33, teso...@gmail.com : > >> Hi, >> >>could be the problem that you are using the same external array for >> both xm and ym?. >> The clone message just creates a shallow copy of the external array. >> It does not allocates a new external array, it only copies the address in >> both xm and ym. >> >> You should better do something like this: >> >> xm := FFIExternalArray externalNewType: 'float' size: 2. >> ym := FFIExternalArray externalNewType: 'float' size: 2. >> >> Cheers. >> >> On Mon, Nov 26, 2018 at 9:30 AM Yuriy Babah >> wrote: >> >>> Hi ! >>> >>> I'm trying to call a very simple function from C ++ lib, writed for the >>> test. >>> function with prototype: >>> >>> extern "C" float interpolationFunc(float* xm, float* ym, int size, float >>> x). >>> >>> In Pharo7 wrote: >>> FFIExamples class >> interpolationFunc_xm: xM ym: yM size: size x: x >>> ^ self ffiCall: #(float interpolationFunc #(float * xM , float * yM >>> , int size , float x)) module: 'libinterpolationLib.so' >>> >>> in Playground i'm doing: >>> xm := FFIExternalArray externalNewType: 'float' size: 2. >>> ym := xm clone. >>> #(2 3) doWithIndex: [:each :i | xm at: i put: each]. >>> #(3 4) doWithIndex: [:each :i | ym at: i put: each]. >>> FFIExamples interpolationFunc_xm: xm pointer ym: ym pointer size: 2 x: >>> 2.5 . >>> >>> last expression returninп me 0.0, but right is 3.5. >>> >>> I'm dit the same in Python3 ctypes, and there work's fine. >>> >>> In UnifiedFFI booklet is absent chapter "Arrays", anybody may help with >>> whot i'm doing wrong? >>> >> >> >> -- >> Pablo Tesone. >> teso...@gmail.com >> > libinterpolationLib.so Description: Binary data
Re: [Pharo-users] question about FFI
Hi, could be the problem that you are using the same external array for both xm and ym?. The clone message just creates a shallow copy of the external array. It does not allocates a new external array, it only copies the address in both xm and ym. You should better do something like this: xm := FFIExternalArray externalNewType: 'float' size: 2. ym := FFIExternalArray externalNewType: 'float' size: 2. Cheers. On Mon, Nov 26, 2018 at 9:30 AM Yuriy Babah wrote: > Hi ! > > I'm trying to call a very simple function from C ++ lib, writed for the > test. > function with prototype: > > extern "C" float interpolationFunc(float* xm, float* ym, int size, float > x). > > In Pharo7 wrote: > FFIExamples class >> interpolationFunc_xm: xM ym: yM size: size x: x > ^ self ffiCall: #(float interpolationFunc #(float * xM , float * yM , > int size , float x)) module: 'libinterpolationLib.so' > > in Playground i'm doing: > xm := FFIExternalArray externalNewType: 'float' size: 2. > ym := xm clone. > #(2 3) doWithIndex: [:each :i | xm at: i put: each]. > #(3 4) doWithIndex: [:each :i | ym at: i put: each]. > FFIExamples interpolationFunc_xm: xm pointer ym: ym pointer size: 2 x: > 2.5 . > > last expression returninп me 0.0, but right is 3.5. > > I'm dit the same in Python3 ctypes, and there work's fine. > > In UnifiedFFI booklet is absent chapter "Arrays", anybody may help with > whot i'm doing wrong? > -- Pablo Tesone. teso...@gmail.com
[Pharo-users] question about FFI
Hi ! I'm trying to call a very simple function from C ++ lib, writed for the test. function with prototype: extern "C" float interpolationFunc(float* xm, float* ym, int size, float x). In Pharo7 wrote: FFIExamples class >> interpolationFunc_xm: xM ym: yM size: size x: x ^ self ffiCall: #(float interpolationFunc #(float * xM , float * yM , int size , float x)) module: 'libinterpolationLib.so' in Playground i'm doing: xm := FFIExternalArray externalNewType: 'float' size: 2. ym := xm clone. #(2 3) doWithIndex: [:each :i | xm at: i put: each]. #(3 4) doWithIndex: [:each :i | ym at: i put: each]. FFIExamples interpolationFunc_xm: xm pointer ym: ym pointer size: 2 x: 2.5 . last expression returninп me 0.0, but right is 3.5. I'm dit the same in Python3 ctypes, and there work's fine. In UnifiedFFI booklet is absent chapter "Arrays", anybody may help with whot i'm doing wrong?
