Re: [Pharo-users] FFI structs
This is good news !
Annick
Le 30 oct. 2014 à 23:37, stepharo steph...@free.fr a écrit :
Ronie is working on unifying all the api and proposing one syntax mechanism
for
- nativeBoost back-end
- FFI
and may be Alien
The FFI situation is not good and we know we should improve it.
On 29/10/14 20:18, Thomas Bany wrote:
Oops, sorry, I was misslead by Steph reply.
Some of the comments might still hold. For the time: ’05:45’ code to work,
you would need FFI to handle all the hassle of memory management and
actually allocate the memory for 5 characters and copying it. I never used
FFI but I doubt it does this.
Looking at FFI library, you both have ExternalAddress (for the struct with
char*) and ExternalType (for the struct with char[5]) that you can use. For
the later solution, it still looks like you should define a specific 5 bytes
ArrayOf5Char type.
2014-10-29 18:34 GMT+01:00 Annick Fron l...@afceurope.com:
I can’t use NativeBoost on the Raspberry, I would be glad if I could !!!
Le 29 oct. 2014 à 12:18, stepharo steph...@free.fr a écrit :
did you read the NativeBoost tutorial on the PharoForTheEntreprise book?
If you do please report potential mistakes so that we can improve.
On 29/10/14 05:59, Annick Fron wrote:
I I have a C struct with a char*
struct result {
char* time }
I define an ExternalStructure in FFI , with one field of type char* (note
that the syntax char [5] is not accepted ! ).
defineFields generates the accessors time and time:
If I use
time: ’05:45’
I get an error.
How do I set a string value in an ExternalStructure ?
Annick
Re: [Pharo-users] FFI structs
Hi Ronie,
Great that you work on a threaded FFI because it is a pain for some
libraries. FFI ODBC for example, works very well but is not usable in
real applications because of sql locks that locks the pharo vm.
I don't like FFI too much, NativeBoost is much better, unfortunately I don't
know about other libraries you are talking about (Alien, LowCode and UFFI),
but if you achieve doing something better than NativeBoost, it will be a
great thing.
I wish you succeed.
Regards,
Alain
Le 01/11/2014 00:54, Ronie Salgado a écrit :
Ronie is working on unifying all the api and proposing one syntax
mechanism for
- nativeBoost back-end
- FFI
and may be Alien
I had a skype session with Eliot the last. He taught me about the
callback mechanism and I am actually going to use Alien for the
callbacks, by adapting it to perform the marshalling into the
UFFI/NativeBoost types.
In the future, I am planning in using Lowcode to perform the whole
callback process, but now for simplicity I am just going to piggy back
in Alien.
I still have to finish the callout by fixing a complicated bug. With
Eliot we discussed a workaround for this bug. I haven't implemented
those workaround yet, because I have been a bit busy with my university
studies.
As long as we keep what is working, ahem, working. I now depend on
quite a couple of FFI related libs.
What I need is an easy FFI wrapping tool, like
https://github.com/ronsaldo/swig. Is UFFI going that way?
Well, I made the swig adaptation for NativeBoost. Making it for the UFFI
is actually something trivial. So, we are going to have a powerful FFI
and a binding generator for it.
The only problem with Swig, is that the bindings generated by it are not
perfect, because it exposes the exact same C API. A C library that uses
some kind of object model, cannot be exposed in a clean object oriented
way cleanly by a generic automatic tool.
The FFI situation is not good and we know we should improve it.
For the record, the current FFI situation can be traced to the
historical origins of Smalltalk and even Squeak. The original Smalltalk
was an actual operating system, and Squeak was also made as an operating
system. Because of this, they were not designed to interact with other
languages.
Getting a perfect FFI is going to take a lot of time, because of other
problems, such as Multi-threading and the mandatory use of non-blocking
IO. Fortunately, Eliot made a way to have a threaded FFI, in which a
single thread owns the VM at a single time. With this threaded FFI we
can have things such as a callback from a different thread, which is
required by some libraries such as the sound API of SDL2.
Of course the UFFI is going to support this threaded FFI in some point
of time. To support the threaded FFI I only have to pin/unpin some
object, and call two VM functions, disownVM() and ownVM().
As for getting some actual parallelism in Pharo, this is something that
I think is going to take a big amount of time. For now the best thing we
can do is to use OpenCL. This week I have been doing some experimenting
in making an API for linear algebra, that uses OpenCL to perform
computations in parallel. Later I will publish a video.
Greetings,
Ronie
2014-10-31 19:23 GMT-03:00 Alain Rastoul
alf.mmm@gmail.com
mailto:alf.mmm@gmail.com:
Hi Annick,
you can't pass smalltalk strings or objects to ffi as parameters,
you have to allocate the buffer member of your structure
on the external heap ( plus to avoid being gc'd before ffi call)
with ExternalAddress allocate: your buffer/string size +1 for
string null termination
fill your buffer with byteAt:put: method,
and release this memory with free when you have finished.
not sure, but you could try something like:
s := '05:45' copyWith: (Character value: 0).
a := ExternalAddress allocate: s size.
s asByteArray withIndexDo: [ :b :i | a byteAt: i put: b ].
myStruct time: a.
... call your ffi ...
a free
Regards,
Alain
Le 29/10/2014 11:59, Annick Fron a écrit :
I I have a C struct with a char*
struct result {
char* time }
I define an ExternalStructure in FFI , with one field of type
char* (note that the syntax char [5] is not accepted ! ).
defineFields generates the accessors time and time:
If I use
time: ’05:45’
I get an error.
How do I set a string value in an ExternalStructure ?
Annick
Re: [Pharo-users] FFI structs
On Fri, Oct 31, 2014 at 6:51 AM, Tudor Girba tu...@tudorgirba.com wrote:
That is cool.
As long as we keep what is working, ahem, working. I now depend on quite a
couple of FFI related libs.
What I need is an easy FFI wrapping tool, like
https://github.com/ronsaldo/swig. Is UFFI going that way?
Phil
Doru
On Thu, Oct 30, 2014 at 11:37 PM, stepharo steph...@free.fr wrote:
Ronie is working on unifying all the api and proposing one syntax
mechanism for
- nativeBoost back-end
- FFI
and may be Alien
The FFI situation is not good and we know we should improve it.
On 29/10/14 20:18, Thomas Bany wrote:
Oops, sorry, I was misslead by Steph reply.
Some of the comments might still hold. For the *time: ’05:45’* code to
work, you would need FFI to handle all the hassle of memory management and
actually allocate the memory for 5 characters and copying it. I never used
FFI but I doubt it does this.
Looking at FFI library, you both have ExternalAddress (for the struct
with char*) and ExternalType (for the struct with char[5]) that you can
use. For the later solution, it still looks like you should define a
specific 5 bytes ArrayOf5Char type.
2014-10-29 18:34 GMT+01:00 Annick Fron l...@afceurope.com:
I can’t use NativeBoost on the Raspberry, I would be glad if I could !!!
Le 29 oct. 2014 à 12:18, stepharo steph...@free.fr a écrit :
did you read the NativeBoost tutorial on the PharoForTheEntreprise
book?
If you do please report potential mistakes so that we can improve.
On 29/10/14 05:59, Annick Fron wrote:
I I have a C struct with a char*
struct result {
char* time }
I define an ExternalStructure in FFI , with one field of type char*
(note that the syntax char [5] is not accepted ! ).
defineFields generates the accessors time and time:
If I use
time: ’05:45’
I get an error.
How do I set a string value in an ExternalStructure ?
Annick
--
www.tudorgirba.com
Every thing has its own flow
Re: [Pharo-users] FFI structs
Ronie is working on unifying all the api and proposing one syntax
mechanism for
- nativeBoost back-end
- FFI
and may be Alien
I had a skype session with Eliot the last. He taught me about the callback
mechanism and I am actually going to use Alien for the callbacks, by
adapting it to perform the marshalling into the UFFI/NativeBoost types.
In the future, I am planning in using Lowcode to perform the whole callback
process, but now for simplicity I am just going to piggy back in Alien.
I still have to finish the callout by fixing a complicated bug. With Eliot
we discussed a workaround for this bug. I haven't implemented those
workaround yet, because I have been a bit busy with my university studies.
As long as we keep what is working, ahem, working. I now depend on quite a
couple of FFI related libs.
What I need is an easy FFI wrapping tool, like
https://github.com/ronsaldo/swig. Is UFFI going that way?
Well, I made the swig adaptation for NativeBoost. Making it for the UFFI is
actually something trivial. So, we are going to have a powerful FFI and a
binding generator for it.
The only problem with Swig, is that the bindings generated by it are not
perfect, because it exposes the exact same C API. A C library that uses
some kind of object model, cannot be exposed in a clean object oriented way
cleanly by a generic automatic tool.
The FFI situation is not good and we know we should improve it.
For the record, the current FFI situation can be traced to the historical
origins of Smalltalk and even Squeak. The original Smalltalk was an actual
operating system, and Squeak was also made as an operating system. Because
of this, they were not designed to interact with other languages.
Getting a perfect FFI is going to take a lot of time, because of other
problems, such as Multi-threading and the mandatory use of non-blocking IO.
Fortunately, Eliot made a way to have a threaded FFI, in which a single
thread owns the VM at a single time. With this threaded FFI we can have
things such as a callback from a different thread, which is required by
some libraries such as the sound API of SDL2.
Of course the UFFI is going to support this threaded FFI in some point of
time. To support the threaded FFI I only have to pin/unpin some object, and
call two VM functions, disownVM() and ownVM().
As for getting some actual parallelism in Pharo, this is something that I
think is going to take a big amount of time. For now the best thing we can
do is to use OpenCL. This week I have been doing some experimenting in
making an API for linear algebra, that uses OpenCL to perform computations
in parallel. Later I will publish a video.
Greetings,
Ronie
2014-10-31 19:23 GMT-03:00 Alain Rastoul alf.mmm@gmail.com:
Hi Annick,
you can't pass smalltalk strings or objects to ffi as parameters,
you have to allocate the buffer member of your structure
on the external heap ( plus to avoid being gc'd before ffi call)
with ExternalAddress allocate: your buffer/string size +1 for string null
termination
fill your buffer with byteAt:put: method,
and release this memory with free when you have finished.
not sure, but you could try something like:
s := '05:45' copyWith: (Character value: 0).
a := ExternalAddress allocate: s size.
s asByteArray withIndexDo: [ :b :i | a byteAt: i put: b ].
myStruct time: a.
... call your ffi ...
a free
Regards,
Alain
Le 29/10/2014 11:59, Annick Fron a écrit :
I I have a C struct with a char*
struct result {
char* time }
I define an ExternalStructure in FFI , with one field of type char* (note
that the syntax char [5] is not accepted ! ).
defineFields generates the accessors time and time:
If I use
time: ’05:45’
I get an error.
How do I set a string value in an ExternalStructure ?
Annick
Re: [Pharo-users] FFI structs
Ronie is working on unifying all the api and proposing one syntax
mechanism for
- nativeBoost back-end
- FFI
and may be Alien
The FFI situation is not good and we know we should improve it.
On 29/10/14 20:18, Thomas Bany wrote:
Oops, sorry, I was misslead by Steph reply.
Some of the comments might still hold. For the /time: ’05:45’/ code to
work, you would need FFI to handle all the hassle of memory management
and actually allocate the memory for 5 characters and copying it. I
never used FFI but I doubt it does this.
Looking at FFI library, you both have ExternalAddress (for the struct
with char*) and ExternalType (for the struct with char[5]) that you
can use. For the later solution, it still looks like you should define
a specific 5 bytes ArrayOf5Char type.
2014-10-29 18:34 GMT+01:00 Annick Fron l...@afceurope.com
mailto:l...@afceurope.com:
I can’t use NativeBoost on the Raspberry, I would be glad if I
could !!!
Le 29 oct. 2014 à 12:18, stepharo steph...@free.fr
mailto:steph...@free.fr a écrit :
did you read the NativeBoost tutorial on the
PharoForTheEntreprise book?
If you do please report potential mistakes so that we can improve.
On 29/10/14 05:59, Annick Fron wrote:
I I have a C struct with a char*
struct result {
char* time }
I define an ExternalStructure in FFI , with one field of type
char* (note that the syntax char [5] is not accepted ! ).
defineFields generates the accessors time and time:
If I use
time: ’05:45’
I get an error.
How do I set a string value in an ExternalStructure ?
Annick
Re: [Pharo-users] FFI structs
That is cool.
Doru
On Thu, Oct 30, 2014 at 11:37 PM, stepharo steph...@free.fr wrote:
Ronie is working on unifying all the api and proposing one syntax
mechanism for
- nativeBoost back-end
- FFI
and may be Alien
The FFI situation is not good and we know we should improve it.
On 29/10/14 20:18, Thomas Bany wrote:
Oops, sorry, I was misslead by Steph reply.
Some of the comments might still hold. For the *time: ’05:45’* code to
work, you would need FFI to handle all the hassle of memory management and
actually allocate the memory for 5 characters and copying it. I never used
FFI but I doubt it does this.
Looking at FFI library, you both have ExternalAddress (for the struct
with char*) and ExternalType (for the struct with char[5]) that you can
use. For the later solution, it still looks like you should define a
specific 5 bytes ArrayOf5Char type.
2014-10-29 18:34 GMT+01:00 Annick Fron l...@afceurope.com:
I can’t use NativeBoost on the Raspberry, I would be glad if I could !!!
Le 29 oct. 2014 à 12:18, stepharo steph...@free.fr a écrit :
did you read the NativeBoost tutorial on the PharoForTheEntreprise book?
If you do please report potential mistakes so that we can improve.
On 29/10/14 05:59, Annick Fron wrote:
I I have a C struct with a char*
struct result {
char* time }
I define an ExternalStructure in FFI , with one field of type char*
(note that the syntax char [5] is not accepted ! ).
defineFields generates the accessors time and time:
If I use
time: ’05:45’
I get an error.
How do I set a string value in an ExternalStructure ?
Annick
--
www.tudorgirba.com
Every thing has its own flow
Re: [Pharo-users] FFI structs
did you read the NativeBoost tutorial on the PharoForTheEntreprise book?
If you do please report potential mistakes so that we can improve.
On 29/10/14 05:59, Annick Fron wrote:
I I have a C struct with a char*
struct result {
char* time }
I define an ExternalStructure in FFI , with one field of type char* (note that
the syntax char [5] is not accepted ! ).
defineFields generates the accessors time and time:
If I use
time: ’05:45’
I get an error.
How do I set a string value in an ExternalStructure ?
Annick
Re: [Pharo-users] FFI structs
Hi Annick !
I'll explain first why you got the error.
The assignment time: ’05:45’ failed because you tried to put an array of
char (of size 5*sizeof(char)) inside an address.
At some point, you need to allocate the memory that will hold the data. In
your case, you can do it quite easily with the class-side method
#fromString: of class NBExternalAdress. This will return a pointer, which
you can assign to the field of your struct.
Regarding what you really want to do, having a char[5] field in your
struct, I'm not totaly sure how you can do it with NativeBoost. A C struc
is just a chunk of memory with a well defined size, so if you want to
specify a field as a char[5], you must have a type that match that size. It
does not look like the field parser of NBExternalStruct can do it
dynamicaly. You could maybe hard code it by subclassing NBExternalType into
NBExternalArrayOf5Char, with a valueSize of 5.
As a final word, be wary of where you have allocated your objects, whether
it is in object-space (#new), or in C heap (#externalNew). The first is
garbage collected so the address are volatile, but you bare the duty of
freeing the memory in the second.
2014-10-29 12:18 GMT+01:00 stepharo steph...@free.fr:
did you read the NativeBoost tutorial on the PharoForTheEntreprise book?
If you do please report potential mistakes so that we can improve.
On 29/10/14 05:59, Annick Fron wrote:
I I have a C struct with a char*
struct result {
char* time }
I define an ExternalStructure in FFI , with one field of type char* (note
that the syntax char [5] is not accepted ! ).
defineFields generates the accessors time and time:
If I use
time: ’05:45’
I get an error.
How do I set a string value in an ExternalStructure ?
Annick
Re: [Pharo-users] FFI structs
I can’t use NativeBoost on the Raspberry, I would be glad if I could !!!
Le 29 oct. 2014 à 12:18, stepharo steph...@free.fr a écrit :
did you read the NativeBoost tutorial on the PharoForTheEntreprise book?
If you do please report potential mistakes so that we can improve.
On 29/10/14 05:59, Annick Fron wrote:
I I have a C struct with a char*
struct result {
char* time }
I define an ExternalStructure in FFI , with one field of type char* (note
that the syntax char [5] is not accepted ! ).
defineFields generates the accessors time and time:
If I use
time: ’05:45’
I get an error.
How do I set a string value in an ExternalStructure ?
Annick
Re: [Pharo-users] FFI structs
Oops, sorry, I was misslead by Steph reply.
Some of the comments might still hold. For the *time: ’05:45’* code to
work, you would need FFI to handle all the hassle of memory management and
actually allocate the memory for 5 characters and copying it. I never used
FFI but I doubt it does this.
Looking at FFI library, you both have ExternalAddress (for the struct with
char*) and ExternalType (for the struct with char[5]) that you can use. For
the later solution, it still looks like you should define a specific 5
bytes ArrayOf5Char type.
2014-10-29 18:34 GMT+01:00 Annick Fron l...@afceurope.com:
I can’t use NativeBoost on the Raspberry, I would be glad if I could !!!
Le 29 oct. 2014 à 12:18, stepharo steph...@free.fr a écrit :
did you read the NativeBoost tutorial on the PharoForTheEntreprise book?
If you do please report potential mistakes so that we can improve.
On 29/10/14 05:59, Annick Fron wrote:
I I have a C struct with a char*
struct result {
char* time }
I define an ExternalStructure in FFI , with one field of type char*
(note that the syntax char [5] is not accepted ! ).
defineFields generates the accessors time and time:
If I use
time: ’05:45’
I get an error.
How do I set a string value in an ExternalStructure ?
Annick
