cffi-devel June 2008

cffi-devel@common-lisp.net

14 participants
21 discussions

[cffi-devel] Re: CFFI + Slime + std::cout
by Stephen Compall 28 Jun '08

28 Jun '08

The following message is a courtesy copy of an article that has been posted to comp.lang.lisp as well. Sohail Somani <sohail(a)taggedtype.net> writes: > How can I get Slime to relay the output (through std::cout) of a C++ > function called through CFFI through to the REPL? This is really a CFFI question, and you may wish to send further followups to the CFFI list instead. Create a C++ shared library with a few elements, then load and initialize it using CFFI: 1. A subclass of std::ostream that holds a void(*)(const char*) as an instance variable, forwarding all output received to that function. 2. A function like extern "C" void init_mylispcout (void (*writer) (const char*)); that replaces std::cout with an instance of #1. I forget whether C++ allows you to change std::cout. 3. A CFFI callback in Lisp to be passed to #2, that writes the output on some Lisp stream. 4. A CFFI defcfun on #2. -- But you know how reluctant paranormal phenomena are to reveal themselves when skeptics are present. --Robert Sheaffer, SkI 9/2003

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[cffi-devel] strange behaviour of CFFI with LW on OS X
by Antoine Allombert 25 Jun '08

25 Jun '08

Hello everybody, I face a weird situation with LW and CFFI on OS X 10.4. When I evaluate the form : > (cffi:with-foreign-pointer (ptr 2) (setf (cffi:mem-ref ptr :int 0) 0) (setf (cffi:mem-ref ptr :int 1) 1) (let ((i 0)) (loop for i from 0 below 2 collect (cffi:mem-ref ptr :int i)))) The result is : (256 1) The first value of the pointer has been turned from 0 to 256. I tried other similar tests using explicit "foreign-alloc" with similar results. Note that in each case, the last modified place of the pointer keeps his right value while the value of the other places of the pointer are changed. I use the correct package. So I am wondering if it could be a problem in my system. Any idea or ptoposition welcome. Regards.

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[cffi-devel] WITH-FOREIGN-STRING allocates on heap?
by Hans Hübner 20 Jun '08

20 Jun '08

Hi, is there a good reason why WITH-FOREIGN-STRING allocates the buffer on the heap instead of using WITH-FOREIGN-OBJECT, which will allocate on the stack on platforms that support it? Thanks, -Hans

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[cffi-devel] Re: First usages of CFFI
by Marko Tapio Manninen 17 Jun '08

17 Jun '08

Thanks you for help. That made a trick. I managed to create a small server that responds well with cffi and libevent now. -Marko Stephen Compall kirjoitti 17.6.2008 kello 20.07: > Marko Tapio Manninen <mmstud(a)gmail.com> writes: > >> Thank you for comments. I have advanced with this (actually almost >> ready compared to my starting point), but still im getting an error, >> when server is running and i am trying to get response from it. > > Note the return type here: > >> (defcfun ("evhttp_send_reply" %evhttp-send-reply) :void >> (req evhttp-request) >> (flag :int) >> (msg :string) >> (buf evbuffer)) >> >> ;;; unwind-protect to create evbuffer-new??? >> >> (defcallback generic-handler :pointer ((req :pointer) (arg :pointer)) >> (let ((buf (%evbuffer-new))) >> (if (null buf) >> (format t "Failed to create response buffer") >> (progn >> (%evbuffer-add-printf buf "Requested: %sn" (%evhttp-request-uri >> req)) >> (%evhttp-send-reply req HTTP_OK "OK" buf))))) > > what you answer above from this callback, and what you declared the > return type of the callback to be. > > -- > But you know how reluctant paranormal phenomena are to reveal > themselves when skeptics are present. --Robert Sheaffer, SkI 9/2003

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[cffi-devel] First usages of CFFI
by Marko Tapio Manninen 17 Jun '08

17 Jun '08

Hi, so far i have compiled some programs, that use CFFI, but now id like to create my own. As usual i counter my limits of knowledge and hope to find some answers here. I'm using libevent library (later doing same with libev), that has a simple event based server application, which i want to use from ccl / sbcl. I'll put two c functions first, and then some header information and finally some lisp code i have created. Im particularry interested getting some comments, how the work should be done. Yet there re two parts of the code, where i have stuck and they are: void evhttp_set_gencb(struct evhttp *http, void (*cb)(struct evhttp_request *, void *), void *cbarg) {} (defcfun ("evhttp_set_gencb" %evhttp-set-gencb) :void (http evhttp) ???) Actually same part occurs on evbuffer: void (*cb)(struct evbuffer *, size_t, size_t, void *); Regards, -Marko -------------------------------------------------------------------------------------------------------------------------------------- // ACTUAL APPLICATION void generic_handler(struct evhttp_request *req, void *arg) { struct evbuffer *buf; buf = evbuffer_new(); if (buf == NULL) err(1, "failed to create response buffer"); evbuffer_add_printf(buf, "Requested: %sn", evhttp_request_uri(req)); evhttp_send_reply(req, HTTP_OK, "OK", buf); } int main(int argc, char **argv) { struct evhttp *httpd; event_init(); httpd = evhttp_start("0.0.0.0", 5007); /* Set a callback for requests to "/specific". */ /* evhttp_set_cb(httpd, "/specific", another_handler, NULL); */ /* Set a callback for all other requests. */ evhttp_set_gencb(httpd, generic_handler, NULL); event_dispatch(); /* Not reached in this code as it is now. */ evhttp_free(httpd); return 0; } // SOME C CODE TO DEFINE #define HTTP_OK 200 struct evhttp; struct evhttp_request; struct evbuffer { u_char *buffer; u_char *orig_buffer; size_t misalign; size_t totallen; size_t off; void (*cb)(struct evbuffer *, size_t, size_t, void *); void *cbarg; }; struct event_base * event_init(void) {} struct evhttp * evhttp_start(const char *address, u_short port) {} void evhttp_free(struct evhttp* http) {} void evhttp_set_gencb(struct evhttp *http, void (*cb)(struct evhttp_request *, void *), void *cbarg) {} // LISP PART (cffi:define-foreign-library libevent (:darwin "libevent.dylib") (t (:default "libevent"))) (cffi:use-foreign-library libevent) (defconstant HTTP_OK 200) (defconstant HTTP_NOCONTENT 204) (defconstant HTTP_MOVEPERM 301) (defconstant HTTP_MOVETEMP 302) (defconstant HTTP_NOTMODIFIED 304) (defconstant HTTP_BADREQUEST 400) (defconstant HTTP_NOTFOUND 404) (defconstant HTTP_SERVUNAVAIL 503) (defctype size-t :unsigned-int) (defcstruct evbuffer (*buffer :unsigned-char) (*orig_buffer :unsigned-char) (misalign size-t) (totallen size-t) (off size-t) (*cb :pointer) ; struct? (*cbarg :pointer)) (defcstruct event-base) (defcstruct evhttp-request) (defcstruct evhttp) (defcfun ("evbuffer_new" %evbuffer-new) :pointer) (defcfun ("evbuffer_add_printf" %evbuffer-add-printf) :void (buf evbuffer) (msg :string) (uri :string)) (defcfun ("evhttp_request_uri" %evhttp-request-uri) :string (req evhttp-request)) (defcfun ("evhttp_send_reply" %evhttp-send-reply) :void (req evhttp-request) (flag :int) (msg :string) (buf evbuffer)) ;;; unwind-protect to create evbuffer-new? (defun generic-handler (req &optional (arg nil)) (let ((buf (%evbuffer-new))) (if (null buf) (error "Failed to create response buffer") (progn (%evbuffer-add-printf buf "Requested: %sn" (%evhttp-request-uri req)) (%evhttp-send-reply req HTTP_OK "OK" buf))))) (defcfun ("event_init" %event-init) :event-base) (defcfun ("evhttp_start" %evhttp-start) :evhttp (address :char) (port :unsigned-short)) (defcfun ("evhttp_set_gencb" %evhttp-set-gencb) :void (http evhttp) ???) (defcfun ("event_dispatch" %event-dispatch) :int) (defcfun ("evhttp_free" %evhttp-free) :void (http evhttp)) ;;; MAIN SERVER START UP FUNCTION ;(server "0.0.0.0" 5009) (defun server (host port) (%event-init) (let ((httpd %evhttp-start host port) (%evhttp-set-gencb httpd #'generic-handler nil) (%event-dispatch) (%evhttp-free httpd))))

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[cffi-devel] New patches: 15-Jun-2008
by loliveira＠common-lisp.net 16 Jun '08

16 Jun '08

Sun Jun 15 20:06:10 EDT 2008 Luis Oliveira <loliveira(a)common-lisp.net> * tests/Makefile: deal with BSD systems properly Suggestion and initial patch courtesy of Josh Elsasser. ./tests/Makefile -> ./tests/GNUmakefile M ./cffi-tests.asd -4 +3 M ./tests/GNUmakefile -1 +1 A ./tests/Makefile An updated tarball of CFFI's source can be downloaded here: http://common-lisp.net/project/cffi/tarballs/cffi-080615.tar.gz Darcsweb URL: http://common-lisp.net/cgi-bin/darcsweb/darcsweb.cgi?r=cffi-cffi;a=summary

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[cffi-devel] [SPAM] FIM DO DRAMA.
by FIM＠common-lisp.net 13 Jun '08

13 Jun '08

Spam detection software, running on the system "clnet", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: FIM DO DRAMA, CASO ISABELLA NARDONI CHEGOU AO FIM! Alexandre Nardoni confessa que a sua esposa Ana Carolina a madastra de Isabella foi a autora do crime de Isabella. [...] Content analysis details: (8.6 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 1.6 FROM_HAS_MIXED_NUMS3 From: contains numbers mixed in with letters 1.7 MSGID_FROM_MTA_ID Message-Id for external message added locally 0.7 SUBJ_ALL_CAPS Subject is all capitals 1.2 FORGED_HOTMAIL_RCVD2 hotmail.com 'From' address, but no 'Received:' 0.0 HTML_MESSAGE BODY: HTML included in message 0.2 MIME_HTML_ONLY BODY: Message only has text/html MIME parts -2.6 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] 0.6 FORGED_OUTLOOK_HTML Outlook can't send HTML message only 0.0 UPPERCASE_25_50 message body is 25-50% uppercase 0.0 MISSING_MIMEOLE Message has X-MSMail-Priority, but no X-MimeOLE 3.9 FORGED_MUA_OUTLOOK Forged mail pretending to be from MS Outlook 1.3 AWL AWL: From: address is in the auto white-list The original message was not completely plain text, and may be unsafe to open with some email clients; in particular, it may contain a virus, or confirm that your address can receive spam. If you wish to view it, it may be safer to save it to a file and open it with an editor.

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[cffi-devel] Weird segfaults interfacing with libsane
by Rupert Swarbrick 12 Jun '08

12 Jun '08

Hi there, I'm trying to use cffi to write some bindings for libsane. Having quite some success, but for the following (rather bizarre) problem. libsane expects: sane_init(), do some stuff, sane_exit() but when I call sane_exit after having done anything non-trivial (for example, called sane_get_devices), sbcl segfaults and dies. I realise that that's not the sort of question for the cffi list, _but_ I wrote a trivial C program that I think should be equivalent and it doesn't die. I can't work out *how* libsane can work in one case and not the other (!) so I was wondering if anyone could make any suggestions. I'm attaching the two source files here. The other piece of information is that I asked about this on #lisp a few minutes ago, and hefner very kindly tested it out, with no segfault at his end. I've had the same symptom with both the asdf-installed cffi and the darcs lotsastuff branch. I presume there's an error somewhere in my libsane config which explains why it's dying, but I'm hoping that someone can explain how it can fail in the lisp program and not in the C one. Oh, it's linux i386 with SBCL from CVS this evening. Thanks, Rupert

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[cffi-devel] CFFI::SYMBOLICATE undefined
by Chun Tian 12 Jun '08

12 Jun '08

Hi, CFFI developers I'm testing CFFI on this darcs url: http://common-lisp.net/project/cffi/darcs/cffi When I compiled CFFI, CMUCL and LispWorks both tell me: function CFFI::SYMBOLICATE is undefined in macro CFFI:DEFCVAR in file src/foreign-vars.lisp. Is this a bug? P.S. In LispWorks, I found this function in LW's system package: SYSTEM:SYMBOLICATE, I don't know if this function can be used. Regards, Chun Tian (binghe)

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[cffi-devel] Foreign struct
by Liam Healy 11 Jun '08

11 Jun '08

I'm having a problem defining/using a foreign struct for my package GSLL (http://common-lisp.net/project/gsll), an interface to the GNU Scientific Library (http://www.gnu.org/software/gsl/), written in C. I am trying to handle complex numbers; GSL has a struct defined to represent complex numbers in /usr/include/gsl/gsl_complex.h: typedef struct { double dat[2]; } gsl_complex; So I define (cffi:defcstruct complex-double-c (dat :double :count 2)) I set this value with a function (defun complex-to-gsl-df (number) (let* ((gsl (cffi:foreign-alloc 'complex-double-c)) (datslot (cffi:foreign-slot-pointer gsl 'complex-double-c 'dat))) (setf (cffi:mem-aref datslot :double 0) (realpart number) (cffi:mem-aref datslot :double 1) (imagpart number)) gsl)) When I pass a complex number generated with this function to a GSL function, I always get the following result: the real part is what I specified for the imaginary part, and the imaginary part is the number 5.2635442471208903e-315, which I discovered is the single-float number -1.0f0 interpreted as a double float (I don't know if that's significant). So for example the function #'test-set-all should set every element of the complex vector to the same number 3+4i, but I get 4+5.2635442471208903e-315i: (letm ((intvec (vector-complex-double-float 2))) (test-set-all intvec #c(3.0d0 4.0d0)) (maref intvec 1)) #C(4.0 5.2635442471208903e-315) There is a GSL function that sets the real and imaginary parts of the struct (in C of course). When I use this, I get the answer I expect. Unfortunately, it's more restricted than setting the structure in CL, so I'd like to solve the structure problem. My platform is SBCL 0.9.16, amd64 Debian (stable). I have a feeling I have misinterpreted the defcstruct usage. Any ideas? Thanks, Liam

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cffi-devel June 2008