Hi, I have a project going to make Racket bindings to the libhackrf C library installed on my Debian 9 system. I have successfully made and used bindings to around a dozen procedures in the library. However, when I get to the first really important one, my call is crashing with a SIGSEGV. I have this procedure defined:
(define-hackrf hackrf_start_rx (_fun (_cpointer 'hackrf_device) (_fun _pointer -> _int) _pointer -> _int)) This procedure takes a pointer to a device, a callback function, and another pointer (which I won't go into but is supposed to be null usually). Internally, hackrf_start_rx is a C procedure which generates a pthread which repeatedly calls the callback function while receiving data, while the original thread returns 0. christopher@nightshade:~/Repos/hackrf-rkt$ racketWelcome to Racket v6.7.> ,load hackrf.rkt> ,enter hackrf.rkt"hackrf.rkt"> transf- cb#<procedure:transf-cb>"hackrf.rkt"> (hackrf-init)"hackrf.rkt"> (define h (hackrf-open))"hackrf.rkt"> h#<cpointer:hackrf_device>"hackrf.rkt"> (sensible-defaults h)"hackrf.rkt"> (define cb (transf-cb))"hackrf.rkt"> cb#<procedure:...f-rkt/hackrf.rkt:257:2>"hackrf.rkt"> (trace-call 'hackrf_start_rx hackrf_start_rx h cb #f)>(hackrf_start_rx #<cpointer:hackrf_device> #<procedure:...f-rkt/hackrf.rkt:257:2> #f)<00"hackrf.rkt"> SIGSEGV MAPERR si_code 1 fault on addr (nil)Aborted I can't figure out how to debug this further because I don't know how to get Racket to display the C backtrace, and I don't know how to get Racket to run successfully in gdb. I'm thinking either (1) I'm somehow passing in my callback function wrong, or (2) something about Racket is incompatible with C library functions that use pthreads. You can see that hackrf_start_rx is returning 0, so the SIGSEGV MAPERR must be occurring in the still running thread, but I'm not sure what I can conclude from that. For the whole code see git clone git://lavender.qlfiles.net/pub/git/hackrf-rkt.git git checkout cf81011be6509da00b779881a5d388af399a4d2e -- Christopher Howard p: +1 (907) 374-0257 w: https://librehacker.com xmpp: creation...@member.fsf.org otr: E9685B53 01F038DD D29281C9 30FDA71E BD0095D4 gnupg: 23FD5CC5 (keys.gnupg.net) radio: KL1TL featured: http://www.foi.org -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/1561523686.14508.3.camel%40qlfiles.net. For more options, visit https://groups.google.com/d/optout.
