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: [email protected] 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 [email protected]. 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.
