Hi Nala, I am pretty sure this also segfaulted, but I can try again this evening to be sure. (Or you can try, the code linked should build)
Best wishes, Dan On March 4, 2025 11:02:33 AM GMT, Nala Ginrut <nalagin...@gmail.com> wrote: >Hi Daniel! >Just simply took a glance at the code, I'm curious why you don't just call >scm_init_guile() in fuse operation init function? >This should let you call scm_init_guile() just once. > >Best regards. > > >On Mon, Mar 3, 2025 at 6:41 PM Daniel Littlewood via General Guile related >discussions <guile-user@gnu.org> wrote: > >> Hi guile-users, >> >> I am working on a guile program to interact with FUSE. The code is at >> https://gitlab.com/danielittlewood0/diffuse. I have managed to get it to >> basically work, but there are some things I don't understand. It >> consists of essentially two files at the moment: >> >> * other.scm, which implements the actual logic of the filesystem in >> guile. >> * hello.c, which does the plumbing into the FUSE library. >> >> I managed to get it to work by doing the following in each of the FUSE >> handlers: >> >> scm_init_guile() >> scm_c_primitive_load("/full/path/to/other.scm") >> scm_call_1(scm_variable_ref(scm_c_lookup("whatever-function-I-want"))) >> >> That worked fine, but I was a bit confused about having to call >> scm_init_guile so many times. I expected to just call it once in main >> and then never again. If I do that, i.e. just move scm_init_guile to >> main and remove all the other callers (rest of the code unchanged) I get >> a segfault. >> >> I was also surprised that I had to give the absolute file path of my >> guile script to scm_c_primitive_load. If I called it from main then I >> didn't have to do that. If I call scm_c_primitive_load from main then I >> can give a relative path, but from e.g. hello_read I get a "No such file >> or directory" error and have to provide the absolute path. >> >> I think this is something peculiar to how FUSE is set up, but I don't >> know what exactly. I don't actually call the handlers, I pass the >> function pointers to the library and the library calls them for me. For >> instance if I try to print the current working directory from within one >> of the handlers, I get / - which probably refers to the root of the FUSE >> filesystem tree. I managed to avoid giving the absolute path by calling >> scm_init_guile() and then scm_c_primitive_load("other.scm") from main. >> This works (with the relative path). What's surprising to me is: >> >> * I still have to call scm_init_guile before every use of guile within >> the current function, even if I called it in main. >> * When I call scm_init_guile a second time, I don't have to call >> scm_primitive_load a second time. I can just call scm_variable_ref >> immediately. >> >> This is a bit confusing to me. I could understand if I had to load the >> code every time I call scm_init_guile (although then I'd want to reduce >> the boilerplate) and I could understand calling scm_init_guile and >> scm_c_primitive_load only once, but the arrangement above doesn't make >> sense to me. I feel like I must be missing something. >> >> Note that this is the first project I've really written in either C or >> guile, so I might be missing something obvious. >> >> Best wishes, >> Dan >>
