Requesting Documentation for Using Subprocess

[kalaxy]

I'm exploring the v3.3.2 (in a Linux env) subproccess api and am not getting very far. I have a test program:

#include <mimalloc.h>
#include <thread>

int main() {
    auto my_subproc = mi_subproc_new();
    std::thread t([&]() {
        mi_subproc_add_current_thread(my_subproc);
        mi_free(mi_malloc(1024));
    });
    t.join();
    mi_subproc_destroy(my_subproc);
    return 0;
}

It fails with the assertion:

mimalloc: assertion failed: at "/home/kmills/.conan2/p/b/mimal197d35e7834f1/b/src/src/init.c":446, _mi_subproc_heap_main
  assertion: "mi_atomic_load_relaxed(&subproc->heap_main) != NULL"

Is there more to initializing a subprocess than calling mi_subproc_new()?

[daanx]

Ah, there were many issues I see :-( I think these are fixed with the latest dev3 and I added tests for subprocesses as well.
I will add more documentation too, but:

1. you are using it right above (and this should work now)
2. you should create and destroy a subprocess from another subprocess that should stay alive for the duration of the created subprocess. (Usually this is the main implicit subprocess when starting the program)
3. you should not allocate/free across subprocesses -- these are meant to be fully isolated; for example to run multiple python interpreters from the same process. (I am thinking of exposing _mi_free_subproc_safe though but not sure if it is needed in the user API).
4. subprocesses do not share any memory and have their own arenas. If you want more memory sharing you need to use multiple heaps (which belong to a single subprocess and do share the underlying memory/arenas of the subprocess).