Function with_vm

crates/vm/src/vm/thread.rs:500–522

(obj: &PyObject, f: F)

}

pub fn with_vm<F, R>(obj: &PyObject, f: F) -> Option<R>
where
    F: Fn(&VirtualMachine) -> R,
{
    let vm_owns_obj = |interp: NonNull<VirtualMachine>| {
        // SAFETY: all references in VM_STACK should be valid
        let vm = unsafe { interp.as_ref() };
        obj.fast_isinstance(vm.ctx.types.object_type)
    };
    VM_STACK.with(|vms| {
        let interp = match vms.borrow().iter().copied().exactly_one() {
            Ok(x) => {
                debug_assert!(vm_owns_obj(x));
                x
            }
            Err(mut others) => others.find(|x| vm_owns_obj(*x))?,
        };
        // SAFETY: all references in VM_STACK should be valid, and should not be changed or moved
        // at least until this function returns and the stack unwinds to an enter_vm() call
        let vm = unsafe { interp.as_ref() };
        Some(VM_CURRENT.set(vm, || f(vm)))
    })
}

#[must_use = "ThreadedVirtualMachine does nothing unless you move it to another thread and call .run()"]
#[cfg(feature = "threading")]