Memory issue with zero-sized types
Closed this issue · 2 comments
eun-ice commented
I have a serious issue I cannot explain. My guess is that copyless creates some sort of memory issue when called with static functions.
assume the following traits:
pub struct Runnable {
runnable_box: Box<RunnableBox + Send>
}
impl Runnable {
pub fn run(self) {
self.runnable_box.run();
}
}
trait RunnableBox {
fn run(self: Box<Self>);
}
impl<F: FnOnce()> RunnableBox for F {
fn run(self: Box<F>) {
(*self)()
}
}And these two constructors, one using Box::new, the other using Box::alloc().init
impl Runnable {
pub fn new_box<F>(func: F) -> Runnable
where
F: FnOnce() + Send + 'static {
Runnable { runnable_box: Box::new(func) }
}
#[allow(dead_code)]
pub fn new_copyless<F>(func: F) -> Runnable
where
F: FnOnce() + Send + 'static {
Runnable { runnable_box: Box::alloc().init(func) }
}
}Creating a static Runnable seems to create some sort of memory overwrite I cannot exactly pin down:
Runnable::new_box(move || { println!("scheduled task 1"); }); // Works
Runnable::new_copyless(move || { println!("scheduled task 1"); }) // Error
let now = Instant::now();
Runnable::new_copyless(move || { println!("scheduled task 1 {:?}", now); }) // WorksI have attached a testcase that fails on macos and on linux using Rust 1.33 stable and rustc 1.35.0-nightly (0576ac109 2019-03-24).