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libfringe/tests/generator.rs

138 lines
3.5 KiB
Rust

// This file is part of libfringe, a low-level green threading library.
// Copyright (c) whitequark <whitequark@whitequark.org>,
// edef <edef@edef.eu>
// Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or
// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
// http://opensource.org/licenses/MIT>, at your option. This file may not be
// copied, modified, or distributed except according to those terms.
extern crate fringe;
use fringe::{SliceStack, OwnedStack, OsStack};
use fringe::generator::{Generator, Yielder};
fn add_one_fn(yielder: &Yielder<i32, i32>, mut input: i32) {
loop {
if input == 0 { break }
input = yielder.suspend(input + 1)
}
}
fn new_add_one() -> Generator<'static, i32, i32, OsStack> {
let stack = OsStack::new(0).unwrap();
Generator::new(stack, add_one_fn)
}
#[test]
fn generator() {
let mut add_one = new_add_one();
assert_eq!(add_one.resume(1), Some(2));
assert_eq!(add_one.resume(2), Some(3));
assert_eq!(add_one.resume(0), None);
}
#[test]
fn move_after_new() {
let mut add_one = new_add_one();
assert_eq!(add_one.resume(1), Some(2));
#[inline(never)]
fn run_moved(mut add_one: Generator<i32, i32, OsStack>) {
assert_eq!(add_one.resume(2), Some(3));
assert_eq!(add_one.resume(3), Some(4));
assert_eq!(add_one.resume(0), None);
}
run_moved(add_one);
}
#[test]
#[should_panic]
fn panic_safety() {
struct Wrapper {
gen: Generator<'static, (), (), OsStack>
}
impl Drop for Wrapper {
fn drop(&mut self) {
self.gen.resume(());
}
}
let stack = OsStack::new(4 << 20).unwrap();
let gen = Generator::new(stack, move |_yielder, ()| {
panic!("foo")
});
let mut wrapper = Wrapper { gen: gen };
wrapper.gen.resume(());
}
#[test]
fn with_slice_stack() {
let mut memory = [0; 1024];
let stack = SliceStack::new(&mut memory);
let mut add_one = unsafe { Generator::unsafe_new(stack, add_one_fn) };
assert_eq!(add_one.resume(1), Some(2));
assert_eq!(add_one.resume(2), Some(3));
assert_eq!(add_one.resume(0), None);
}
#[test]
fn with_owned_stack() {
let stack = OwnedStack::new(1024);
let mut add_one = unsafe { Generator::unsafe_new(stack, add_one_fn) };
assert_eq!(add_one.resume(1), Some(2));
assert_eq!(add_one.resume(2), Some(3));
assert_eq!(add_one.resume(0), None);
}
#[test]
fn forget_yielded() {
use std::cell::Cell;
struct Dropper<'a>(&'a Cell<bool>);
impl<'a> Drop for Dropper<'a> {
fn drop(&mut self) {
if self.0.get() {
panic!("double drop!")
}
self.0.set(true);
}
}
let stack = fringe::OsStack::new(1<<16).unwrap();
let flag = Cell::new(false);
let mut generator = Generator::new(stack, |yielder, ()| {
yielder.suspend(Dropper(&flag));
});
generator.resume(());
generator.resume(());
}
#[test]
fn unwrap_returned() {
let stack = OsStack::new(0).unwrap();
let mut generator = Generator::new(stack, |_, ()| {});
assert_eq!(generator.resume(()), None::<()>);
generator.unwrap();
}
#[test]
fn unwrap_panicked() {
use std::panic;
let stack = OsStack::new(4 << 20).unwrap();
let mut generator: Generator<(), (), OsStack> = Generator::new(stack, |_, ()| panic!("unwind"));
{
let closure = panic::AssertUnwindSafe(|| generator.resume(()));
assert!(panic::catch_unwind(closure).is_err());
}
generator.unwrap();
}
#[test]
#[should_panic(expected = "Argh! Bastard! Don't touch that!")]
fn unwrap_running() {
let mut add_one = new_add_one();
assert_eq!(add_one.resume(1), Some(2));
add_one.unwrap();
}