rust/src/test/run-pass/binary-heap-panic-safe.rs
Alex Crichton b64c9d5670 std: Clean out old unstable + deprecated APIs
These should all have been deprecated for at least one cycle, so this commit
cleans them all out.
2016-05-30 20:46:32 -07:00

100 lines
3.3 KiB
Rust

// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.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.
#![feature(rand, std_panic)]
use std::__rand::{thread_rng, Rng};
use std::panic::{self, AssertUnwindSafe};
use std::collections::BinaryHeap;
use std::cmp;
use std::sync::atomic::{AtomicUsize, ATOMIC_USIZE_INIT, Ordering};
static DROP_COUNTER: AtomicUsize = ATOMIC_USIZE_INIT;
// old binaryheap failed this test
//
// Integrity means that all elements are present after a comparison panics,
// even if the order may not be correct.
//
// Destructors must be called exactly once per element.
fn test_integrity() {
#[derive(Eq, PartialEq, Ord, Clone, Debug)]
struct PanicOrd<T>(T, bool);
impl<T> Drop for PanicOrd<T> {
fn drop(&mut self) {
// update global drop count
DROP_COUNTER.fetch_add(1, Ordering::SeqCst);
}
}
impl<T: PartialOrd> PartialOrd for PanicOrd<T> {
fn partial_cmp(&self, other: &Self) -> Option<cmp::Ordering> {
if self.1 || other.1 {
panic!("Panicking comparison");
}
self.0.partial_cmp(&other.0)
}
}
let mut rng = thread_rng();
const DATASZ: usize = 32;
const NTEST: usize = 10;
// don't use 0 in the data -- we want to catch the zeroed-out case.
let data = (1..DATASZ + 1).collect::<Vec<_>>();
// since it's a fuzzy test, run several tries.
for _ in 0..NTEST {
for i in 1..DATASZ + 1 {
DROP_COUNTER.store(0, Ordering::SeqCst);
let mut panic_ords: Vec<_> = data.iter()
.filter(|&&x| x != i)
.map(|&x| PanicOrd(x, false))
.collect();
let panic_item = PanicOrd(i, true);
// heapify the sane items
rng.shuffle(&mut panic_ords);
let mut heap = BinaryHeap::from(panic_ords);
let inner_data;
{
// push the panicking item to the heap and catch the panic
let thread_result = {
let mut heap_ref = AssertUnwindSafe(&mut heap);
panic::catch_unwind(move || {
heap_ref.push(panic_item);
})
};
assert!(thread_result.is_err());
// Assert no elements were dropped
let drops = DROP_COUNTER.load(Ordering::SeqCst);
assert!(drops == 0, "Must not drop items. drops={}", drops);
inner_data = heap.clone().into_vec();
drop(heap);
}
let drops = DROP_COUNTER.load(Ordering::SeqCst);
assert_eq!(drops, DATASZ);
let mut data_sorted = inner_data.into_iter().map(|p| p.0).collect::<Vec<_>>();
data_sorted.sort();
assert_eq!(data_sorted, data);
}
}
}
fn main() {
test_integrity();
}