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// Copyright 2013 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, num_bits_bytes)]
#![feature(const_fn)]
use std::sync::atomic::{AtomicUsize, Ordering};
use std::__rand::{thread_rng, Rng};
use std::thread;
const REPEATS: usize = 5;
const MAX_LEN: usize = 32;
static drop_counts: [AtomicUsize; MAX_LEN] =
// FIXME #5244: AtomicUsize is not Copy.
[
AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
AtomicUsize::new(0), AtomicUsize::new(0), AtomicUsize::new(0),
AtomicUsize::new(0), AtomicUsize::new(0),
];
static creation_count: AtomicUsize = AtomicUsize::new(0);
#[derive(Clone, PartialEq, PartialOrd, Eq, Ord)]
struct DropCounter { x: u32, creation_id: usize }
impl Drop for DropCounter {
fn drop(&mut self) {
drop_counts[self.creation_id].fetch_add(1, Ordering::Relaxed);
}
}
pub fn main() {
assert!(MAX_LEN <= std::usize::BITS);
// len can't go above 64.
for len in 2..MAX_LEN {
for _ in 0..REPEATS {
// reset the count for these new DropCounters, so their
// IDs start from 0.
creation_count.store(0, Ordering::Relaxed);
let mut rng = thread_rng();
let main = (0..len).map(|_| {
DropCounter {
x: rng.next_u32(),
creation_id: creation_count.fetch_add(1, Ordering::Relaxed),
}
}).collect::<Vec<_>>();
// work out the total number of comparisons required to sort
// this array...
let mut count = 0_usize;
main.clone().sort_by(|a, b| { count += 1; a.cmp(b) });
// ... and then panic on each and every single one.
for panic_countdown in 0..count {
// refresh the counters.
for c in &drop_counts {
c.store(0, Ordering::Relaxed);
}
let v = main.clone();
let _ = thread::spawn(move|| {
let mut v = v;
let mut panic_countdown = panic_countdown;
v.sort_by(|a, b| {
if panic_countdown == 0 {
panic!()
}
panic_countdown -= 1;
a.cmp(b)
})
}).join();
// check that the number of things dropped is exactly
// what we expect (i.e. the contents of `v`).
for (i, c) in drop_counts.iter().enumerate().take(len) {
let count = c.load(Ordering::Relaxed);
assert!(count == 1,
"found drop count == {} for i == {}, len == {}",
count, i, len);
}
}
}
}
}
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