src/test/run-pass/box-of-array-of-drop-2.rs

   1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 // Test that we cleanup dynamic sized Box<[D]> properly when D has a
  12 // destructor.
  13
  14 use std::thread;
  15 use std::sync::atomic::{AtomicUsize, ATOMIC_USIZE_INIT, Ordering};
  16
  17 static LOG: AtomicUsize = ATOMIC_USIZE_INIT;
  18
  19 struct D(u8);
  20
  21 impl Drop for D {
  22     fn drop(&mut self) {
  23         println!("Dropping {}", self.0);
  24         let old = LOG.load(Ordering::SeqCst);
  25         LOG.compare_and_swap(old, old << 4 | self.0 as usize, Ordering::SeqCst);
  26     }
  27 }
  28
  29 fn main() {
  30     fn die() -> D { panic!("Oh no"); }
  31     let g = thread::spawn(|| {
  32         let _b1: Box<[D; 4]> = Box::new([D( 1), D( 2), D( 3), D( 4)]);
  33         let _b2: Box<[D; 4]> = Box::new([D( 5), D( 6), D( 7), D( 8)]);
  34         let _b3: Box<[D; 4]> = Box::new([D( 9), D(10), die(), D(12)]);
  35         let _b4: Box<[D; 4]> = Box::new([D(13), D(14), D(15), D(16)]);
  36     });
  37     assert!(g.join().is_err());
  38
  39     // When the panic occurs, we will be in the midst of constructing
  40     // the input to `_b3`.  Therefore, we drop the elements of the
  41     // partially filled array first, before we get around to dropping
  42     // the elements of `_b1` and _b2`.
  43
  44     // Issue 23222: The order in which the elements actually get
  45     // dropped is a little funky. See similar notes in nested-vec-3;
  46     // in essence, I would not be surprised if we change the ordering
  47     // given in `expect` in the future.
  48
  49     let expect = 0x__A_9__5_6_7_8__1_2_3_4;
  50     let actual = LOG.load(Ordering::SeqCst);
  51     assert!(actual == expect, "expect: 0x{:x} actual: 0x{:x}", expect, actual);
  52 }