tests/pass/atomic.rs

   1 use std::sync::atomic::{compiler_fence, fence, AtomicBool, AtomicIsize, AtomicU64, Ordering::*};
   2
   3 fn main() {
   4     atomic_bool();
   5     atomic_isize();
   6     atomic_u64();
   7     atomic_fences();
   8     weak_sometimes_fails();
   9 }
  10
  11 fn atomic_bool() {
  12     static mut ATOMIC: AtomicBool = AtomicBool::new(false);
  13
  14     unsafe {
  15         assert_eq!(*ATOMIC.get_mut(), false);
  16         ATOMIC.store(true, SeqCst);
  17         assert_eq!(*ATOMIC.get_mut(), true);
  18         ATOMIC.fetch_or(false, SeqCst);
  19         assert_eq!(*ATOMIC.get_mut(), true);
  20         ATOMIC.fetch_and(false, SeqCst);
  21         assert_eq!(*ATOMIC.get_mut(), false);
  22         ATOMIC.fetch_nand(true, SeqCst);
  23         assert_eq!(*ATOMIC.get_mut(), true);
  24         ATOMIC.fetch_xor(true, SeqCst);
  25         assert_eq!(*ATOMIC.get_mut(), false);
  26     }
  27 }
  28 // There isn't a trait to use to make this generic, so just use a macro
  29 macro_rules! compare_exchange_weak_loop {
  30     ($atom:expr, $from:expr, $to:expr, $succ_order:expr, $fail_order:expr) => {
  31         loop {
  32             match $atom.compare_exchange_weak($from, $to, $succ_order, $fail_order) {
  33                 Ok(n) => {
  34                     assert_eq!(n, $from);
  35                     break;
  36                 }
  37                 Err(n) => assert_eq!(n, $from),
  38             }
  39         }
  40     };
  41 }
  42 fn atomic_isize() {
  43     static ATOMIC: AtomicIsize = AtomicIsize::new(0);
  44
  45     // Make sure trans can emit all the intrinsics correctly
  46     assert_eq!(ATOMIC.compare_exchange(0, 1, Relaxed, Relaxed), Ok(0));
  47     assert_eq!(ATOMIC.compare_exchange(0, 2, Acquire, Relaxed), Err(1));
  48     assert_eq!(ATOMIC.compare_exchange(0, 1, Release, Relaxed), Err(1));
  49     assert_eq!(ATOMIC.compare_exchange(1, 0, AcqRel, Relaxed), Ok(1));
  50     ATOMIC.compare_exchange(0, 1, SeqCst, Relaxed).ok();
  51     ATOMIC.compare_exchange(0, 1, Acquire, Acquire).ok();
  52     ATOMIC.compare_exchange(0, 1, AcqRel, Acquire).ok();
  53     ATOMIC.compare_exchange(0, 1, SeqCst, Acquire).ok();
  54     ATOMIC.compare_exchange(0, 1, SeqCst, SeqCst).ok();
  55
  56     ATOMIC.store(0, SeqCst);
  57     compare_exchange_weak_loop!(ATOMIC, 0, 1, Relaxed, Relaxed);
  58     assert_eq!(ATOMIC.compare_exchange_weak(0, 2, Acquire, Relaxed), Err(1));
  59     assert_eq!(ATOMIC.compare_exchange_weak(0, 1, Release, Relaxed), Err(1));
  60     compare_exchange_weak_loop!(ATOMIC, 1, 0, AcqRel, Relaxed);
  61     assert_eq!(ATOMIC.load(Relaxed), 0);
  62     ATOMIC.compare_exchange_weak(0, 1, AcqRel, Relaxed).ok();
  63     ATOMIC.compare_exchange_weak(0, 1, SeqCst, Relaxed).ok();
  64     ATOMIC.compare_exchange_weak(0, 1, Acquire, Acquire).ok();
  65     ATOMIC.compare_exchange_weak(0, 1, AcqRel, Acquire).ok();
  66     ATOMIC.compare_exchange_weak(0, 1, SeqCst, Acquire).ok();
  67     ATOMIC.compare_exchange_weak(0, 1, SeqCst, SeqCst).ok();
  68 }
  69
  70 fn atomic_u64() {
  71     static ATOMIC: AtomicU64 = AtomicU64::new(0);
  72
  73     ATOMIC.store(1, SeqCst);
  74     assert_eq!(ATOMIC.compare_exchange(0, 0x100, AcqRel, Acquire), Err(1));
  75     compare_exchange_weak_loop!(ATOMIC, 1, 0x100, AcqRel, Acquire);
  76     assert_eq!(ATOMIC.load(Relaxed), 0x100);
  77
  78     assert_eq!(ATOMIC.fetch_max(0x10, SeqCst), 0x100);
  79     assert_eq!(ATOMIC.fetch_max(0x100, SeqCst), 0x100);
  80     assert_eq!(ATOMIC.fetch_max(0x1000, SeqCst), 0x100);
  81     assert_eq!(ATOMIC.fetch_max(0x1000, SeqCst), 0x1000);
  82     assert_eq!(ATOMIC.fetch_max(0x2000, SeqCst), 0x1000);
  83     assert_eq!(ATOMIC.fetch_max(0x2000, SeqCst), 0x2000);
  84
  85     assert_eq!(ATOMIC.fetch_min(0x2000, SeqCst), 0x2000);
  86     assert_eq!(ATOMIC.fetch_min(0x2000, SeqCst), 0x2000);
  87     assert_eq!(ATOMIC.fetch_min(0x1000, SeqCst), 0x2000);
  88     assert_eq!(ATOMIC.fetch_min(0x1000, SeqCst), 0x1000);
  89     assert_eq!(ATOMIC.fetch_min(0x100, SeqCst), 0x1000);
  90     assert_eq!(ATOMIC.fetch_min(0x10, SeqCst), 0x100);
  91 }
  92
  93 fn atomic_fences() {
  94     fence(SeqCst);
  95     fence(Release);
  96     fence(Acquire);
  97     fence(AcqRel);
  98     compiler_fence(SeqCst);
  99     compiler_fence(Release);
 100     compiler_fence(Acquire);
 101     compiler_fence(AcqRel);
 102 }
 103
 104 fn weak_sometimes_fails() {
 105     let atomic = AtomicBool::new(false);
 106     let tries = 100;
 107     for _ in 0..tries {
 108         let cur = atomic.load(Relaxed);
 109         // Try (weakly) to flip the flag.
 110         if atomic.compare_exchange_weak(cur, !cur, Relaxed, Relaxed).is_err() {
 111             // We failed, so return and skip the panic.
 112             return;
 113         }
 114     }
 115     panic!("compare_exchange_weak succeeded {} tries in a row", tries);
 116 }