tokio/loom/std/
mod.rs

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1#![cfg_attr(any(not(feature = "full"), loom), allow(unused_imports, dead_code))]
2
3mod atomic_u16;
4mod atomic_u32;
5mod atomic_u64;
6mod atomic_usize;
7mod barrier;
8mod mutex;
9#[cfg(all(feature = "parking_lot", not(miri)))]
10mod parking_lot;
11mod unsafe_cell;
12
13pub(crate) mod cell {
14    pub(crate) use super::unsafe_cell::UnsafeCell;
15}
16
17#[cfg(any(
18    feature = "net",
19    feature = "process",
20    feature = "signal",
21    feature = "sync",
22))]
23pub(crate) mod future {
24    pub(crate) use crate::sync::AtomicWaker;
25}
26
27pub(crate) mod hint {
28    pub(crate) use std::hint::spin_loop;
29}
30
31pub(crate) mod rand {
32    use std::collections::hash_map::RandomState;
33    use std::hash::{BuildHasher, Hash, Hasher};
34    use std::sync::atomic::AtomicU32;
35    use std::sync::atomic::Ordering::Relaxed;
36
37    static COUNTER: AtomicU32 = AtomicU32::new(1);
38
39    pub(crate) fn seed() -> u64 {
40        let rand_state = RandomState::new();
41
42        let mut hasher = rand_state.build_hasher();
43
44        // Hash some unique-ish data to generate some new state
45        COUNTER.fetch_add(1, Relaxed).hash(&mut hasher);
46
47        // Get the seed
48        hasher.finish()
49    }
50}
51
52pub(crate) mod sync {
53    pub(crate) use std::sync::{Arc, Weak};
54
55    // Below, make sure all the feature-influenced types are exported for
56    // internal use. Note however that some are not _currently_ named by
57    // consuming code.
58
59    #[cfg(all(feature = "parking_lot", not(miri)))]
60    #[allow(unused_imports)]
61    pub(crate) use crate::loom::std::parking_lot::{
62        Condvar, Mutex, MutexGuard, RwLock, RwLockReadGuard, WaitTimeoutResult,
63    };
64
65    #[cfg(not(all(feature = "parking_lot", not(miri))))]
66    #[allow(unused_imports)]
67    pub(crate) use std::sync::{Condvar, MutexGuard, RwLock, RwLockReadGuard, WaitTimeoutResult};
68
69    #[cfg(not(all(feature = "parking_lot", not(miri))))]
70    pub(crate) use crate::loom::std::mutex::Mutex;
71
72    pub(crate) mod atomic {
73        pub(crate) use crate::loom::std::atomic_u16::AtomicU16;
74        pub(crate) use crate::loom::std::atomic_u32::AtomicU32;
75        pub(crate) use crate::loom::std::atomic_u64::{AtomicU64, StaticAtomicU64};
76        pub(crate) use crate::loom::std::atomic_usize::AtomicUsize;
77
78        pub(crate) use std::sync::atomic::{fence, AtomicBool, AtomicPtr, AtomicU8, Ordering};
79    }
80
81    pub(crate) use super::barrier::Barrier;
82}
83
84pub(crate) mod sys {
85    #[cfg(feature = "rt-multi-thread")]
86    pub(crate) fn num_cpus() -> usize {
87        const ENV_WORKER_THREADS: &str = "TOKIO_WORKER_THREADS";
88
89        match std::env::var(ENV_WORKER_THREADS) {
90            Ok(s) => {
91                let n = s.parse().unwrap_or_else(|e| {
92                    panic!(
93                        "\"{}\" must be usize, error: {}, value: {}",
94                        ENV_WORKER_THREADS, e, s
95                    )
96                });
97                assert!(n > 0, "\"{}\" cannot be set to 0", ENV_WORKER_THREADS);
98                n
99            }
100            Err(std::env::VarError::NotPresent) => usize::max(1, num_cpus::get()),
101            Err(std::env::VarError::NotUnicode(e)) => {
102                panic!(
103                    "\"{}\" must be valid unicode, error: {:?}",
104                    ENV_WORKER_THREADS, e
105                )
106            }
107        }
108    }
109
110    #[cfg(not(feature = "rt-multi-thread"))]
111    pub(crate) fn num_cpus() -> usize {
112        1
113    }
114}
115
116pub(crate) mod thread {
117    #[inline]
118    pub(crate) fn yield_now() {
119        std::hint::spin_loop();
120    }
121
122    #[allow(unused_imports)]
123    pub(crate) use std::thread::{
124        current, panicking, park, park_timeout, sleep, spawn, AccessError, Builder, JoinHandle,
125        LocalKey, Result, Thread, ThreadId,
126    };
127}
tokio/loom/std/mod.rs

tokio/loom/std/
mod.rs
