tokio/loom/std/
mod.rs

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 rwlock;
12mod unsafe_cell;
13
14pub(crate) mod cell {
15    pub(crate) use super::unsafe_cell::UnsafeCell;
16}
17
18#[cfg(any(
19    feature = "net",
20    feature = "process",
21    feature = "signal",
22    feature = "sync",
23))]
24pub(crate) mod future {
25    pub(crate) use crate::sync::AtomicWaker;
26}
27
28pub(crate) mod hint {
29    pub(crate) use std::hint::spin_loop;
30}
31
32pub(crate) mod rand {
33    use std::collections::hash_map::RandomState;
34    use std::hash::{BuildHasher, Hash, Hasher};
35    use std::sync::atomic::AtomicU32;
36    use std::sync::atomic::Ordering::Relaxed;
37
38    static COUNTER: AtomicU32 = AtomicU32::new(1);
39
40    pub(crate) fn seed() -> u64 {
41        let rand_state = RandomState::new();
42        // Hash some unique-ish data to generate some new state
43        rand_state.hash_one(COUNTER.fetch_add(1, Relaxed))
44    }
45}
46
47pub(crate) mod sync {
48    pub(crate) use std::sync::{Arc, Weak};
49
50    // Below, make sure all the feature-influenced types are exported for
51    // internal use. Note however that some are not _currently_ named by
52    // consuming code.
53
54    // Not using parking_lot in Miri due to <https://github.com/Amanieu/parking_lot/issues/477>.
55    #[cfg(all(feature = "parking_lot", not(miri)))]
56    #[allow(unused_imports)]
57    pub(crate) use crate::loom::std::parking_lot::{
58        Condvar, Mutex, MutexGuard, RwLock, RwLockReadGuard, WaitTimeoutResult,
59    };
60
61    #[cfg(not(all(feature = "parking_lot", not(miri))))]
62    #[allow(unused_imports)]
63    pub(crate) use std::sync::{Condvar, MutexGuard, RwLockReadGuard, WaitTimeoutResult};
64
65    #[cfg(not(all(feature = "parking_lot", not(miri))))]
66    pub(crate) use crate::loom::std::mutex::Mutex;
67
68    #[cfg(not(all(feature = "parking_lot", not(miri))))]
69    pub(crate) use crate::loom::std::rwlock::RwLock;
70
71    pub(crate) mod atomic {
72        pub(crate) use crate::loom::std::atomic_u16::AtomicU16;
73        pub(crate) use crate::loom::std::atomic_u32::AtomicU32;
74        pub(crate) use crate::loom::std::atomic_u64::{AtomicU64, StaticAtomicU64};
75        pub(crate) use crate::loom::std::atomic_usize::AtomicUsize;
76
77        pub(crate) use std::sync::atomic::{fence, AtomicBool, AtomicPtr, AtomicU8, Ordering};
78    }
79
80    pub(crate) use super::barrier::Barrier;
81}
82
83pub(crate) mod sys {
84    #[cfg(feature = "rt-multi-thread")]
85    pub(crate) fn num_cpus() -> usize {
86        use std::num::NonZeroUsize;
87
88        const ENV_WORKER_THREADS: &str = "TOKIO_WORKER_THREADS";
89
90        match std::env::var(ENV_WORKER_THREADS) {
91            Ok(s) => {
92                let n = s.parse().unwrap_or_else(|e| {
93                    panic!("\"{ENV_WORKER_THREADS}\" must be usize, error: {e}, value: {s}")
94                });
95                assert!(n > 0, "\"{ENV_WORKER_THREADS}\" cannot be set to 0");
96                n
97            }
98            Err(std::env::VarError::NotPresent) => {
99                std::thread::available_parallelism().map_or(1, NonZeroUsize::get)
100            }
101            Err(std::env::VarError::NotUnicode(e)) => {
102                panic!("\"{ENV_WORKER_THREADS}\" must be valid unicode, error: {e:?}")
103            }
104        }
105    }
106
107    #[cfg(not(feature = "rt-multi-thread"))]
108    pub(crate) fn num_cpus() -> usize {
109        1
110    }
111}
112
113pub(crate) mod thread {
114    #[inline]
115    pub(crate) fn yield_now() {
116        std::hint::spin_loop();
117    }
118
119    #[allow(unused_imports)]
120    pub(crate) use std::thread::{
121        current, panicking, park, park_timeout, sleep, spawn, AccessError, Builder, JoinHandle,
122        LocalKey, Result, Thread, ThreadId,
123    };
124}
tokio/loom/std/mod.rs

tokio/loom/std/
mod.rs
