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    #[cfg(all(feature = "parking_lot", not(miri)))]
55    #[allow(unused_imports)]
56    pub(crate) use crate::loom::std::parking_lot::{
57        Condvar, Mutex, MutexGuard, RwLock, RwLockReadGuard, WaitTimeoutResult,
58    };
59
60    #[cfg(not(all(feature = "parking_lot", not(miri))))]
61    #[allow(unused_imports)]
62    pub(crate) use std::sync::{Condvar, MutexGuard, RwLockReadGuard, WaitTimeoutResult};
63
64    #[cfg(not(all(feature = "parking_lot", not(miri))))]
65    pub(crate) use crate::loom::std::mutex::Mutex;
66
67    #[cfg(not(all(feature = "parking_lot", not(miri))))]
68    pub(crate) use crate::loom::std::rwlock::RwLock;
69
70    pub(crate) mod atomic {
71        pub(crate) use crate::loom::std::atomic_u16::AtomicU16;
72        pub(crate) use crate::loom::std::atomic_u32::AtomicU32;
73        pub(crate) use crate::loom::std::atomic_u64::{AtomicU64, StaticAtomicU64};
74        pub(crate) use crate::loom::std::atomic_usize::AtomicUsize;
75
76        pub(crate) use std::sync::atomic::{fence, AtomicBool, AtomicPtr, AtomicU8, Ordering};
77    }
78
79    pub(crate) use super::barrier::Barrier;
80}
81
82pub(crate) mod sys {
83    #[cfg(feature = "rt-multi-thread")]
84    pub(crate) fn num_cpus() -> usize {
85        use std::num::NonZeroUsize;
86
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!("\"{ENV_WORKER_THREADS}\" must be usize, error: {e}, value: {s}")
93                });
94                assert!(n > 0, "\"{ENV_WORKER_THREADS}\" cannot be set to 0");
95                n
96            }
97            Err(std::env::VarError::NotPresent) => {
98                std::thread::available_parallelism().map_or(1, NonZeroUsize::get)
99            }
100            Err(std::env::VarError::NotUnicode(e)) => {
101                panic!("\"{ENV_WORKER_THREADS}\" must be valid unicode, error: {e:?}")
102            }
103        }
104    }
105
106    #[cfg(not(feature = "rt-multi-thread"))]
107    pub(crate) fn num_cpus() -> usize {
108        1
109    }
110}
111
112pub(crate) mod thread {
113    #[inline]
114    pub(crate) fn yield_now() {
115        std::hint::spin_loop();
116    }
117
118    #[allow(unused_imports)]
119    pub(crate) use std::thread::{
120        current, panicking, park, park_timeout, sleep, spawn, AccessError, Builder, JoinHandle,
121        LocalKey, Result, Thread, ThreadId,
122    };
123}
tokio/loom/std/mod.rs

tokio/loom/std/
mod.rs
