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
43        let mut hasher = rand_state.build_hasher();
44
45        // Hash some unique-ish data to generate some new state
46        COUNTER.fetch_add(1, Relaxed).hash(&mut hasher);
47
48        // Get the seed
49        hasher.finish()
50    }
51}
52
53pub(crate) mod sync {
54    pub(crate) use std::sync::{Arc, Weak};
55
56    // Below, make sure all the feature-influenced types are exported for
57    // internal use. Note however that some are not _currently_ named by
58    // consuming code.
59
60    #[cfg(all(feature = "parking_lot", not(miri)))]
61    #[allow(unused_imports)]
62    pub(crate) use crate::loom::std::parking_lot::{
63        Condvar, Mutex, MutexGuard, RwLock, RwLockReadGuard, WaitTimeoutResult,
64    };
65
66    #[cfg(not(all(feature = "parking_lot", not(miri))))]
67    #[allow(unused_imports)]
68    pub(crate) use std::sync::{Condvar, MutexGuard, RwLockReadGuard, WaitTimeoutResult};
69
70    #[cfg(not(all(feature = "parking_lot", not(miri))))]
71    pub(crate) use crate::loom::std::mutex::Mutex;
72
73    #[cfg(not(all(feature = "parking_lot", not(miri))))]
74    pub(crate) use crate::loom::std::rwlock::RwLock;
75
76    pub(crate) mod atomic {
77        pub(crate) use crate::loom::std::atomic_u16::AtomicU16;
78        pub(crate) use crate::loom::std::atomic_u32::AtomicU32;
79        pub(crate) use crate::loom::std::atomic_u64::{AtomicU64, StaticAtomicU64};
80        pub(crate) use crate::loom::std::atomic_usize::AtomicUsize;
81
82        pub(crate) use std::sync::atomic::{fence, AtomicBool, AtomicPtr, AtomicU8, Ordering};
83    }
84
85    pub(crate) use super::barrier::Barrier;
86}
87
88pub(crate) mod sys {
89    #[cfg(feature = "rt-multi-thread")]
90    pub(crate) fn num_cpus() -> usize {
91        use std::num::NonZeroUsize;
92
93        const ENV_WORKER_THREADS: &str = "TOKIO_WORKER_THREADS";
94
95        match std::env::var(ENV_WORKER_THREADS) {
96            Ok(s) => {
97                let n = s.parse().unwrap_or_else(|e| {
98                    panic!("\"{ENV_WORKER_THREADS}\" must be usize, error: {e}, value: {s}")
99                });
100                assert!(n > 0, "\"{ENV_WORKER_THREADS}\" cannot be set to 0");
101                n
102            }
103            Err(std::env::VarError::NotPresent) => {
104                std::thread::available_parallelism().map_or(1, NonZeroUsize::get)
105            }
106            Err(std::env::VarError::NotUnicode(e)) => {
107                panic!("\"{ENV_WORKER_THREADS}\" must be valid unicode, error: {e:?}")
108            }
109        }
110    }
111
112    #[cfg(not(feature = "rt-multi-thread"))]
113    pub(crate) fn num_cpus() -> usize {
114        1
115    }
116}
117
118pub(crate) mod thread {
119    #[inline]
120    pub(crate) fn yield_now() {
121        std::hint::spin_loop();
122    }
123
124    #[allow(unused_imports)]
125    pub(crate) use std::thread::{
126        current, panicking, park, park_timeout, sleep, spawn, AccessError, Builder, JoinHandle,
127        LocalKey, Result, Thread, ThreadId,
128    };
129}
tokio/loom/std/mod.rs

tokio/loom/std/
mod.rs
