num_threads/
lib.rs

1//! Minimum supported Rust version: 1.28
2
3use std::num::NonZeroUsize;
4
5#[cfg_attr(any(target_os = "linux", target_os = "android"), path = "linux.rs")]
6#[cfg_attr(target_os = "freebsd", path = "freebsd.rs")]
7#[cfg_attr(any(target_os = "macos", target_os = "ios"), path = "apple.rs")]
8#[cfg_attr(target_os = "aix", path = "aix.rs")]
9mod imp;
10
11/// Obtain the number of threads currently part of the active process. Returns `None` if the number
12/// of threads cannot be determined.
13pub fn num_threads() -> Option<NonZeroUsize> {
14    imp::num_threads()
15}
16
17/// Determine if the current process is single-threaded. Returns `None` if the number of threads
18/// cannot be determined.
19pub fn is_single_threaded() -> Option<bool> {
20    num_threads().map(|n| n.get() == 1)
21}