1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116

//! Replaces the deprecated functionality of std::os::num_cpus.
#![cfg_attr(test, deny(warnings))]
#![deny(missing_docs)]
#![allow(non_snake_case)]

#[cfg(not(windows))]
extern crate libc;

/// Returns the number of CPUs of the current machine.
#[inline]
pub fn get() -> usize {
    get_num_cpus()
}

#[cfg(windows)]
fn get_num_cpus() -> usize {
    #[repr(C)]
    struct SYSTEM_INFO {
        wProcessorArchitecture: u16,
        wReserved: u16,
        dwPageSize: u32,
        lpMinimumApplicationAddress: *mut u8,
        lpMaximumApplicationAddress: *mut u8,
        dwActiveProcessorMask: *mut u8,
        dwNumberOfProcessors: u32,
        dwProcessorType: u32,
        dwAllocationGranularity: u32,
        wProcessorLevel: u16,
        wProcessorRevision: u16,
    }

    extern "system" {
        fn GetSystemInfo(lpSystemInfo: *mut SYSTEM_INFO);
    }

    unsafe {
        let mut sysinfo: SYSTEM_INFO = std::mem::uninitialized();
        GetSystemInfo(&mut sysinfo);
        sysinfo.dwNumberOfProcessors as usize
    }
}

#[cfg(any(target_os = "freebsd",
          target_os = "dragonfly",
          target_os = "bitrig",
          target_os = "netbsd"))]
fn get_num_cpus() -> usize {
    let mut cpus: libc::c_uint = 0;
    let mut cpus_size = std::mem::size_of_val(&cpus);

    unsafe {
        cpus = libc::sysconf(libc::_SC_NPROCESSORS_ONLN) as libc::c_uint;
    }
    if cpus < 1 {
        let mut mib = [libc::CTL_HW, libc::HW_NCPU, 0, 0];
        unsafe {
            libc::sysctl(mib.as_mut_ptr(),
                         2,
                         &mut cpus as *mut _ as *mut _,
                         &mut cpus_size as *mut _ as *mut _,
                         0 as *mut _,
                         0);
        }
        if cpus < 1 {
            cpus = 1;
        }
    }
    cpus as usize
}

#[cfg(target_os = "openbsd")]
fn get_num_cpus() -> usize {
    let mut cpus: libc::c_uint = 0;
    let mut cpus_size = std::mem::size_of_val(&cpus);
    let mut mib = [libc::CTL_HW, libc::HW_NCPU, 0, 0];

    unsafe {
        libc::sysctl(mib.as_mut_ptr(),
                     2,
                     &mut cpus as *mut _ as *mut _,
                     &mut cpus_size as *mut _ as *mut _,
                     0 as *mut _,
                     0);
    }
    if cpus < 1 {
        cpus = 1;
    }
    cpus as usize
}

#[cfg(
    any(
        target_os = "linux",
        target_os = "nacl",
        target_os = "macos",
        target_os = "ios",
        target_os = "android",
        target_os = "solaris",
    )
)]
fn get_num_cpus() -> usize {
    unsafe {
        libc::sysconf(libc::_SC_NPROCESSORS_ONLN) as usize
    }
}

#[test]
fn lower_bound() {
    assert!(get() > 0);
}


#[test]
fn upper_bound() {
    assert!(get() < 236_451);
}