nativethread 0.2.0

/*
Copyright 2025 YÜce Tekol

Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the "Software"),
to deal in the Software without restriction, including without limitation
the rights to use, copy, modify, merge, publish, distribute, sublicense,
and/or sell copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.
*/

/// Returns the native thread ID for the current platform
///
/// # Examples
///
/// ```
/// let tid = nativethread::get_id();
/// println!("thread ID: {tid}");
/// ```
pub fn get_id() -> u64 {
    _get_native_thread_id()
}

mod inner {
    #[cfg(target_os = "haiku")]
    use std::os::raw::c_char;

    #[cfg(target_os = "linux")]
    unsafe extern "C" {
        pub fn gettid() -> i32;
    }

    #[cfg(target_os = "openbsd")]
    unsafe extern "C" {
        pub fn getthrid() -> i32;
    }

    #[cfg(target_os = "freebsd")]
    unsafe extern "C" {
        pub fn pthread_getthreadid_np() -> i32;
    }

    #[cfg(target_os = "netbsd")]
    unsafe extern "C" {
        pub fn _lwp_self() -> i32;
    }

    #[cfg(any(target_os = "illumos", target_os = "solaris"))]
    unsafe extern "C" {
        pub fn thr_self() -> u32;
    }

    #[cfg(target_os = "haiku")]
    unsafe extern "C" {
        pub fn find_thread(name: *const c_char) -> i32;
    }

    #[cfg(target_os = "macos")]
    unsafe extern "C" {
        pub fn pthread_threadid_np(thread: *const c_void, thread_id: *mut u64);
    }
}

#[cfg(target_os = "linux")]
fn _get_native_thread_id() -> u64 {
    unsafe { inner::gettid() as u64 }
}

#[cfg(target_os = "openbsd")]
fn _get_native_thread_id() -> u64 {
    unsafe { inner::getthrid() as u64 }
}

#[cfg(target_os = "freebsd")]
fn _get_native_thread_id() -> u64 {
    unsafe { inner::pthread_getthreadid_np() as u64 }
}

#[cfg(target_os = "netbsd")]
fn _get_native_thread_id() -> u64 {
    unsafe { inner::_lwp_self() as u64 }
}

#[cfg(any(target_os = "illumos", target_os = "solaris"))]
fn _get_native_thread_id() -> u64 {
    unsafe { inner::thr_self() as u64 }
}

#[cfg(target_os = "haiku")]
fn _get_native_thread_id() -> u64 {
    unsafe { inner::find_thread(std::ptr::null()) as u64 }
}

#[cfg(target_os = "macos")]
fn _get_native_thread_id() -> u64 {
    unsafe {
        let mut tid: u64 = 0;
        inner::pthread_threadid_np(std::ptr::null(), &mut tid);
        tid
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::thread;

    #[test]
    fn test_get_native_thread_id() {
        let main_tid = get_id();
        assert_ne!(main_tid, 0);
        let t = thread::spawn(move || {
            let tid = get_id();
            assert_ne!(tid, 0);
            assert_ne!(tid, main_tid);
        });
        t.join().unwrap();
    }
}