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use crate::env;
use crate::sync::atomic::{self, Ordering};
use crate::sys::stack_overflow;
use crate::sys::thread as imp;
#[allow(dead_code)]
pub unsafe fn start_thread(main: *mut u8) {
    
    
    let _handler = stack_overflow::Handler::new();
    
    Box::from_raw(main as *mut Box<dyn FnOnce()>)()
}
pub fn min_stack() -> usize {
    static MIN: atomic::AtomicUsize = atomic::AtomicUsize::new(0);
    match MIN.load(Ordering::SeqCst) {
        0 => {}
        n => return n - 1,
    }
    let amt = env::var("RUST_MIN_STACK").ok().and_then(|s| s.parse().ok());
    let amt = amt.unwrap_or(imp::DEFAULT_MIN_STACK_SIZE);
    
    
    MIN.store(amt + 1, Ordering::SeqCst);
    amt
}