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use boxed::FnBox;
use ptr;
use mem;
use sys_common::mutex::Mutex;
type Queue = Vec<Box<dyn FnBox()>>;
static LOCK: Mutex = Mutex::new();
static mut QUEUE: *mut Queue = ptr::null_mut();
const DONE: *mut Queue = 1_usize as *mut _;
const ITERS: usize = 10;
unsafe fn init() -> bool {
    if QUEUE.is_null() {
        let state: Box<Queue> = box Vec::new();
        QUEUE = Box::into_raw(state);
    } else if QUEUE == DONE {
        
        return false
    }
    true
}
pub fn cleanup() {
    for i in 1..=ITERS {
        unsafe {
            let queue = {
                let _guard = LOCK.lock();
                mem::replace(&mut QUEUE, if i == ITERS { DONE } else { ptr::null_mut() })
            };
            
            assert!(queue != DONE);
            
            if !queue.is_null() {
                let queue: Box<Queue> = Box::from_raw(queue);
                for to_run in *queue {
                    
                    to_run();
                }
            }
        }
    }
}
pub fn push(f: Box<dyn FnBox()>) -> bool {
    unsafe {
        let _guard = LOCK.lock();
        if init() {
            
            
            (*QUEUE).push(f);
            true
        } else {
            false
        }
    }
}