module sync

import sync.stdatomic

pub struct ManyTimes {
mut:
    m RwMutex
pub:
    times u64 = 1
    count u64
}

// new_many_times return a new ManyTimes struct.
pub fn new_many_times(times u64) &ManyTimes {
    mut many_times := &ManyTimes{
        times: times
    }
    many_times.m.init()
    return many_times
}

// do execute the function only setting times.
pub fn (mut m ManyTimes) do(f fn ()) {
    if stdatomic.load_u64(&m.count) < m.times {
        m.do_slow(f)
    }
}

fn (mut m ManyTimes) do_slow(f fn ()) {
    m.m.@lock()
    if m.count < m.times {
        stdatomic.store_u64(&m.count, m.count + 1)
        f()
    }
    m.m.unlock()
}