import sync

struct Counter {
pub mut:
    i int
}

fn write_10000(mut co Counter, mut mx sync.Mutex) {
    mx.lock()
    co.i = 10000
    mx.unlock()
}

fn test_mutex() {
    mut co := &Counter{10086}
    mut mx := sync.new_mutex()
    mx.lock()
    co.i = 888
    th := spawn write_10000(mut co, mut mx)
    mx.unlock() // after mx unlock, thread write_10000 can continue
    th.wait()
    mx.destroy()
    assert co.i == 10000
}

fn test_try_lock_mutex() {
    // In Windows, try_lock only avalible after Windows 7
    $if windows {
        $if !windows_7 ? {
            return
        }
    }
    mut mx := sync.new_mutex()
    mx.lock()
    try_fail := mx.try_lock()
    assert try_fail == false
    mx.unlock()
    try_success := mx.try_lock()
    assert try_success == true
    mx.unlock() // you must unlock it, after try_lock success
    mx.destroy()
}