source: tests/concurrency/sleep.cfa @ 0e8f4c6

#include <fstream.hfa>
#include <thread.hfa>
#include <mutex_stmt.hfa>
#include <time.hfa>

Duration default_preemption() {
        return 0;
}

volatile int counter = 0;

thread fast_sleeper {};
void main(fast_sleeper &) {
        Duration wait = 47`ms;
        for(i; 20) {
                sleep(wait);
                __atomic_fetch_add( &counter, 1, __ATOMIC_RELAXED );
        }
}

thread slow_sleeper {};
void main(slow_sleeper &) {
        Duration wait = 277`ms;
        for(i; 4) {
                sleep(wait);
                int val = __atomic_add_fetch( &counter, -5, __ATOMIC_RELAXED );
                if(val < -9) abort | "Value reached negative value:" | val;
        }
}

int main() {
        mutex( sout ) sout | "start";
        {
                slow_sleeper slow;
                yield();
                fast_sleeper fast;
                yield();
        }
        mutex( sout ) sout | "done";
}