package main

import (
	"flag"
	"fmt"
	"math/rand"
	"runtime"
	"sync"
	"sync/atomic"
	"time"
	"golang.org/x/text/language"
	"golang.org/x/text/message"
)

func churner(result chan uint64, start *sync.WaitGroup, spots [] chan struct {}) {
	s := rand.NewSource(time.Now().UnixNano())
	rng := rand.New(s)

	count := uint64(0)
	start.Wait()
	for true {

		sem := spots[ rng.Intn(100) % len(spots) ];
		sem <- (struct {}{})
		<- sem;

		count += 1
		if  clock_mode && atomic.LoadInt32(&stop) == 1 { break }
		if !clock_mode && count >= stop_count { break }
	}

	atomic.AddInt64(&threads_left, -1);
	result <- count
}

func main() {
	var spot_cnt int

	spot_cntOpt := flag.Int("s", 1, "Number of spots in the system")

	bench_init()

	spot_cnt = *spot_cntOpt

	threads_left = int64(nthreads)

	result := make(chan uint64)
	var wg sync.WaitGroup
	wg.Add(1)

	spots := make([] chan struct {}, spot_cnt)
	for i := range spots {
		spots[i] = make(chan struct {}, 1)
	}

	for i := 0; i < nthreads; i++ {
		go churner(result, &wg, spots)
	}
	fmt.Printf("Starting\n");
	atomic.StoreInt32(&stop, 0)
	start := time.Now()
	wg.Done();
	wait(start, true);

	atomic.StoreInt32(&stop, 1)
	end := time.Now()
	duration := end.Sub(start)

	fmt.Printf("\nDone\n")

	for atomic.LoadInt64(&threads_left) != 0 {
		for i := range spots {
			select {
			case <- spots[i]:
			default:
			}
			select {
			case spots[i] <- (struct {}{}):
			default:
			}
			runtime.Gosched()
		}
	}

	global_counter := uint64(0)
	for i := 0; i < nthreads; i++ {
		global_counter += <- result
	}

	p := message.NewPrinter(language.English)
	p.Printf("Duration (ms)        : %d\n", duration.Milliseconds())
	p.Printf("Number of processors : %d\n", nprocs);
	p.Printf("Number of threads    : %d\n", nthreads);
	p.Printf("Number of spots      : %d\n", spot_cnt);
	p.Printf("Total Operations(ops): %15d\n", global_counter);
	// p.Printf("Total blocks         : %15d\n", global_blocks);
	p.Printf("Ops per second       : %18.2f\n", float64(global_counter) / duration.Seconds());
	p.Printf("ns per ops           : %18.2f\n", float64(duration.Nanoseconds()) / float64(global_counter))
	p.Printf("Ops per threads      : %15d\n", global_counter / uint64(nthreads))
	p.Printf("Ops per procs        : %15d\n", global_counter / uint64(nprocs))
	p.Printf("Ops/sec/procs        : %18.2f\n", (float64(global_counter) / float64(nprocs)) / duration.Seconds())
	p.Printf("ns per ops/procs     : %18.2f\n", float64(duration.Nanoseconds()) / (float64(global_counter) / float64(nprocs)))
}