ppwt2.go

package main

import (
	"log"
	"math/rand"
	"time"
)

type Threader struct {
	TIME_LIMIT    time.Time
	numWorkers    int
	jobs          int
	jobsProduced  int
	doneProducing chan bool
	doneReceiving chan bool
	pwChan        chan int
	wrChan        chan int
	errChan       chan error
	initTime      time.Time
}

const TIME_LIMIT = time.Second

func main() {
	mimt := Threader{}
	mimt.Init(4, 8)
}

func (tr Threader) Init(numWorkers int, jobs int) {

	tr.doneProducing = make(chan bool)
	tr.doneReceiving = make(chan bool)

	tr.pwChan = make(chan int)
	tr.wrChan = make(chan int)

	tr.errChan = make(chan error)

	tr.initTime = time.Now()

	tr.numWorkers = numWorkers
	tr.jobs = jobs
	// start producing jobs
	go tr.produce()
	// start waiting for jobs done
	go tr.receiver()
	// start workers for jobs
	for i := 0; i < tr.numWorkers; i++ {
		go tr.work()
	}
	// wait for done producing
	<-tr.doneProducing
}

func (tr Threader) produce() {
	// current job
	i := 0
	// marker for timing
	tr.jobsProduced = 0
	// start tracking time passed producing
	t := time.Now()
	for {
		// we have sent 1 job per worker, trap till tl has passed
		if tr.jobsProduced == tr.numWorkers {
			// if moreThanTimeLimit has passed
			if moreThanTL(t) {
				// reset
				tr.jobsProduced = 0
				t = time.Now()
			}
		} else {
			// normal round, send work
			log.Printf("Sending %d", i)
			// send job
			tr.pwChan <- i

			// add to counters
			i += 1
			tr.jobsProduced += 1

		}
		// we finished doing our jobs, quit producing
		if i == tr.jobs {
			//log.Printf("Rondas done %d", i)
			break
		}

	}
	end(tr.initTime, "PRODUCE")
	// make main wait for all to finish
	tr.doneProducing <- <-tr.doneReceiving

}

func (tr Threader) work() {
	// the routine receives the data,
	// sleeps for a random time
	// and sends response to receiver (wrChan)
	for {
		resp := <-tr.pwChan
		// do work

		myrand := time.Duration(random(0, 100))
		time.Sleep(myrand * (time.Second / 100))
		// rend response
		tr.wrChan <- resp
	}
}

func (tr Threader) receiver() {
	// waits for msgs from workers
	for {
		u := <-tr.wrChan
		log.Printf("Received %d", u)
		// all workers finished, quit
		if u == (tr.jobs - 1) {
			break
		}
	}
	end(tr.initTime, "RECEIVE")
	tr.doneReceiving <- true
}

////
// helpers
////

func moreThanTL(t time.Time) bool {
	elapsed := time.Since(t)
	if TIME_LIMIT < elapsed {
		return true
	}
	return false
}

func end(t time.Time, s string) {
	elapsed := time.Since(t)
	log.Printf("%s took %s", s, elapsed)
}

func random(min, max int) int {
	rand.Seed(time.Now().Unix())
	return rand.Intn(max-min) + min
}