non-preemptive golang https://play.golang.org/p/5JLZzHhg02C

non-preemptive-golang.go

package main

import (
	"fmt"
)

func main() {
	js := []Job{
		{pno: 1, prio: 2, at: 0, bt: 4},
		{pno: 2, prio: 4, at: 1, bt: 2},
		{pno: 3, prio: 6, at: 2, bt: 3},
		{pno: 4, prio: 10, at: 3, bt: 5},
		{pno: 5, prio: 8, at: 4, bt: 1},
		{pno: 6, prio: 12, at: 5, bt: 4},
		{pno: 7, prio: 9, at: 6, bt: 6},
	}
	var s []Job
	var working Job
	var elapsed uint
	for len(js) > 0 {
		working, js = arrive(js, elapsed)
		elapsed += working.bt
		s = append(s, Job{
			pno: working.pno,
			bt:  elapsed,
		})
		// fmt.Println("working:", working, "\tjs:", js)
	}
	for _, v := range s {
		fmt.Println("no:", v.pno, "\tbt:", v.bt)
	}
}

type Job struct {
	pno  uint
	prio uint
	at   uint
	bt   uint
}

func arrive(js []Job, currentTime uint) (job Job, jobs []Job) {
	if currentTime > 0 {
		// get all pending jobs before currentTime
		var pjobs []Job
		for _, j := range js {
			if j.at < currentTime {
				pjobs = append(pjobs, j)
			}
		}
		// get the highest priority before currentTime
		var prio uint
		for _, j := range pjobs {
			if j.prio > prio {
				prio = j.prio
			}
		}
		// get the job by prio
		for k, j := range pjobs {
			if j.prio == prio {
				job, jobs = j, append(js[:k], js[k+1:]...)
				return
			}
		}
		panic("prio and job doesn't match")
	}

	// if there is no pending task, get the next job
	job = js[0]
	for k, j := range js {
		if j.at < job.at {
			job, jobs = j, append(js[:k], js[k+1:]...)
			return
		}
	}
	jobs = js[1:]
	return
}