// Init runs before the simulation begins, and its job is to set up the
// queues, processors, and behaviors.
func (sys *BlogSystem) Init() {
var i int
rand.Seed(time.Now().UnixNano())
sys.arrProc = qsim.NewPoissonArrProc(sys.ArrivalInterval)
procTimeGenerator := func(j *qsim.Job) int {
return int(rand.ExpFloat64() * 1000.0)
}
// There is 1 processor and 1 queue
sys.queues = make([]*qsim.Queue, 1)
sys.processors = make([]*qsim.Processor, 1)
sys.queues[i] = qsim.NewQueue()
sys.processors[i] = qsim.NewProcessor(procTimeGenerator)
sys.arrBeh = qsim.NewShortestQueueArrBeh(sys.queues, sys.processors, sys.arrProc)
qsim.NewOneToOneFIFODiscipline(sys.queues, sys.processors)
}
// Init runs before the simulation begins, and its job is to set up the
// queues, processors, and behaviors.
func (sys *PortaPottySystem) Init() {
var i int
var maleMean, femaleMean, stdev float64
rand.Seed(time.Now().UnixNano())
maleMean = 40000.0
femaleMean = 60000.0
stdev = 5000.0
// The time taken to use the porta-potty depends on the sex of the
// person using it.
procTimeGenerator := func(j *qsim.Job) int {
if j.StrAttrs["sex"] == "male" {
// Normal distribution of pee times with stdev=5s
return int(rand.NormFloat64()*stdev + maleMean)
} else {
return int(rand.NormFloat64()*stdev + femaleMean)
}
}
// There are 15 porta-potties, each with its own queue.
sys.queues = make([]*qsim.Queue, 15)
sys.processors = make([]*qsim.Processor, 15)
for i = 0; i < 15; i++ {
sys.queues[i] = qsim.NewQueue()
sys.queues[i].MaxLength = 8
sys.processors[i] = qsim.NewProcessor(procTimeGenerator)
}
// Processor callback to keep track of wait times for strategy users and non
// strategy users. This saves finished Jobs to a slice so that we can do
// calculations on those Jobs after each tick in AfterEvents.
for i, _ = range sys.processors {
sys.processors[i].AfterFinish(func(p *qsim.Processor, j *qsim.Job) {
if !sys.statsStarted {
return
}
sys.finishedJobs = append(sys.finishedJobs, j)
})
}
// The mean of this Poisson distribution is the maxmimum rate at which
// porta-potties can be vacated. This ensures that queues will usually be
// long.
sys.arrProc = qsim.NewPoissonArrProc((maleMean + femaleMean) / 2.0 / 15.0)
// Assign a gender to each incoming person.
sys.arrProc.AfterArrive(func(ap qsim.ArrProc, jobs []*qsim.Job, interval int) {
sexes := []string{"male", "female"}
jobs[0].StrAttrs["sex"] = sexes[rand.Intn(2)]
})
// Occasionally pick a person to use the strategy.
sys.arrProc.AfterArrive(func(ap qsim.ArrProc, jobs []*qsim.Job, interval int) {
if rand.Float64() < sys.PStrategy {
jobs[0].IntAttrs["use_strategy"] = 1
} else {
jobs[0].IntAttrs["use_strategy"] = 0
}
})
// When customers arrive, they pick the shortest queue. If all the queues
// are too long, the queue MaxLength parameter means they go do something
// else.
sys.arrBeh = qsim.NewShortestQueueArrBeh(sys.queues, sys.processors, sys.arrProc)
// This callback overrides the default arrival behavior for people that
// are using our clever strategy.
sys.arrBeh.BeforeAssign(func(ab qsim.ArrBeh, j *qsim.Job) *qsim.Assignment {
if j.IntAttrs["use_strategy"] == 1 {
return sys.strategicAssignment()
} else {
return nil
}
})
// Customers stay in the queue they originally joined, and each queue
// leads to exactly one porta-potty.
qsim.NewOneToOneFIFODiscipline(sys.queues, sys.processors)
}