如何串行一些 goroutings 才能完成

Question

I have a Go Project sample, trying to simulate something like baking 1000 pizza concurrency but the oven just has 10 parts to put the pizza. I developed like this, but goroutines are deadlocked. would anyone help

package main

import (
    "fmt"
    "sync"
    "time"
)

type Material struct {
    material int
    mutex    sync.Mutex
}

var (
    mOven  sync.Mutex
    inOven int
)

func main() {
    rawMaterial := Material{material: 10000}

    var waitGroup sync.WaitGroup

    for i := 0; i < 1000; i++ {
        waitGroup.Add(1)
        go perparePizza(&waitGroup, &rawMaterial, i)

    }
    waitGroup.Wait()
    fmt.Println("finished with remained material:", rawMaterial.material)
}

func perparePizza(wg *sync.WaitGroup, m *Material, num int) {
    defer wg.Done()
    fmt.Println("Preparing Pizza:", num)
    m.mutex.Lock()
    m.material--
    m.mutex.Unlock()
    //  time.Sleep(time.Second * 2)
    var isCooking chan bool
    for {
        ovenManeger(num, isCooking)
        select {
        case <-isCooking:
            putInOven(num)
        default:
            fmt.Println("waiting for accepting cook!", num)
            time.Sleep(time.Second)
        }
    }

    fmt.Printf("Pizza %d is ready \n", num)
}

func ovenManeger(num int, couldPleaseCook chan bool) {
    if inOven < 10 {
        mOven.Lock()
        inOven = inOven + 1
        couldPleaseCook <- true
        mOven.Unlock()
    }
}
func putInOven(num int) {
    fmt.Println("putInOven", num)
    time.Sleep(time.Second * 30)
    mOven.Lock()
    inOven = inOven - 1
    mOven.Unlock()
}

error raise when 10 oven part filled with deadlocking

Preparing Pizza: 9 Preparing Pizza: 0 Preparing Pizza: 1 Preparing Pizza: 2 Preparing Pizza: 3 Preparing Pizza: 4 Preparing Pizza: 5 Preparing Pizza: 6 Preparing Pizza: 7 Preparing Pizza: 8 fatal error: all goroutines are asleep - deadlock!

Answer 1

I changed Like this, but I think there would be a better solution too.

package main

import (
    "fmt"
    "sync"
    "time"
)

type Material struct {
    material int
    mutex    sync.RWMutex
}

var readValue = make(chan int)
var writeValue = make(chan int)

func set(newValue int) {
    writeValue <- newValue
}

func read() int {
    return <-readValue
}

func backing() {
    var value int
    var internalCounter int
    for {
        select {
        case newValue := <-writeValue:
            internalCounter = internalCounter + 1
            value = newValue
            putInOven(value)

        case readValue <- value:
            internalCounter = internalCounter - 1
        }
    }
}
func main() {
    rawMaterial := Material{material: 10000}

    var waitGroup sync.WaitGroup

    for i := 1; i <= 100; i++ {
        waitGroup.Add(1)
        go perparePizza(&waitGroup, &rawMaterial, i)

    }
    for i := 0; i < 10; i++ {
        go backing()
    }
    waitGroup.Wait()
    fmt.Println("finished with remained material:", rawMaterial.material)
}

func perparePizza(wg *sync.WaitGroup, m *Material, num int) {
    defer wg.Done()
    //  fmt.Println("Preparing Pizza:", num)
    m.mutex.Lock()
    m.material--
    m.mutex.Unlock()
    //  time.Sleep(time.Second * 2)
    set(num)

    fmt.Printf("Pizza %d is ready \n", num)
}

func putInOven(num int) {
    //  fmt.Println("putInOven", num)
    time.Sleep(time.Second * 3)
}