我正在學習并發，我想實現一個簡單的示例，該示例從矩陣中獲取行并將值的數組（切片）添加到每一行。由于我使用的是通道，因此我嘗試等待每一行從 goroutine 獲得相應的結果。但是，這并不比僅同步執行此操作更好。如何讓每一行等待它們各自的結果并允許其他行同時計算它們的結果？https://play.golang.org/p/uCOGwOBeIQLpackage mainimport "fmt"/*Array:0 1 2 3 4 5 6 7 8 9+Matrix:1 0 0 0 0 0 0 0 0 00 1 0 0 0 0 0 0 0 00 0 1 0 0 0 0 0 0 00 0 0 1 0 0 0 0 0 00 0 0 0 1 0 0 0 0 00 0 0 0 0 1 0 0 0 00 0 0 0 0 0 1 0 0 00 0 0 0 0 0 0 1 0 00 0 0 0 0 0 0 0 1 00 0 0 0 0 0 0 0 0 1-> Expected result:1 1 2 3 4 5 6 7 8 90 2 2 3 4 5 6 7 8 90 1 3 3 4 5 6 7 8 90 1 2 4 4 5 6 7 8 90 1 2 3 5 5 6 7 8 90 1 2 3 4 6 6 7 8 90 1 2 3 4 5 7 7 8 90 1 2 3 4 5 6 8 8 90 1 2 3 4 5 6 7 9 90 1 2 3 4 5 6 7 8 10*/func main() { numbers := []int {0,1,2,3,4,5,6,7,8,9} matrix := [][]int{ {1,0,0,0,0,0,0,0,0,0}, {0,1,0,0,0,0,0,0,0,0}, {0,0,1,0,0,0,0,0,0,0}, {0,0,0,1,0,0,0,0,0,0}, {0,0,0,0,1,0,0,0,0,0}, {0,0,0,0,0,1,0,0,0,0}, {0,0,0,0,0,0,1,0,0,0}, {0,0,0,0,0,0,0,1,0,0}, {0,0,0,0,0,0,0,0,1,0}, {0,0,0,0,0,0,0,0,0,1}, } rmatrix := make([][]int, 10) for i, row := range matrix { cResult := make(chan []int) go func(row []int, numbers []int, c chan <- []int) { c <- addRow(row,numbers) }(row,numbers,cResult) //this read from the channel will block until the goroutine sends its result over the channel rmatrix[i] = <- cResult } fmt.Println(rmatrix)}func addRow(row []int, numbers []int) []int{ result := make([]int, len(row)) for i,e := range row { result[i] = e + numbers[i]; } return result}
3 回答
Helenr
TA貢獻1780條經驗 獲得超4個贊
我需要使用 async.WaitGroup并直接分配調用的結果（以保證它們返回到索引行）。謝謝@彼得
package main
import (
"fmt"
"sync"
)
func main() {
numbers := []int{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
matrix := [][]int{
{1, 0, 0, 0, 0, 0, 0, 0, 0, 0},
{0, 1, 0, 0, 0, 0, 0, 0, 0, 0},
{0, 0, 1, 0, 0, 0, 0, 0, 0, 0},
{0, 0, 0, 1, 0, 0, 0, 0, 0, 0},
{0, 0, 0, 0, 1, 0, 0, 0, 0, 0},
{0, 0, 0, 0, 0, 1, 0, 0, 0, 0},
{0, 0, 0, 0, 0, 0, 1, 0, 0, 0},
{0, 0, 0, 0, 0, 0, 0, 1, 0, 0},
{0, 0, 0, 0, 0, 0, 0, 0, 1, 0},
{0, 0, 0, 0, 0, 0, 0, 0, 0, 1},
}
rmatrix := make([][]int, 10)
var waitGroup sync.WaitGroup
for i, row := range matrix {
waitGroup.Add(1)
go func(i int, row []int) {
rmatrix[i] = addRow(row, numbers)
waitGroup.Done()
}(i, row)
}
waitGroup.Wait()
fmt.Println(rmatrix)
}
func addRow(row []int, numbers []int) []int {
result := make([]int, len(row))
for i, e := range row {
result[i] = e + numbers[i]
}
return result
}
慕容3067478
TA貢獻1773條經驗 獲得超3個贊
這個例子產生了較少數量的 goroutine，并且也保證了正確的順序，不管哪個 goroutine 先完成了它的處理。
package main
import (
"fmt"
"sync"
)
type rowRes struct {
index int
result *[]int
}
func addRow(index int, row []int, numbers []int) rowRes {
result := make([]int, len(row))
for i, e := range row {
result[i] = e + numbers[i]
}
return rowRes{
index: index,
result: &result,
}
}
func main() {
numbers := []int{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
matrix := [][]int{
{1, 0, 0, 0, 0, 0, 0, 0, 0, 0},
{0, 1, 0, 0, 0, 0, 0, 0, 0, 0},
{0, 0, 1, 0, 0, 0, 0, 0, 0, 0},
{0, 0, 0, 1, 0, 0, 0, 0, 0, 0},
{0, 0, 0, 0, 1, 0, 0, 0, 0, 0},
{0, 0, 0, 0, 0, 1, 0, 0, 0, 0},
{0, 0, 0, 0, 0, 0, 1, 0, 0, 0},
{0, 0, 0, 0, 0, 0, 0, 1, 0, 0},
{0, 0, 0, 0, 0, 0, 0, 0, 1, 0},
{0, 0, 0, 0, 0, 0, 0, 0, 0, 1},
}
rmatrix := make([][]int, 10)
// Buffered channel
rowChan := make(chan rowRes, 10)
wg := sync.WaitGroup{}
// Reciever goroutine
go recv(rowChan, rmatrix)
for i := range matrix {
wg.Add(1)
go func(index int, row []int, w *sync.WaitGroup) {
rowChan <- addRow(index, row, numbers)
w.Done()
}(i, matrix[i], &wg)
}
wg.Wait()
close(rowChan)
fmt.Println(rmatrix)
}
func recv(res chan rowRes, rmatrix [][]int) {
for {
select {
case k, ok := <-res:
if !ok {
return
}
rmatrix[k.index] = *k.result
}
}
}
楊魅力
TA貢獻1811條經驗 獲得超6個贊
流水線法
taskChannel := make(chan string,1000); // Set up the task queue
wg := sync.WaitGroup
// Task release
wg.add(1)
go func(&wg,taskChannel) {
defer wg.Down()
for i in "task list" {
taskChannel <- "Stuff the characters you want to deal with here"
}
// After the task is sent and closed
close(taskChannel)
}(wg *sync.WaitGroup,taskChannel chan string)
// Task execution
go func(&wg,taskChannel,1000) {
defer wg.Down()
limit := make(chan bool,limitNumber); // Limit the number of concurrent
tg := sync.WaitGroup
loop:
for {
select {
case task,over := <-taskChannel:
if !over { // If there are no more tasks, quit
tg.Wait() // Wait for all tasks to end
break loop
}
tg.Add(1)
limit<-true
go func(&tg,limitm) {
defer func() {
<-limit
tg.Down()
}
// Business processing logic, processing tasks
}(tg *sync.WaitGroup,limit chan bool,task string)
}
}
}(wg *sync.WaitGroup,taskChannel chan string,limitNumber int)
wg.Wait()
希望能幫到你
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