Go conc
Contents
Go conc
参考链接
go
package main
import (
"fmt"
"time"
)
func main() {
for i := 0; i < 5; i++ {
go func(num int) {
fmt.Println(num)
}(i)
}
time.Sleep(5 * time.Second)
}
sync.WaitGroup 控制并发
package main
import (
"fmt"
"sync"
)
var wg sync.WaitGroup
func hello(i int) {
defer wg.Done()
fmt.Println("Hello Goroutine!", i)
}
func main() {
for i := 0; i < 10; i++ {
wg.Add(1)
go hello(i)
}
wg.Wait()
}
conc 并发库
优点：
- 封装了官方库的wg.Add和wg.Done，简化了代码
- 官方库需要手动实现recover，conc 内部封装好了
package main
import (
"fmt"
"github.com/sourcegraph/conc"
)
func main() {
wg := conc.NewWaitGroup()
for i := 0; i < 10; i++ {
wg.Go(doSomething)
}
wg.Wait()
}
func doSomething() {
fmt.Println("test")
}
并发池限制
package main
import (
"fmt"
"github.com/sourcegraph/conc/pool"
)
func main() {
p := pool.New().WithMaxGoroutines(3)
for i := 1; i <= 5; i++ {
p.Go(func() {
fmt.Println(i)
})
}
p.Wait()
}
package main
import (
"context"
"errors"
"fmt"
"github.com/sourcegraph/conc/pool"
)
func main() {
p := pool.New().
WithMaxGoroutines(4).
WithContext(context.Background()).
WithCancelOnError()
for i := 0; i < 3; i++ {
i := i
p.Go(func(ctx context.Context) error {
if i == 2 {
return errors.New("I will cancel all other tasks!")
}
<-ctx.Done()
return nil
})
}
err := p.Wait()
fmt.Println(err)
// Output:
// I will cancel all other tasks!
}