1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
|
package main
import (
"fmt"
"time"
)
func main() {
go func() {
fmt.Println("hello")
}()
go func() {
fmt.Println("world")
}()
time.Sleep(time.Second * 2) //如果没有Sleep，主线程可能立即退出，goroutine来不及执行
}
|
sync.Waitgroup用于等待一组 goroutine 完成的同步工具，特别适用于需要阻塞主 goroutine 直到所有子 goroutine 执行完毕的场景。
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
|
//完全等待并发结束
package main
import (
"fmt"
"sync"
)
func main() {
wg := sync.WaitGroup{}
wg.Add(2) //2个任务
go func() {
defer wg.Done()
fmt.Println("hello")
}()
go func() {
defer wg.Done()
fmt.Println("world")
}()
wg.Wait()
}
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
|
//子协程隔离错误，不影响mian
package main
import (
"fmt"
"time"
)
func f1() {
defer func() {
recover()
}() //关键隔离匿名函数
a, b := 10, 0
a = a / b
}
func main() {
go f1()
time.Sleep(time.Second * 1)
fmt.Println("over")
}
|
安全性
锁机制
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
|
package main
import (
"fmt"
"sync"
)
var (
n int32
lock = sync.Mutex{}
)
func foo() {
for i := 0; i < 10000; i++ {
lock.Lock()
n++
lock.Unlock()
}
fmt.Printf("foo %d\n", n)
}
func main() {
wg := sync.WaitGroup{}
wg.Add(2) //2个任务
go func() {
defer wg.Done()
foo()
}()
go func() {
defer wg.Done()
foo()
}()
wg.Wait()
}
|
atomic
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
|
package main
import (
"fmt"
"sync"
"sync/atomic"
)
var (
n int32
lock = sync.Mutex{}
)
func foo() {
for i := 0; i < 10000; i++ {
atomic.AddInt32(&n, 1)
}
fmt.Printf("foo %d\n", n)
}
func main() {
wg := sync.WaitGroup{}
wg.Add(2) //2个任务
go func() {
defer wg.Done()
foo()
}()
go func() {
defer wg.Done()
foo()
}()
wg.Wait()
}
|
Scan