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
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
|
package task
import (
"context"
"v2ray.com/core/common/signal/semaphore"
)
// OnSuccess executes g() after f() returns nil.
func OnSuccess(f func() error, g func() error) func() error {
return func() error {
if err := f(); err != nil {
return err
}
return g()
}
}
// Run executes a list of tasks in parallel, returns the first error encountered or nil if all tasks pass.
func Run(ctx context.Context, tasks ...func() error) error {
n := len(tasks)
s := semaphore.New(n)
done := make(chan error, 1)
for _, task := range tasks {
<-s.Wait()
go func(f func() error) {
err := f()
if err == nil {
s.Signal()
return
}
select {
case done <- err:
default:
}
}(task)
}
for i := 0; i < n; i++ {
select {
case err := <-done:
return err
case <-ctx.Done():
return ctx.Err()
case <-s.Wait():
}
}
return nil
}
|
