mirror of
https://github.com/k3s-io/kubernetes.git
synced 2025-07-22 11:21:47 +00:00
WaitFor returns immediately when done is closed
This commit is contained in:
parent
aee1ab34ab
commit
a766ed2d2b
@ -351,22 +351,21 @@ type WaitFunc func(done <-chan struct{}) <-chan struct{}
|
||||
// WaitFor continually checks 'fn' as driven by 'wait'.
|
||||
//
|
||||
// WaitFor gets a channel from 'wait()'', and then invokes 'fn' once for every value
|
||||
// placed on the channel and once more when the channel is closed.
|
||||
// placed on the channel and once more when the channel is closed. If the channel is closed
|
||||
// and 'fn' returns false without error, WaitFor returns ErrWaitTimeout.
|
||||
//
|
||||
// If 'fn' returns an error the loop ends and that error is returned, and if
|
||||
// If 'fn' returns an error the loop ends and that error is returned. If
|
||||
// 'fn' returns true the loop ends and nil is returned.
|
||||
//
|
||||
// ErrWaitTimeout will be returned if the channel is closed without fn ever
|
||||
// ErrWaitTimeout will be returned if the 'done' channel is closed without fn ever
|
||||
// returning true.
|
||||
//
|
||||
// When the done channel is closed, because the golang `select` statement is
|
||||
// "uniform pseudo-random", the `fn` might still run one or multiple time,
|
||||
// though eventually `WaitFor` will return.
|
||||
func WaitFor(wait WaitFunc, fn ConditionFunc, done <-chan struct{}) error {
|
||||
stopCh := make(chan struct{})
|
||||
once := sync.Once{}
|
||||
closeCh := func() {
|
||||
once.Do(func() {
|
||||
close(stopCh)
|
||||
})
|
||||
}
|
||||
defer closeCh()
|
||||
defer close(stopCh)
|
||||
c := wait(stopCh)
|
||||
for {
|
||||
select {
|
||||
@ -382,11 +381,10 @@ func WaitFor(wait WaitFunc, fn ConditionFunc, done <-chan struct{}) error {
|
||||
return ErrWaitTimeout
|
||||
}
|
||||
case <-done:
|
||||
closeCh()
|
||||
}
|
||||
}
|
||||
return ErrWaitTimeout
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// poller returns a WaitFunc that will send to the channel every interval until
|
||||
// timeout has elapsed and then closes the channel.
|
||||
|
@ -456,11 +456,42 @@ func TestWaitFor(t *testing.T) {
|
||||
}
|
||||
}
|
||||
|
||||
// TestWaitForWithEarlyClosingWaitFunc tests WaitFor when the WaitFunc closes its channel. The WaitFor should
|
||||
// always return ErrWaitTimeout.
|
||||
func TestWaitForWithEarlyClosingWaitFunc(t *testing.T) {
|
||||
stopCh := make(chan struct{})
|
||||
defer close(stopCh)
|
||||
|
||||
start := time.Now()
|
||||
err := WaitFor(func(done <-chan struct{}) <-chan struct{} {
|
||||
c := make(chan struct{})
|
||||
close(c)
|
||||
return c
|
||||
}, func() (bool, error) {
|
||||
return false, nil
|
||||
}, stopCh)
|
||||
duration := time.Now().Sub(start)
|
||||
|
||||
// The WaitFor should return immediately, so the duration is close to 0s.
|
||||
if duration >= ForeverTestTimeout/2 {
|
||||
t.Errorf("expected short timeout duration")
|
||||
}
|
||||
if err != ErrWaitTimeout {
|
||||
t.Errorf("expected ErrWaitTimeout from WaitFunc")
|
||||
}
|
||||
}
|
||||
|
||||
// TestWaitForWithClosedChannel tests WaitFor when it receives a closed channel. The WaitFor should
|
||||
// always return ErrWaitTimeout.
|
||||
func TestWaitForWithClosedChannel(t *testing.T) {
|
||||
stopCh := make(chan struct{})
|
||||
close(stopCh)
|
||||
c := make(chan struct{})
|
||||
defer close(c)
|
||||
start := time.Now()
|
||||
err := WaitFor(poller(ForeverTestTimeout, ForeverTestTimeout), func() (bool, error) {
|
||||
err := WaitFor(func(done <-chan struct{}) <-chan struct{} {
|
||||
return c
|
||||
}, func() (bool, error) {
|
||||
return false, nil
|
||||
}, stopCh)
|
||||
duration := time.Now().Sub(start)
|
||||
|
Loading…
Reference in New Issue
Block a user