WaitFor waits for a condition to be true or the timeout to expire. It will wait for the condition to be true with exponential backoff. A single sleep timer is reused across iterations via Reset so that mock-clock tests always have a pending timer to advance.
(ctx context.Context, timeout WaitTimeout, condition func() (bool, error))
| 26 | // A single sleep timer is reused across iterations via Reset so that |
| 27 | // mock-clock tests always have a pending timer to advance. |
| 28 | func WaitFor(ctx context.Context, timeout WaitTimeout, condition func() (bool, error)) error { |
| 29 | clock := timeout.Clock |
| 30 | if clock == nil { |
| 31 | clock = quartz.NewReal() |
| 32 | } |
| 33 | |
| 34 | minInterval := timeout.MinInterval |
| 35 | maxInterval := timeout.MaxInterval |
| 36 | timeoutDuration := timeout.Timeout |
| 37 | if minInterval == 0 { |
| 38 | minInterval = 10 * time.Millisecond |
| 39 | } |
| 40 | if maxInterval == 0 { |
| 41 | maxInterval = 500 * time.Millisecond |
| 42 | } |
| 43 | if timeoutDuration == 0 { |
| 44 | timeoutDuration = 10 * time.Second |
| 45 | } |
| 46 | if minInterval > maxInterval { |
| 47 | return xerrors.Errorf("minInterval is greater than maxInterval") |
| 48 | } |
| 49 | |
| 50 | timeoutTimer := clock.NewTimer(timeoutDuration) |
| 51 | defer timeoutTimer.Stop() |
| 52 | |
| 53 | interval := minInterval |
| 54 | sleepTimer := clock.NewTimer(interval) |
| 55 | defer sleepTimer.Stop() |
| 56 | |
| 57 | waitForTimer := timeout.InitialWait |
| 58 | for { |
| 59 | if waitForTimer { |
| 60 | select { |
| 61 | case <-sleepTimer.C: |
| 62 | case <-ctx.Done(): |
| 63 | return ctx.Err() |
| 64 | case <-timeoutTimer.C: |
| 65 | return WaitTimedOut |
| 66 | } |
| 67 | } |
| 68 | waitForTimer = true |
| 69 | |
| 70 | ok, err := condition() |
| 71 | if err != nil { |
| 72 | return err |
| 73 | } |
| 74 | if ok { |
| 75 | return nil |
| 76 | } |
| 77 | |
| 78 | interval = min(interval*2, maxInterval) |
| 79 | if !sleepTimer.Stop() { |
| 80 | select { |
| 81 | case <-sleepTimer.C: |
| 82 | default: |
| 83 | } |
| 84 | } |
| 85 | sleepTimer.Reset(interval) |