rebase: update all k8s packages to 0.27.2

Signed-off-by: Niels de Vos <ndevos@ibm.com>
This commit is contained in:
Niels de Vos
2023-06-01 18:58:10 +02:00
committed by mergify[bot]
parent 07b05616a0
commit 2551a0b05f
618 changed files with 42944 additions and 16168 deletions

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vendor/k8s.io/apimachinery/pkg/util/wait/backoff.go generated vendored Normal file
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/*
Copyright 2023 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package wait
import (
"context"
"math"
"sync"
"time"
"k8s.io/apimachinery/pkg/util/runtime"
"k8s.io/utils/clock"
)
// Backoff holds parameters applied to a Backoff function.
type Backoff struct {
// The initial duration.
Duration time.Duration
// Duration is multiplied by factor each iteration, if factor is not zero
// and the limits imposed by Steps and Cap have not been reached.
// Should not be negative.
// The jitter does not contribute to the updates to the duration parameter.
Factor float64
// The sleep at each iteration is the duration plus an additional
// amount chosen uniformly at random from the interval between
// zero and `jitter*duration`.
Jitter float64
// The remaining number of iterations in which the duration
// parameter may change (but progress can be stopped earlier by
// hitting the cap). If not positive, the duration is not
// changed. Used for exponential backoff in combination with
// Factor and Cap.
Steps int
// A limit on revised values of the duration parameter. If a
// multiplication by the factor parameter would make the duration
// exceed the cap then the duration is set to the cap and the
// steps parameter is set to zero.
Cap time.Duration
}
// Step returns an amount of time to sleep determined by the original
// Duration and Jitter. The backoff is mutated to update its Steps and
// Duration. A nil Backoff always has a zero-duration step.
func (b *Backoff) Step() time.Duration {
if b == nil {
return 0
}
var nextDuration time.Duration
nextDuration, b.Duration, b.Steps = delay(b.Steps, b.Duration, b.Cap, b.Factor, b.Jitter)
return nextDuration
}
// DelayFunc returns a function that will compute the next interval to
// wait given the arguments in b. It does not mutate the original backoff
// but the function is safe to use only from a single goroutine.
func (b Backoff) DelayFunc() DelayFunc {
steps := b.Steps
duration := b.Duration
cap := b.Cap
factor := b.Factor
jitter := b.Jitter
return func() time.Duration {
var nextDuration time.Duration
// jitter is applied per step and is not cumulative over multiple steps
nextDuration, duration, steps = delay(steps, duration, cap, factor, jitter)
return nextDuration
}
}
// Timer returns a timer implementation appropriate to this backoff's parameters
// for use with wait functions.
func (b Backoff) Timer() Timer {
if b.Steps > 1 || b.Jitter != 0 {
return &variableTimer{new: internalClock.NewTimer, fn: b.DelayFunc()}
}
if b.Duration > 0 {
return &fixedTimer{new: internalClock.NewTicker, interval: b.Duration}
}
return newNoopTimer()
}
// delay implements the core delay algorithm used in this package.
func delay(steps int, duration, cap time.Duration, factor, jitter float64) (_ time.Duration, next time.Duration, nextSteps int) {
// when steps is non-positive, do not alter the base duration
if steps < 1 {
if jitter > 0 {
return Jitter(duration, jitter), duration, 0
}
return duration, duration, 0
}
steps--
// calculate the next step's interval
if factor != 0 {
next = time.Duration(float64(duration) * factor)
if cap > 0 && next > cap {
next = cap
steps = 0
}
} else {
next = duration
}
// add jitter for this step
if jitter > 0 {
duration = Jitter(duration, jitter)
}
return duration, next, steps
}
// DelayWithReset returns a DelayFunc that will return the appropriate next interval to
// wait. Every resetInterval the backoff parameters are reset to their initial state.
// This method is safe to invoke from multiple goroutines, but all calls will advance
// the backoff state when Factor is set. If Factor is zero, this method is the same as
// invoking b.DelayFunc() since Steps has no impact without Factor. If resetInterval is
// zero no backoff will be performed as the same calling DelayFunc with a zero factor
// and steps.
func (b Backoff) DelayWithReset(c clock.Clock, resetInterval time.Duration) DelayFunc {
if b.Factor <= 0 {
return b.DelayFunc()
}
if resetInterval <= 0 {
b.Steps = 0
b.Factor = 0
return b.DelayFunc()
}
return (&backoffManager{
backoff: b,
initialBackoff: b,
resetInterval: resetInterval,
clock: c,
lastStart: c.Now(),
timer: nil,
}).Step
}
// Until loops until stop channel is closed, running f every period.
//
// Until is syntactic sugar on top of JitterUntil with zero jitter factor and
// with sliding = true (which means the timer for period starts after the f
// completes).
func Until(f func(), period time.Duration, stopCh <-chan struct{}) {
JitterUntil(f, period, 0.0, true, stopCh)
}
// UntilWithContext loops until context is done, running f every period.
//
// UntilWithContext is syntactic sugar on top of JitterUntilWithContext
// with zero jitter factor and with sliding = true (which means the timer
// for period starts after the f completes).
func UntilWithContext(ctx context.Context, f func(context.Context), period time.Duration) {
JitterUntilWithContext(ctx, f, period, 0.0, true)
}
// NonSlidingUntil loops until stop channel is closed, running f every
// period.
//
// NonSlidingUntil is syntactic sugar on top of JitterUntil with zero jitter
// factor, with sliding = false (meaning the timer for period starts at the same
// time as the function starts).
func NonSlidingUntil(f func(), period time.Duration, stopCh <-chan struct{}) {
JitterUntil(f, period, 0.0, false, stopCh)
}
// NonSlidingUntilWithContext loops until context is done, running f every
// period.
//
// NonSlidingUntilWithContext is syntactic sugar on top of JitterUntilWithContext
// with zero jitter factor, with sliding = false (meaning the timer for period
// starts at the same time as the function starts).
func NonSlidingUntilWithContext(ctx context.Context, f func(context.Context), period time.Duration) {
JitterUntilWithContext(ctx, f, period, 0.0, false)
}
// JitterUntil loops until stop channel is closed, running f every period.
//
// If jitterFactor is positive, the period is jittered before every run of f.
// If jitterFactor is not positive, the period is unchanged and not jittered.
//
// If sliding is true, the period is computed after f runs. If it is false then
// period includes the runtime for f.
//
// Close stopCh to stop. f may not be invoked if stop channel is already
// closed. Pass NeverStop to if you don't want it stop.
func JitterUntil(f func(), period time.Duration, jitterFactor float64, sliding bool, stopCh <-chan struct{}) {
BackoffUntil(f, NewJitteredBackoffManager(period, jitterFactor, &clock.RealClock{}), sliding, stopCh)
}
// BackoffUntil loops until stop channel is closed, run f every duration given by BackoffManager.
//
// If sliding is true, the period is computed after f runs. If it is false then
// period includes the runtime for f.
func BackoffUntil(f func(), backoff BackoffManager, sliding bool, stopCh <-chan struct{}) {
var t clock.Timer
for {
select {
case <-stopCh:
return
default:
}
if !sliding {
t = backoff.Backoff()
}
func() {
defer runtime.HandleCrash()
f()
}()
if sliding {
t = backoff.Backoff()
}
// NOTE: b/c there is no priority selection in golang
// it is possible for this to race, meaning we could
// trigger t.C and stopCh, and t.C select falls through.
// In order to mitigate we re-check stopCh at the beginning
// of every loop to prevent extra executions of f().
select {
case <-stopCh:
if !t.Stop() {
<-t.C()
}
return
case <-t.C():
}
}
}
// JitterUntilWithContext loops until context is done, running f every period.
//
// If jitterFactor is positive, the period is jittered before every run of f.
// If jitterFactor is not positive, the period is unchanged and not jittered.
//
// If sliding is true, the period is computed after f runs. If it is false then
// period includes the runtime for f.
//
// Cancel context to stop. f may not be invoked if context is already expired.
func JitterUntilWithContext(ctx context.Context, f func(context.Context), period time.Duration, jitterFactor float64, sliding bool) {
JitterUntil(func() { f(ctx) }, period, jitterFactor, sliding, ctx.Done())
}
// backoffManager provides simple backoff behavior in a threadsafe manner to a caller.
type backoffManager struct {
backoff Backoff
initialBackoff Backoff
resetInterval time.Duration
clock clock.Clock
lock sync.Mutex
lastStart time.Time
timer clock.Timer
}
// Step returns the expected next duration to wait.
func (b *backoffManager) Step() time.Duration {
b.lock.Lock()
defer b.lock.Unlock()
switch {
case b.resetInterval == 0:
b.backoff = b.initialBackoff
case b.clock.Now().Sub(b.lastStart) > b.resetInterval:
b.backoff = b.initialBackoff
b.lastStart = b.clock.Now()
}
return b.backoff.Step()
}
// Backoff implements BackoffManager.Backoff, it returns a timer so caller can block on the timer
// for exponential backoff. The returned timer must be drained before calling Backoff() the second
// time.
func (b *backoffManager) Backoff() clock.Timer {
b.lock.Lock()
defer b.lock.Unlock()
if b.timer == nil {
b.timer = b.clock.NewTimer(b.Step())
} else {
b.timer.Reset(b.Step())
}
return b.timer
}
// Timer returns a new Timer instance that shares the clock and the reset behavior with all other
// timers.
func (b *backoffManager) Timer() Timer {
return DelayFunc(b.Step).Timer(b.clock)
}
// BackoffManager manages backoff with a particular scheme based on its underlying implementation.
type BackoffManager interface {
// Backoff returns a shared clock.Timer that is Reset on every invocation. This method is not
// safe for use from multiple threads. It returns a timer for backoff, and caller shall backoff
// until Timer.C() drains. If the second Backoff() is called before the timer from the first
// Backoff() call finishes, the first timer will NOT be drained and result in undetermined
// behavior.
Backoff() clock.Timer
}
// Deprecated: Will be removed when the legacy polling functions are removed.
type exponentialBackoffManagerImpl struct {
backoff *Backoff
backoffTimer clock.Timer
lastBackoffStart time.Time
initialBackoff time.Duration
backoffResetDuration time.Duration
clock clock.Clock
}
// NewExponentialBackoffManager returns a manager for managing exponential backoff. Each backoff is jittered and
// backoff will not exceed the given max. If the backoff is not called within resetDuration, the backoff is reset.
// This backoff manager is used to reduce load during upstream unhealthiness.
//
// Deprecated: Will be removed when the legacy Poll methods are removed. Callers should construct a
// Backoff struct, use DelayWithReset() to get a DelayFunc that periodically resets itself, and then
// invoke Timer() when calling wait.BackoffUntil.
//
// Instead of:
//
// bm := wait.NewExponentialBackoffManager(init, max, reset, factor, jitter, clock)
// ...
// wait.BackoffUntil(..., bm.Backoff, ...)
//
// Use:
//
// delayFn := wait.Backoff{
// Duration: init,
// Cap: max,
// Steps: int(math.Ceil(float64(max) / float64(init))), // now a required argument
// Factor: factor,
// Jitter: jitter,
// }.DelayWithReset(reset, clock)
// wait.BackoffUntil(..., delayFn.Timer(), ...)
func NewExponentialBackoffManager(initBackoff, maxBackoff, resetDuration time.Duration, backoffFactor, jitter float64, c clock.Clock) BackoffManager {
return &exponentialBackoffManagerImpl{
backoff: &Backoff{
Duration: initBackoff,
Factor: backoffFactor,
Jitter: jitter,
// the current impl of wait.Backoff returns Backoff.Duration once steps are used up, which is not
// what we ideally need here, we set it to max int and assume we will never use up the steps
Steps: math.MaxInt32,
Cap: maxBackoff,
},
backoffTimer: nil,
initialBackoff: initBackoff,
lastBackoffStart: c.Now(),
backoffResetDuration: resetDuration,
clock: c,
}
}
func (b *exponentialBackoffManagerImpl) getNextBackoff() time.Duration {
if b.clock.Now().Sub(b.lastBackoffStart) > b.backoffResetDuration {
b.backoff.Steps = math.MaxInt32
b.backoff.Duration = b.initialBackoff
}
b.lastBackoffStart = b.clock.Now()
return b.backoff.Step()
}
// Backoff implements BackoffManager.Backoff, it returns a timer so caller can block on the timer for exponential backoff.
// The returned timer must be drained before calling Backoff() the second time
func (b *exponentialBackoffManagerImpl) Backoff() clock.Timer {
if b.backoffTimer == nil {
b.backoffTimer = b.clock.NewTimer(b.getNextBackoff())
} else {
b.backoffTimer.Reset(b.getNextBackoff())
}
return b.backoffTimer
}
// Deprecated: Will be removed when the legacy polling functions are removed.
type jitteredBackoffManagerImpl struct {
clock clock.Clock
duration time.Duration
jitter float64
backoffTimer clock.Timer
}
// NewJitteredBackoffManager returns a BackoffManager that backoffs with given duration plus given jitter. If the jitter
// is negative, backoff will not be jittered.
//
// Deprecated: Will be removed when the legacy Poll methods are removed. Callers should construct a
// Backoff struct and invoke Timer() when calling wait.BackoffUntil.
//
// Instead of:
//
// bm := wait.NewJitteredBackoffManager(duration, jitter, clock)
// ...
// wait.BackoffUntil(..., bm.Backoff, ...)
//
// Use:
//
// wait.BackoffUntil(..., wait.Backoff{Duration: duration, Jitter: jitter}.Timer(), ...)
func NewJitteredBackoffManager(duration time.Duration, jitter float64, c clock.Clock) BackoffManager {
return &jitteredBackoffManagerImpl{
clock: c,
duration: duration,
jitter: jitter,
backoffTimer: nil,
}
}
func (j *jitteredBackoffManagerImpl) getNextBackoff() time.Duration {
jitteredPeriod := j.duration
if j.jitter > 0.0 {
jitteredPeriod = Jitter(j.duration, j.jitter)
}
return jitteredPeriod
}
// Backoff implements BackoffManager.Backoff, it returns a timer so caller can block on the timer for jittered backoff.
// The returned timer must be drained before calling Backoff() the second time
func (j *jitteredBackoffManagerImpl) Backoff() clock.Timer {
backoff := j.getNextBackoff()
if j.backoffTimer == nil {
j.backoffTimer = j.clock.NewTimer(backoff)
} else {
j.backoffTimer.Reset(backoff)
}
return j.backoffTimer
}
// ExponentialBackoff repeats a condition check with exponential backoff.
//
// It repeatedly checks the condition and then sleeps, using `backoff.Step()`
// to determine the length of the sleep and adjust Duration and Steps.
// Stops and returns as soon as:
// 1. the condition check returns true or an error,
// 2. `backoff.Steps` checks of the condition have been done, or
// 3. a sleep truncated by the cap on duration has been completed.
// In case (1) the returned error is what the condition function returned.
// In all other cases, ErrWaitTimeout is returned.
//
// Since backoffs are often subject to cancellation, we recommend using
// ExponentialBackoffWithContext and passing a context to the method.
func ExponentialBackoff(backoff Backoff, condition ConditionFunc) error {
for backoff.Steps > 0 {
if ok, err := runConditionWithCrashProtection(condition); err != nil || ok {
return err
}
if backoff.Steps == 1 {
break
}
time.Sleep(backoff.Step())
}
return ErrWaitTimeout
}
// ExponentialBackoffWithContext repeats a condition check with exponential backoff.
// It immediately returns an error if the condition returns an error, the context is cancelled
// or hits the deadline, or if the maximum attempts defined in backoff is exceeded (ErrWaitTimeout).
// If an error is returned by the condition the backoff stops immediately. The condition will
// never be invoked more than backoff.Steps times.
func ExponentialBackoffWithContext(ctx context.Context, backoff Backoff, condition ConditionWithContextFunc) error {
for backoff.Steps > 0 {
select {
case <-ctx.Done():
return ctx.Err()
default:
}
if ok, err := runConditionWithCrashProtectionWithContext(ctx, condition); err != nil || ok {
return err
}
if backoff.Steps == 1 {
break
}
waitBeforeRetry := backoff.Step()
select {
case <-ctx.Done():
return ctx.Err()
case <-time.After(waitBeforeRetry):
}
}
return ErrWaitTimeout
}

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vendor/k8s.io/apimachinery/pkg/util/wait/delay.go generated vendored Normal file
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/*
Copyright 2023 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package wait
import (
"context"
"sync"
"time"
"k8s.io/utils/clock"
)
// DelayFunc returns the next time interval to wait.
type DelayFunc func() time.Duration
// Timer takes an arbitrary delay function and returns a timer that can handle arbitrary interval changes.
// Use Backoff{...}.Timer() for simple delays and more efficient timers.
func (fn DelayFunc) Timer(c clock.Clock) Timer {
return &variableTimer{fn: fn, new: c.NewTimer}
}
// Until takes an arbitrary delay function and runs until cancelled or the condition indicates exit. This
// offers all of the functionality of the methods in this package.
func (fn DelayFunc) Until(ctx context.Context, immediate, sliding bool, condition ConditionWithContextFunc) error {
return loopConditionUntilContext(ctx, &variableTimer{fn: fn, new: internalClock.NewTimer}, immediate, sliding, condition)
}
// Concurrent returns a version of this DelayFunc that is safe for use by multiple goroutines that
// wish to share a single delay timer.
func (fn DelayFunc) Concurrent() DelayFunc {
var lock sync.Mutex
return func() time.Duration {
lock.Lock()
defer lock.Unlock()
return fn()
}
}

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/*
Copyright 2023 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package wait
import (
"context"
"errors"
)
// ErrWaitTimeout is returned when the condition was not satisfied in time.
//
// Deprecated: This type will be made private in favor of Interrupted()
// for checking errors or ErrorInterrupted(err) for returning a wrapped error.
var ErrWaitTimeout = ErrorInterrupted(errors.New("timed out waiting for the condition"))
// Interrupted returns true if the error indicates a Poll, ExponentialBackoff, or
// Until loop exited for any reason besides the condition returning true or an
// error. A loop is considered interrupted if the calling context is cancelled,
// the context reaches its deadline, or a backoff reaches its maximum allowed
// steps.
//
// Callers should use this method instead of comparing the error value directly to
// ErrWaitTimeout, as methods that cancel a context may not return that error.
//
// Instead of:
//
// err := wait.Poll(...)
// if err == wait.ErrWaitTimeout {
// log.Infof("Wait for operation exceeded")
// } else ...
//
// Use:
//
// err := wait.Poll(...)
// if wait.Interrupted(err) {
// log.Infof("Wait for operation exceeded")
// } else ...
func Interrupted(err error) bool {
switch {
case errors.Is(err, errWaitTimeout),
errors.Is(err, context.Canceled),
errors.Is(err, context.DeadlineExceeded):
return true
default:
return false
}
}
// errInterrupted
type errInterrupted struct {
cause error
}
// ErrorInterrupted returns an error that indicates the wait was ended
// early for a given reason. If no cause is provided a generic error
// will be used but callers are encouraged to provide a real cause for
// clarity in debugging.
func ErrorInterrupted(cause error) error {
switch cause.(type) {
case errInterrupted:
// no need to wrap twice since errInterrupted is only needed
// once in a chain
return cause
default:
return errInterrupted{cause}
}
}
// errWaitTimeout is the private version of the previous ErrWaitTimeout
// and is private to prevent direct comparison. Use ErrorInterrupted(err)
// to get an error that will return true for Interrupted(err).
var errWaitTimeout = errInterrupted{}
func (e errInterrupted) Unwrap() error { return e.cause }
func (e errInterrupted) Is(target error) bool { return target == errWaitTimeout }
func (e errInterrupted) Error() string {
if e.cause == nil {
// returns the same error message as historical behavior
return "timed out waiting for the condition"
}
return e.cause.Error()
}

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/*
Copyright 2023 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package wait
import (
"context"
"time"
"k8s.io/apimachinery/pkg/util/runtime"
)
// loopConditionUntilContext executes the provided condition at intervals defined by
// the provided timer until the provided context is cancelled, the condition returns
// true, or the condition returns an error. If sliding is true, the period is computed
// after condition runs. If it is false then period includes the runtime for condition.
// If immediate is false the first delay happens before any call to condition. The
// returned error is the error returned by the last condition or the context error if
// the context was terminated.
//
// This is the common loop construct for all polling in the wait package.
func loopConditionUntilContext(ctx context.Context, t Timer, immediate, sliding bool, condition ConditionWithContextFunc) error {
defer t.Stop()
var timeCh <-chan time.Time
doneCh := ctx.Done()
// if we haven't requested immediate execution, delay once
if !immediate {
timeCh = t.C()
select {
case <-doneCh:
return ctx.Err()
case <-timeCh:
}
}
for {
// checking ctx.Err() is slightly faster than checking a select
if err := ctx.Err(); err != nil {
return err
}
if !sliding {
t.Next()
}
if ok, err := func() (bool, error) {
defer runtime.HandleCrash()
return condition(ctx)
}(); err != nil || ok {
return err
}
if sliding {
t.Next()
}
if timeCh == nil {
timeCh = t.C()
}
// NOTE: b/c there is no priority selection in golang
// it is possible for this to race, meaning we could
// trigger t.C and doneCh, and t.C select falls through.
// In order to mitigate we re-check doneCh at the beginning
// of every loop to guarantee at-most one extra execution
// of condition.
select {
case <-doneCh:
return ctx.Err()
case <-timeCh:
}
}
}

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/*
Copyright 2023 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package wait
import (
"context"
"time"
)
// PollUntilContextCancel tries a condition func until it returns true, an error, or the context
// is cancelled or hits a deadline. condition will be invoked after the first interval if the
// context is not cancelled first. The returned error will be from ctx.Err(), the condition's
// err return value, or nil. If invoking condition takes longer than interval the next condition
// will be invoked immediately. When using very short intervals, condition may be invoked multiple
// times before a context cancellation is detected. If immediate is true, condition will be
// invoked before waiting and guarantees that condition is invoked at least once, regardless of
// whether the context has been cancelled.
func PollUntilContextCancel(ctx context.Context, interval time.Duration, immediate bool, condition ConditionWithContextFunc) error {
return loopConditionUntilContext(ctx, Backoff{Duration: interval}.Timer(), immediate, false, condition)
}
// PollUntilContextTimeout will terminate polling after timeout duration by setting a context
// timeout. This is provided as a convenience function for callers not currently executing under
// a deadline and is equivalent to:
//
// deadlineCtx, deadlineCancel := context.WithTimeout(ctx, timeout)
// err := PollUntilContextCancel(ctx, interval, immediate, condition)
//
// The deadline context will be cancelled if the Poll succeeds before the timeout, simplifying
// inline usage. All other behavior is identical to PollWithContextTimeout.
func PollUntilContextTimeout(ctx context.Context, interval, timeout time.Duration, immediate bool, condition ConditionWithContextFunc) error {
deadlineCtx, deadlineCancel := context.WithTimeout(ctx, timeout)
defer deadlineCancel()
return loopConditionUntilContext(deadlineCtx, Backoff{Duration: interval}.Timer(), immediate, false, condition)
}
// Poll tries a condition func until it returns true, an error, or the timeout
// is reached.
//
// Poll always waits the interval before the run of 'condition'.
// 'condition' will always be invoked at least once.
//
// Some intervals may be missed if the condition takes too long or the time
// window is too short.
//
// If you want to Poll something forever, see PollInfinite.
//
// Deprecated: This method does not return errors from context, use PollWithContextTimeout.
// Note that the new method will no longer return ErrWaitTimeout and instead return errors
// defined by the context package. Will be removed in a future release.
func Poll(interval, timeout time.Duration, condition ConditionFunc) error {
return PollWithContext(context.Background(), interval, timeout, condition.WithContext())
}
// PollWithContext tries a condition func until it returns true, an error,
// or when the context expires or the timeout is reached, whichever
// happens first.
//
// PollWithContext always waits the interval before the run of 'condition'.
// 'condition' will always be invoked at least once.
//
// Some intervals may be missed if the condition takes too long or the time
// window is too short.
//
// If you want to Poll something forever, see PollInfinite.
//
// Deprecated: This method does not return errors from context, use PollWithContextTimeout.
// Note that the new method will no longer return ErrWaitTimeout and instead return errors
// defined by the context package. Will be removed in a future release.
func PollWithContext(ctx context.Context, interval, timeout time.Duration, condition ConditionWithContextFunc) error {
return poll(ctx, false, poller(interval, timeout), condition)
}
// PollUntil tries a condition func until it returns true, an error or stopCh is
// closed.
//
// PollUntil always waits interval before the first run of 'condition'.
// 'condition' will always be invoked at least once.
//
// Deprecated: This method does not return errors from context, use PollWithContextCancel.
// Note that the new method will no longer return ErrWaitTimeout and instead return errors
// defined by the context package. Will be removed in a future release.
func PollUntil(interval time.Duration, condition ConditionFunc, stopCh <-chan struct{}) error {
return PollUntilWithContext(ContextForChannel(stopCh), interval, condition.WithContext())
}
// PollUntilWithContext tries a condition func until it returns true,
// an error or the specified context is cancelled or expired.
//
// PollUntilWithContext always waits interval before the first run of 'condition'.
// 'condition' will always be invoked at least once.
//
// Deprecated: This method does not return errors from context, use PollWithContextCancel.
// Note that the new method will no longer return ErrWaitTimeout and instead return errors
// defined by the context package. Will be removed in a future release.
func PollUntilWithContext(ctx context.Context, interval time.Duration, condition ConditionWithContextFunc) error {
return poll(ctx, false, poller(interval, 0), condition)
}
// PollInfinite tries a condition func until it returns true or an error
//
// PollInfinite always waits the interval before the run of 'condition'.
//
// Some intervals may be missed if the condition takes too long or the time
// window is too short.
//
// Deprecated: This method does not return errors from context, use PollWithContextCancel.
// Note that the new method will no longer return ErrWaitTimeout and instead return errors
// defined by the context package. Will be removed in a future release.
func PollInfinite(interval time.Duration, condition ConditionFunc) error {
return PollInfiniteWithContext(context.Background(), interval, condition.WithContext())
}
// PollInfiniteWithContext tries a condition func until it returns true or an error
//
// PollInfiniteWithContext always waits the interval before the run of 'condition'.
//
// Some intervals may be missed if the condition takes too long or the time
// window is too short.
//
// Deprecated: This method does not return errors from context, use PollWithContextCancel.
// Note that the new method will no longer return ErrWaitTimeout and instead return errors
// defined by the context package. Will be removed in a future release.
func PollInfiniteWithContext(ctx context.Context, interval time.Duration, condition ConditionWithContextFunc) error {
return poll(ctx, false, poller(interval, 0), condition)
}
// PollImmediate tries a condition func until it returns true, an error, or the timeout
// is reached.
//
// PollImmediate always checks 'condition' before waiting for the interval. 'condition'
// will always be invoked at least once.
//
// Some intervals may be missed if the condition takes too long or the time
// window is too short.
//
// If you want to immediately Poll something forever, see PollImmediateInfinite.
//
// Deprecated: This method does not return errors from context, use PollWithContextTimeout.
// Note that the new method will no longer return ErrWaitTimeout and instead return errors
// defined by the context package. Will be removed in a future release.
func PollImmediate(interval, timeout time.Duration, condition ConditionFunc) error {
return PollImmediateWithContext(context.Background(), interval, timeout, condition.WithContext())
}
// PollImmediateWithContext tries a condition func until it returns true, an error,
// or the timeout is reached or the specified context expires, whichever happens first.
//
// PollImmediateWithContext always checks 'condition' before waiting for the interval.
// 'condition' will always be invoked at least once.
//
// Some intervals may be missed if the condition takes too long or the time
// window is too short.
//
// If you want to immediately Poll something forever, see PollImmediateInfinite.
//
// Deprecated: This method does not return errors from context, use PollWithContextTimeout.
// Note that the new method will no longer return ErrWaitTimeout and instead return errors
// defined by the context package. Will be removed in a future release.
func PollImmediateWithContext(ctx context.Context, interval, timeout time.Duration, condition ConditionWithContextFunc) error {
return poll(ctx, true, poller(interval, timeout), condition)
}
// PollImmediateUntil tries a condition func until it returns true, an error or stopCh is closed.
//
// PollImmediateUntil runs the 'condition' before waiting for the interval.
// 'condition' will always be invoked at least once.
//
// Deprecated: This method does not return errors from context, use PollWithContextCancel.
// Note that the new method will no longer return ErrWaitTimeout and instead return errors
// defined by the context package. Will be removed in a future release.
func PollImmediateUntil(interval time.Duration, condition ConditionFunc, stopCh <-chan struct{}) error {
return PollImmediateUntilWithContext(ContextForChannel(stopCh), interval, condition.WithContext())
}
// PollImmediateUntilWithContext tries a condition func until it returns true,
// an error or the specified context is cancelled or expired.
//
// PollImmediateUntilWithContext runs the 'condition' before waiting for the interval.
// 'condition' will always be invoked at least once.
//
// Deprecated: This method does not return errors from context, use PollWithContextCancel.
// Note that the new method will no longer return ErrWaitTimeout and instead return errors
// defined by the context package. Will be removed in a future release.
func PollImmediateUntilWithContext(ctx context.Context, interval time.Duration, condition ConditionWithContextFunc) error {
return poll(ctx, true, poller(interval, 0), condition)
}
// PollImmediateInfinite tries a condition func until it returns true or an error
//
// PollImmediateInfinite runs the 'condition' before waiting for the interval.
//
// Some intervals may be missed if the condition takes too long or the time
// window is too short.
//
// Deprecated: This method does not return errors from context, use PollWithContextCancel.
// Note that the new method will no longer return ErrWaitTimeout and instead return errors
// defined by the context package. Will be removed in a future release.
func PollImmediateInfinite(interval time.Duration, condition ConditionFunc) error {
return PollImmediateInfiniteWithContext(context.Background(), interval, condition.WithContext())
}
// PollImmediateInfiniteWithContext tries a condition func until it returns true
// or an error or the specified context gets cancelled or expired.
//
// PollImmediateInfiniteWithContext runs the 'condition' before waiting for the interval.
//
// Some intervals may be missed if the condition takes too long or the time
// window is too short.
//
// Deprecated: This method does not return errors from context, use PollWithContextCancel.
// Note that the new method will no longer return ErrWaitTimeout and instead return errors
// defined by the context package. Will be removed in a future release.
func PollImmediateInfiniteWithContext(ctx context.Context, interval time.Duration, condition ConditionWithContextFunc) error {
return poll(ctx, true, poller(interval, 0), condition)
}
// Internally used, each of the public 'Poll*' function defined in this
// package should invoke this internal function with appropriate parameters.
// ctx: the context specified by the caller, for infinite polling pass
// a context that never gets cancelled or expired.
// immediate: if true, the 'condition' will be invoked before waiting for the interval,
// in this case 'condition' will always be invoked at least once.
// wait: user specified WaitFunc function that controls at what interval the condition
// function should be invoked periodically and whether it is bound by a timeout.
// condition: user specified ConditionWithContextFunc function.
//
// Deprecated: will be removed in favor of loopConditionUntilContext.
func poll(ctx context.Context, immediate bool, wait waitWithContextFunc, condition ConditionWithContextFunc) error {
if immediate {
done, err := runConditionWithCrashProtectionWithContext(ctx, condition)
if err != nil {
return err
}
if done {
return nil
}
}
select {
case <-ctx.Done():
// returning ctx.Err() will break backward compatibility, use new PollUntilContext*
// methods instead
return ErrWaitTimeout
default:
return waitForWithContext(ctx, wait, condition)
}
}
// poller returns a WaitFunc that will send to the channel every interval until
// timeout has elapsed and then closes the channel.
//
// Over very short intervals you may receive no ticks before the channel is
// closed. A timeout of 0 is interpreted as an infinity, and in such a case
// it would be the caller's responsibility to close the done channel.
// Failure to do so would result in a leaked goroutine.
//
// Output ticks are not buffered. If the channel is not ready to receive an
// item, the tick is skipped.
//
// Deprecated: Will be removed in a future release.
func poller(interval, timeout time.Duration) waitWithContextFunc {
return waitWithContextFunc(func(ctx context.Context) <-chan struct{} {
ch := make(chan struct{})
go func() {
defer close(ch)
tick := time.NewTicker(interval)
defer tick.Stop()
var after <-chan time.Time
if timeout != 0 {
// time.After is more convenient, but it
// potentially leaves timers around much longer
// than necessary if we exit early.
timer := time.NewTimer(timeout)
after = timer.C
defer timer.Stop()
}
for {
select {
case <-tick.C:
// If the consumer isn't ready for this signal drop it and
// check the other channels.
select {
case ch <- struct{}{}:
default:
}
case <-after:
return
case <-ctx.Done():
return
}
}
}()
return ch
})
}

121
vendor/k8s.io/apimachinery/pkg/util/wait/timer.go generated vendored Normal file
View File

@ -0,0 +1,121 @@
/*
Copyright 2023 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package wait
import (
"time"
"k8s.io/utils/clock"
)
// Timer abstracts how wait functions interact with time runtime efficiently. Test
// code may implement this interface directly but package consumers are encouraged
// to use the Backoff type as the primary mechanism for acquiring a Timer. The
// interface is a simplification of clock.Timer to prevent misuse. Timers are not
// expected to be safe for calls from multiple goroutines.
type Timer interface {
// C returns a channel that will receive a struct{} each time the timer fires.
// The channel should not be waited on after Stop() is invoked. It is allowed
// to cache the returned value of C() for the lifetime of the Timer.
C() <-chan time.Time
// Next is invoked by wait functions to signal timers that the next interval
// should begin. You may only use Next() if you have drained the channel C().
// You should not call Next() after Stop() is invoked.
Next()
// Stop releases the timer. It is safe to invoke if no other methods have been
// called.
Stop()
}
type noopTimer struct {
closedCh <-chan time.Time
}
// newNoopTimer creates a timer with a unique channel to avoid contention
// for the channel's lock across multiple unrelated timers.
func newNoopTimer() noopTimer {
ch := make(chan time.Time)
close(ch)
return noopTimer{closedCh: ch}
}
func (t noopTimer) C() <-chan time.Time {
return t.closedCh
}
func (noopTimer) Next() {}
func (noopTimer) Stop() {}
type variableTimer struct {
fn DelayFunc
t clock.Timer
new func(time.Duration) clock.Timer
}
func (t *variableTimer) C() <-chan time.Time {
if t.t == nil {
d := t.fn()
t.t = t.new(d)
}
return t.t.C()
}
func (t *variableTimer) Next() {
if t.t == nil {
return
}
d := t.fn()
t.t.Reset(d)
}
func (t *variableTimer) Stop() {
if t.t == nil {
return
}
t.t.Stop()
t.t = nil
}
type fixedTimer struct {
interval time.Duration
t clock.Ticker
new func(time.Duration) clock.Ticker
}
func (t *fixedTimer) C() <-chan time.Time {
if t.t == nil {
t.t = t.new(t.interval)
}
return t.t.C()
}
func (t *fixedTimer) Next() {
// no-op for fixed timers
}
func (t *fixedTimer) Stop() {
if t.t == nil {
return
}
t.t.Stop()
t.t = nil
}
var (
// RealTimer can be passed to methods that need a clock.Timer.
RealTimer = clock.RealClock{}.NewTimer
)
var (
// internalClock is used for test injection of clocks
internalClock = clock.RealClock{}
)

View File

@ -18,14 +18,11 @@ package wait
import (
"context"
"errors"
"math"
"math/rand"
"sync"
"time"
"k8s.io/apimachinery/pkg/util/runtime"
"k8s.io/utils/clock"
)
// For any test of the style:
@ -83,113 +80,6 @@ func Forever(f func(), period time.Duration) {
Until(f, period, NeverStop)
}
// Until loops until stop channel is closed, running f every period.
//
// Until is syntactic sugar on top of JitterUntil with zero jitter factor and
// with sliding = true (which means the timer for period starts after the f
// completes).
func Until(f func(), period time.Duration, stopCh <-chan struct{}) {
JitterUntil(f, period, 0.0, true, stopCh)
}
// UntilWithContext loops until context is done, running f every period.
//
// UntilWithContext is syntactic sugar on top of JitterUntilWithContext
// with zero jitter factor and with sliding = true (which means the timer
// for period starts after the f completes).
func UntilWithContext(ctx context.Context, f func(context.Context), period time.Duration) {
JitterUntilWithContext(ctx, f, period, 0.0, true)
}
// NonSlidingUntil loops until stop channel is closed, running f every
// period.
//
// NonSlidingUntil is syntactic sugar on top of JitterUntil with zero jitter
// factor, with sliding = false (meaning the timer for period starts at the same
// time as the function starts).
func NonSlidingUntil(f func(), period time.Duration, stopCh <-chan struct{}) {
JitterUntil(f, period, 0.0, false, stopCh)
}
// NonSlidingUntilWithContext loops until context is done, running f every
// period.
//
// NonSlidingUntilWithContext is syntactic sugar on top of JitterUntilWithContext
// with zero jitter factor, with sliding = false (meaning the timer for period
// starts at the same time as the function starts).
func NonSlidingUntilWithContext(ctx context.Context, f func(context.Context), period time.Duration) {
JitterUntilWithContext(ctx, f, period, 0.0, false)
}
// JitterUntil loops until stop channel is closed, running f every period.
//
// If jitterFactor is positive, the period is jittered before every run of f.
// If jitterFactor is not positive, the period is unchanged and not jittered.
//
// If sliding is true, the period is computed after f runs. If it is false then
// period includes the runtime for f.
//
// Close stopCh to stop. f may not be invoked if stop channel is already
// closed. Pass NeverStop to if you don't want it stop.
func JitterUntil(f func(), period time.Duration, jitterFactor float64, sliding bool, stopCh <-chan struct{}) {
BackoffUntil(f, NewJitteredBackoffManager(period, jitterFactor, &clock.RealClock{}), sliding, stopCh)
}
// BackoffUntil loops until stop channel is closed, run f every duration given by BackoffManager.
//
// If sliding is true, the period is computed after f runs. If it is false then
// period includes the runtime for f.
func BackoffUntil(f func(), backoff BackoffManager, sliding bool, stopCh <-chan struct{}) {
var t clock.Timer
for {
select {
case <-stopCh:
return
default:
}
if !sliding {
t = backoff.Backoff()
}
func() {
defer runtime.HandleCrash()
f()
}()
if sliding {
t = backoff.Backoff()
}
// NOTE: b/c there is no priority selection in golang
// it is possible for this to race, meaning we could
// trigger t.C and stopCh, and t.C select falls through.
// In order to mitigate we re-check stopCh at the beginning
// of every loop to prevent extra executions of f().
select {
case <-stopCh:
if !t.Stop() {
<-t.C()
}
return
case <-t.C():
}
}
}
// JitterUntilWithContext loops until context is done, running f every period.
//
// If jitterFactor is positive, the period is jittered before every run of f.
// If jitterFactor is not positive, the period is unchanged and not jittered.
//
// If sliding is true, the period is computed after f runs. If it is false then
// period includes the runtime for f.
//
// Cancel context to stop. f may not be invoked if context is already expired.
func JitterUntilWithContext(ctx context.Context, f func(context.Context), period time.Duration, jitterFactor float64, sliding bool) {
JitterUntil(func() { f(ctx) }, period, jitterFactor, sliding, ctx.Done())
}
// Jitter returns a time.Duration between duration and duration + maxFactor *
// duration.
//
@ -203,9 +93,6 @@ func Jitter(duration time.Duration, maxFactor float64) time.Duration {
return wait
}
// ErrWaitTimeout is returned when the condition exited without success.
var ErrWaitTimeout = errors.New("timed out waiting for the condition")
// ConditionFunc returns true if the condition is satisfied, or an error
// if the loop should be aborted.
type ConditionFunc func() (done bool, err error)
@ -223,425 +110,80 @@ func (cf ConditionFunc) WithContext() ConditionWithContextFunc {
}
}
// runConditionWithCrashProtection runs a ConditionFunc with crash protection
func runConditionWithCrashProtection(condition ConditionFunc) (bool, error) {
return runConditionWithCrashProtectionWithContext(context.TODO(), condition.WithContext())
// ContextForChannel provides a context that will be treated as cancelled
// when the provided parentCh is closed. The implementation returns
// context.Canceled for Err() if and only if the parentCh is closed.
func ContextForChannel(parentCh <-chan struct{}) context.Context {
return channelContext{stopCh: parentCh}
}
// runConditionWithCrashProtectionWithContext runs a
// ConditionWithContextFunc with crash protection.
var _ context.Context = channelContext{}
// channelContext will behave as if the context were cancelled when stopCh is
// closed.
type channelContext struct {
stopCh <-chan struct{}
}
func (c channelContext) Done() <-chan struct{} { return c.stopCh }
func (c channelContext) Err() error {
select {
case <-c.stopCh:
return context.Canceled
default:
return nil
}
}
func (c channelContext) Deadline() (time.Time, bool) { return time.Time{}, false }
func (c channelContext) Value(key any) any { return nil }
// runConditionWithCrashProtection runs a ConditionFunc with crash protection.
//
// Deprecated: Will be removed when the legacy polling methods are removed.
func runConditionWithCrashProtection(condition ConditionFunc) (bool, error) {
defer runtime.HandleCrash()
return condition()
}
// runConditionWithCrashProtectionWithContext runs a ConditionWithContextFunc
// with crash protection.
//
// Deprecated: Will be removed when the legacy polling methods are removed.
func runConditionWithCrashProtectionWithContext(ctx context.Context, condition ConditionWithContextFunc) (bool, error) {
defer runtime.HandleCrash()
return condition(ctx)
}
// Backoff holds parameters applied to a Backoff function.
type Backoff struct {
// The initial duration.
Duration time.Duration
// Duration is multiplied by factor each iteration, if factor is not zero
// and the limits imposed by Steps and Cap have not been reached.
// Should not be negative.
// The jitter does not contribute to the updates to the duration parameter.
Factor float64
// The sleep at each iteration is the duration plus an additional
// amount chosen uniformly at random from the interval between
// zero and `jitter*duration`.
Jitter float64
// The remaining number of iterations in which the duration
// parameter may change (but progress can be stopped earlier by
// hitting the cap). If not positive, the duration is not
// changed. Used for exponential backoff in combination with
// Factor and Cap.
Steps int
// A limit on revised values of the duration parameter. If a
// multiplication by the factor parameter would make the duration
// exceed the cap then the duration is set to the cap and the
// steps parameter is set to zero.
Cap time.Duration
}
// Step (1) returns an amount of time to sleep determined by the
// original Duration and Jitter and (2) mutates the provided Backoff
// to update its Steps and Duration.
func (b *Backoff) Step() time.Duration {
if b.Steps < 1 {
if b.Jitter > 0 {
return Jitter(b.Duration, b.Jitter)
}
return b.Duration
}
b.Steps--
duration := b.Duration
// calculate the next step
if b.Factor != 0 {
b.Duration = time.Duration(float64(b.Duration) * b.Factor)
if b.Cap > 0 && b.Duration > b.Cap {
b.Duration = b.Cap
b.Steps = 0
}
}
if b.Jitter > 0 {
duration = Jitter(duration, b.Jitter)
}
return duration
}
// ContextForChannel derives a child context from a parent channel.
//
// The derived context's Done channel is closed when the returned cancel function
// is called or when the parent channel is closed, whichever happens first.
//
// Note the caller must *always* call the CancelFunc, otherwise resources may be leaked.
func ContextForChannel(parentCh <-chan struct{}) (context.Context, context.CancelFunc) {
ctx, cancel := context.WithCancel(context.Background())
go func() {
select {
case <-parentCh:
cancel()
case <-ctx.Done():
}
}()
return ctx, cancel
}
// BackoffManager manages backoff with a particular scheme based on its underlying implementation. It provides
// an interface to return a timer for backoff, and caller shall backoff until Timer.C() drains. If the second Backoff()
// is called before the timer from the first Backoff() call finishes, the first timer will NOT be drained and result in
// undetermined behavior.
// The BackoffManager is supposed to be called in a single-threaded environment.
type BackoffManager interface {
Backoff() clock.Timer
}
type exponentialBackoffManagerImpl struct {
backoff *Backoff
backoffTimer clock.Timer
lastBackoffStart time.Time
initialBackoff time.Duration
backoffResetDuration time.Duration
clock clock.Clock
}
// NewExponentialBackoffManager returns a manager for managing exponential backoff. Each backoff is jittered and
// backoff will not exceed the given max. If the backoff is not called within resetDuration, the backoff is reset.
// This backoff manager is used to reduce load during upstream unhealthiness.
func NewExponentialBackoffManager(initBackoff, maxBackoff, resetDuration time.Duration, backoffFactor, jitter float64, c clock.Clock) BackoffManager {
return &exponentialBackoffManagerImpl{
backoff: &Backoff{
Duration: initBackoff,
Factor: backoffFactor,
Jitter: jitter,
// the current impl of wait.Backoff returns Backoff.Duration once steps are used up, which is not
// what we ideally need here, we set it to max int and assume we will never use up the steps
Steps: math.MaxInt32,
Cap: maxBackoff,
},
backoffTimer: nil,
initialBackoff: initBackoff,
lastBackoffStart: c.Now(),
backoffResetDuration: resetDuration,
clock: c,
}
}
func (b *exponentialBackoffManagerImpl) getNextBackoff() time.Duration {
if b.clock.Now().Sub(b.lastBackoffStart) > b.backoffResetDuration {
b.backoff.Steps = math.MaxInt32
b.backoff.Duration = b.initialBackoff
}
b.lastBackoffStart = b.clock.Now()
return b.backoff.Step()
}
// Backoff implements BackoffManager.Backoff, it returns a timer so caller can block on the timer for exponential backoff.
// The returned timer must be drained before calling Backoff() the second time
func (b *exponentialBackoffManagerImpl) Backoff() clock.Timer {
if b.backoffTimer == nil {
b.backoffTimer = b.clock.NewTimer(b.getNextBackoff())
} else {
b.backoffTimer.Reset(b.getNextBackoff())
}
return b.backoffTimer
}
type jitteredBackoffManagerImpl struct {
clock clock.Clock
duration time.Duration
jitter float64
backoffTimer clock.Timer
}
// NewJitteredBackoffManager returns a BackoffManager that backoffs with given duration plus given jitter. If the jitter
// is negative, backoff will not be jittered.
func NewJitteredBackoffManager(duration time.Duration, jitter float64, c clock.Clock) BackoffManager {
return &jitteredBackoffManagerImpl{
clock: c,
duration: duration,
jitter: jitter,
backoffTimer: nil,
}
}
func (j *jitteredBackoffManagerImpl) getNextBackoff() time.Duration {
jitteredPeriod := j.duration
if j.jitter > 0.0 {
jitteredPeriod = Jitter(j.duration, j.jitter)
}
return jitteredPeriod
}
// Backoff implements BackoffManager.Backoff, it returns a timer so caller can block on the timer for jittered backoff.
// The returned timer must be drained before calling Backoff() the second time
func (j *jitteredBackoffManagerImpl) Backoff() clock.Timer {
backoff := j.getNextBackoff()
if j.backoffTimer == nil {
j.backoffTimer = j.clock.NewTimer(backoff)
} else {
j.backoffTimer.Reset(backoff)
}
return j.backoffTimer
}
// ExponentialBackoff repeats a condition check with exponential backoff.
//
// It repeatedly checks the condition and then sleeps, using `backoff.Step()`
// to determine the length of the sleep and adjust Duration and Steps.
// Stops and returns as soon as:
// 1. the condition check returns true or an error,
// 2. `backoff.Steps` checks of the condition have been done, or
// 3. a sleep truncated by the cap on duration has been completed.
// In case (1) the returned error is what the condition function returned.
// In all other cases, ErrWaitTimeout is returned.
func ExponentialBackoff(backoff Backoff, condition ConditionFunc) error {
for backoff.Steps > 0 {
if ok, err := runConditionWithCrashProtection(condition); err != nil || ok {
return err
}
if backoff.Steps == 1 {
break
}
time.Sleep(backoff.Step())
}
return ErrWaitTimeout
}
// Poll tries a condition func until it returns true, an error, or the timeout
// is reached.
//
// Poll always waits the interval before the run of 'condition'.
// 'condition' will always be invoked at least once.
//
// Some intervals may be missed if the condition takes too long or the time
// window is too short.
//
// If you want to Poll something forever, see PollInfinite.
func Poll(interval, timeout time.Duration, condition ConditionFunc) error {
return PollWithContext(context.Background(), interval, timeout, condition.WithContext())
}
// PollWithContext tries a condition func until it returns true, an error,
// or when the context expires or the timeout is reached, whichever
// happens first.
//
// PollWithContext always waits the interval before the run of 'condition'.
// 'condition' will always be invoked at least once.
//
// Some intervals may be missed if the condition takes too long or the time
// window is too short.
//
// If you want to Poll something forever, see PollInfinite.
func PollWithContext(ctx context.Context, interval, timeout time.Duration, condition ConditionWithContextFunc) error {
return poll(ctx, false, poller(interval, timeout), condition)
}
// PollUntil tries a condition func until it returns true, an error or stopCh is
// closed.
//
// PollUntil always waits interval before the first run of 'condition'.
// 'condition' will always be invoked at least once.
func PollUntil(interval time.Duration, condition ConditionFunc, stopCh <-chan struct{}) error {
ctx, cancel := ContextForChannel(stopCh)
defer cancel()
return PollUntilWithContext(ctx, interval, condition.WithContext())
}
// PollUntilWithContext tries a condition func until it returns true,
// an error or the specified context is cancelled or expired.
//
// PollUntilWithContext always waits interval before the first run of 'condition'.
// 'condition' will always be invoked at least once.
func PollUntilWithContext(ctx context.Context, interval time.Duration, condition ConditionWithContextFunc) error {
return poll(ctx, false, poller(interval, 0), condition)
}
// PollInfinite tries a condition func until it returns true or an error
//
// PollInfinite always waits the interval before the run of 'condition'.
//
// Some intervals may be missed if the condition takes too long or the time
// window is too short.
func PollInfinite(interval time.Duration, condition ConditionFunc) error {
return PollInfiniteWithContext(context.Background(), interval, condition.WithContext())
}
// PollInfiniteWithContext tries a condition func until it returns true or an error
//
// PollInfiniteWithContext always waits the interval before the run of 'condition'.
//
// Some intervals may be missed if the condition takes too long or the time
// window is too short.
func PollInfiniteWithContext(ctx context.Context, interval time.Duration, condition ConditionWithContextFunc) error {
return poll(ctx, false, poller(interval, 0), condition)
}
// PollImmediate tries a condition func until it returns true, an error, or the timeout
// is reached.
//
// PollImmediate always checks 'condition' before waiting for the interval. 'condition'
// will always be invoked at least once.
//
// Some intervals may be missed if the condition takes too long or the time
// window is too short.
//
// If you want to immediately Poll something forever, see PollImmediateInfinite.
func PollImmediate(interval, timeout time.Duration, condition ConditionFunc) error {
return PollImmediateWithContext(context.Background(), interval, timeout, condition.WithContext())
}
// PollImmediateWithContext tries a condition func until it returns true, an error,
// or the timeout is reached or the specified context expires, whichever happens first.
//
// PollImmediateWithContext always checks 'condition' before waiting for the interval.
// 'condition' will always be invoked at least once.
//
// Some intervals may be missed if the condition takes too long or the time
// window is too short.
//
// If you want to immediately Poll something forever, see PollImmediateInfinite.
func PollImmediateWithContext(ctx context.Context, interval, timeout time.Duration, condition ConditionWithContextFunc) error {
return poll(ctx, true, poller(interval, timeout), condition)
}
// PollImmediateUntil tries a condition func until it returns true, an error or stopCh is closed.
//
// PollImmediateUntil runs the 'condition' before waiting for the interval.
// 'condition' will always be invoked at least once.
func PollImmediateUntil(interval time.Duration, condition ConditionFunc, stopCh <-chan struct{}) error {
ctx, cancel := ContextForChannel(stopCh)
defer cancel()
return PollImmediateUntilWithContext(ctx, interval, condition.WithContext())
}
// PollImmediateUntilWithContext tries a condition func until it returns true,
// an error or the specified context is cancelled or expired.
//
// PollImmediateUntilWithContext runs the 'condition' before waiting for the interval.
// 'condition' will always be invoked at least once.
func PollImmediateUntilWithContext(ctx context.Context, interval time.Duration, condition ConditionWithContextFunc) error {
return poll(ctx, true, poller(interval, 0), condition)
}
// PollImmediateInfinite tries a condition func until it returns true or an error
//
// PollImmediateInfinite runs the 'condition' before waiting for the interval.
//
// Some intervals may be missed if the condition takes too long or the time
// window is too short.
func PollImmediateInfinite(interval time.Duration, condition ConditionFunc) error {
return PollImmediateInfiniteWithContext(context.Background(), interval, condition.WithContext())
}
// PollImmediateInfiniteWithContext tries a condition func until it returns true
// or an error or the specified context gets cancelled or expired.
//
// PollImmediateInfiniteWithContext runs the 'condition' before waiting for the interval.
//
// Some intervals may be missed if the condition takes too long or the time
// window is too short.
func PollImmediateInfiniteWithContext(ctx context.Context, interval time.Duration, condition ConditionWithContextFunc) error {
return poll(ctx, true, poller(interval, 0), condition)
}
// Internally used, each of the public 'Poll*' function defined in this
// package should invoke this internal function with appropriate parameters.
// ctx: the context specified by the caller, for infinite polling pass
// a context that never gets cancelled or expired.
// immediate: if true, the 'condition' will be invoked before waiting for the interval,
// in this case 'condition' will always be invoked at least once.
// wait: user specified WaitFunc function that controls at what interval the condition
// function should be invoked periodically and whether it is bound by a timeout.
// condition: user specified ConditionWithContextFunc function.
func poll(ctx context.Context, immediate bool, wait WaitWithContextFunc, condition ConditionWithContextFunc) error {
if immediate {
done, err := runConditionWithCrashProtectionWithContext(ctx, condition)
if err != nil {
return err
}
if done {
return nil
}
}
select {
case <-ctx.Done():
// returning ctx.Err() will break backward compatibility
return ErrWaitTimeout
default:
return WaitForWithContext(ctx, wait, condition)
}
}
// WaitFunc creates a channel that receives an item every time a test
// waitFunc creates a channel that receives an item every time a test
// should be executed and is closed when the last test should be invoked.
type WaitFunc func(done <-chan struct{}) <-chan struct{}
//
// Deprecated: Will be removed in a future release in favor of
// loopConditionUntilContext.
type waitFunc func(done <-chan struct{}) <-chan struct{}
// WithContext converts the WaitFunc to an equivalent WaitWithContextFunc
func (w WaitFunc) WithContext() WaitWithContextFunc {
func (w waitFunc) WithContext() waitWithContextFunc {
return func(ctx context.Context) <-chan struct{} {
return w(ctx.Done())
}
}
// WaitWithContextFunc creates a channel that receives an item every time a test
// waitWithContextFunc creates a channel that receives an item every time a test
// should be executed and is closed when the last test should be invoked.
//
// When the specified context gets cancelled or expires the function
// stops sending item and returns immediately.
type WaitWithContextFunc func(ctx context.Context) <-chan struct{}
//
// Deprecated: Will be removed in a future release in favor of
// loopConditionUntilContext.
type waitWithContextFunc func(ctx context.Context) <-chan struct{}
// WaitFor continually checks 'fn' as driven by 'wait'.
// waitForWithContext 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. 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. If
// 'fn' returns true the loop ends and nil is returned.
//
// 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 {
ctx, cancel := ContextForChannel(done)
defer cancel()
return WaitForWithContext(ctx, wait.WithContext(), fn.WithContext())
}
// WaitForWithContext continually checks 'fn' as driven by 'wait'.
//
// WaitForWithContext gets a channel from 'wait()”, and then invokes 'fn'
// waitForWithContext 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. If the channel is closed and 'fn'
// returns false without error, WaitForWithContext returns ErrWaitTimeout.
// returns false without error, waitForWithContext returns ErrWaitTimeout.
//
// If 'fn' returns an error the loop ends and that error is returned. If
// 'fn' returns true the loop ends and nil is returned.
@ -651,8 +193,11 @@ func WaitFor(wait WaitFunc, fn ConditionFunc, done <-chan struct{}) error {
//
// When the ctx.Done() channel is closed, because the golang `select` statement is
// "uniform pseudo-random", the `fn` might still run one or multiple times,
// though eventually `WaitForWithContext` will return.
func WaitForWithContext(ctx context.Context, wait WaitWithContextFunc, fn ConditionWithContextFunc) error {
// though eventually `waitForWithContext` will return.
//
// Deprecated: Will be removed in a future release in favor of
// loopConditionUntilContext.
func waitForWithContext(ctx context.Context, wait waitWithContextFunc, fn ConditionWithContextFunc) error {
waitCtx, cancel := context.WithCancel(context.Background())
defer cancel()
c := wait(waitCtx)
@ -670,88 +215,9 @@ func WaitForWithContext(ctx context.Context, wait WaitWithContextFunc, fn Condit
return ErrWaitTimeout
}
case <-ctx.Done():
// returning ctx.Err() will break backward compatibility
// returning ctx.Err() will break backward compatibility, use new PollUntilContext*
// methods instead
return ErrWaitTimeout
}
}
}
// poller returns a WaitFunc that will send to the channel every interval until
// timeout has elapsed and then closes the channel.
//
// Over very short intervals you may receive no ticks before the channel is
// closed. A timeout of 0 is interpreted as an infinity, and in such a case
// it would be the caller's responsibility to close the done channel.
// Failure to do so would result in a leaked goroutine.
//
// Output ticks are not buffered. If the channel is not ready to receive an
// item, the tick is skipped.
func poller(interval, timeout time.Duration) WaitWithContextFunc {
return WaitWithContextFunc(func(ctx context.Context) <-chan struct{} {
ch := make(chan struct{})
go func() {
defer close(ch)
tick := time.NewTicker(interval)
defer tick.Stop()
var after <-chan time.Time
if timeout != 0 {
// time.After is more convenient, but it
// potentially leaves timers around much longer
// than necessary if we exit early.
timer := time.NewTimer(timeout)
after = timer.C
defer timer.Stop()
}
for {
select {
case <-tick.C:
// If the consumer isn't ready for this signal drop it and
// check the other channels.
select {
case ch <- struct{}{}:
default:
}
case <-after:
return
case <-ctx.Done():
return
}
}
}()
return ch
})
}
// ExponentialBackoffWithContext works with a request context and a Backoff. It ensures that the retry wait never
// exceeds the deadline specified by the request context.
func ExponentialBackoffWithContext(ctx context.Context, backoff Backoff, condition ConditionFunc) error {
for backoff.Steps > 0 {
select {
case <-ctx.Done():
return ctx.Err()
default:
}
if ok, err := runConditionWithCrashProtection(condition); err != nil || ok {
return err
}
if backoff.Steps == 1 {
break
}
waitBeforeRetry := backoff.Step()
select {
case <-ctx.Done():
return ctx.Err()
case <-time.After(waitBeforeRetry):
}
}
return ErrWaitTimeout
}