Merge pull request #3933 from giuseppe/skip-polling-on-run

libpod: avoid polling container status

5 files changed, 23 insertions, 543 deletions

diff --git a/libpod/container_api.go b/libpod/container_api.go
index 9e59104cc..9bf97c5d4 100644
--- a/libpod/container_api.go
+++ b/libpod/container_api.go
@@ -14,7 +14,6 @@ import (
 	"github.com/opentracing/opentracing-go"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
-	"k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/client-go/tools/remotecommand"
 )
 
@@ -524,24 +523,25 @@ func (c *Container) WaitWithInterval(waitTimeout time.Duration) (int32, error) {
 	if !c.valid {
 		return -1, define.ErrCtrRemoved
 	}
-	err := wait.PollImmediateInfinite(waitTimeout,
-		func() (bool, error) {
-			logrus.Debugf("Checking container %s status...", c.ID())
-			stopped, err := c.isStopped()
-			if err != nil {
-				return false, err
-			}
-			if !stopped {
-				return false, nil
-			}
-			return true, nil
-		},
-	)
-	if err != nil {
-		return 0, err
+
+	exitFile := c.exitFilePath()
+	chWait := make(chan error, 1)
+
+	defer close(chWait)
+
+	for {
+		// ignore errors here, it is only used to avoid waiting
+		// too long.
+		_, _ = WaitForFile(exitFile, chWait, waitTimeout)
+
+		stopped, err := c.isStopped()
+		if err != nil {
+			return -1, err
+		}
+		if stopped {
+			return c.state.ExitCode, nil
+		}
 	}
-	exitCode := c.state.ExitCode
-	return exitCode, nil
 }
 
 // Cleanup unmounts all mount points in container and cleans up container storage
diff --git a/libpod/util.go b/libpod/util.go
index b60575264..164800af4 100644
--- a/libpod/util.go
+++ b/libpod/util.go
@@ -69,7 +69,11 @@ func WaitForFile(path string, chWait chan error, timeout time.Duration) (bool, e
 		defer watcher.Close()
 	}
 
-	timeoutChan := time.After(timeout)
+	var timeoutChan <-chan time.Time
+
+	if timeout != 0 {
+		timeoutChan = time.After(timeout)
+	}
 
 	for {
 		select {
diff --git a/vendor/k8s.io/apimachinery/pkg/util/wait/doc.go b/vendor/k8s.io/apimachinery/pkg/util/wait/doc.go
deleted file mode 100644
index 3f0c968ec..000000000
--- a/vendor/k8s.io/apimachinery/pkg/util/wait/doc.go
+++ /dev/null
@@ -1,19 +0,0 @@
-/*
-Copyright 2014 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 provides tools for polling or listening for changes
-// to a condition.
-package wait // import "k8s.io/apimachinery/pkg/util/wait"
diff --git a/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go b/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go
deleted file mode 100644
index bc6b18d2b..000000000
--- a/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go
+++ /dev/null
@@ -1,504 +0,0 @@
-/*
-Copyright 2014 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"
-	"math/rand"
-	"sync"
-	"time"
-
-	"k8s.io/apimachinery/pkg/util/runtime"
-)
-
-// For any test of the style:
-//   ...
-//   <- time.After(timeout):
-//      t.Errorf("Timed out")
-// The value for timeout should effectively be "forever." Obviously we don't want our tests to truly lock up forever, but 30s
-// is long enough that it is effectively forever for the things that can slow down a run on a heavily contended machine
-// (GC, seeks, etc), but not so long as to make a developer ctrl-c a test run if they do happen to break that test.
-var ForeverTestTimeout = time.Second * 30
-
-// NeverStop may be passed to Until to make it never stop.
-var NeverStop <-chan struct{} = make(chan struct{})
-
-// Group allows to start a group of goroutines and wait for their completion.
-type Group struct {
-	wg sync.WaitGroup
-}
-
-func (g *Group) Wait() {
-	g.wg.Wait()
-}
-
-// StartWithChannel starts f in a new goroutine in the group.
-// stopCh is passed to f as an argument. f should stop when stopCh is available.
-func (g *Group) StartWithChannel(stopCh <-chan struct{}, f func(stopCh <-chan struct{})) {
-	g.Start(func() {
-		f(stopCh)
-	})
-}
-
-// StartWithContext starts f in a new goroutine in the group.
-// ctx is passed to f as an argument. f should stop when ctx.Done() is available.
-func (g *Group) StartWithContext(ctx context.Context, f func(context.Context)) {
-	g.Start(func() {
-		f(ctx)
-	})
-}
-
-// Start starts f in a new goroutine in the group.
-func (g *Group) Start(f func()) {
-	g.wg.Add(1)
-	go func() {
-		defer g.wg.Done()
-		f()
-	}()
-}
-
-// Forever calls f every period for ever.
-//
-// Forever is syntactic sugar on top of Until.
-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{}) {
-	var t *time.Timer
-	var sawTimeout bool
-
-	for {
-		select {
-		case <-stopCh:
-			return
-		default:
-		}
-
-		jitteredPeriod := period
-		if jitterFactor > 0.0 {
-			jitteredPeriod = Jitter(period, jitterFactor)
-		}
-
-		if !sliding {
-			t = resetOrReuseTimer(t, jitteredPeriod, sawTimeout)
-		}
-
-		func() {
-			defer runtime.HandleCrash()
-			f()
-		}()
-
-		if sliding {
-			t = resetOrReuseTimer(t, jitteredPeriod, sawTimeout)
-		}
-
-		// 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:
-			return
-		case <-t.C:
-			sawTimeout = true
-		}
-	}
-}
-
-// 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.
-//
-// This allows clients to avoid converging on periodic behavior. If maxFactor
-// is 0.0, a suggested default value will be chosen.
-func Jitter(duration time.Duration, maxFactor float64) time.Duration {
-	if maxFactor <= 0.0 {
-		maxFactor = 1.0
-	}
-	wait := duration + time.Duration(rand.Float64()*maxFactor*float64(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)
-
-// Backoff holds parameters applied to a Backoff function.
-type Backoff struct {
-	// The initial duration.
-	Duration time.Duration
-	// Duration is multiplied by factor each iteration. Must be greater
-	// than or equal to zero.
-	Factor float64
-	// The amount of jitter applied each iteration. Jitter is applied after
-	// cap.
-	Jitter float64
-	// The number of steps before duration stops changing. If zero, initial
-	// duration is always used. Used for exponential backoff in combination
-	// with Factor.
-	Steps int
-	// The returned duration will never be greater than cap *before* jitter
-	// is applied. The actual maximum cap is `cap * (1.0 + jitter)`.
-	Cap time.Duration
-}
-
-// Step returns the next interval in the exponential backoff. This method
-// will mutate the provided backoff.
-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
-}
-
-// ExponentialBackoff repeats a condition check with exponential backoff.
-//
-// It checks the condition up to Steps times, increasing the wait by multiplying
-// the previous duration by Factor.
-//
-// If Jitter is greater than zero, a random amount of each duration is added
-// (between duration and duration*(1+jitter)).
-//
-// If the condition never returns true, ErrWaitTimeout is returned. All other
-// errors terminate immediately.
-func ExponentialBackoff(backoff Backoff, condition ConditionFunc) error {
-	for backoff.Steps > 0 {
-		if ok, err := 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 pollInternal(poller(interval, timeout), condition)
-}
-
-func pollInternal(wait WaitFunc, condition ConditionFunc) error {
-	done := make(chan struct{})
-	defer close(done)
-	return WaitFor(wait, condition, done)
-}
-
-// 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 pollImmediateInternal(poller(interval, timeout), condition)
-}
-
-func pollImmediateInternal(wait WaitFunc, condition ConditionFunc) error {
-	done, err := condition()
-	if err != nil {
-		return err
-	}
-	if done {
-		return nil
-	}
-	return pollInternal(wait, 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 {
-	done := make(chan struct{})
-	defer close(done)
-	return PollUntil(interval, condition, done)
-}
-
-// 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 {
-	done, err := condition()
-	if err != nil {
-		return err
-	}
-	if done {
-		return nil
-	}
-	return PollInfinite(interval, 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 WaitFor(poller(interval, 0), condition, ctx.Done())
-}
-
-// 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 {
-	done, err := condition()
-	if err != nil {
-		return err
-	}
-	if done {
-		return nil
-	}
-	select {
-	case <-stopCh:
-		return ErrWaitTimeout
-	default:
-		return PollUntil(interval, condition, stopCh)
-	}
-}
-
-// 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{}
-
-// 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. 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 {
-	stopCh := make(chan struct{})
-	defer close(stopCh)
-	c := wait(stopCh)
-	for {
-		select {
-		case _, open := <-c:
-			ok, err := fn()
-			if err != nil {
-				return err
-			}
-			if ok {
-				return nil
-			}
-			if !open {
-				return ErrWaitTimeout
-			}
-		case <-done:
-			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) WaitFunc {
-	return WaitFunc(func(done <-chan struct{}) <-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 <-done:
-					return
-				}
-			}
-		}()
-
-		return ch
-	})
-}
-
-// resetOrReuseTimer avoids allocating a new timer if one is already in use.
-// Not safe for multiple threads.
-func resetOrReuseTimer(t *time.Timer, d time.Duration, sawTimeout bool) *time.Timer {
-	if t == nil {
-		return time.NewTimer(d)
-	}
-	if !t.Stop() && !sawTimeout {
-		<-t.C
-	}
-	t.Reset(d)
-	return t
-}
diff --git a/vendor/modules.txt b/vendor/modules.txt
index 3acff38c9..7d9095aac 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -543,7 +543,6 @@ gopkg.in/yaml.v2
 k8s.io/api/core/v1
 # k8s.io/apimachinery v0.0.0-20190624085041-961b39a1baa0
 k8s.io/apimachinery/pkg/apis/meta/v1
-k8s.io/apimachinery/pkg/util/wait
 k8s.io/apimachinery/pkg/util/runtime
 k8s.io/apimachinery/pkg/api/resource
 k8s.io/apimachinery/pkg/runtime