280
vendor/k8s.io/client-go/util/workqueue/delaying_queue.go
generated
vendored
Normal file
280
vendor/k8s.io/client-go/util/workqueue/delaying_queue.go
generated
vendored
Normal file
@ -0,0 +1,280 @@
|
||||
/*
|
||||
Copyright 2016 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 workqueue
|
||||
|
||||
import (
|
||||
"container/heap"
|
||||
"sync"
|
||||
"time"
|
||||
|
||||
"k8s.io/apimachinery/pkg/util/clock"
|
||||
utilruntime "k8s.io/apimachinery/pkg/util/runtime"
|
||||
)
|
||||
|
||||
// DelayingInterface is an Interface that can Add an item at a later time. This makes it easier to
|
||||
// requeue items after failures without ending up in a hot-loop.
|
||||
type DelayingInterface interface {
|
||||
Interface
|
||||
// AddAfter adds an item to the workqueue after the indicated duration has passed
|
||||
AddAfter(item interface{}, duration time.Duration)
|
||||
}
|
||||
|
||||
// NewDelayingQueue constructs a new workqueue with delayed queuing ability
|
||||
func NewDelayingQueue() DelayingInterface {
|
||||
return NewDelayingQueueWithCustomClock(clock.RealClock{}, "")
|
||||
}
|
||||
|
||||
// NewDelayingQueueWithCustomQueue constructs a new workqueue with ability to
|
||||
// inject custom queue Interface instead of the default one
|
||||
func NewDelayingQueueWithCustomQueue(q Interface, name string) DelayingInterface {
|
||||
return newDelayingQueue(clock.RealClock{}, q, name)
|
||||
}
|
||||
|
||||
// NewNamedDelayingQueue constructs a new named workqueue with delayed queuing ability
|
||||
func NewNamedDelayingQueue(name string) DelayingInterface {
|
||||
return NewDelayingQueueWithCustomClock(clock.RealClock{}, name)
|
||||
}
|
||||
|
||||
// NewDelayingQueueWithCustomClock constructs a new named workqueue
|
||||
// with ability to inject real or fake clock for testing purposes
|
||||
func NewDelayingQueueWithCustomClock(clock clock.Clock, name string) DelayingInterface {
|
||||
return newDelayingQueue(clock, NewNamed(name), name)
|
||||
}
|
||||
|
||||
func newDelayingQueue(clock clock.Clock, q Interface, name string) *delayingType {
|
||||
ret := &delayingType{
|
||||
Interface: q,
|
||||
clock: clock,
|
||||
heartbeat: clock.NewTicker(maxWait),
|
||||
stopCh: make(chan struct{}),
|
||||
waitingForAddCh: make(chan *waitFor, 1000),
|
||||
metrics: newRetryMetrics(name),
|
||||
}
|
||||
|
||||
go ret.waitingLoop()
|
||||
return ret
|
||||
}
|
||||
|
||||
// delayingType wraps an Interface and provides delayed re-enquing
|
||||
type delayingType struct {
|
||||
Interface
|
||||
|
||||
// clock tracks time for delayed firing
|
||||
clock clock.Clock
|
||||
|
||||
// stopCh lets us signal a shutdown to the waiting loop
|
||||
stopCh chan struct{}
|
||||
// stopOnce guarantees we only signal shutdown a single time
|
||||
stopOnce sync.Once
|
||||
|
||||
// heartbeat ensures we wait no more than maxWait before firing
|
||||
heartbeat clock.Ticker
|
||||
|
||||
// waitingForAddCh is a buffered channel that feeds waitingForAdd
|
||||
waitingForAddCh chan *waitFor
|
||||
|
||||
// metrics counts the number of retries
|
||||
metrics retryMetrics
|
||||
}
|
||||
|
||||
// waitFor holds the data to add and the time it should be added
|
||||
type waitFor struct {
|
||||
data t
|
||||
readyAt time.Time
|
||||
// index in the priority queue (heap)
|
||||
index int
|
||||
}
|
||||
|
||||
// waitForPriorityQueue implements a priority queue for waitFor items.
|
||||
//
|
||||
// waitForPriorityQueue implements heap.Interface. The item occurring next in
|
||||
// time (i.e., the item with the smallest readyAt) is at the root (index 0).
|
||||
// Peek returns this minimum item at index 0. Pop returns the minimum item after
|
||||
// it has been removed from the queue and placed at index Len()-1 by
|
||||
// container/heap. Push adds an item at index Len(), and container/heap
|
||||
// percolates it into the correct location.
|
||||
type waitForPriorityQueue []*waitFor
|
||||
|
||||
func (pq waitForPriorityQueue) Len() int {
|
||||
return len(pq)
|
||||
}
|
||||
func (pq waitForPriorityQueue) Less(i, j int) bool {
|
||||
return pq[i].readyAt.Before(pq[j].readyAt)
|
||||
}
|
||||
func (pq waitForPriorityQueue) Swap(i, j int) {
|
||||
pq[i], pq[j] = pq[j], pq[i]
|
||||
pq[i].index = i
|
||||
pq[j].index = j
|
||||
}
|
||||
|
||||
// Push adds an item to the queue. Push should not be called directly; instead,
|
||||
// use `heap.Push`.
|
||||
func (pq *waitForPriorityQueue) Push(x interface{}) {
|
||||
n := len(*pq)
|
||||
item := x.(*waitFor)
|
||||
item.index = n
|
||||
*pq = append(*pq, item)
|
||||
}
|
||||
|
||||
// Pop removes an item from the queue. Pop should not be called directly;
|
||||
// instead, use `heap.Pop`.
|
||||
func (pq *waitForPriorityQueue) Pop() interface{} {
|
||||
n := len(*pq)
|
||||
item := (*pq)[n-1]
|
||||
item.index = -1
|
||||
*pq = (*pq)[0:(n - 1)]
|
||||
return item
|
||||
}
|
||||
|
||||
// Peek returns the item at the beginning of the queue, without removing the
|
||||
// item or otherwise mutating the queue. It is safe to call directly.
|
||||
func (pq waitForPriorityQueue) Peek() interface{} {
|
||||
return pq[0]
|
||||
}
|
||||
|
||||
// ShutDown stops the queue. After the queue drains, the returned shutdown bool
|
||||
// on Get() will be true. This method may be invoked more than once.
|
||||
func (q *delayingType) ShutDown() {
|
||||
q.stopOnce.Do(func() {
|
||||
q.Interface.ShutDown()
|
||||
close(q.stopCh)
|
||||
q.heartbeat.Stop()
|
||||
})
|
||||
}
|
||||
|
||||
// AddAfter adds the given item to the work queue after the given delay
|
||||
func (q *delayingType) AddAfter(item interface{}, duration time.Duration) {
|
||||
// don't add if we're already shutting down
|
||||
if q.ShuttingDown() {
|
||||
return
|
||||
}
|
||||
|
||||
q.metrics.retry()
|
||||
|
||||
// immediately add things with no delay
|
||||
if duration <= 0 {
|
||||
q.Add(item)
|
||||
return
|
||||
}
|
||||
|
||||
select {
|
||||
case <-q.stopCh:
|
||||
// unblock if ShutDown() is called
|
||||
case q.waitingForAddCh <- &waitFor{data: item, readyAt: q.clock.Now().Add(duration)}:
|
||||
}
|
||||
}
|
||||
|
||||
// maxWait keeps a max bound on the wait time. It's just insurance against weird things happening.
|
||||
// Checking the queue every 10 seconds isn't expensive and we know that we'll never end up with an
|
||||
// expired item sitting for more than 10 seconds.
|
||||
const maxWait = 10 * time.Second
|
||||
|
||||
// waitingLoop runs until the workqueue is shutdown and keeps a check on the list of items to be added.
|
||||
func (q *delayingType) waitingLoop() {
|
||||
defer utilruntime.HandleCrash()
|
||||
|
||||
// Make a placeholder channel to use when there are no items in our list
|
||||
never := make(<-chan time.Time)
|
||||
|
||||
// Make a timer that expires when the item at the head of the waiting queue is ready
|
||||
var nextReadyAtTimer clock.Timer
|
||||
|
||||
waitingForQueue := &waitForPriorityQueue{}
|
||||
heap.Init(waitingForQueue)
|
||||
|
||||
waitingEntryByData := map[t]*waitFor{}
|
||||
|
||||
for {
|
||||
if q.Interface.ShuttingDown() {
|
||||
return
|
||||
}
|
||||
|
||||
now := q.clock.Now()
|
||||
|
||||
// Add ready entries
|
||||
for waitingForQueue.Len() > 0 {
|
||||
entry := waitingForQueue.Peek().(*waitFor)
|
||||
if entry.readyAt.After(now) {
|
||||
break
|
||||
}
|
||||
|
||||
entry = heap.Pop(waitingForQueue).(*waitFor)
|
||||
q.Add(entry.data)
|
||||
delete(waitingEntryByData, entry.data)
|
||||
}
|
||||
|
||||
// Set up a wait for the first item's readyAt (if one exists)
|
||||
nextReadyAt := never
|
||||
if waitingForQueue.Len() > 0 {
|
||||
if nextReadyAtTimer != nil {
|
||||
nextReadyAtTimer.Stop()
|
||||
}
|
||||
entry := waitingForQueue.Peek().(*waitFor)
|
||||
nextReadyAtTimer = q.clock.NewTimer(entry.readyAt.Sub(now))
|
||||
nextReadyAt = nextReadyAtTimer.C()
|
||||
}
|
||||
|
||||
select {
|
||||
case <-q.stopCh:
|
||||
return
|
||||
|
||||
case <-q.heartbeat.C():
|
||||
// continue the loop, which will add ready items
|
||||
|
||||
case <-nextReadyAt:
|
||||
// continue the loop, which will add ready items
|
||||
|
||||
case waitEntry := <-q.waitingForAddCh:
|
||||
if waitEntry.readyAt.After(q.clock.Now()) {
|
||||
insert(waitingForQueue, waitingEntryByData, waitEntry)
|
||||
} else {
|
||||
q.Add(waitEntry.data)
|
||||
}
|
||||
|
||||
drained := false
|
||||
for !drained {
|
||||
select {
|
||||
case waitEntry := <-q.waitingForAddCh:
|
||||
if waitEntry.readyAt.After(q.clock.Now()) {
|
||||
insert(waitingForQueue, waitingEntryByData, waitEntry)
|
||||
} else {
|
||||
q.Add(waitEntry.data)
|
||||
}
|
||||
default:
|
||||
drained = true
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// insert adds the entry to the priority queue, or updates the readyAt if it already exists in the queue
|
||||
func insert(q *waitForPriorityQueue, knownEntries map[t]*waitFor, entry *waitFor) {
|
||||
// if the entry already exists, update the time only if it would cause the item to be queued sooner
|
||||
existing, exists := knownEntries[entry.data]
|
||||
if exists {
|
||||
if existing.readyAt.After(entry.readyAt) {
|
||||
existing.readyAt = entry.readyAt
|
||||
heap.Fix(q, existing.index)
|
||||
}
|
||||
|
||||
return
|
||||
}
|
||||
|
||||
heap.Push(q, entry)
|
||||
knownEntries[entry.data] = entry
|
||||
}
|
Reference in New Issue
Block a user