forgejo/modules/queue/queue_disk_channel.go
zeripath 92b715e0f2
Attempt to prevent the deadlock in the QueueDiskChannel Test again (#18415)
* Attempt to prevent the deadlock in the QueueDiskChannel Test again

This time we're going to adjust the pause tests to only test the right
flag.

* Only switch off pushback once we know that we are not pushing anything else
* Ensure full redirection occurs
* More nicely handle a closed datachan
* And handle similar problems in queue_channel_test

Signed-off-by: Andrew Thornton <art27@cantab.net>
2022-01-29 11:37:08 +00:00

342 lines
9.4 KiB
Go

// Copyright 2019 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package queue
import (
"context"
"fmt"
"sync"
"sync/atomic"
"time"
"code.gitea.io/gitea/modules/log"
)
// PersistableChannelQueueType is the type for persistable queue
const PersistableChannelQueueType Type = "persistable-channel"
// PersistableChannelQueueConfiguration is the configuration for a PersistableChannelQueue
type PersistableChannelQueueConfiguration struct {
Name string
DataDir string
BatchLength int
QueueLength int
Timeout time.Duration
MaxAttempts int
Workers int
MaxWorkers int
BlockTimeout time.Duration
BoostTimeout time.Duration
BoostWorkers int
}
// PersistableChannelQueue wraps a channel queue and level queue together
// The disk level queue will be used to store data at shutdown and terminate - and will be restored
// on start up.
type PersistableChannelQueue struct {
channelQueue *ChannelQueue
delayedStarter
lock sync.Mutex
closed chan struct{}
}
// NewPersistableChannelQueue creates a wrapped batched channel queue with persistable level queue backend when shutting down
// This differs from a wrapped queue in that the persistent queue is only used to persist at shutdown/terminate
func NewPersistableChannelQueue(handle HandlerFunc, cfg, exemplar interface{}) (Queue, error) {
configInterface, err := toConfig(PersistableChannelQueueConfiguration{}, cfg)
if err != nil {
return nil, err
}
config := configInterface.(PersistableChannelQueueConfiguration)
queue := &PersistableChannelQueue{
closed: make(chan struct{}),
}
wrappedHandle := func(data ...Data) (failed []Data) {
for _, unhandled := range handle(data...) {
if fail := queue.PushBack(unhandled); fail != nil {
failed = append(failed, fail)
}
}
return
}
channelQueue, err := NewChannelQueue(wrappedHandle, ChannelQueueConfiguration{
WorkerPoolConfiguration: WorkerPoolConfiguration{
QueueLength: config.QueueLength,
BatchLength: config.BatchLength,
BlockTimeout: config.BlockTimeout,
BoostTimeout: config.BoostTimeout,
BoostWorkers: config.BoostWorkers,
MaxWorkers: config.MaxWorkers,
},
Workers: config.Workers,
Name: config.Name + "-channel",
}, exemplar)
if err != nil {
return nil, err
}
// the level backend only needs temporary workers to catch up with the previously dropped work
levelCfg := LevelQueueConfiguration{
ByteFIFOQueueConfiguration: ByteFIFOQueueConfiguration{
WorkerPoolConfiguration: WorkerPoolConfiguration{
QueueLength: config.QueueLength,
BatchLength: config.BatchLength,
BlockTimeout: 1 * time.Second,
BoostTimeout: 5 * time.Minute,
BoostWorkers: 1,
MaxWorkers: 5,
},
Workers: 0,
Name: config.Name + "-level",
},
DataDir: config.DataDir,
}
levelQueue, err := NewLevelQueue(wrappedHandle, levelCfg, exemplar)
if err == nil {
queue.channelQueue = channelQueue.(*ChannelQueue)
queue.delayedStarter = delayedStarter{
internal: levelQueue.(*LevelQueue),
name: config.Name,
}
_ = GetManager().Add(queue, PersistableChannelQueueType, config, exemplar)
return queue, nil
}
if IsErrInvalidConfiguration(err) {
// Retrying ain't gonna make this any better...
return nil, ErrInvalidConfiguration{cfg: cfg}
}
queue.channelQueue = channelQueue.(*ChannelQueue)
queue.delayedStarter = delayedStarter{
cfg: levelCfg,
underlying: LevelQueueType,
timeout: config.Timeout,
maxAttempts: config.MaxAttempts,
name: config.Name,
}
_ = GetManager().Add(queue, PersistableChannelQueueType, config, exemplar)
return queue, nil
}
// Name returns the name of this queue
func (q *PersistableChannelQueue) Name() string {
return q.delayedStarter.name
}
// Push will push the indexer data to queue
func (q *PersistableChannelQueue) Push(data Data) error {
select {
case <-q.closed:
return q.internal.Push(data)
default:
return q.channelQueue.Push(data)
}
}
// PushBack will push the indexer data to queue
func (q *PersistableChannelQueue) PushBack(data Data) error {
select {
case <-q.closed:
if pbr, ok := q.internal.(PushBackable); ok {
return pbr.PushBack(data)
}
return q.internal.Push(data)
default:
return q.channelQueue.Push(data)
}
}
// Run starts to run the queue
func (q *PersistableChannelQueue) Run(atShutdown, atTerminate func(func())) {
log.Debug("PersistableChannelQueue: %s Starting", q.delayedStarter.name)
_ = q.channelQueue.AddWorkers(q.channelQueue.workers, 0)
q.lock.Lock()
if q.internal == nil {
err := q.setInternal(atShutdown, q.channelQueue.handle, q.channelQueue.exemplar)
q.lock.Unlock()
if err != nil {
log.Fatal("Unable to create internal queue for %s Error: %v", q.Name(), err)
return
}
} else {
q.lock.Unlock()
}
atShutdown(q.Shutdown)
atTerminate(q.Terminate)
if lq, ok := q.internal.(*LevelQueue); ok && lq.byteFIFO.Len(lq.shutdownCtx) != 0 {
// Just run the level queue - we shut it down once it's flushed
go q.internal.Run(func(_ func()) {}, func(_ func()) {})
go func() {
for !q.IsEmpty() {
_ = q.internal.Flush(0)
select {
case <-time.After(100 * time.Millisecond):
case <-q.internal.(*LevelQueue).shutdownCtx.Done():
log.Warn("LevelQueue: %s shut down before completely flushed", q.internal.(*LevelQueue).Name())
return
}
}
log.Debug("LevelQueue: %s flushed so shutting down", q.internal.(*LevelQueue).Name())
q.internal.(*LevelQueue).Shutdown()
GetManager().Remove(q.internal.(*LevelQueue).qid)
}()
} else {
log.Debug("PersistableChannelQueue: %s Skipping running the empty level queue", q.delayedStarter.name)
q.internal.(*LevelQueue).Shutdown()
GetManager().Remove(q.internal.(*LevelQueue).qid)
}
}
// Flush flushes the queue and blocks till the queue is empty
func (q *PersistableChannelQueue) Flush(timeout time.Duration) error {
var ctx context.Context
var cancel context.CancelFunc
if timeout > 0 {
ctx, cancel = context.WithTimeout(context.Background(), timeout)
} else {
ctx, cancel = context.WithCancel(context.Background())
}
defer cancel()
return q.FlushWithContext(ctx)
}
// FlushWithContext flushes the queue and blocks till the queue is empty
func (q *PersistableChannelQueue) FlushWithContext(ctx context.Context) error {
errChan := make(chan error, 1)
go func() {
errChan <- q.channelQueue.FlushWithContext(ctx)
}()
go func() {
q.lock.Lock()
if q.internal == nil {
q.lock.Unlock()
errChan <- fmt.Errorf("not ready to flush internal queue %s yet", q.Name())
return
}
q.lock.Unlock()
errChan <- q.internal.FlushWithContext(ctx)
}()
err1 := <-errChan
err2 := <-errChan
if err1 != nil {
return err1
}
return err2
}
// IsEmpty checks if a queue is empty
func (q *PersistableChannelQueue) IsEmpty() bool {
if !q.channelQueue.IsEmpty() {
return false
}
q.lock.Lock()
defer q.lock.Unlock()
if q.internal == nil {
return false
}
return q.internal.IsEmpty()
}
// IsPaused returns if the pool is paused
func (q *PersistableChannelQueue) IsPaused() bool {
return q.channelQueue.IsPaused()
}
// IsPausedIsResumed returns if the pool is paused and a channel that is closed when it is resumed
func (q *PersistableChannelQueue) IsPausedIsResumed() (<-chan struct{}, <-chan struct{}) {
return q.channelQueue.IsPausedIsResumed()
}
// Pause pauses the WorkerPool
func (q *PersistableChannelQueue) Pause() {
q.channelQueue.Pause()
q.lock.Lock()
defer q.lock.Unlock()
if q.internal == nil {
return
}
pausable, ok := q.internal.(Pausable)
if !ok {
return
}
pausable.Pause()
}
// Resume resumes the WorkerPool
func (q *PersistableChannelQueue) Resume() {
q.channelQueue.Resume()
q.lock.Lock()
defer q.lock.Unlock()
if q.internal == nil {
return
}
pausable, ok := q.internal.(Pausable)
if !ok {
return
}
pausable.Resume()
}
// Shutdown processing this queue
func (q *PersistableChannelQueue) Shutdown() {
log.Trace("PersistableChannelQueue: %s Shutting down", q.delayedStarter.name)
q.lock.Lock()
select {
case <-q.closed:
q.lock.Unlock()
return
default:
}
q.channelQueue.Shutdown()
if q.internal != nil {
q.internal.(*LevelQueue).Shutdown()
}
close(q.closed)
q.lock.Unlock()
log.Trace("PersistableChannelQueue: %s Cancelling pools", q.delayedStarter.name)
q.channelQueue.baseCtxCancel()
q.internal.(*LevelQueue).baseCtxCancel()
log.Trace("PersistableChannelQueue: %s Waiting til done", q.delayedStarter.name)
q.channelQueue.Wait()
q.internal.(*LevelQueue).Wait()
// Redirect all remaining data in the chan to the internal channel
log.Trace("PersistableChannelQueue: %s Redirecting remaining data", q.delayedStarter.name)
close(q.channelQueue.dataChan)
for data := range q.channelQueue.dataChan {
_ = q.internal.Push(data)
atomic.AddInt64(&q.channelQueue.numInQueue, -1)
}
log.Trace("PersistableChannelQueue: %s Done Redirecting remaining data", q.delayedStarter.name)
log.Debug("PersistableChannelQueue: %s Shutdown", q.delayedStarter.name)
}
// Terminate this queue and close the queue
func (q *PersistableChannelQueue) Terminate() {
log.Trace("PersistableChannelQueue: %s Terminating", q.delayedStarter.name)
q.Shutdown()
q.lock.Lock()
defer q.lock.Unlock()
q.channelQueue.Terminate()
if q.internal != nil {
q.internal.(*LevelQueue).Terminate()
}
log.Debug("PersistableChannelQueue: %s Terminated", q.delayedStarter.name)
}
func init() {
queuesMap[PersistableChannelQueueType] = NewPersistableChannelQueue
}