| // Licensed to the Apache Software Foundation (ASF) under one or more |
| // contributor license agreements. See the NOTICE file distributed with |
| // this work for additional information regarding copyright ownership. |
| // The ASF licenses this file to You 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 queue |
| |
| import ( |
| "sync" |
| "time" |
| |
| "github.com/apache/dubbo-kubernetes/pkg/core/logger" |
| ) |
| |
| // Task to be performed. |
| type Task func() error |
| |
| // Instance of work tickets processed using a rate-limiting loop |
| type Instance interface { |
| // Push a task. |
| Push(task Task) |
| // Run the loop until a signal on the channel |
| Run(<-chan struct{}) |
| } |
| |
| type queueImpl struct { |
| delay time.Duration |
| tasks []Task |
| cond *sync.Cond |
| closing bool |
| } |
| |
| // NewQueue instantiates a queue with a processing function |
| func NewQueue(errorDelay time.Duration) Instance { |
| return &queueImpl{ |
| delay: errorDelay, |
| tasks: make([]Task, 0), |
| closing: false, |
| cond: sync.NewCond(&sync.Mutex{}), |
| } |
| } |
| |
| func (q *queueImpl) Push(item Task) { |
| q.cond.L.Lock() |
| defer q.cond.L.Unlock() |
| if !q.closing { |
| q.tasks = append(q.tasks, item) |
| } |
| q.cond.Signal() |
| } |
| |
| func (q *queueImpl) Run(stop <-chan struct{}) { |
| go func() { |
| <-stop |
| q.cond.L.Lock() |
| q.cond.Signal() |
| q.closing = true |
| q.cond.L.Unlock() |
| }() |
| |
| for { |
| q.cond.L.Lock() |
| for !q.closing && len(q.tasks) == 0 { |
| q.cond.Wait() |
| } |
| |
| if len(q.tasks) == 0 { |
| q.cond.L.Unlock() |
| // We must be shutting down. |
| return |
| } |
| |
| var task Task |
| task, q.tasks = q.tasks[0], q.tasks[1:] |
| q.cond.L.Unlock() |
| |
| if err := task(); err != nil { |
| logger.Sugar().Infof("Work item handle failed (%v), retry after delay %v", err, q.delay) |
| time.AfterFunc(q.delay, func() { |
| q.Push(task) |
| }) |
| } |
| } |
| } |