| /* |
| * 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 gopool |
| |
| import ( |
| "context" |
| "github.com/apache/servicecomb-service-center/pkg/log" |
| "github.com/apache/servicecomb-service-center/pkg/util" |
| "sync" |
| "time" |
| ) |
| |
| var GlobalConfig = Configure() |
| |
| var defaultGo *Pool |
| |
| func init() { |
| defaultGo = New(context.Background()) |
| } |
| |
| type Config struct { |
| Concurrent int |
| IdleTimeout time.Duration |
| } |
| |
| func (c *Config) Workers(max int) *Config { |
| c.Concurrent = max |
| return c |
| } |
| |
| func (c *Config) Idle(time time.Duration) *Config { |
| c.IdleTimeout = time |
| return c |
| } |
| |
| func Configure() *Config { |
| return &Config{ |
| Concurrent: 1000, |
| IdleTimeout: 60 * time.Second, |
| } |
| } |
| |
| type Pool struct { |
| Cfg *Config |
| |
| // job context |
| ctx context.Context |
| cancel context.CancelFunc |
| // pending is the chan to block Pool.Do() when go pool is full |
| pending chan func(ctx context.Context) |
| // workers is the counter of the worker |
| workers chan struct{} |
| |
| mux sync.RWMutex |
| wg sync.WaitGroup |
| closed bool |
| } |
| |
| func (g *Pool) execute(f func(ctx context.Context)) { |
| defer log.Recover() |
| f(g.ctx) |
| } |
| |
| // Do pick one idle goroutine to do the f once |
| func (g *Pool) Do(f func(context.Context)) *Pool { |
| defer log.Recover() |
| select { |
| case g.pending <- f: // block if workers are busy |
| case g.workers <- struct{}{}: |
| g.wg.Add(1) |
| go g.loop(f) |
| } |
| return g |
| } |
| |
| func (g *Pool) loop(f func(context.Context)) { |
| defer g.wg.Done() |
| defer func() { <-g.workers }() |
| |
| timer := time.NewTimer(g.Cfg.IdleTimeout) |
| defer timer.Stop() |
| for { |
| g.execute(f) |
| |
| select { |
| case <-timer.C: |
| return |
| case f = <-g.pending: |
| if f == nil { |
| return |
| } |
| util.ResetTimer(timer, g.Cfg.IdleTimeout) |
| } |
| } |
| } |
| |
| // Close will call context.Cancel(), so all goroutines maybe exit when job does not complete |
| func (g *Pool) Close(grace bool) { |
| g.mux.Lock() |
| if g.closed { |
| g.mux.Unlock() |
| return |
| } |
| g.closed = true |
| g.mux.Unlock() |
| |
| close(g.pending) |
| close(g.workers) |
| g.cancel() |
| if grace { |
| g.wg.Wait() |
| } |
| } |
| |
| // Done will wait for all goroutines complete the jobs and then close the pool |
| func (g *Pool) Done() { |
| g.mux.Lock() |
| if g.closed { |
| g.mux.Unlock() |
| return |
| } |
| g.closed = true |
| g.mux.Unlock() |
| |
| close(g.pending) |
| close(g.workers) |
| g.wg.Wait() |
| } |
| |
| func New(ctx context.Context, cfgs ...*Config) *Pool { |
| ctx, cancel := context.WithCancel(ctx) |
| if len(cfgs) == 0 { |
| cfgs = append(cfgs, GlobalConfig) |
| } |
| cfg := cfgs[0] |
| gr := &Pool{ |
| Cfg: cfg, |
| ctx: ctx, |
| cancel: cancel, |
| pending: make(chan func(context.Context)), |
| workers: make(chan struct{}, cfg.Concurrent), |
| } |
| return gr |
| } |
| |
| func Go(f func(context.Context)) { |
| defaultGo.Do(f) |
| } |
| |
| func CloseAndWait() { |
| defaultGo.Close(true) |
| log.Debugf("all goroutines exited") |
| } |