ants/pool_func.go

326 lines
9.0 KiB
Go
Raw Normal View History

// MIT License
// Copyright (c) 2018 Andy Pan
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
package ants
import (
"sync"
"sync/atomic"
2018-07-06 09:39:24 +03:00
"time"
2019-10-04 06:24:13 +03:00
"github.com/panjf2000/ants/v2/internal"
)
2020-04-08 08:16:14 +03:00
// PoolWithFunc accepts the tasks from client,
// it limits the total of goroutines to a given number by recycling goroutines.
type PoolWithFunc struct {
// capacity of the pool.
capacity int32
// running is the number of the currently running goroutines.
running int32
2021-05-23 15:23:43 +03:00
// lock for protecting the worker queue.
lock sync.Locker
// workers is a slice that store the available workers.
workers []*goWorkerWithFunc
// state is used to notice the pool to closed itself.
state int32
// cond for waiting to get an idle worker.
2018-09-29 05:19:17 +03:00
cond *sync.Cond
2018-09-30 04:41:47 +03:00
2019-02-02 05:32:51 +03:00
// poolFunc is the function for processing tasks.
poolFunc func(interface{})
2018-05-24 13:30:58 +03:00
// workerCache speeds up the obtainment of a usable worker in function:retrieveWorker.
workerCache sync.Pool
2019-01-26 16:45:49 +03:00
// blockingNum is the number of the goroutines already been blocked on pool.Submit, protected by pool.lock
blockingNum int
options *Options
}
2020-08-12 07:11:51 +03:00
// purgePeriodically clears expired workers periodically which runs in an individual goroutine, as a scavenger.
func (p *PoolWithFunc) purgePeriodically() {
heartbeat := time.NewTicker(p.options.ExpiryDuration)
2018-11-19 05:57:53 +03:00
defer heartbeat.Stop()
var expiredWorkers []*goWorkerWithFunc
2018-07-24 17:30:37 +03:00
for range heartbeat.C {
if p.IsClosed() {
break
}
2018-07-24 17:30:37 +03:00
currentTime := time.Now()
p.lock.Lock()
idleWorkers := p.workers
n := len(idleWorkers)
var i int
for i = 0; i < n && currentTime.Sub(idleWorkers[i].recycleTime) > p.options.ExpiryDuration; i++ {
2018-07-06 09:39:24 +03:00
}
expiredWorkers = append(expiredWorkers[:0], idleWorkers[:i]...)
if i > 0 {
m := copy(idleWorkers, idleWorkers[i:])
for i = m; i < n; i++ {
idleWorkers[i] = nil
2018-08-08 13:08:06 +03:00
}
p.workers = idleWorkers[:m]
2018-07-24 17:30:37 +03:00
}
p.lock.Unlock()
// Notify obsolete workers to stop.
// This notification must be outside the p.lock, since w.task
// may be blocking and may consume a lot of time if many workers
// are located on non-local CPUs.
for i, w := range expiredWorkers {
w.args <- nil
expiredWorkers[i] = nil
}
// There might be a situation that all workers have been cleaned up(no worker is running)
// while some invokers still get stuck in "p.cond.Wait()",
2021-05-23 15:23:43 +03:00
// then it ought to wake all those invokers.
if p.Running() == 0 {
p.cond.Broadcast()
}
2018-07-24 17:30:37 +03:00
}
2018-07-06 09:39:24 +03:00
}
2018-08-04 06:12:06 +03:00
// NewPoolWithFunc generates an instance of ants pool with a specific function.
func NewPoolWithFunc(size int, pf func(interface{}), options ...Option) (*PoolWithFunc, error) {
if size <= 0 {
size = -1
2018-07-12 19:11:42 +03:00
}
if pf == nil {
return nil, ErrLackPoolFunc
}
2020-03-12 19:02:19 +03:00
opts := loadOptions(options...)
if expiry := opts.ExpiryDuration; expiry < 0 {
2018-07-12 19:11:42 +03:00
return nil, ErrInvalidPoolExpiry
} else if expiry == 0 {
2019-10-04 06:24:13 +03:00
opts.ExpiryDuration = DefaultCleanIntervalTime
}
2020-03-12 19:02:19 +03:00
if opts.Logger == nil {
opts.Logger = defaultLogger
}
2019-10-04 06:24:13 +03:00
p := &PoolWithFunc{
capacity: int32(size),
poolFunc: pf,
lock: internal.NewSpinLock(),
options: opts,
2019-10-04 06:24:13 +03:00
}
2019-10-24 17:32:12 +03:00
p.workerCache.New = func() interface{} {
return &goWorkerWithFunc{
pool: p,
args: make(chan interface{}, workerChanCap),
}
2019-10-05 21:02:40 +03:00
}
if p.options.PreAlloc {
if size == -1 {
return nil, ErrInvalidPreAllocSize
}
2019-10-04 06:24:13 +03:00
p.workers = make([]*goWorkerWithFunc, 0, size)
}
2019-09-27 15:51:46 +03:00
p.cond = sync.NewCond(p.lock)
// Start a goroutine to clean up expired workers periodically.
2020-08-12 07:11:51 +03:00
go p.purgePeriodically()
return p, nil
}
2019-01-25 17:01:25 +03:00
//---------------------------------------------------------------------------
// Invoke submits a task to pool.
//
// Note that you are allowed to call Pool.Invoke() from the current Pool.Invoke(),
// but what calls for special attention is that you will get blocked with the latest
// Pool.Invoke() call once the current Pool runs out of its capacity, and to avoid this,
// you should instantiate a PoolWithFunc with ants.WithNonblocking(true).
func (p *PoolWithFunc) Invoke(args interface{}) error {
if p.IsClosed() {
return ErrPoolClosed
}
2019-10-04 06:24:13 +03:00
var w *goWorkerWithFunc
if w = p.retrieveWorker(); w == nil {
return ErrPoolOverload
}
2019-10-04 06:24:13 +03:00
w.args <- args
return nil
}
// Running returns the amount of the currently running goroutines.
2018-05-22 07:01:00 +03:00
func (p *PoolWithFunc) Running() int {
return int(atomic.LoadInt32(&p.running))
}
// Free returns the amount of available goroutines to work, -1 indicates this pool is unlimited.
2018-05-22 07:01:00 +03:00
func (p *PoolWithFunc) Free() int {
c := p.Cap()
if c < 0 {
return -1
}
return c - p.Running()
}
2018-08-04 06:12:06 +03:00
// Cap returns the capacity of this pool.
2018-05-22 07:01:00 +03:00
func (p *PoolWithFunc) Cap() int {
return int(atomic.LoadInt32(&p.capacity))
}
2021-05-23 15:23:43 +03:00
// Tune changes the capacity of this pool, note that it is noneffective to the infinite or pre-allocation pool.
func (p *PoolWithFunc) Tune(size int) {
if capacity := p.Cap(); capacity == -1 || size <= 0 || size == capacity || p.options.PreAlloc {
2018-07-15 21:33:43 +03:00
return
2018-07-15 21:43:38 +03:00
}
atomic.StoreInt32(&p.capacity, int32(size))
}
// IsClosed indicates whether the pool is closed.
func (p *PoolWithFunc) IsClosed() bool {
return atomic.LoadInt32(&p.state) == CLOSED
}
2021-05-23 15:23:43 +03:00
// Release closes this pool and releases the worker queue.
2019-08-19 11:35:58 +03:00
func (p *PoolWithFunc) Release() {
atomic.StoreInt32(&p.state, CLOSED)
p.lock.Lock()
idleWorkers := p.workers
for _, w := range idleWorkers {
w.args <- nil
}
p.workers = nil
p.lock.Unlock()
// There might be some callers waiting in retrieveWorker(), so we need to wake them up to prevent
// those callers blocking infinitely.
p.cond.Broadcast()
}
2021-05-23 15:23:43 +03:00
// Reboot reboots a closed pool.
func (p *PoolWithFunc) Reboot() {
if atomic.CompareAndSwapInt32(&p.state, CLOSED, OPENED) {
2020-08-12 07:11:51 +03:00
go p.purgePeriodically()
}
2018-07-15 20:21:23 +03:00
}
2019-01-25 17:01:25 +03:00
//---------------------------------------------------------------------------
2018-08-04 06:12:06 +03:00
// incRunning increases the number of the currently running goroutines.
2018-08-03 14:28:46 +03:00
func (p *PoolWithFunc) incRunning() {
2018-07-31 06:05:05 +03:00
atomic.AddInt32(&p.running, 1)
}
2018-08-04 06:12:06 +03:00
// decRunning decreases the number of the currently running goroutines.
2018-08-03 14:28:46 +03:00
func (p *PoolWithFunc) decRunning() {
2018-07-31 06:05:05 +03:00
atomic.AddInt32(&p.running, -1)
}
// retrieveWorker returns an available worker to run the tasks.
2020-05-08 15:13:35 +03:00
func (p *PoolWithFunc) retrieveWorker() (w *goWorkerWithFunc) {
spawnWorker := func() {
2019-10-05 21:02:40 +03:00
w = p.workerCache.Get().(*goWorkerWithFunc)
w.run()
}
p.lock.Lock()
2018-07-15 20:21:23 +03:00
idleWorkers := p.workers
n := len(idleWorkers) - 1
2021-05-23 15:23:43 +03:00
if n >= 0 { // first try to fetch the worker from the queue
2018-07-15 20:21:23 +03:00
w = idleWorkers[n]
idleWorkers[n] = nil
p.workers = idleWorkers[:n]
2019-01-26 23:05:58 +03:00
p.lock.Unlock()
} else if capacity := p.Cap(); capacity == -1 || capacity > p.Running() {
2021-05-23 15:23:43 +03:00
// if the worker queue is empty and we don't run out of the pool capacity,
// then just spawn a new worker goroutine.
p.lock.Unlock()
spawnWorker()
2021-05-23 15:23:43 +03:00
} else { // otherwise, we'll have to keep them blocked and wait for at least one worker to be put back into pool.
if p.options.Nonblocking {
p.lock.Unlock()
2020-05-08 15:13:35 +03:00
return
}
2021-05-23 15:23:43 +03:00
retry:
if p.options.MaxBlockingTasks != 0 && p.blockingNum >= p.options.MaxBlockingTasks {
p.lock.Unlock()
2020-05-08 15:13:35 +03:00
return
}
p.blockingNum++
2021-05-23 15:23:43 +03:00
p.cond.Wait() // block and wait for an available worker
p.blockingNum--
var nw int
2021-05-23 15:23:43 +03:00
if nw = p.Running(); nw == 0 { // awakened by the scavenger
p.lock.Unlock()
if !p.IsClosed() {
spawnWorker()
}
2020-05-08 15:13:35 +03:00
return
}
l := len(p.workers) - 1
if l < 0 {
if nw < capacity {
p.lock.Unlock()
spawnWorker()
return
}
2021-05-23 15:23:43 +03:00
goto retry
2018-09-29 09:58:58 +03:00
}
w = p.workers[l]
p.workers[l] = nil
p.workers = p.workers[:l]
p.lock.Unlock()
}
2020-05-08 15:13:35 +03:00
return
}
// revertWorker puts a worker back into free pool, recycling the goroutines.
func (p *PoolWithFunc) revertWorker(worker *goWorkerWithFunc) bool {
if capacity := p.Cap(); (capacity > 0 && p.Running() > capacity) || p.IsClosed() {
p.cond.Broadcast()
2019-04-13 05:35:39 +03:00
return false
}
2018-07-06 09:39:24 +03:00
worker.recycleTime = time.Now()
p.lock.Lock()
2020-10-15 06:35:55 +03:00
// To avoid memory leaks, add a double check in the lock scope.
// Issue: https://github.com/panjf2000/ants/issues/113
if p.IsClosed() {
2020-10-15 06:35:55 +03:00
p.lock.Unlock()
return false
}
p.workers = append(p.workers, worker)
2019-08-25 09:25:09 +03:00
// Notify the invoker stuck in 'retrieveWorker()' of there is an available worker in the worker queue.
2018-09-29 05:19:17 +03:00
p.cond.Signal()
p.lock.Unlock()
2019-04-13 05:35:39 +03:00
return true
}