ants/pool_func.go

269 lines
7.4 KiB
Go

// 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"
"time"
)
// PoolWithFunc accept 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
// expiryDuration set the expired time (second) of every worker.
expiryDuration time.Duration
// workers is a slice that store the available workers.
workers []*WorkerWithFunc
// release is used to notice the pool to closed itself.
release int32
// lock for synchronous operation.
lock sync.Mutex
// cond for waiting to get a idle worker.
cond *sync.Cond
// poolFunc is the function for processing tasks.
poolFunc func(interface{})
// once makes sure releasing this pool will just be done for one time.
once sync.Once
// workerCache speeds up the obtainment of the an usable worker in function:retrieveWorker.
workerCache sync.Pool
// PanicHandler is used to handle panics from each worker goroutine.
// if nil, panics will be thrown out again from worker goroutines.
PanicHandler func(interface{})
}
// Clear expired workers periodically.
func (p *PoolWithFunc) periodicallyPurge() {
heartbeat := time.NewTicker(p.expiryDuration)
defer heartbeat.Stop()
var expiredWorkers []*WorkerWithFunc
for range heartbeat.C {
if atomic.LoadInt32(&p.release) == CLOSED {
break
}
currentTime := time.Now()
p.lock.Lock()
idleWorkers := p.workers
n := len(idleWorkers)
i := 0
for i < n && currentTime.Sub(idleWorkers[i].recycleTime) > p.expiryDuration {
i++
}
expiredWorkers = append(expiredWorkers[:0], idleWorkers[:i]...)
if i > 0 {
m := copy(idleWorkers, idleWorkers[i:])
for i = m; i < n; i++ {
idleWorkers[i] = nil
}
p.workers = idleWorkers[:m]
}
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
}
}
}
// NewPoolWithFunc generates an instance of ants pool with a specific function.
func NewPoolWithFunc(size int, pf func(interface{})) (*PoolWithFunc, error) {
return NewUltimatePoolWithFunc(size, DEFAULT_CLEAN_INTERVAL_TIME, pf, false)
}
// NewPoolWithFuncPreMalloc generates an instance of ants pool with a specific function and the memory pre-allocation of pool size.
func NewPoolWithFuncPreMalloc(size int, pf func(interface{})) (*PoolWithFunc, error) {
return NewUltimatePoolWithFunc(size, DEFAULT_CLEAN_INTERVAL_TIME, pf, true)
}
// NewUltimatePoolWithFunc generates an instance of ants pool with a specific function and a custom timed task.
func NewUltimatePoolWithFunc(size, expiry int, pf func(interface{}), preAlloc bool) (*PoolWithFunc, error) {
if size <= 0 {
return nil, ErrInvalidPoolSize
}
if expiry <= 0 {
return nil, ErrInvalidPoolExpiry
}
var p *PoolWithFunc
if preAlloc {
p = &PoolWithFunc{
capacity: int32(size),
expiryDuration: time.Duration(expiry) * time.Second,
poolFunc: pf,
workers: make([]*WorkerWithFunc, 0, size),
}
} else {
p = &PoolWithFunc{
capacity: int32(size),
expiryDuration: time.Duration(expiry) * time.Second,
poolFunc: pf,
}
}
p.cond = sync.NewCond(&p.lock)
go p.periodicallyPurge()
return p, nil
}
//---------------------------------------------------------------------------
// Invoke submits a task to pool.
func (p *PoolWithFunc) Invoke(args interface{}) error {
if atomic.LoadInt32(&p.release) == CLOSED {
return ErrPoolClosed
}
p.retrieveWorker().args <- args
return nil
}
// Running returns the number of the currently running goroutines.
func (p *PoolWithFunc) Running() int {
return int(atomic.LoadInt32(&p.running))
}
// Free returns a available goroutines to work.
func (p *PoolWithFunc) Free() int {
return int(atomic.LoadInt32(&p.capacity) - atomic.LoadInt32(&p.running))
}
// Cap returns the capacity of this pool.
func (p *PoolWithFunc) Cap() int {
return int(atomic.LoadInt32(&p.capacity))
}
// Tune change the capacity of this pool.
func (p *PoolWithFunc) Tune(size int) {
if p.Cap() == size {
return
}
atomic.StoreInt32(&p.capacity, int32(size))
diff := p.Running() - size
for i := 0; i < diff; i++ {
p.retrieveWorker().args <- nil
}
}
// Release Closed this pool.
func (p *PoolWithFunc) Release() error {
p.once.Do(func() {
atomic.StoreInt32(&p.release, 1)
p.lock.Lock()
idleWorkers := p.workers
for i, w := range idleWorkers {
w.args <- nil
idleWorkers[i] = nil
}
p.workers = nil
p.lock.Unlock()
})
return nil
}
//---------------------------------------------------------------------------
// incRunning increases the number of the currently running goroutines.
func (p *PoolWithFunc) incRunning() {
atomic.AddInt32(&p.running, 1)
}
// decRunning decreases the number of the currently running goroutines.
func (p *PoolWithFunc) decRunning() {
atomic.AddInt32(&p.running, -1)
}
// retrieveWorker returns a available worker to run the tasks.
func (p *PoolWithFunc) retrieveWorker() *WorkerWithFunc {
var w *WorkerWithFunc
p.lock.Lock()
idleWorkers := p.workers
n := len(idleWorkers) - 1
RESUME:
if n >= 0 {
w = idleWorkers[n]
idleWorkers[n] = nil
p.workers = idleWorkers[:n]
p.lock.Unlock()
} else if p.Running() < p.Cap() {
p.lock.Unlock()
if cacheWorker := p.workerCache.Get(); cacheWorker != nil {
w = cacheWorker.(*WorkerWithFunc)
} else {
w = &WorkerWithFunc{
pool: p,
args: make(chan interface{}, workerChanCap),
}
}
w.run()
} else {
for {
if p.Running() == 0 {
goto RESUME
}
p.cond.Wait()
l := len(p.workers) - 1
if l < 0 {
continue
}
w = p.workers[l]
p.workers[l] = nil
p.workers = p.workers[:l]
break
}
p.lock.Unlock()
}
return w
}
// revertWorker puts a worker back into free pool, recycling the goroutines.
func (p *PoolWithFunc) revertWorker(worker *WorkerWithFunc) bool {
if atomic.LoadInt32(&p.release) == CLOSED {
return false
}
worker.recycleTime = time.Now()
p.lock.Lock()
p.workers = append(p.workers, worker)
// Notify the invoker stuck in 'retrieveWorker()' of there is an available worker in the worker queue.
p.cond.Signal()
p.lock.Unlock()
return true
}