ants/pool.go

106 lines
1.8 KiB
Go

package ants
import (
"runtime"
"sync/atomic"
"math"
"sync"
)
type sig struct{}
type f func()
type Pool struct {
capacity int32
free int32
tasks chan f
workers chan *Worker
destroy chan sig
m sync.Mutex
}
func NewPool(size int) *Pool {
p := &Pool{
capacity: int32(size),
free: int32(size),
tasks: make(chan f, math.MaxInt32),
//workers: &sync.Pool{New: func() interface{} { return &Worker{} }},
workers: make(chan *Worker, size),
destroy: make(chan sig, runtime.GOMAXPROCS(-1)),
}
p.loop()
return p
}
//-------------------------------------------------------------------------
func (p *Pool) loop() {
for i := 0; i < runtime.GOMAXPROCS(-1); i++ {
go func() {
for {
select {
case task := <-p.tasks:
p.getWorker().sendTask(task)
case <-p.destroy:
return
}
}
}()
}
}
func (p *Pool) Push(task f) error {
if len(p.destroy) > 0 {
return nil
}
p.tasks <- task
return nil
}
func (p *Pool) Running() int32 {
return atomic.LoadInt32(&p.capacity) - atomic.LoadInt32(&p.free)
}
func (p *Pool) Free() int32 {
return atomic.LoadInt32(&p.free)
}
func (p *Pool) Cap() int32 {
return atomic.LoadInt32(&p.capacity)
}
func (p *Pool) Destroy() error {
p.m.Lock()
defer p.m.Unlock()
for i := 0; i < runtime.GOMAXPROCS(-1)+1; i++ {
p.destroy <- sig{}
}
return nil
}
//-------------------------------------------------------------------------
func (p *Pool) reachLimit() bool {
return p.Running() >= p.Cap()
}
func (p *Pool) newWorker() *Worker {
worker := &Worker{
pool: p,
task: make(chan f),
exit: make(chan sig),
}
worker.run()
atomic.AddInt32(&p.free, -1)
return worker
}
func (p *Pool) getWorker() *Worker {
var worker *Worker
if p.reachLimit() || p.Free() > 0 {
worker = <-p.workers
}
worker = p.newWorker()
return worker
}