gf/os/grpool/grpool.go
2019-10-28 17:16:50 +08:00

128 lines
2.9 KiB
Go

// Copyright 2017-2019 gf Author(https://github.com/gogf/gf). All Rights Reserved.
//
// This Source Code Form is subject to the terms of the MIT License.
// If a copy of the MIT was not distributed with this file,
// You can obtain one at https://github.com/gogf/gf.
// Package grpool implements a goroutine reusable pool.
package grpool
import (
"errors"
"github.com/gogf/gf/container/glist"
"github.com/gogf/gf/container/gtype"
)
// Goroutine Pool
type Pool struct {
limit int // Max goroutine count limit.
count *gtype.Int // Current running goroutine count.
list *glist.List // Job list for asynchronous job adding purpose.
closed *gtype.Bool // Is pool closed or not.
}
// Default goroutine pool.
var pool = New()
// New creates and returns a new goroutine pool object.
// The parameter <limit> is used to limit the max goroutine count,
// which is not limited in default.
func New(limit ...int) *Pool {
p := &Pool{
limit: -1,
count: gtype.NewInt(),
list: glist.New(true),
closed: gtype.NewBool(),
}
if len(limit) > 0 && limit[0] > 0 {
p.limit = limit[0]
}
return p
}
// Add pushes a new job to the pool using default goroutine pool.
// The job will be executed asynchronously.
func Add(f func()) error {
return pool.Add(f)
}
// Size returns current goroutine count of default goroutine pool.
func Size() int {
return pool.Size()
}
// Jobs returns current job count of default goroutine pool.
func Jobs() int {
return pool.Jobs()
}
// Add pushes a new job to the pool.
// The job will be executed asynchronously.
func (p *Pool) Add(f func()) error {
for p.closed.Val() {
return errors.New("pool closed")
}
p.list.PushFront(f)
// Check whether fork new goroutine or not.
var n int
for {
n = p.count.Val()
if p.limit != -1 && n >= p.limit {
// No need fork new goroutine.
return nil
}
if p.count.Cas(n, n+1) {
// Use CAS to guarantee atomicity.
break
}
}
p.fork()
return nil
}
// Cap returns the capacity of the pool.
// This capacity is defined when pool is created.
// It returns -1 if there's no limit.
func (p *Pool) Cap() int {
return p.limit
}
// Size returns current goroutine count of the pool.
func (p *Pool) Size() int {
return p.count.Val()
}
// Jobs returns current job count of the pool.
// Note that, it does not return worker/goroutine count but the job/task count.
func (p *Pool) Jobs() int {
return p.list.Size()
}
// fork creates a new goroutine worker.
// Note that the worker dies if the job function panics.
func (p *Pool) fork() {
go func() {
defer p.count.Add(-1)
var job interface{}
for !p.closed.Val() {
if job = p.list.PopBack(); job != nil {
job.(func())()
} else {
return
}
}
}()
}
// IsClosed returns if pool is closed.
func (p *Pool) IsClosed() bool {
return p.closed.Val()
}
// Close closes the goroutine pool, which makes all goroutines exit.
func (p *Pool) Close() {
p.closed.Set(true)
}