golang默认定时器是通过time模块提供的，不管是golang,libev,libevent也好，定时器都是通过最小堆实现的，导致加入定时器时间复杂度为O(lgn)，在需要大量定时器时效率较低，所以Linux提供了基于时间轮的实现，我们本次提供的
定时器实现就是标准的Linux时间轮实现方式。当然，我是把Skynet(https://github.com/cloudwu/skynet/blob/master/skynet-src/skynet_timer.c)的定时器移植了过来，偷窃无罪。。。
贴一张Linux时间轮的数据结构，如果比较陌生的话可以参考一下两篇文章：
1.http://www.ibm.com/developerworks/cn/linux/l-cn-timers/
2.http://blog.csdn.net/lonewolfxw/article/details/8034395
先看一下如何使用
package timer
import (
"fmt"
"sync/atomic"
"testing"
"time"
)
var sum int32 = 0
var N int32 = 300
var tt *Timer
func now() {
fmt.Println(time.Now().Format("2006-01-02 15:04:05"))
atomic.AddInt32(&sum, 1)
v := atomic.LoadInt32(&sum)
if v == 2*N {
tt.Stop()
}
}
func TestTimer(t *testing.T) {
timer := New(time.Millisecond * 10)
tt = timer
fmt.Println(timer)
var i int32
for i = 0; i < N; i++ {
timer.NewTimer(time.Millisecond*time.Duration(10*i), now)
timer.NewTimer(time.Millisecond*time.Duration(10*i), now)
}
timer.Start()
if sum != 2*N {
t.Error("failed")
}
}
timer := New(time.Millisecond * 10)我们定义了一个tick为0.01s的定时器，循环了300次每次启动2个timeout，回调中将sum+1，所以最后sum应该等于600。
这是我golang的处女作,可能代码不是很规范，有空请多review review
github地址：https://github.com/Skycrab/code/blob/master/Go/timer/timer.go
package timerimport ( "container/list" "fmt" "sync" "time")//referer https://github.com/cloudwu/skynet/blob/master/skynet-src/skynet_timer.cconst ( TIME_NEAR_SHIFT = 8 TIME_NEAR = 1 << TIME_NEAR_SHIFT TIME_LEVEL_SHIFT = 6 TIME_LEVEL = 1 << TIME_LEVEL_SHIFT TIME_NEAR_MASK = TIME_NEAR - 1 TIME_LEVEL_MASK = TIME_LEVEL - 1)type Timer struct { near [TIME_NEAR]*list.List t [4][TIME_LEVEL]*list.List sync.Mutex time uint32 tick time.Duration quit chan struct{}}type Node struct { expire uint32 f func()}func (n *Node) String() string { return fmt.Sprintf("Node:expire,%d", n.expire)}func New(d time.Duration) *Timer { t := new(Timer) t.time = 0 t.tick = d t.quit = make(chan struct{}) var i, j int for i = 0; i < TIME_NEAR; i++ { t.near[i] = list.New() } for i = 0; i < 4; i++ { for j = 0; j < TIME_LEVEL; j++ { t.t[i][j] = list.New() } } return t}func (t *Timer) addNode(n *Node) { expire := n.expire current := t.time if (expire | TIME_NEAR_MASK) == (current | TIME_NEAR_MASK) { t.near[expire&TIME_NEAR_MASK].PushBack(n) } else { var i uint32 var mask uint32 = TIME_NEAR << TIME_LEVEL_SHIFT for i = 0; i < 3; i++ { if (expire | (mask - 1)) == (current | (mask - 1)) { break } mask <<= TIME_LEVEL_SHIFT } t.t[i][(expire>>(TIME_NEAR_SHIFT+i*TIME_LEVEL_SHIFT))&TIME_LEVEL_MASK].PushBack(n) }}func (t *Timer) NewTimer(d time.Duration, f func()) *Node { n := new(Node) n.f = f t.Lock() n.expire = uint32(d/t.tick) + t.time t.addNode(n) t.Unlock() return n}func (t *Timer) String() string { return fmt.Sprintf("Timer:time:%d, tick:%s", t.time, t.tick)}func dispatchList(front *list.Element) { for e := front; e != nil; e = e.Next() { node := e.Value.(*Node) go node.f() }}func (t *Timer) moveList(level, idx int) { vec := t.t[level][idx] front := vec.Front() vec.Init() for e := front; e != nil; e = e.Next() { node := e.Value.(*Node) t.addNode(node) }}func (t *Timer) shift() { t.Lock() var mask uint32 = TIME_NEAR t.time++ ct := t.time if ct == 0 { t.moveList(3, 0) } else { time := ct >> TIME_NEAR_SHIFT var i int = 0 for (ct & (mask - 1)) == 0 { idx := int(time & TIME_LEVEL_MASK) if idx != 0 { t.moveList(i, idx) break } mask <<= TIME_LEVEL_SHIFT time >>= TIME_LEVEL_SHIFT i++ } } t.Unlock()}func (t *Timer) execute() { t.Lock() idx := t.time & TIME_NEAR_MASK vec := t.near[idx] if vec.Len() > 0 { front := vec.Front() vec.Init() t.Unlock() // dispatch_list don't need lock dispatchList(front) return } t.Unlock()}func (t *Timer) update() { // try to dispatch timeout 0 (rare condition) t.execute() // shift time first, and then dispatch timer message t.shift() t.execute()}func (t *Timer) Start() { tick := time.NewTicker(t.tick) defer tick.Stop() for { select { case <-tick.C: t.update() case <-t.quit: return } }}func (t *Timer) Stop() { close(t.quit)}
熟悉skynet的童鞋看这段代码应该很熟悉，期待出现了golang大牛也写个牛逼的游戏服务器框架，这应该是很多人的心声吧。