time.Sleep(1) 后發(fā)生了什么

//go:linkname timeSleep time.Sleepfunc timeSleep(ns int64) {    if ns <= 0 { //判斷入?yún)⑹欠裾?/span>      return   }      gp := getg() //獲取當(dāng)前的goroutine???t?:=?gp.timer //如果不存在timer，new一個(gè)   if t == nil {      t = new(timer)      gp.timer = t   }   t.f = goroutineReady  //后面喚醒時(shí)候會(huì)用到，修改goroutine狀態(tài)為goready   t.arg = gp   t.nextwhen = nanotime() + ns  //記錄上喚醒時(shí)間   gopark(resetForSleep, unsafe.Pointer(t), waitReasonSleep, traceEvGoSleep, 1)  //調(diào)用gopark掛起goroutine}

func gopark(unlockf func(*g, unsafe.Pointer) bool, lock unsafe.Pointer, reason waitReason, traceEv byte, traceskip int) { ???......省略了大部分代碼?????   mp.waitlock = lock  //由于runningG和p沒(méi)有連接，將timer賦值到當(dāng)前m上，后面會(huì)給到p   mp.waitunlockf = unlockf  //將函數(shù)付給m   ......???mcall(park_m) //將當(dāng)前的g停放}

?func?park_m(gp?*g)?{    _g_ := getg()  //獲取當(dāng)前goroutine   ......
   casgstatus(gp, _Grunning, _Gwaiting)  //將goroutine狀態(tài)設(shè)為waiting   dropg()
   if fn := _g_.m.waitunlockf; fn != nil { //獲取到mresetForSleep函數(shù)      ok := fn(gp, _g_.m.waitlock) //返回值是true      _g_.m.waitunlockf = nil  //清空該m的函數(shù)空間      _g_.m.waitlock = nil //...   ......      }   schedule()  //觸發(fā)新的調(diào)速循環(huán)，可執(zhí)行隊(duì)列中獲取g到m上進(jìn)行調(diào)度}

func modtimer(t *timer, when, period int64, f func(interface{}, uintptr), arg interface{}, seq uintptr) {     ...... loop:     for {       switch status = atomic.Load(&t.status); status {      ......      case timerNoStatus, timerRemoved:   //由于剛創(chuàng)建，所以timer為默認(rèn)值0，對(duì)應(yīng)timerNoStatus         mp = acquirem()         if atomic.Cas(&t.status, status, timerModifying) {            wasRemoved = true   //設(shè)置標(biāo)志位為true            break loop         }         releasem(mp)              badTimer()      }   }
   t.period = period???t.f?=?f?//上文傳過(guò)來(lái)的goroutineReady函數(shù)，用于將g轉(zhuǎn)變?yōu)閞unnable狀態(tài)   t.arg = arg  //上文的g實(shí)例   t.seq = seq 
???if?wasRemoved?{?//會(huì)執(zhí)行到此處      t.when = when ??????pp?:=?getg().m.p.ptr()?//獲取當(dāng)前的p的指針??????lock(&pp.timersLock)?//加鎖，為了并發(fā)安全，因?yàn)閠imer可以去其他的p偷取??????doaddtimer(pp,?t)?//添加定時(shí)器到當(dāng)前的p??????unlock(&pp.timersLock)?//解鎖??????if?!atomic.Cas(&t.status,?timerModifying,?timerWaiting)?{ //轉(zhuǎn)變到timerWaiting         badTimer()       } ??????......}

func checkTimers(pp *p, now int64) (rnow, pollUntil int64, ran bool) { 
   ......省略掉調(diào)整計(jì)時(shí)器時(shí)間的一些步驟???lock(&pp.timersLock)?//加鎖   adjusttimers(pp) //調(diào)整計(jì)時(shí)器的時(shí)間   rnow = now   if len(pp.timers) > 0 {      if rnow == 0 {         rnow = nanotime()      }      for len(pp.timers) > 0 {?????????if?tw?:=?runtimer(pp,?rnow);?tw?!=?0?{?//進(jìn)入runtimer方法，攜帶系統(tǒng)時(shí)間參數(shù)與處理器            if tw > 0 {               pollUntil = tw            }            break         }         ran = true      }   }......}

func runtimer(pp *p, now int64) int64 {     for {??????t?:=?pp.timers[0]?//遍歷堆頂?shù)亩〞r(shí)器     .......      switch s := atomic.Load(&t.status); s {      case timerWaiting:  //經(jīng)過(guò)time.Sleep的定時(shí)器會(huì)是waiting狀態(tài)         if t.when > now {  //判斷是否超過(guò)時(shí)間             // Not ready to run.            return t.when         }
         if !atomic.Cas(&t.status, s, timerRunning) {  //修改計(jì)時(shí)器狀態(tài)            continue?????????}?????????runOneTimer(pp,?t,?now)?//運(yùn)行該計(jì)時(shí)器函數(shù)         return 0        ........

func runOneTimer(pp *p, t *timer, now int64) {  ........
???f?:=?t.f?//goready函數(shù)???arg?:=?t.arg  //就是之前傳入的goroutine???seq?:=?t.seq? //默認(rèn)值0
   if t.period > 0 {    .........  //由于period為默認(rèn)值0，會(huì)走else里面       } else {      dodeltimer0(pp)  //刪除該計(jì)時(shí)器在p中，該timer在0坐標(biāo)位      if !atomic.Cas(&t.status, timerRunning, timerNoStatus) {  //設(shè)置為nostatus         badTimer()      }   }.......   unlock(&pp.timersLock)
   f(arg, seq) //執(zhí)行g(shù)oroutineReady方法，喚起等待的goroutine   .........}

func goroutineReady(arg interface{}, seq uintptr) {  ???goready(arg.(*g),?0)?//該處傳入的第二個(gè)參數(shù)代表調(diào)度到運(yùn)行隊(duì)列的位置，該處設(shè)置為0，說(shuō)明直接調(diào)度到運(yùn)行隊(duì)列即將要執(zhí)行的位置，等待被執(zhí)行。}