在学习GMP的过程中,runtime/proc.go这个源码里出现了之前没有学习过的源码
```
top:
_p_ := _g_.m.p.ptr()
if sched.gcwaiting != 0 {
gcstopm()
goto top
}
if _p_.runSafePointFn != 0 {
runSafePointFn()
}
now, pollUntil, _ := checkTimers(_p_, 0)
if fingwait && fingwake {
if gp := wakefing(); gp != nil {
ready(gp, 0, true)
}
}
if *cgo_yield != nil {
asmcgocall(*cgo_yield, nil)
}
......
stop:
// We have nothing to do. If we're in the GC mark phase, can
// safely scan and blacken objects, and have work to do, run
// idle-time marking rather than give up the P.
if gcBlackenEnabled != 0 && gcMarkWorkAvailable(_p_) {
node := (*gcBgMarkWorkerNode)(gcBgMarkWorkerPool.pop())
if node != nil {
_p_.gcMarkWorkerMode = gcMarkWorkerIdleMode
gp := node.gp.ptr()
casgstatus(gp, _Gwaiting, _Grunnable)
if trace.enabled {
traceGoUnpark(gp, 0)
}
return gp, false
}
}
......
```
这里想请教一下,top和stop的用法以及触发goto的时候是从top的下一行开始执行吗?
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