goparkunlock_test.go

package main

import (
	_ "unsafe"
	"fmt"
	"runtime/pprof"
	"os"
	"time"
)

// Event types in the trace, args are given in square brackets.
const (
	traceEvNone           = 0  // unused
	traceEvBatch          = 1  // start of per-P batch of events [pid, timestamp]
	traceEvFrequency      = 2  // contains tracer timer frequency [frequency (ticks per second)]
	traceEvStack          = 3  // stack [stack id, number of PCs, array of PCs]
	traceEvGomaxprocs     = 4  // current value of GOMAXPROCS [timestamp, GOMAXPROCS, stack id]
	traceEvProcStart      = 5  // start of P [timestamp, thread id]
	traceEvProcStop       = 6  // stop of P [timestamp]
	traceEvGCStart        = 7  // GC start [timestamp, stack id]
	traceEvGCDone         = 8  // GC done [timestamp]
	traceEvGCScanStart    = 9  // GC scan start [timestamp]
	traceEvGCScanDone     = 10 // GC scan done [timestamp]
	traceEvGCSweepStart   = 11 // GC sweep start [timestamp, stack id]
	traceEvGCSweepDone    = 12 // GC sweep done [timestamp]
	traceEvGoCreate       = 13 // goroutine creation [timestamp, new goroutine id, start PC, stack id]
	traceEvGoStart        = 14 // goroutine starts running [timestamp, goroutine id]
	traceEvGoEnd          = 15 // goroutine ends [timestamp]
	traceEvGoStop         = 16 // goroutine stops (like in select{}) [timestamp, stack]
	traceEvGoSched        = 17 // goroutine calls Gosched [timestamp, stack]
	traceEvGoPreempt      = 18 // goroutine is preempted [timestamp, stack]
	traceEvGoSleep        = 19 // goroutine calls Sleep [timestamp, stack]
	traceEvGoBlock        = 20 // goroutine blocks [timestamp, stack]
	traceEvGoUnblock      = 21 // goroutine is unblocked [timestamp, goroutine id, stack]
	traceEvGoBlockSend    = 22 // goroutine blocks on chan send [timestamp, stack]
	traceEvGoBlockRecv    = 23 // goroutine blocks on chan recv [timestamp, stack]
	traceEvGoBlockSelect  = 24 // goroutine blocks on select [timestamp, stack]
	traceEvGoBlockSync    = 25 // goroutine blocks on Mutex/RWMutex [timestamp, stack]
	traceEvGoBlockCond    = 26 // goroutine blocks on Cond [timestamp, stack]
	traceEvGoBlockNet     = 27 // goroutine blocks on network [timestamp, stack]
	traceEvGoSysCall      = 28 // syscall enter [timestamp, stack]
	traceEvGoSysExit      = 29 // syscall exit [timestamp, goroutine id, real timestamp]
	traceEvGoSysBlock     = 30 // syscall blocks [timestamp]
	traceEvGoWaiting      = 31 // denotes that goroutine is blocked when tracing starts [goroutine id]
	traceEvGoInSyscall    = 32 // denotes that goroutine is in syscall when tracing starts [goroutine id]
	traceEvHeapAlloc      = 33 // memstats.heap_live change [timestamp, heap_alloc]
	traceEvNextGC         = 34 // memstats.next_gc change [timestamp, next_gc]
	traceEvTimerGoroutine = 35 // denotes timer goroutine [timer goroutine id]
	traceEvFutileWakeup   = 36 // denotes that the previous wakeup of this goroutine was futile [timestamp]
	traceEvCount          = 37
)

type mutex struct {
	// Futex-based impl treats it as uint32 key,
	// while sema-based impl as M* waitm.
	// Used to be a union, but unions break precise GC.
	key uintptr
}

type g struct {}

//go:linkname lock runtime.lock
func lock(l *mutex)

//go:linkname unlock runtime.unlock
func unlock(l *mutex)

//go:linkname goparkunlock runtime.goparkunlock
func goparkunlock(lock *mutex, reason string, traceEv byte, traceskip int)

//go:linkname goready runtime.goready
func goready(gp *g, traceskip int)

// func goparkunlock(lock *mutex, reason string, traceEv byte, traceskip int) {
// 	gopark(parkunlock_c, unsafe.Pointer(lock), reason, traceEv, traceskip)
// }

// func goready(gp *g, traceskip int) {
// 	systemstack(func() {
// 		ready(gp, traceskip)
// 	})
// }

// 1go:linkname list_doSpin runtime.sync_runtime_doSpin
// 1go:linkname list_doSpin sync.runtime_doSpin
// 1func list_doSpin()

// go:linkname byteIndex strings.IndexByte
// 1func byteIndex(s string, c byte) int

func main() {
	l := &mutex{}
	go func() {
		lock(l)
		goparkunlock(l, "xxx", traceEvGoBlock, 1)
	}()
	fmt.Println("Hello")
	for {
		pprof.Lookup("goroutine").WriteTo(os.Stdout, 1)
		time.Sleep(time.Second * 1)
	}
}