}

// getfp returns the frame pointer register of its caller or 0 if not implemented.
// TODO: Make this a compiler intrinsic
func getfp() uintptr { return 0 }

func setProcessCPUProfiler(hz int32) {}
func setThreadCPUProfiler(hz int32)  {}
func sigdisable(uint32)              {}
func sigenable(uint32)               {}
func sigignore(uint32)               {}

// Stubs so tests can link correctly. These should never be called.

}

func sigenable(sig uint32) {
}

func sigdisable(sig uint32) {
}

func sigignore(sig uint32) {
}

func setProcessCPUProfiler(hz int32) {
}

func setThreadCPUProfiler(hz int32) {
	// TODO: Enable profiling interrupts.
	getg().m.profilehz = hz
}

// gsignalStack is unused on Plan 9.

	*mask &^= 1 << (uint32(i) - 1)
}

//go:nosplit
func (c *sigctxt) fixsigcode(sig uint32) {
}

func setProcessCPUProfiler(hz int32) {
	setProcessCPUProfilerTimer(hz)
}

func setThreadCPUProfiler(hz int32) {
	setThreadCPUProfilerHz(hz)
}

//go:nosplit
func validSIGPROF(mp *m, c *sigctxt) bool {
	return true
}

func osStackAlloc(s *mspan) {
	osStackRemap(s, _MAP_STACK)
}

}

func sigdelset(mask *sigset, i int) {
	(*mask)[(i-1)/64] &^= 1 << ((uint32(i) - 1) & 63)
}

func setProcessCPUProfiler(hz int32) {
	setProcessCPUProfilerTimer(hz)
}

func setThreadCPUProfiler(hz int32) {
	setThreadCPUProfilerHz(hz)
}

//go:nosplit
func validSIGPROF(mp *m, c *sigctxt) bool {
	return true
}

const (
	_CLOCK_REALTIME  = 9
	_CLOCK_MONOTONIC = 10
)

}

//go:nosplit
func (c *sigctxt) fixsigcode(sig uint32) {
}

func setProcessCPUProfiler(hz int32) {
	setProcessCPUProfilerTimer(hz)
}

func setThreadCPUProfiler(hz int32) {
	setThreadCPUProfilerHz(hz)
}

//go:nosplit
func validSIGPROF(mp *m, c *sigctxt) bool {
	return true
}

func sysargs(argc int32, argv **byte) {
	n := argc + 1

}

//go:nosplit
func (c *sigctxt) fixsigcode(sig uint32) {
}

func setProcessCPUProfiler(hz int32) {
	setProcessCPUProfilerTimer(hz)
}

func setThreadCPUProfiler(hz int32) {
	setThreadCPUProfilerHz(hz)
}

//go:nosplit
func validSIGPROF(mp *m, c *sigctxt) bool {
	return true
}

//go:nosplit
func semacreate(mp *m) {
	if mp.waitsema != 0 {

	}

	// Check whether the profiler needs to be turned on or off; this route to
	// run Go code does not use runtime.execute, so bypasses the check there.
	hz := sched.profilehz
	if gp.m.profilehz != hz {
		setThreadCPUProfiler(hz)
	}

	// Add entry to defer stack in case of panic.
	restore := true
	defer unwindm(&restore)

	if raceenabled {
		raceacquire(unsafe.Pointer(&racecgosync))
	}

	}

	// No active per-thread timer means the only valid profiler is setitimer.
	return setitimer
}

func setProcessCPUProfiler(hz int32) {
	setProcessCPUProfilerTimer(hz)
}

func setThreadCPUProfiler(hz int32) {
	mp := getg().m
	mp.profilehz = hz

	// destroy any active timer
	if mp.profileTimerValid.Load() {
		timerid := mp.profileTimer
		mp.profileTimerValid.Store(false)
		mp.profileTimer = 0

			timer = createHighResTimer()
		} else {
			timer = stdcall3(_CreateWaitableTimerA, 0, 0, 0)
		}
		atomic.Storeuintptr(&profiletimer, timer)
		newm(profileLoop, nil, -1)
	}
}

func setThreadCPUProfiler(hz int32) {
	ms := int32(0)
	due := ^int64(^uint64(1 << 63))
	if hz > 0 {
		ms = 1000 / hz
		if ms == 0 {
			ms = 1
		}
		due = int64(ms) * -10000
	}

	// it would deadlock.
	setThreadCPUProfiler(0)

	for !prof.signalLock.CompareAndSwap(0, 1) {
		osyield()
	}
	if prof.hz.Load() != hz {
		setProcessCPUProfiler(hz)
		prof.hz.Store(hz)
	}
	prof.signalLock.Store(0)

	lock(&sched.lock)
	sched.profilehz = hz
	unlock(&sched.lock)

	if hz != 0 {
		setThreadCPUProfiler(hz)
	}

	gp.m.locks--
}