}

	// 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--
}