}

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.

	}

	// 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))
	}

			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--
}