// license that can be found in the LICENSE file.

// Export guts for testing.

package runtime

import "unsafe"

const MaxArgs = maxArgs

var (
	OsYield                 = osyield
	TimeBeginPeriodRetValue = &timeBeginPeriodRetValue
)

func NumberOfProcessors() int32 {
	var info systeminfo
	stdcall1(_GetSystemInfo, uintptr(unsafe.Pointer(&info)))

func (p *cpuProfile) add(tagPtr *unsafe.Pointer, stk []uintptr) {
	// Simple cas-lock to coordinate with setcpuprofilerate.
	for !prof.signalLock.CompareAndSwap(0, 1) {
		// TODO: Is it safe to osyield here? https://go.dev/issue/52672
		osyield()
	}

	if prof.hz.Load() != 0 { // implies cpuprof.log != nil
		if p.numExtra > 0 || p.lostExtra > 0 || p.lostAtomic > 0 {
			p.addExtra()
		}
		hdr := [1]uint64{1}

	}
	if gp != nil {
		hdr[1] = gp.goid
	}
	hdr[2] = uint64(mp.procid)

	// Allow only one writer at a time
	for !trace.signalLock.CompareAndSwap(0, 1) {
		// TODO: Is it safe to osyield here? https://go.dev/issue/52672
		osyield()
	}

	if log := trace.cpuLogWrite[gen%2].Load(); log != nil {
		// Note: we don't pass a tag pointer here (how should profiling tags

	return 0
}

func initsig(preinit bool) {
	if !preinit {
		notify(unsafe.Pointer(abi.FuncPCABI0(sigtramp)))
	}
}

//go:nosplit
func osyield() {
	sleep(0)
}

//go:nosplit
func osyield_no_g() {
	osyield()
}

//go:nosplit
func usleep(µs uint32) {
	ms := int32(µs / 1000)
	if ms == 0 {
		ms = 1
	}
	sleep(ms)
}

//go:nosplit

		// Try for lock, rescheduling.
		for i := 0; i < passive_spin; i++ {
			for l.key == mutex_unlocked {
				if atomic.Cas(key32(&l.key), mutex_unlocked, wait) {
					timer.end()
					return
				}
			}
			osyield()
		}

		// Sleep.
		v = atomic.Xchg(key32(&l.key), mutex_sleeping)
		if v == mutex_unlocked {
			timer.end()
			return
		}
		wait = mutex_sleeping
		futexsleep(key32(&l.key), mutex_sleeping, -1)

	// have been delivered. Give other threads a chance to run and
	// pick up the signal.
	osyield()
	osyield()
	osyield()

	// If that didn't work, try _SIG_DFL.
	setsig(sig, _SIG_DFL)
	raise(sig)

	osyield()
	osyield()
	osyield()

	// If we are still somehow running, just exit with the wrong status.
	exit(2)
}

			// Unlocked. Try to lock.
			if atomic.Casuintptr(&l.key, v, v|locked) {
				timer.end()
				return
			}
			i = 0
		}
		if i < spin {
			procyield(active_spin_cnt)
		} else if i < spin+passive_spin {
			osyield()
		} else {
			// Someone else has it.
			// l->waitm points to a linked list of M's waiting
			// for this lock, chained through m->nextwaitm.
			// Queue this M.
			for {
				gp.m.nextwaitm = muintptr(v &^ locked)

		// that the goroutine is suspended.
		if i == 0 {
			nextYield = nanotime() + yieldDelay
		}
		if nanotime() < nextYield {
			procyield(10)
		} else {
			osyield()
			nextYield = nanotime() + yieldDelay/2
		}
	}
}

// resumeG undoes the effects of suspendG, allowing the suspended
// goroutine to continue from its current safe-point.

	return stdcall(fn)
}

// These must run on the system stack only.

//go:nosplit
func osyield_no_g() {
	stdcall_no_g(_SwitchToThread, 0, 0)
}

//go:nosplit
func osyield() {
	systemstack(func() {
		stdcall0(_SwitchToThread)
	})
}

//go:nosplit
func usleep_no_g(us uint32) {
	timeout := uintptr(us) / 1000 // ms units

	//
	// The critical section on each goroutine here is going to be quite short, so the likelihood
	// that we observe a zero value is high.
	for trace.exitingSyscall.Load() != 0 {
		osyield()
	}

	// Record some initial pieces of information.
	//
	// N.B. This will also emit a status event for this goroutine.
	tl := traceAcquire()