//
// Hitting this target resolution is easy in the nanotime case: just pick a
// division of 64. In the cputicks case it's a bit more complex.
//
// For x86, on a 3 GHz machine, we'd want to divide by 3*64 to hit our target.
// To keep the division operation efficient, we round that up to 4*64, or 256.
// Given what cputicks represents, we use this on all other platforms except
// for PowerPC.

// See go.dev/issue/67401.

// Notable members of the hall of shame include:
//   - github.com/dgraph-io/ristretto
//   - github.com/outcaste-io/ristretto
//   - github.com/clubpay/ronykit
//go:linkname cputicks

// Notable members of the hall of shame include:
//   - gvisor.dev/gvisor (from assembly)

//
// Must not run concurrently with ticksPerSecond.
func (t *ticksType) init() {
	lock(&ticks.lock)
	t.startTime = nanotime()
	t.startTicks = cputicks()
	unlock(&ticks.lock)
}

// minTimeForTicksPerSecond is the minimum elapsed time we require to consider our ticksPerSecond
// measurement to be of decent enough quality for profiling.
//

	t0 := int64(0)
	s.releasetime = 0
	s.acquiretime = 0
	s.ticket = 0
	if profile&semaBlockProfile != 0 && blockprofilerate > 0 {
		t0 = cputicks()
		s.releasetime = -1
	}
	if profile&semaMutexProfile != 0 && mutexprofilerate > 0 {
		if t0 == 0 {
			t0 = cputicks()
		}
		s.acquiretime = t0
	}
	for {
		lockWithRank(&root.lock, lockRankRoot)
		// Add ourselves to nwait to disable "easy case" in semrelease.

	// chanrecv() and closechan() to update this thread's view of c.closed and full().
	if !block && c.closed == 0 && full(c) {
		return false
	}

	var t0 int64
	if blockprofilerate > 0 {
		t0 = cputicks()
	}

	lock(&c.lock)

	if c.closed != 0 {
		unlock(&c.lock)
		panic(plainError("send on closed channel"))
	}

	if sg := c.recvq.dequeue(); sg != nil {

					// The test imposes a delay with usleep, verified with calls to
					// nanotime. Compare against the runtime/metrics package's view
					// (based on nanotime) rather than runtime/pprof's view (based
					// on cputicks).
					t.Errorf("runtime/metrics reported less than the known minimum contention duration (%fs < %fs)", have, want)
				}
			})
			if have, want := n, int64(len(mus)); have != want {

// call with "if dlogEnabled".
//
//go:nosplit
//go:nowritebarrierrec
func dlog() *dlogger {
	if !dlogEnabled {
		return nil
	}

	// Get the time.
	tick, nano := uint64(cputicks()), uint64(nanotime())

	// Try to get a cached logger.
	l := getCachedDlogger()

	// If we couldn't get a cached logger, try to get one from the
	// global pool.
	if l == nil {

	}

	if rate > 0 && int64(cheaprand())%rate == 0 {
		lt.tickStart = cputicks()
	}
}

func (lt *lockTimer) end() {
	gp := getg()

	if lt.timeStart != 0 {
		nowTime := nanotime()
		gp.m.mLockProfile.waitTime.Add((nowTime - lt.timeStart) * lt.timeRate)
	}

	if lt.tickStart != 0 {
		nowTick := cputicks()
		gp.m.mLockProfile.recordLock(nowTick-lt.tickStart, lt.lock)
	}
}

	BREAK
	RET

TEXT runtime·asminit(SB),NOSPLIT|NOFRAME,$0-0
	RET

TEXT runtime·mstart(SB),NOSPLIT|TOPFRAME,$0
	JAL     runtime·mstart0(SB)
	RET // not reached

// func cputicks() int64
TEXT runtime·cputicks(SB),NOSPLIT,$0-8
	RDTIMED	R0, R4
	MOVV	R4, ret+0(FP)
	RET

/*
 *  go-routine
 */

// void gogo(Gobuf*)
// restore state from Gobuf; longjmp

	get_tls(CX)
	MOVQ	g(CX), AX
	CMPQ	(g_stack+stack_hi)(AX), SP
	JHI	2(PC)
	CALL	runtime·abort(SB)
	CMPQ	SP, (g_stack+stack_lo)(AX)
	JHI	2(PC)
	CALL	runtime·abort(SB)
	RET

// func cputicks() int64
TEXT runtime·cputicks(SB),NOSPLIT,$0-0
	CMPB	internal∕cpu·X86+const_offsetX86HasRDTSCP(SB), $1
	JNE	fences
	// Instruction stream serializing RDTSCP is supported.