throw("too many writes on closed pipe")
}

//go:linkname syscall_now syscall.now
func syscall_now() (sec int64, nsec int32) {
	sec, nsec, _ = time_now()
	return
}

//go:nosplit
func cputicks() int64 {
	// runtime·nanotime() is a poor approximation of CPU ticks that is enough for the profiler.
	return nanotime()
}

// gsignalStack is unused on js.
type gsignalStack struct{}

	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 {

		pcs = pc1[:ncases:ncases]
	}
	casePC := func(casi int) uintptr {
		if pcs == nil {
			return 0
		}
		return pcs[casi]
	}

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

	// The compiler rewrites selects that statically have
	// only 0 or 1 cases plus default into simpler constructs.
	// The only way we can end up with such small sel.ncase

// 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)
	}
}

	CALL	runtime·mstart0(SB)
	RET // not reached

// void setg_gcc(G*); set g called from gcc with g in A0
TEXT setg_gcc<>(SB),NOSPLIT,$0-0
	MOV	A0, g
	CALL	runtime·save_g(SB)
	RET

// func cputicks() int64
TEXT runtime·cputicks(SB),NOSPLIT,$0-8
	// RDTIME to emulate cpu ticks
	// RDCYCLE reads counter that is per HART(core) based
	// according to the riscv manual, see issue 46737
	RDTIME	A0
	MOV	A0, ret+0(FP)

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

// func cputicks() int64
TEXT runtime·cputicks(SB),NOSPLIT,$0-8
	// LFENCE/MFENCE instruction support is dependent on SSE2.
	// When no SSE2 support is present do not enforce any serialization