// mapping, especially since we have no way to unmap it.
	const threshold = 16 << 10
	if length < threshold {
		return nil, false
	}

	// Have we reached the mmap limit?
	if atomic.AddInt32(&mmapLimit, -1) < 0 {
		atomic.AddInt32(&mmapLimit, 1)
		return nil, false
	}

	// Page-align the offset.
	off := r.Offset()
	align := syscall.Getpagesize()
	aoff := off &^ int64(align-1)

			target.Arch.ByteOrder.PutUint64(P[off:], uint64(o))
		}
	}
	if target.IsExternal() {
		// We'll stream out the external relocations in asmb2 (e.g. elfrelocsect)
		// and we only need the count here.
		atomic.AddUint32(&ldr.SymSect(s).Relcount, uint32(nExtReloc))
	}
}

// Convert a Go relocation to an external relocation.
func extreloc(ctxt *Link, ldr *loader.Loader, s loader.Sym, r loader.Reloc) (loader.ExtReloc, bool) {

	for i := 0; i < numIterations; i++ {
		if rwm.GetRLock(context.Background(), nil, id, source, Options{Timeout: time.Second}) {
			n := atomic.AddInt32(activity, 1)
			if n < 1 || n >= 10000 {
				panic(fmt.Sprintf("wlock(%d)\n", n))
			}
			for i := 0; i < 100; i++ {
			}
			atomic.AddInt32(activity, -1)
			rwm.RUnlock(context.Background())
		}
	}
	cdone <- true
}

// Borrowed from rwmutex_test.go

)

var sigioCount int32

// Catch SIGIO.
//
//export GoCatchSIGIO
func GoCatchSIGIO() {
	c := make(chan os.Signal, 1)
	signal.Notify(c, syscall.SIGIO)
	go func() {
		for range c {
			atomic.AddInt32(&sigioCount, 1)
		}
	}()
}

// Raise SIGIO.
//
//export GoRaiseSIGIO
func GoRaiseSIGIO(p *C.pthread_t) {
	C.CRaiseSIGIO(p)
}

// Return the number of SIGIO signals seen.
//

		// we expect CollectionDeleter to be executed once
		atomic.AddInt32(&invokedGot, 1)

		// we don't expect any context deadline to be set
		if _, hasDeadline := ctx.Deadline(); hasDeadline {
			atomic.AddInt32(&hasDeadlineGot, 1)
		}
		return nil, nil
	}

	// do the minimum setup to ensure that it gets as far as CollectionDeleter

// TODO(matloob): Should these functions have the go:noescape annotation?

//go:noescape
func Loadint32(ptr *int32) int32

//go:noescape
func Loadint64(ptr *int64) int64

//go:noescape
func Xaddint32(ptr *int32, delta int32) int32

//go:noescape
func Xaddint64(ptr *int64, delta int64) int64

//go:noescape
func Xchgint32(ptr *int32, new int32) int32

//go:noescape

			watermark.recordMutating(int(atomic.AddInt32(&atomicMutatingExecuting, delta)))
		} else {
			watermark.recordReadOnly(int(atomic.AddInt32(&atomicReadOnlyExecuting, delta)))
		}
	}
	noteWaitingDelta := func(delta int32) {
		if isMutatingRequest {
			waitingMark.recordMutating(int(atomic.AddInt32(&atomicMutatingWaiting, delta)))
		} else {
			waitingMark.recordReadOnly(int(atomic.AddInt32(&atomicReadOnlyWaiting, delta)))
		}
	}

pkg structs, type HostLayout struct #66408
pkg sync, method (*Map) Clear() #61696
pkg sync/atomic, func AndInt32(*int32, int32) int32 #61395
pkg sync/atomic, func AndInt64(*int64, int64) int64 #61395
pkg sync/atomic, func AndUint32(*uint32, uint32) uint32 #61395
pkg sync/atomic, func AndUint64(*uint64, uint64) uint64 #61395
pkg sync/atomic, func AndUintptr(*uintptr, uintptr) uintptr #61395

//
//go:linkname Load
//go:linkname Loadp
//go:linkname Load64
//go:linkname Loadint32
//go:linkname Loadint64
//go:linkname Loaduintptr
//go:linkname LoadAcquintptr
//go:linkname Xadd
//go:linkname Xaddint32
//go:linkname Xaddint64
//go:linkname Xadd64
//go:linkname Xadduintptr
//go:linkname Xchg
//go:linkname Xchg64
//go:linkname Xchgint32
//go:linkname Xchgint64
//go:linkname Xchguintptr
//go:linkname Cas

	for atomic.LoadInt32(&issue1560) != 1 {
		runtime.Gosched()
	}
	atomic.AddInt32(&issue1560, 1)
	for atomic.LoadInt32(&issue1560) != 3 {
		runtime.Gosched()
	}
	issue1560Ch <- true
}

func Issue1560FromGo() {
	atomic.AddInt32(&issue1560, 1)
	for atomic.LoadInt32(&issue1560) != 2 {
		runtime.Gosched()
	}
	atomic.AddInt32(&issue1560, 1)
	issue1560Ch <- true
}

func test1560(t *testing.T) {