//
	// We're going to scan the whole heap (that was available at the time the
	// mark phase started, i.e. markArenas) for in-use spans which have specials.
	//
	// Break up the work into arenas, and further into chunks.
	//
	// Snapshot allArenas as markArenas. This snapshot is safe because allArenas
	// is append-only.
	mheap_.markArenas = mheap_.allArenas[:len(mheap_.allArenas):len(mheap_.allArenas)]

	var s *mspan
	systemstack(func() {
		lock(&mheap_.lock)
		s = (*mspan)(mheap_.spanalloc.alloc())
		unlock(&mheap_.lock)
	})
	return (*MSpan)(s)
}

// Free an allocated mspan.
func FreeMSpan(s *MSpan) {
	systemstack(func() {
		lock(&mheap_.lock)
		mheap_.spanalloc.free(unsafe.Pointer(s))
		unlock(&mheap_.lock)
	})
}

			s = stackLarge.free[log2npage].first
			stackLarge.free[log2npage].remove(s)
		}
		unlock(&stackLarge.lock)

		lockWithRankMayAcquire(&mheap_.lock, lockRankMheap)

		if s == nil {
			// Allocate a new stack from the heap.
			s = mheap_.allocManual(npage, spanAllocStack)
			if s == nil {
				throw("out of memory")
			}
			osStackAlloc(s)
			s.elemsize = uintptr(n)
		}

	}
	getg().m.traceback = 2
	throw("found bad pointer in Go heap (incorrect use of unsafe or cgo?)")
}

// findObject returns the base address for the heap object containing
// the address p, the object's span, and the index of the object in s.
// If p does not point into a heap object, it returns base == 0.
//
// If p points is an invalid heap pointer and debug.invalidptr != 0,
// findObject panics.
//

	// Heap -> stack pointer eventually causes badness when stack reallocation
	// occurs.

	var fn func() // ERROR "moved to heap: fn$"
	i := 0        // ERROR "moved to heap: i$"
	for ; i < maxI; i++ {
		// var fn func() // this makes it work, because fn stays off heap
		j := 0        // ERROR "moved to heap: j$"
		fn = func() { // ERROR "func literal escapes to heap$"
			m[i] = append(m[i], 0)
			if j < 25 {

	x := &ConstPtr{} // ERROR "&ConstPtr{} does not escape"
	x.p = &i
	return *x
}

func constptr03() **ConstPtr {
	i := 0           // ERROR "moved to heap: i"
	x := &ConstPtr{} // ERROR "&ConstPtr{} escapes to heap" "moved to heap: x"
	x.p = &i
	return &x
}

func constptr1() {
	i := 0           // ERROR "moved to heap: i"
	x := &ConstPtr{} // ERROR "&ConstPtr{} escapes to heap"
	x.p = &i
	sink = x
}

// output to a writer during profiling.
//
// # Heap profile
//
// The heap profile reports statistics as of the most recently completed
// garbage collection; it elides more recent allocation to avoid skewing
// the profile away from live data and toward garbage.
// If there has been no garbage collection at all, the heap profile reports
// all known allocations. This exception helps mainly in programs running

	heap[len(heap)-1].ev.time = 21
	heapUpdate(heap, len(heap)-1)
	checkHeap(t, heap)
	if heap[len(heap)-1].ev.time != 21 {
		t.Fatalf("heap update failed, expected %d as heap min: %s", 21, heapDebugString(heap))
	}

	// Update the last element to be smaller.
	heap[len(heap)-1].ev.time = 7
	heapUpdate(heap, len(heap)-1)
	checkHeap(t, heap)
	if heap[len(heap)-1].ev.time == 21 {

func ClosureCallArgs9() {
	// BAD: x should not leak
	x := 0 // ERROR "moved to heap: x"
	for {
		defer func(p *int) { // ERROR "func literal escapes to heap" "p does not escape"
			*p = 1
		}(&x)
	}
}

func ClosureCallArgs10() {
	for {
		x := 0               // ERROR "moved to heap: x"
		defer func(p *int) { // ERROR "func literal escapes to heap" "p does not escape"
			*p = 1
		}(&x)
	}
}

	heapSiftDown(heap, i)
}

func heapRemove(heap []*batchCursor, i int) []*batchCursor {
	// Sift index i up to the root, ignoring actual values.
	for i > 0 {
		heap[(i-1)/2], heap[i] = heap[i], heap[(i-1)/2]
		i = (i - 1) / 2
	}
	// Swap the root with the last element, then remove it.
	heap[0], heap[len(heap)-1] = heap[len(heap)-1], heap[0]
	heap = heap[:len(heap)-1]
	// Sift the root down.
	heapSiftDown(heap, 0)