Imported Upstream version 1.4upstream/1.4

1 files changed, 0 insertions, 932 deletions

diff --git a/src/pkg/runtime/mheap.c b/src/pkg/runtime/mheap.c
deleted file mode 100644
index 7e83eb283..000000000
--- a/src/pkg/runtime/mheap.c
+++ /dev/null
@@ -1,932 +0,0 @@
-// Copyright 2009 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Page heap.
-//
-// See malloc.h for overview.
-//
-// When a MSpan is in the heap free list, state == MSpanFree
-// and heapmap(s->start) == span, heapmap(s->start+s->npages-1) == span.
-//
-// When a MSpan is allocated, state == MSpanInUse
-// and heapmap(i) == span for all s->start <= i < s->start+s->npages.
-
-#include "runtime.h"
-#include "arch_GOARCH.h"
-#include "malloc.h"
-
-static MSpan *MHeap_AllocLocked(MHeap*, uintptr, int32);
-static bool MHeap_Grow(MHeap*, uintptr);
-static void MHeap_FreeLocked(MHeap*, MSpan*);
-static MSpan *MHeap_AllocLarge(MHeap*, uintptr);
-static MSpan *BestFit(MSpan*, uintptr, MSpan*);
-
-static void
-RecordSpan(void *vh, byte *p)
-{
-	MHeap *h;
-	MSpan *s;
-	MSpan **all;
-	uint32 cap;
-
-	h = vh;
-	s = (MSpan*)p;
-	if(h->nspan >= h->nspancap) {
-		cap = 64*1024/sizeof(all[0]);
-		if(cap < h->nspancap*3/2)
-			cap = h->nspancap*3/2;
-		all = (MSpan**)runtime·SysAlloc(cap*sizeof(all[0]), &mstats.other_sys);
-		if(all == nil)
-			runtime·throw("runtime: cannot allocate memory");
-		if(h->allspans) {
-			runtime·memmove(all, h->allspans, h->nspancap*sizeof(all[0]));
-			// Don't free the old array if it's referenced by sweep.
-			// See the comment in mgc0.c.
-			if(h->allspans != runtime·mheap.sweepspans)
-				runtime·SysFree(h->allspans, h->nspancap*sizeof(all[0]), &mstats.other_sys);
-		}
-		h->allspans = all;
-		h->nspancap = cap;
-	}
-	h->allspans[h->nspan++] = s;
-}
-
-// Initialize the heap; fetch memory using alloc.
-void
-runtime·MHeap_Init(MHeap *h)
-{
-	uint32 i;
-
-	runtime·FixAlloc_Init(&h->spanalloc, sizeof(MSpan), RecordSpan, h, &mstats.mspan_sys);
-	runtime·FixAlloc_Init(&h->cachealloc, sizeof(MCache), nil, nil, &mstats.mcache_sys);
-	runtime·FixAlloc_Init(&h->specialfinalizeralloc, sizeof(SpecialFinalizer), nil, nil, &mstats.other_sys);
-	runtime·FixAlloc_Init(&h->specialprofilealloc, sizeof(SpecialProfile), nil, nil, &mstats.other_sys);
-	// h->mapcache needs no init
-	for(i=0; i<nelem(h->free); i++) {
-		runtime·MSpanList_Init(&h->free[i]);
-		runtime·MSpanList_Init(&h->busy[i]);
-	}
-	runtime·MSpanList_Init(&h->freelarge);
-	runtime·MSpanList_Init(&h->busylarge);
-	for(i=0; i<nelem(h->central); i++)
-		runtime·MCentral_Init(&h->central[i], i);
-}
-
-void
-runtime·MHeap_MapSpans(MHeap *h)
-{
-	uintptr n;
-
-	// Map spans array, PageSize at a time.
-	n = (uintptr)h->arena_used;
-	n -= (uintptr)h->arena_start;
-	n = n / PageSize * sizeof(h->spans[0]);
-	n = ROUND(n, PhysPageSize);
-	if(h->spans_mapped >= n)
-		return;
-	runtime·SysMap((byte*)h->spans + h->spans_mapped, n - h->spans_mapped, h->arena_reserved, &mstats.other_sys);
-	h->spans_mapped = n;
-}
-
-// Sweeps spans in list until reclaims at least npages into heap.
-// Returns the actual number of pages reclaimed.
-static uintptr
-MHeap_ReclaimList(MHeap *h, MSpan *list, uintptr npages)
-{
-	MSpan *s;
-	uintptr n;
-	uint32 sg;
-
-	n = 0;
-	sg = runtime·mheap.sweepgen;
-retry:
-	for(s = list->next; s != list; s = s->next) {
-		if(s->sweepgen == sg-2 && runtime·cas(&s->sweepgen, sg-2, sg-1)) {
-			runtime·MSpanList_Remove(s);
-			// swept spans are at the end of the list
-			runtime·MSpanList_InsertBack(list, s);
-			runtime·unlock(h);
-			n += runtime·MSpan_Sweep(s);
-			runtime·lock(h);
-			if(n >= npages)
-				return n;
-			// the span could have been moved elsewhere
-			goto retry;
-		}
-		if(s->sweepgen == sg-1) {
-			// the span is being sweept by background sweeper, skip
-			continue;
-		}
-		// already swept empty span,
-		// all subsequent ones must also be either swept or in process of sweeping
-		break;
-	}
-	return n;
-}
-
-// Sweeps and reclaims at least npage pages into heap.
-// Called before allocating npage pages.
-static void
-MHeap_Reclaim(MHeap *h, uintptr npage)
-{
-	uintptr reclaimed, n;
-
-	// First try to sweep busy spans with large objects of size >= npage,
-	// this has good chances of reclaiming the necessary space.
-	for(n=npage; n < nelem(h->busy); n++) {
-		if(MHeap_ReclaimList(h, &h->busy[n], npage))
-			return;  // Bingo!
-	}
-
-	// Then -- even larger objects.
-	if(MHeap_ReclaimList(h, &h->busylarge, npage))
-		return;  // Bingo!
-
-	// Now try smaller objects.
-	// One such object is not enough, so we need to reclaim several of them.
-	reclaimed = 0;
-	for(n=0; n < npage && n < nelem(h->busy); n++) {
-		reclaimed += MHeap_ReclaimList(h, &h->busy[n], npage-reclaimed);
-		if(reclaimed >= npage)
-			return;
-	}
-
-	// Now sweep everything that is not yet swept.
-	runtime·unlock(h);
-	for(;;) {
-		n = runtime·sweepone();
-		if(n == -1)  // all spans are swept
-			break;
-		reclaimed += n;
-		if(reclaimed >= npage)
-			break;
-	}
-	runtime·lock(h);
-}
-
-// Allocate a new span of npage pages from the heap
-// and record its size class in the HeapMap and HeapMapCache.
-MSpan*
-runtime·MHeap_Alloc(MHeap *h, uintptr npage, int32 sizeclass, bool large, bool needzero)
-{
-	MSpan *s;
-
-	runtime·lock(h);
-	mstats.heap_alloc += m->mcache->local_cachealloc;
-	m->mcache->local_cachealloc = 0;
-	s = MHeap_AllocLocked(h, npage, sizeclass);
-	if(s != nil) {
-		mstats.heap_inuse += npage<<PageShift;
-		if(large) {
-			mstats.heap_objects++;
-			mstats.heap_alloc += npage<<PageShift;
-			// Swept spans are at the end of lists.
-			if(s->npages < nelem(h->free))
-				runtime·MSpanList_InsertBack(&h->busy[s->npages], s);
-			else
-				runtime·MSpanList_InsertBack(&h->busylarge, s);
-		}
-	}
-	runtime·unlock(h);
-	if(s != nil) {
-		if(needzero && s->needzero)
-			runtime·memclr((byte*)(s->start<<PageShift), s->npages<<PageShift);
-		s->needzero = 0;
-	}
-	return s;
-}
-
-static MSpan*
-MHeap_AllocLocked(MHeap *h, uintptr npage, int32 sizeclass)
-{
-	uintptr n;
-	MSpan *s, *t;
-	PageID p;
-
-	// To prevent excessive heap growth, before allocating n pages
-	// we need to sweep and reclaim at least n pages.
-	if(!h->sweepdone)
-		MHeap_Reclaim(h, npage);
-
-	// Try in fixed-size lists up to max.
-	for(n=npage; n < nelem(h->free); n++) {
-		if(!runtime·MSpanList_IsEmpty(&h->free[n])) {
-			s = h->free[n].next;
-			goto HaveSpan;
-		}
-	}
-
-	// Best fit in list of large spans.
-	if((s = MHeap_AllocLarge(h, npage)) == nil) {
-		if(!MHeap_Grow(h, npage))
-			return nil;
-		if((s = MHeap_AllocLarge(h, npage)) == nil)
-			return nil;
-	}
-
-HaveSpan:
-	// Mark span in use.
-	if(s->state != MSpanFree)
-		runtime·throw("MHeap_AllocLocked - MSpan not free");
-	if(s->npages < npage)
-		runtime·throw("MHeap_AllocLocked - bad npages");
-	runtime·MSpanList_Remove(s);
-	runtime·atomicstore(&s->sweepgen, h->sweepgen);
-	s->state = MSpanInUse;
-	mstats.heap_idle -= s->npages<<PageShift;
-	mstats.heap_released -= s->npreleased<<PageShift;
-	if(s->npreleased > 0)
-		runtime·SysUsed((void*)(s->start<<PageShift), s->npages<<PageShift);
-	s->npreleased = 0;
-
-	if(s->npages > npage) {
-		// Trim extra and put it back in the heap.
-		t = runtime·FixAlloc_Alloc(&h->spanalloc);
-		runtime·MSpan_Init(t, s->start + npage, s->npages - npage);
-		s->npages = npage;
-		p = t->start;
-		p -= ((uintptr)h->arena_start>>PageShift);
-		if(p > 0)
-			h->spans[p-1] = s;
-		h->spans[p] = t;
-		h->spans[p+t->npages-1] = t;
-		t->needzero = s->needzero;
-		runtime·atomicstore(&t->sweepgen, h->sweepgen);
-		t->state = MSpanInUse;
-		MHeap_FreeLocked(h, t);
-		t->unusedsince = s->unusedsince; // preserve age
-	}
-	s->unusedsince = 0;
-
-	// Record span info, because gc needs to be
-	// able to map interior pointer to containing span.
-	s->sizeclass = sizeclass;
-	s->elemsize = (sizeclass==0 ? s->npages<<PageShift : runtime·class_to_size[sizeclass]);
-	s->types.compression = MTypes_Empty;
-	p = s->start;
-	p -= ((uintptr)h->arena_start>>PageShift);
-	for(n=0; n<npage; n++)
-		h->spans[p+n] = s;
-	return s;
-}
-
-// Allocate a span of exactly npage pages from the list of large spans.
-static MSpan*
-MHeap_AllocLarge(MHeap *h, uintptr npage)
-{
-	return BestFit(&h->freelarge, npage, nil);
-}
-
-// Search list for smallest span with >= npage pages.
-// If there are multiple smallest spans, take the one
-// with the earliest starting address.
-static MSpan*
-BestFit(MSpan *list, uintptr npage, MSpan *best)
-{
-	MSpan *s;
-
-	for(s=list->next; s != list; s=s->next) {
-		if(s->npages < npage)
-			continue;
-		if(best == nil
-		|| s->npages < best->npages
-		|| (s->npages == best->npages && s->start < best->start))
-			best = s;
-	}
-	return best;
-}
-
-// Try to add at least npage pages of memory to the heap,
-// returning whether it worked.
-static bool
-MHeap_Grow(MHeap *h, uintptr npage)
-{
-	uintptr ask;
-	void *v;
-	MSpan *s;
-	PageID p;
-
-	// Ask for a big chunk, to reduce the number of mappings
-	// the operating system needs to track; also amortizes
-	// the overhead of an operating system mapping.
-	// Allocate a multiple of 64kB (16 pages).
-	npage = (npage+15)&~15;
-	ask = npage<<PageShift;
-	if(ask < HeapAllocChunk)
-		ask = HeapAllocChunk;
-
-	v = runtime·MHeap_SysAlloc(h, ask);
-	if(v == nil) {
-		if(ask > (npage<<PageShift)) {
-			ask = npage<<PageShift;
-			v = runtime·MHeap_SysAlloc(h, ask);
-		}
-		if(v == nil) {
-			runtime·printf("runtime: out of memory: cannot allocate %D-byte block (%D in use)\n", (uint64)ask, mstats.heap_sys);
-			return false;
-		}
-	}
-
-	// Create a fake "in use" span and free it, so that the
-	// right coalescing happens.
-	s = runtime·FixAlloc_Alloc(&h->spanalloc);
-	runtime·MSpan_Init(s, (uintptr)v>>PageShift, ask>>PageShift);
-	p = s->start;
-	p -= ((uintptr)h->arena_start>>PageShift);
-	h->spans[p] = s;
-	h->spans[p + s->npages - 1] = s;
-	runtime·atomicstore(&s->sweepgen, h->sweepgen);
-	s->state = MSpanInUse;
-	MHeap_FreeLocked(h, s);
-	return true;
-}
-
-// Look up the span at the given address.
-// Address is guaranteed to be in map
-// and is guaranteed to be start or end of span.
-MSpan*
-runtime·MHeap_Lookup(MHeap *h, void *v)
-{
-	uintptr p;
-	
-	p = (uintptr)v;
-	p -= (uintptr)h->arena_start;
-	return h->spans[p >> PageShift];
-}
-
-// Look up the span at the given address.
-// Address is *not* guaranteed to be in map
-// and may be anywhere in the span.
-// Map entries for the middle of a span are only
-// valid for allocated spans.  Free spans may have
-// other garbage in their middles, so we have to
-// check for that.
-MSpan*
-runtime·MHeap_LookupMaybe(MHeap *h, void *v)
-{
-	MSpan *s;
-	PageID p, q;
-
-	if((byte*)v < h->arena_start || (byte*)v >= h->arena_used)
-		return nil;
-	p = (uintptr)v>>PageShift;
-	q = p;
-	q -= (uintptr)h->arena_start >> PageShift;
-	s = h->spans[q];
-	if(s == nil || p < s->start || v >= s->limit || s->state != MSpanInUse)
-		return nil;
-	return s;
-}
-
-// Free the span back into the heap.
-void
-runtime·MHeap_Free(MHeap *h, MSpan *s, int32 acct)
-{
-	runtime·lock(h);
-	mstats.heap_alloc += m->mcache->local_cachealloc;
-	m->mcache->local_cachealloc = 0;
-	mstats.heap_inuse -= s->npages<<PageShift;
-	if(acct) {
-		mstats.heap_alloc -= s->npages<<PageShift;
-		mstats.heap_objects--;
-	}
-	MHeap_FreeLocked(h, s);
-	runtime·unlock(h);
-}
-
-static void
-MHeap_FreeLocked(MHeap *h, MSpan *s)
-{
-	MSpan *t;
-	PageID p;
-
-	s->types.compression = MTypes_Empty;
-
-	if(s->state != MSpanInUse || s->ref != 0 || s->sweepgen != h->sweepgen) {
-		runtime·printf("MHeap_FreeLocked - span %p ptr %p state %d ref %d sweepgen %d/%d\n",
-			s, s->start<<PageShift, s->state, s->ref, s->sweepgen, h->sweepgen);
-		runtime·throw("MHeap_FreeLocked - invalid free");
-	}
-	mstats.heap_idle += s->npages<<PageShift;
-	s->state = MSpanFree;
-	runtime·MSpanList_Remove(s);
-	// Stamp newly unused spans. The scavenger will use that
-	// info to potentially give back some pages to the OS.
-	s->unusedsince = runtime·nanotime();
-	s->npreleased = 0;
-
-	// Coalesce with earlier, later spans.
-	p = s->start;
-	p -= (uintptr)h->arena_start >> PageShift;
-	if(p > 0 && (t = h->spans[p-1]) != nil && t->state != MSpanInUse) {
-		s->start = t->start;
-		s->npages += t->npages;
-		s->npreleased = t->npreleased; // absorb released pages
-		s->needzero |= t->needzero;
-		p -= t->npages;
-		h->spans[p] = s;
-		runtime·MSpanList_Remove(t);
-		t->state = MSpanDead;
-		runtime·FixAlloc_Free(&h->spanalloc, t);
-	}
-	if((p+s->npages)*sizeof(h->spans[0]) < h->spans_mapped && (t = h->spans[p+s->npages]) != nil && t->state != MSpanInUse) {
-		s->npages += t->npages;
-		s->npreleased += t->npreleased;
-		s->needzero |= t->needzero;
-		h->spans[p + s->npages - 1] = s;
-		runtime·MSpanList_Remove(t);
-		t->state = MSpanDead;
-		runtime·FixAlloc_Free(&h->spanalloc, t);
-	}
-
-	// Insert s into appropriate list.
-	if(s->npages < nelem(h->free))
-		runtime·MSpanList_Insert(&h->free[s->npages], s);
-	else
-		runtime·MSpanList_Insert(&h->freelarge, s);
-}
-
-static void
-forcegchelper(Note *note)
-{
-	runtime·gc(1);
-	runtime·notewakeup(note);
-}
-
-static uintptr
-scavengelist(MSpan *list, uint64 now, uint64 limit)
-{
-	uintptr released, sumreleased;
-	MSpan *s;
-
-	if(runtime·MSpanList_IsEmpty(list))
-		return 0;
-
-	sumreleased = 0;
-	for(s=list->next; s != list; s=s->next) {
-		if((now - s->unusedsince) > limit && s->npreleased != s->npages) {
-			released = (s->npages - s->npreleased) << PageShift;
-			mstats.heap_released += released;
-			sumreleased += released;
-			s->npreleased = s->npages;
-			runtime·SysUnused((void*)(s->start << PageShift), s->npages << PageShift);
-		}
-	}
-	return sumreleased;
-}
-
-static void
-scavenge(int32 k, uint64 now, uint64 limit)
-{
-	uint32 i;
-	uintptr sumreleased;
-	MHeap *h;
-	
-	h = &runtime·mheap;
-	sumreleased = 0;
-	for(i=0; i < nelem(h->free); i++)
-		sumreleased += scavengelist(&h->free[i], now, limit);
-	sumreleased += scavengelist(&h->freelarge, now, limit);
-
-	if(runtime·debug.gctrace > 0) {
-		if(sumreleased > 0)
-			runtime·printf("scvg%d: %D MB released\n", k, (uint64)sumreleased>>20);
-		runtime·printf("scvg%d: inuse: %D, idle: %D, sys: %D, released: %D, consumed: %D (MB)\n",
-			k, mstats.heap_inuse>>20, mstats.heap_idle>>20, mstats.heap_sys>>20,
-			mstats.heap_released>>20, (mstats.heap_sys - mstats.heap_released)>>20);
-	}
-}
-
-static FuncVal forcegchelperv = {(void(*)(void))forcegchelper};
-
-// Release (part of) unused memory to OS.
-// Goroutine created at startup.
-// Loop forever.
-void
-runtime·MHeap_Scavenger(void)
-{
-	MHeap *h;
-	uint64 tick, now, forcegc, limit;
-	int64 unixnow;
-	int32 k;
-	Note note, *notep;
-
-	g->issystem = true;
-	g->isbackground = true;
-
-	// If we go two minutes without a garbage collection, force one to run.
-	forcegc = 2*60*1e9;
-	// If a span goes unused for 5 minutes after a garbage collection,
-	// we hand it back to the operating system.
-	limit = 5*60*1e9;
-	// Make wake-up period small enough for the sampling to be correct.
-	if(forcegc < limit)
-		tick = forcegc/2;
-	else
-		tick = limit/2;
-
-	h = &runtime·mheap;
-	for(k=0;; k++) {
-		runtime·noteclear(&note);
-		runtime·notetsleepg(&note, tick);
-
-		runtime·lock(h);
-		unixnow = runtime·unixnanotime();
-		if(unixnow - mstats.last_gc > forcegc) {
-			runtime·unlock(h);
-			// The scavenger can not block other goroutines,
-			// otherwise deadlock detector can fire spuriously.
-			// GC blocks other goroutines via the runtime·worldsema.
-			runtime·noteclear(&note);
-			notep = &note;
-			runtime·newproc1(&forcegchelperv, (byte*)&notep, sizeof(notep), 0, runtime·MHeap_Scavenger);
-			runtime·notetsleepg(&note, -1);
-			if(runtime·debug.gctrace > 0)
-				runtime·printf("scvg%d: GC forced\n", k);
-			runtime·lock(h);
-		}
-		now = runtime·nanotime();
-		scavenge(k, now, limit);
-		runtime·unlock(h);
-	}
-}
-
-void
-runtime∕debug·freeOSMemory(void)
-{
-	runtime·gc(2);  // force GC and do eager sweep
-	runtime·lock(&runtime·mheap);
-	scavenge(-1, ~(uintptr)0, 0);
-	runtime·unlock(&runtime·mheap);
-}
-
-// Initialize a new span with the given start and npages.
-void
-runtime·MSpan_Init(MSpan *span, PageID start, uintptr npages)
-{
-	span->next = nil;
-	span->prev = nil;
-	span->start = start;
-	span->npages = npages;
-	span->freelist = nil;
-	span->ref = 0;
-	span->sizeclass = 0;
-	span->incache = false;
-	span->elemsize = 0;
-	span->state = MSpanDead;
-	span->unusedsince = 0;
-	span->npreleased = 0;
-	span->types.compression = MTypes_Empty;
-	span->specialLock.key = 0;
-	span->specials = nil;
-	span->needzero = 0;
-	span->freebuf = nil;
-}
-
-// Initialize an empty doubly-linked list.
-void
-runtime·MSpanList_Init(MSpan *list)
-{
-	list->state = MSpanListHead;
-	list->next = list;
-	list->prev = list;
-}
-
-void
-runtime·MSpanList_Remove(MSpan *span)
-{
-	if(span->prev == nil && span->next == nil)
-		return;
-	span->prev->next = span->next;
-	span->next->prev = span->prev;
-	span->prev = nil;
-	span->next = nil;
-}
-
-bool
-runtime·MSpanList_IsEmpty(MSpan *list)
-{
-	return list->next == list;
-}
-
-void
-runtime·MSpanList_Insert(MSpan *list, MSpan *span)
-{
-	if(span->next != nil || span->prev != nil) {
-		runtime·printf("failed MSpanList_Insert %p %p %p\n", span, span->next, span->prev);
-		runtime·throw("MSpanList_Insert");
-	}
-	span->next = list->next;
-	span->prev = list;
-	span->next->prev = span;
-	span->prev->next = span;
-}
-
-void
-runtime·MSpanList_InsertBack(MSpan *list, MSpan *span)
-{
-	if(span->next != nil || span->prev != nil) {
-		runtime·printf("failed MSpanList_Insert %p %p %p\n", span, span->next, span->prev);
-		runtime·throw("MSpanList_Insert");
-	}
-	span->next = list;
-	span->prev = list->prev;
-	span->next->prev = span;
-	span->prev->next = span;
-}
-
-// Adds the special record s to the list of special records for
-// the object p.  All fields of s should be filled in except for
-// offset & next, which this routine will fill in.
-// Returns true if the special was successfully added, false otherwise.
-// (The add will fail only if a record with the same p and s->kind
-//  already exists.)
-static bool
-addspecial(void *p, Special *s)
-{
-	MSpan *span;
-	Special **t, *x;
-	uintptr offset;
-	byte kind;
-
-	span = runtime·MHeap_LookupMaybe(&runtime·mheap, p);
-	if(span == nil)
-		runtime·throw("addspecial on invalid pointer");
-
-	// Ensure that the span is swept.
-	// GC accesses specials list w/o locks. And it's just much safer.
-	m->locks++;
-	runtime·MSpan_EnsureSwept(span);
-
-	offset = (uintptr)p - (span->start << PageShift);
-	kind = s->kind;
-
-	runtime·lock(&span->specialLock);
-
-	// Find splice point, check for existing record.
-	t = &span->specials;
-	while((x = *t) != nil) {
-		if(offset == x->offset && kind == x->kind) {
-			runtime·unlock(&span->specialLock);
-			m->locks--;
-			return false; // already exists
-		}
-		if(offset < x->offset || (offset == x->offset && kind < x->kind))
-			break;
-		t = &x->next;
-	}
-	// Splice in record, fill in offset.
-	s->offset = offset;
-	s->next = x;
-	*t = s;
-	runtime·unlock(&span->specialLock);
-	m->locks--;
-	return true;
-}
-
-// Removes the Special record of the given kind for the object p.
-// Returns the record if the record existed, nil otherwise.
-// The caller must FixAlloc_Free the result.
-static Special*
-removespecial(void *p, byte kind)
-{
-	MSpan *span;
-	Special *s, **t;
-	uintptr offset;
-
-	span = runtime·MHeap_LookupMaybe(&runtime·mheap, p);
-	if(span == nil)
-		runtime·throw("removespecial on invalid pointer");
-
-	// Ensure that the span is swept.
-	// GC accesses specials list w/o locks. And it's just much safer.
-	m->locks++;
-	runtime·MSpan_EnsureSwept(span);
-
-	offset = (uintptr)p - (span->start << PageShift);
-
-	runtime·lock(&span->specialLock);
-	t = &span->specials;
-	while((s = *t) != nil) {
-		// This function is used for finalizers only, so we don't check for
-		// "interior" specials (p must be exactly equal to s->offset).
-		if(offset == s->offset && kind == s->kind) {
-			*t = s->next;
-			runtime·unlock(&span->specialLock);
-			m->locks--;
-			return s;
-		}
-		t = &s->next;
-	}
-	runtime·unlock(&span->specialLock);
-	m->locks--;
-	return nil;
-}
-
-// Adds a finalizer to the object p.  Returns true if it succeeded.
-bool
-runtime·addfinalizer(void *p, FuncVal *f, uintptr nret, Type *fint, PtrType *ot)
-{
-	SpecialFinalizer *s;
-
-	runtime·lock(&runtime·mheap.speciallock);
-	s = runtime·FixAlloc_Alloc(&runtime·mheap.specialfinalizeralloc);
-	runtime·unlock(&runtime·mheap.speciallock);
-	s->kind = KindSpecialFinalizer;
-	s->fn = f;
-	s->nret = nret;
-	s->fint = fint;
-	s->ot = ot;
-	if(addspecial(p, s))
-		return true;
-
-	// There was an old finalizer
-	runtime·lock(&runtime·mheap.speciallock);
-	runtime·FixAlloc_Free(&runtime·mheap.specialfinalizeralloc, s);
-	runtime·unlock(&runtime·mheap.speciallock);
-	return false;
-}
-
-// Removes the finalizer (if any) from the object p.
-void
-runtime·removefinalizer(void *p)
-{
-	SpecialFinalizer *s;
-
-	s = (SpecialFinalizer*)removespecial(p, KindSpecialFinalizer);
-	if(s == nil)
-		return; // there wasn't a finalizer to remove
-	runtime·lock(&runtime·mheap.speciallock);
-	runtime·FixAlloc_Free(&runtime·mheap.specialfinalizeralloc, s);
-	runtime·unlock(&runtime·mheap.speciallock);
-}
-
-// Set the heap profile bucket associated with addr to b.
-void
-runtime·setprofilebucket(void *p, Bucket *b)
-{
-	SpecialProfile *s;
-
-	runtime·lock(&runtime·mheap.speciallock);
-	s = runtime·FixAlloc_Alloc(&runtime·mheap.specialprofilealloc);
-	runtime·unlock(&runtime·mheap.speciallock);
-	s->kind = KindSpecialProfile;
-	s->b = b;
-	if(!addspecial(p, s))
-		runtime·throw("setprofilebucket: profile already set");
-}
-
-// Do whatever cleanup needs to be done to deallocate s.  It has
-// already been unlinked from the MSpan specials list.
-// Returns true if we should keep working on deallocating p.
-bool
-runtime·freespecial(Special *s, void *p, uintptr size, bool freed)
-{
-	SpecialFinalizer *sf;
-	SpecialProfile *sp;
-
-	switch(s->kind) {
-	case KindSpecialFinalizer:
-		sf = (SpecialFinalizer*)s;
-		runtime·queuefinalizer(p, sf->fn, sf->nret, sf->fint, sf->ot);
-		runtime·lock(&runtime·mheap.speciallock);
-		runtime·FixAlloc_Free(&runtime·mheap.specialfinalizeralloc, sf);
-		runtime·unlock(&runtime·mheap.speciallock);
-		return false; // don't free p until finalizer is done
-	case KindSpecialProfile:
-		sp = (SpecialProfile*)s;
-		runtime·MProf_Free(sp->b, size, freed);
-		runtime·lock(&runtime·mheap.speciallock);
-		runtime·FixAlloc_Free(&runtime·mheap.specialprofilealloc, sp);
-		runtime·unlock(&runtime·mheap.speciallock);
-		return true;
-	default:
-		runtime·throw("bad special kind");
-		return true;
-	}
-}
-
-// Free all special records for p.
-void
-runtime·freeallspecials(MSpan *span, void *p, uintptr size)
-{
-	Special *s, **t, *list;
-	uintptr offset;
-
-	if(span->sweepgen != runtime·mheap.sweepgen)
-		runtime·throw("runtime: freeallspecials: unswept span");
-	// first, collect all specials into the list; then, free them
-	// this is required to not cause deadlock between span->specialLock and proflock
-	list = nil;
-	offset = (uintptr)p - (span->start << PageShift);
-	runtime·lock(&span->specialLock);
-	t = &span->specials;
-	while((s = *t) != nil) {
-		if(offset + size <= s->offset)
-			break;
-		if(offset <= s->offset) {
-			*t = s->next;
-			s->next = list;
-			list = s;
-		} else
-			t = &s->next;
-	}
-	runtime·unlock(&span->specialLock);
-
-	while(list != nil) {
-		s = list;
-		list = s->next;
-		if(!runtime·freespecial(s, p, size, true))
-			runtime·throw("can't explicitly free an object with a finalizer");
-	}
-}
-
-// Split an allocated span into two equal parts.
-void
-runtime·MHeap_SplitSpan(MHeap *h, MSpan *s)
-{
-	MSpan *t;
-	MCentral *c;
-	uintptr i;
-	uintptr npages;
-	PageID p;
-
-	if(s->state != MSpanInUse)
-		runtime·throw("MHeap_SplitSpan on a free span");
-	if(s->sizeclass != 0 && s->ref != 1)
-		runtime·throw("MHeap_SplitSpan doesn't have an allocated object");
-	npages = s->npages;
-
-	// remove the span from whatever list it is in now
-	if(s->sizeclass > 0) {
-		// must be in h->central[x].empty
-		c = &h->central[s->sizeclass];
-		runtime·lock(c);
-		runtime·MSpanList_Remove(s);
-		runtime·unlock(c);
-		runtime·lock(h);
-	} else {
-		// must be in h->busy/busylarge
-		runtime·lock(h);
-		runtime·MSpanList_Remove(s);
-	}
-	// heap is locked now
-
-	if(npages == 1) {
-		// convert span of 1 PageSize object to a span of 2 PageSize/2 objects.
-		s->ref = 2;
-		s->sizeclass = runtime·SizeToClass(PageSize/2);
-		s->elemsize = PageSize/2;
-	} else {
-		// convert span of n>1 pages into two spans of n/2 pages each.
-		if((s->npages & 1) != 0)
-			runtime·throw("MHeap_SplitSpan on an odd size span");
-
-		// compute position in h->spans
-		p = s->start;
-		p -= (uintptr)h->arena_start >> PageShift;
-
-		// Allocate a new span for the first half.
-		t = runtime·FixAlloc_Alloc(&h->spanalloc);
-		runtime·MSpan_Init(t, s->start, npages/2);
-		t->limit = (byte*)((t->start + npages/2) << PageShift);
-		t->state = MSpanInUse;
-		t->elemsize = npages << (PageShift - 1);
-		t->sweepgen = s->sweepgen;
-		if(t->elemsize <= MaxSmallSize) {
-			t->sizeclass = runtime·SizeToClass(t->elemsize);
-			t->ref = 1;
-		}
-
-		// the old span holds the second half.
-		s->start += npages/2;
-		s->npages = npages/2;
-		s->elemsize = npages << (PageShift - 1);
-		if(s->elemsize <= MaxSmallSize) {
-			s->sizeclass = runtime·SizeToClass(s->elemsize);
-			s->ref = 1;
-		}
-
-		// update span lookup table
-		for(i = p; i < p + npages/2; i++)
-			h->spans[i] = t;
-	}
-
-	// place the span into a new list
-	if(s->sizeclass > 0) {
-		runtime·unlock(h);
-		c = &h->central[s->sizeclass];
-		runtime·lock(c);
-		// swept spans are at the end of the list
-		runtime·MSpanList_InsertBack(&c->empty, s);
-		runtime·unlock(c);
-	} else {
-		// Swept spans are at the end of lists.
-		if(s->npages < nelem(h->free))
-			runtime·MSpanList_InsertBack(&h->busy[s->npages], s);
-		else
-			runtime·MSpanList_InsertBack(&h->busylarge, s);
-		runtime·unlock(h);
-	}
-}