runtime: rename mheap.maps to mheap.spans

as was dicussed in cl/9791044

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/9853046

src/pkg/runtime/malloc.goc

@@ -374,7 +374,7 @@ runtime·mallocinit(void)
 		// If this fails we fall back to the 32 bit memory mechanism
 		arena_size = MaxMem;
 		bitmap_size = arena_size / (sizeof(void*)*8/4);
-		spans_size = arena_size / PageSize * sizeof(runtime·mheap.map[0]);
+		spans_size = arena_size / PageSize * sizeof(runtime·mheap.spans[0]);
 		p = runtime·SysReserve((void*)(0x00c0ULL<<32), bitmap_size + spans_size + arena_size);
 	}
 	if (p == nil) {
@@ -397,11 +397,11 @@ runtime·mallocinit(void)
 		// of address space, which is probably too much in a 32-bit world.
 		bitmap_size = MaxArena32 / (sizeof(void*)*8/4);
 		arena_size = 512<<20;
-		spans_size = MaxArena32 / PageSize * sizeof(runtime·mheap.map[0]);
+		spans_size = MaxArena32 / PageSize * sizeof(runtime·mheap.spans[0]);
 		if(limit > 0 && arena_size+bitmap_size+spans_size > limit) {
 			bitmap_size = (limit / 9) & ~((1<<PageShift) - 1);
 			arena_size = bitmap_size * 8;
-			spans_size = arena_size / PageSize * sizeof(runtime·mheap.map[0]);
+			spans_size = arena_size / PageSize * sizeof(runtime·mheap.spans[0]);
 		}
 
 		// SysReserve treats the address we ask for, end, as a hint,
@@ -424,7 +424,7 @@ runtime·mallocinit(void)
 	if((uintptr)p & (((uintptr)1<<PageShift)-1))
 		runtime·throw("runtime: SysReserve returned unaligned address");
 
-	runtime·mheap.map = (MSpan**)p;
+	runtime·mheap.spans = (MSpan**)p;
 	runtime·mheap.bitmap = p + spans_size;
 	runtime·mheap.arena_start = p + spans_size + bitmap_size;
 	runtime·mheap.arena_used = runtime·mheap.arena_start;
@@ -532,7 +532,7 @@ runtime·settype_flush(M *mp, bool sysalloc)
 		p = (uintptr)v>>PageShift;
 		if(sizeof(void*) == 8)
 			p -= (uintptr)runtime·mheap.arena_start >> PageShift;
-		s = runtime·mheap.map[p];
+		s = runtime·mheap.spans[p];
 
 		if(s->sizeclass == 0) {
 			s->types.compression = MTypes_Single;

src/pkg/runtime/malloc.h

@@ -411,7 +411,7 @@ struct MHeap
 	uint32	nspancap;
 
 	// span lookup
-	MSpan**	map;
+	MSpan**	spans;
 	uintptr	spans_mapped;
 
 	// range of addresses we might see in the heap

src/pkg/runtime/mgc0.c

@@ -230,7 +230,7 @@ markonly(void *obj)
 	x = k;
 	if(sizeof(void*) == 8)
 		x -= (uintptr)runtime·mheap.arena_start>>PageShift;
-	s = runtime·mheap.map[x];
+	s = runtime·mheap.spans[x];
 	if(s == nil || k < s->start || k - s->start >= s->npages || s->state != MSpanInUse)
 		return false;
 	p = (byte*)((uintptr)s->start<<PageShift);
@@ -410,7 +410,7 @@ flushptrbuf(PtrTarget *ptrbuf, PtrTarget **ptrbufpos, Obj **_wp, Workbuf **_wbuf
 			x = k;
 			if(sizeof(void*) == 8)
 				x -= (uintptr)arena_start>>PageShift;
-			s = runtime·mheap.map[x];
+			s = runtime·mheap.spans[x];
 			if(s == nil || k < s->start || k - s->start >= s->npages || s->state != MSpanInUse)
 				continue;
 			p = (byte*)((uintptr)s->start<<PageShift);
@@ -458,7 +458,7 @@ flushptrbuf(PtrTarget *ptrbuf, PtrTarget **ptrbufpos, Obj **_wp, Workbuf **_wbuf
 			x = (uintptr)obj >> PageShift;
 			if(sizeof(void*) == 8)
 				x -= (uintptr)arena_start>>PageShift;
-			s = runtime·mheap.map[x];
+			s = runtime·mheap.spans[x];
 
 			PREFETCH(obj);
 
@@ -575,7 +575,7 @@ checkptr(void *obj, uintptr objti)
 	x = (uintptr)obj >> PageShift;
 	if(sizeof(void*) == 8)
 		x -= (uintptr)(runtime·mheap.arena_start)>>PageShift;
-	s = runtime·mheap.map[x];
+	s = runtime·mheap.spans[x];
 	objstart = (byte*)((uintptr)s->start<<PageShift);
 	if(s->sizeclass != 0) {
 		i = ((byte*)obj - objstart)/s->elemsize;

src/pkg/runtime/mheap.c

@@ -75,11 +75,11 @@ runtime·MHeap_MapSpans(MHeap *h)
 	if(sizeof(void*) == 8)
 		n -= (uintptr)h->arena_start;
 	// Coalescing code reads spans past the end of mapped arena, thus +1.
-	n = (n / PageSize + 1) * sizeof(h->map[0]);
+	n = (n / PageSize + 1) * sizeof(h->spans[0]);
 	n = ROUND(n, PageSize);
 	if(h->spans_mapped >= n)
 		return;
-	runtime·SysMap((byte*)h->map + h->spans_mapped, n - h->spans_mapped);
+	runtime·SysMap((byte*)h->spans + h->spans_mapped, n - h->spans_mapped);
 	h->spans_mapped = n;
 }
 
@@ -172,9 +172,9 @@ HaveSpan:
 		if(sizeof(void*) == 8)
 			p -= ((uintptr)h->arena_start>>PageShift);
 		if(p > 0)
-			h->map[p-1] = s;
-		h->map[p] = t;
-		h->map[p+t->npages-1] = t;
+			h->spans[p-1] = s;
+		h->spans[p] = t;
+		h->spans[p+t->npages-1] = t;
 		*(uintptr*)(t->start<<PageShift) = *(uintptr*)(s->start<<PageShift);  // copy "needs zeroing" mark
 		t->state = MSpanInUse;
 		MHeap_FreeLocked(h, t);
@@ -191,7 +191,7 @@ HaveSpan:
 	if(sizeof(void*) == 8)
 		p -= ((uintptr)h->arena_start>>PageShift);
 	for(n=0; n<npage; n++)
-		h->map[p+n] = s;
+		h->spans[p+n] = s;
 	return s;
 }
 
@@ -262,8 +262,8 @@ MHeap_Grow(MHeap *h, uintptr npage)
 	p = s->start;
 	if(sizeof(void*) == 8)
 		p -= ((uintptr)h->arena_start>>PageShift);
-	h->map[p] = s;
-	h->map[p + s->npages - 1] = s;
+	h->spans[p] = s;
+	h->spans[p + s->npages - 1] = s;
 	s->state = MSpanInUse;
 	MHeap_FreeLocked(h, s);
 	return true;
@@ -280,7 +280,7 @@ runtime·MHeap_Lookup(MHeap *h, void *v)
 	p = (uintptr)v;
 	if(sizeof(void*) == 8)
 		p -= (uintptr)h->arena_start;
-	return h->map[p >> PageShift];
+	return h->spans[p >> PageShift];
 }
 
 // Look up the span at the given address.
@@ -302,7 +302,7 @@ runtime·MHeap_LookupMaybe(MHeap *h, void *v)
 	q = p;
 	if(sizeof(void*) == 8)
 		q -= (uintptr)h->arena_start >> PageShift;
-	s = h->map[q];
+	s = h->spans[q];
 	if(s == nil || p < s->start || p - s->start >= s->npages)
 		return nil;
 	if(s->state != MSpanInUse)
@@ -354,26 +354,26 @@ MHeap_FreeLocked(MHeap *h, MSpan *s)
 	p = s->start;
 	if(sizeof(void*) == 8)
 		p -= (uintptr)h->arena_start >> PageShift;
-	if(p > 0 && (t = h->map[p-1]) != nil && t->state != MSpanInUse) {
+	if(p > 0 && (t = h->spans[p-1]) != nil && t->state != MSpanInUse) {
 		tp = (uintptr*)(t->start<<PageShift);
 		*tp |= *sp;	// propagate "needs zeroing" mark
 		s->start = t->start;
 		s->npages += t->npages;
 		s->npreleased = t->npreleased; // absorb released pages
 		p -= t->npages;
-		h->map[p] = s;
+		h->spans[p] = s;
 		runtime·MSpanList_Remove(t);
 		t->state = MSpanDead;
 		runtime·FixAlloc_Free(&h->spanalloc, t);
 		mstats.mspan_inuse = h->spanalloc.inuse;
 		mstats.mspan_sys = h->spanalloc.sys;
 	}
-	if(p+s->npages < nelem(h->map) && (t = h->map[p+s->npages]) != nil && t->state != MSpanInUse) {
+	if(p+s->npages < nelem(h->spans) && (t = h->spans[p+s->npages]) != nil && t->state != MSpanInUse) {
 		tp = (uintptr*)(t->start<<PageShift);
 		*sp |= *tp;	// propagate "needs zeroing" mark
 		s->npages += t->npages;
 		s->npreleased += t->npreleased;
-		h->map[p + s->npages - 1] = s;
+		h->spans[p + s->npages - 1] = s;
 		runtime·MSpanList_Remove(t);
 		t->state = MSpanDead;
 		runtime·FixAlloc_Free(&h->spanalloc, t);