Imported Upstream version 1.4upstream/1.4

1 files changed, 396 insertions, 0 deletions

diff --git a/src/runtime/malloc.c b/src/runtime/malloc.c
new file mode 100644
index 000000000..b79c30b72
--- /dev/null
+++ b/src/runtime/malloc.c
@@ -0,0 +1,396 @@
+// 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.
+
+// See malloc.h for overview.
+//
+// TODO(rsc): double-check stats.
+
+#include "runtime.h"
+#include "arch_GOARCH.h"
+#include "malloc.h"
+#include "type.h"
+#include "typekind.h"
+#include "race.h"
+#include "stack.h"
+#include "textflag.h"
+
+// Mark mheap as 'no pointers', it does not contain interesting pointers but occupies ~45K.
+#pragma dataflag NOPTR
+MHeap runtime·mheap;
+#pragma dataflag NOPTR
+MStats runtime·memstats;
+
+int32
+runtime·mlookup(void *v, byte **base, uintptr *size, MSpan **sp)
+{
+	uintptr n, i;
+	byte *p;
+	MSpan *s;
+
+	g->m->mcache->local_nlookup++;
+	if (sizeof(void*) == 4 && g->m->mcache->local_nlookup >= (1<<30)) {
+		// purge cache stats to prevent overflow
+		runtime·lock(&runtime·mheap.lock);
+		runtime·purgecachedstats(g->m->mcache);
+		runtime·unlock(&runtime·mheap.lock);
+	}
+
+	s = runtime·MHeap_LookupMaybe(&runtime·mheap, v);
+	if(sp)
+		*sp = s;
+	if(s == nil) {
+		if(base)
+			*base = nil;
+		if(size)
+			*size = 0;
+		return 0;
+	}
+
+	p = (byte*)((uintptr)s->start<<PageShift);
+	if(s->sizeclass == 0) {
+		// Large object.
+		if(base)
+			*base = p;
+		if(size)
+			*size = s->npages<<PageShift;
+		return 1;
+	}
+
+	n = s->elemsize;
+	if(base) {
+		i = ((byte*)v - p)/n;
+		*base = p + i*n;
+	}
+	if(size)
+		*size = n;
+
+	return 1;
+}
+
+#pragma textflag NOSPLIT
+void
+runtime·purgecachedstats(MCache *c)
+{
+	MHeap *h;
+	int32 i;
+
+	// Protected by either heap or GC lock.
+	h = &runtime·mheap;
+	mstats.heap_alloc += c->local_cachealloc;
+	c->local_cachealloc = 0;
+	mstats.tinyallocs += c->local_tinyallocs;
+	c->local_tinyallocs = 0;
+	mstats.nlookup += c->local_nlookup;
+	c->local_nlookup = 0;
+	h->largefree += c->local_largefree;
+	c->local_largefree = 0;
+	h->nlargefree += c->local_nlargefree;
+	c->local_nlargefree = 0;
+	for(i=0; i<nelem(c->local_nsmallfree); i++) {
+		h->nsmallfree[i] += c->local_nsmallfree[i];
+		c->local_nsmallfree[i] = 0;
+	}
+}
+
+// Size of the trailing by_size array differs between Go and C,
+// and all data after by_size is local to C, not exported to Go.
+// NumSizeClasses was changed, but we can not change Go struct because of backward compatibility.
+// sizeof_C_MStats is what C thinks about size of Go struct.
+uintptr runtime·sizeof_C_MStats = offsetof(MStats, by_size[61]);
+
+#define MaxArena32 (2U<<30)
+
+// For use by Go. If it were a C enum it would be made available automatically,
+// but the value of MaxMem is too large for enum.
+uintptr runtime·maxmem = MaxMem;
+
+void
+runtime·mallocinit(void)
+{
+	byte *p, *p1;
+	uintptr arena_size, bitmap_size, spans_size, p_size;
+	extern byte runtime·end[];
+	uintptr limit;
+	uint64 i;
+	bool reserved;
+
+	p = nil;
+	p_size = 0;
+	arena_size = 0;
+	bitmap_size = 0;
+	spans_size = 0;
+	reserved = false;
+
+	// for 64-bit build
+	USED(p);
+	USED(p_size);
+	USED(arena_size);
+	USED(bitmap_size);
+	USED(spans_size);
+
+	runtime·InitSizes();
+
+	if(runtime·class_to_size[TinySizeClass] != TinySize)
+		runtime·throw("bad TinySizeClass");
+
+	// limit = runtime·memlimit();
+	// See https://code.google.com/p/go/issues/detail?id=5049
+	// TODO(rsc): Fix after 1.1.
+	limit = 0;
+
+	// Set up the allocation arena, a contiguous area of memory where
+	// allocated data will be found.  The arena begins with a bitmap large
+	// enough to hold 4 bits per allocated word.
+	if(sizeof(void*) == 8 && (limit == 0 || limit > (1<<30))) {
+		// On a 64-bit machine, allocate from a single contiguous reservation.
+		// 128 GB (MaxMem) should be big enough for now.
+		//
+		// The code will work with the reservation at any address, but ask
+		// SysReserve to use 0x0000XXc000000000 if possible (XX=00...7f).
+		// Allocating a 128 GB region takes away 37 bits, and the amd64
+		// doesn't let us choose the top 17 bits, so that leaves the 11 bits
+		// in the middle of 0x00c0 for us to choose.  Choosing 0x00c0 means
+		// that the valid memory addresses will begin 0x00c0, 0x00c1, ..., 0x00df.
+		// In little-endian, that's c0 00, c1 00, ..., df 00. None of those are valid
+		// UTF-8 sequences, and they are otherwise as far away from 
+		// ff (likely a common byte) as possible.  If that fails, we try other 0xXXc0
+		// addresses.  An earlier attempt to use 0x11f8 caused out of memory errors
+		// on OS X during thread allocations.  0x00c0 causes conflicts with
+		// AddressSanitizer which reserves all memory up to 0x0100.
+		// These choices are both for debuggability and to reduce the
+		// odds of the conservative garbage collector not collecting memory
+		// because some non-pointer block of memory had a bit pattern
+		// that matched a memory address.
+		//
+		// Actually we reserve 136 GB (because the bitmap ends up being 8 GB)
+		// but it hardly matters: e0 00 is not valid UTF-8 either.
+		//
+		// 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.spans[0]);
+		spans_size = ROUND(spans_size, PageSize);
+		for(i = 0; i <= 0x7f; i++) {
+			p = (void*)(i<<40 | 0x00c0ULL<<32);
+			p_size = bitmap_size + spans_size + arena_size + PageSize;
+			p = runtime·SysReserve(p, p_size, &reserved);
+			if(p != nil)
+				break;
+		}
+	}
+	if (p == nil) {
+		// On a 32-bit machine, we can't typically get away
+		// with a giant virtual address space reservation.
+		// Instead we map the memory information bitmap
+		// immediately after the data segment, large enough
+		// to handle another 2GB of mappings (256 MB),
+		// along with a reservation for another 512 MB of memory.
+		// When that gets used up, we'll start asking the kernel
+		// for any memory anywhere and hope it's in the 2GB
+		// following the bitmap (presumably the executable begins
+		// near the bottom of memory, so we'll have to use up
+		// most of memory before the kernel resorts to giving out
+		// memory before the beginning of the text segment).
+		//
+		// Alternatively we could reserve 512 MB bitmap, enough
+		// for 4GB of mappings, and then accept any memory the
+		// kernel threw at us, but normally that's a waste of 512 MB
+		// 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.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.spans[0]);
+		}
+		spans_size = ROUND(spans_size, PageSize);
+
+		// SysReserve treats the address we ask for, end, as a hint,
+		// not as an absolute requirement.  If we ask for the end
+		// of the data segment but the operating system requires
+		// a little more space before we can start allocating, it will
+		// give out a slightly higher pointer.  Except QEMU, which
+		// is buggy, as usual: it won't adjust the pointer upward.
+		// So adjust it upward a little bit ourselves: 1/4 MB to get
+		// away from the running binary image and then round up
+		// to a MB boundary.
+		p = (byte*)ROUND((uintptr)runtime·end + (1<<18), 1<<20);
+		p_size = bitmap_size + spans_size + arena_size + PageSize;
+		p = runtime·SysReserve(p, p_size, &reserved);
+		if(p == nil)
+			runtime·throw("runtime: cannot reserve arena virtual address space");
+	}
+
+	// PageSize can be larger than OS definition of page size,
+	// so SysReserve can give us a PageSize-unaligned pointer.
+	// To overcome this we ask for PageSize more and round up the pointer.
+	p1 = (byte*)ROUND((uintptr)p, PageSize);
+
+	runtime·mheap.spans = (MSpan**)p1;
+	runtime·mheap.bitmap = p1 + spans_size;
+	runtime·mheap.arena_start = p1 + spans_size + bitmap_size;
+	runtime·mheap.arena_used = runtime·mheap.arena_start;
+	runtime·mheap.arena_end = p + p_size;
+	runtime·mheap.arena_reserved = reserved;
+
+	if(((uintptr)runtime·mheap.arena_start & (PageSize-1)) != 0)
+		runtime·throw("misrounded allocation in mallocinit");
+
+	// Initialize the rest of the allocator.	
+	runtime·MHeap_Init(&runtime·mheap);
+	g->m->mcache = runtime·allocmcache();
+}
+
+void*
+runtime·MHeap_SysAlloc(MHeap *h, uintptr n)
+{
+	byte *p, *p_end;
+	uintptr p_size;
+	bool reserved;
+
+	if(n > h->arena_end - h->arena_used) {
+		// We are in 32-bit mode, maybe we didn't use all possible address space yet.
+		// Reserve some more space.
+		byte *new_end;
+
+		p_size = ROUND(n + PageSize, 256<<20);
+		new_end = h->arena_end + p_size;
+		if(new_end <= h->arena_start + MaxArena32) {
+			// TODO: It would be bad if part of the arena
+			// is reserved and part is not.
+			p = runtime·SysReserve(h->arena_end, p_size, &reserved);
+			if(p == h->arena_end) {
+				h->arena_end = new_end;
+				h->arena_reserved = reserved;
+			}
+			else if(p+p_size <= h->arena_start + MaxArena32) {
+				// Keep everything page-aligned.
+				// Our pages are bigger than hardware pages.
+				h->arena_end = p+p_size;
+				h->arena_used = p + (-(uintptr)p&(PageSize-1));
+				h->arena_reserved = reserved;
+			} else {
+				uint64 stat;
+				stat = 0;
+				runtime·SysFree(p, p_size, &stat);
+			}
+		}
+	}
+	if(n <= h->arena_end - h->arena_used) {
+		// Keep taking from our reservation.
+		p = h->arena_used;
+		runtime·SysMap(p, n, h->arena_reserved, &mstats.heap_sys);
+		h->arena_used += n;
+		runtime·MHeap_MapBits(h);
+		runtime·MHeap_MapSpans(h);
+		if(raceenabled)
+			runtime·racemapshadow(p, n);
+		
+		if(((uintptr)p & (PageSize-1)) != 0)
+			runtime·throw("misrounded allocation in MHeap_SysAlloc");
+		return p;
+	}
+	
+	// If using 64-bit, our reservation is all we have.
+	if(h->arena_end - h->arena_start >= MaxArena32)
+		return nil;
+
+	// On 32-bit, once the reservation is gone we can
+	// try to get memory at a location chosen by the OS
+	// and hope that it is in the range we allocated bitmap for.
+	p_size = ROUND(n, PageSize) + PageSize;
+	p = runtime·sysAlloc(p_size, &mstats.heap_sys);
+	if(p == nil)
+		return nil;
+
+	if(p < h->arena_start || p+p_size - h->arena_start >= MaxArena32) {
+		runtime·printf("runtime: memory allocated by OS (%p) not in usable range [%p,%p)\n",
+			p, h->arena_start, h->arena_start+MaxArena32);
+		runtime·SysFree(p, p_size, &mstats.heap_sys);
+		return nil;
+	}
+	
+	p_end = p + p_size;
+	p += -(uintptr)p & (PageSize-1);
+	if(p+n > h->arena_used) {
+		h->arena_used = p+n;
+		if(p_end > h->arena_end)
+			h->arena_end = p_end;
+		runtime·MHeap_MapBits(h);
+		runtime·MHeap_MapSpans(h);
+		if(raceenabled)
+			runtime·racemapshadow(p, n);
+	}
+	
+	if(((uintptr)p & (PageSize-1)) != 0)
+		runtime·throw("misrounded allocation in MHeap_SysAlloc");
+	return p;
+}
+
+void
+runtime·setFinalizer_m(void)
+{
+	FuncVal *fn;
+	void *arg;
+	uintptr nret;
+	Type *fint;
+	PtrType *ot;
+
+	fn = g->m->ptrarg[0];
+	arg = g->m->ptrarg[1];
+	nret = g->m->scalararg[0];
+	fint = g->m->ptrarg[2];
+	ot = g->m->ptrarg[3];
+	g->m->ptrarg[0] = nil;
+	g->m->ptrarg[1] = nil;
+	g->m->ptrarg[2] = nil;
+	g->m->ptrarg[3] = nil;
+
+	g->m->scalararg[0] = runtime·addfinalizer(arg, fn, nret, fint, ot);
+}
+
+void
+runtime·removeFinalizer_m(void)
+{
+	void *p;
+
+	p = g->m->ptrarg[0];
+	g->m->ptrarg[0] = nil;
+	runtime·removefinalizer(p);
+}
+
+// mcallable cache refill
+void 
+runtime·mcacheRefill_m(void)
+{
+	runtime·MCache_Refill(g->m->mcache, (int32)g->m->scalararg[0]);
+}
+
+void
+runtime·largeAlloc_m(void)
+{
+	uintptr npages, size;
+	MSpan *s;
+	void *v;
+	int32 flag;
+
+	//runtime·printf("largeAlloc size=%D\n", g->m->scalararg[0]);
+	// Allocate directly from heap.
+	size = g->m->scalararg[0];
+	flag = (int32)g->m->scalararg[1];
+	if(size + PageSize < size)
+		runtime·throw("out of memory");
+	npages = size >> PageShift;
+	if((size & PageMask) != 0)
+		npages++;
+	s = runtime·MHeap_Alloc(&runtime·mheap, npages, 0, 1, !(flag & FlagNoZero));
+	if(s == nil)
+		runtime·throw("out of memory");
+	s->limit = (byte*)(s->start<<PageShift) + size;
+	v = (void*)(s->start << PageShift);
+	// setup for mark sweep
+	runtime·markspan(v, 0, 0, true);
+	g->m->ptrarg[0] = s;
+}