Files
sdk/runtime/vm/virtual_memory.cc
T
sgjesse@google.com 65896148c9 Move utils.h and utils.cc from runtime/vm to runtime/platform
Moved additional parts of globals.h from vm/ to platform/ to support
types and constants used by utils.*.

R=ager@google.com, iposva@google.com

BUG=
TEST=

Review URL: http://codereview.chromium.org//9209001

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@3337 260f80e4-7a28-3924-810f-c04153c831b5
2012-01-16 13:23:40 +00:00

41 lines
1.3 KiB
C++

// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#include "vm/virtual_memory.h"
#include "platform/assert.h"
#include "platform/utils.h"
namespace dart {
VirtualMemory* VirtualMemory::ReserveAligned(intptr_t size,
intptr_t alignment) {
ASSERT((size & (PageSize() - 1)) == 0);
ASSERT(Utils::IsPowerOfTwo(alignment));
ASSERT(alignment >= PageSize());
VirtualMemory* result = VirtualMemory::Reserve(size + alignment);
uword start = result->start();
uword real_start = (start + alignment - 1) & ~(alignment - 1);
result->Truncate(real_start, size);
return result;
}
void VirtualMemory::Truncate(uword new_start, intptr_t new_size) {
ASSERT(new_start >= start());
ASSERT((new_size & (PageSize() - 1)) == 0);
if (new_start > start()) {
uword split = new_start - start();
ASSERT((split & (PageSize() - 1)) == 0);
FreeSubSegment(address(), split);
region_.Subregion(region_, split, size() - split);
}
ASSERT(new_size <= size());
FreeSubSegment(reinterpret_cast<void*>(start() + new_size),
size() - new_size);
region_.Subregion(region_, 0, new_size);
}
} // namespace dart