| // 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 { |
| |
| bool VirtualMemory::InSamePage(uword address0, uword address1) { |
| return (Utils::RoundDown(address0, PageSize()) == |
| Utils::RoundDown(address1, PageSize())); |
| } |
| |
| void VirtualMemory::Truncate(intptr_t new_size) { |
| ASSERT(Utils::IsAligned(new_size, PageSize())); |
| ASSERT(new_size <= size()); |
| if (reserved_.size() == |
| region_.size()) { // Don't create holes in reservation. |
| FreeSubSegment(reinterpret_cast<void*>(start() + new_size), |
| size() - new_size); |
| reserved_.set_size(new_size); |
| if (AliasOffset() != 0) { |
| FreeSubSegment(reinterpret_cast<void*>(alias_.start() + new_size), |
| alias_.size() - new_size); |
| } |
| } |
| region_.Subregion(region_, 0, new_size); |
| alias_.Subregion(alias_, 0, new_size); |
| } |
| |
| VirtualMemory* VirtualMemory::ForImagePage(void* pointer, uword size) { |
| // Memory for precompilated instructions was allocated by the embedder, so |
| // create a VirtualMemory without allocating. |
| MemoryRegion region(pointer, size); |
| MemoryRegion reserved(0, 0); // NULL reservation indicates VM should not |
| // attempt to free this memory. |
| VirtualMemory* memory = new VirtualMemory(region, region, reserved); |
| ASSERT(!memory->vm_owns_region()); |
| return memory; |
| } |
| |
| } // namespace dart |