dgrove@google.com
4c0f559d23
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@15 260f80e4-7a28-3924-810f-c04153c831b5
62 lines
1.6 KiB
C++
62 lines
1.6 KiB
C++
// Copyright (c) 2011, the Dart project authors. Please see the AUTHORS file
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// for details. All rights reserved. Use of this source code is governed by a
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// BSD-style license that can be found in the LICENSE file.
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#include "vm/virtual_memory.h"
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#include "vm/assert.h"
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namespace dart {
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uword VirtualMemory::page_size_ = 0;
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void VirtualMemory::InitOnce() {
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SYSTEM_INFO info;
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GetSystemInfo(&info);
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page_size_ = info.dwPageSize;
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}
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VirtualMemory* VirtualMemory::Reserve(intptr_t size) {
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void* address = VirtualAlloc(NULL, size, MEM_RESERVE, PAGE_NOACCESS);
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if (address == NULL) {
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return NULL;
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}
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MemoryRegion region(address, size);
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return new VirtualMemory(region, address);
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}
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VirtualMemory::~VirtualMemory() {
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if (size() == 0) {
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return;
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}
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// Since sub-segments are not freed, free the entire virtual segment
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// here by passing the originally reserved pointer to VirtualFree.
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ASSERT(reserved_pointer_ != NULL);
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if (VirtualFree(reserved_pointer_, 0, MEM_RELEASE) == 0) {
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FATAL("VirtualFree failed");
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}
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}
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void VirtualMemory::FreeSubSegment(void* address, intptr_t size) {
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// On Windows only the entire segment returned by VirtualAlloc
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// can be freed. Therefore we will have to waste these unused
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// virtual memory sub-segments.
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}
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bool VirtualMemory::Commit(uword addr, intptr_t size, bool executable) {
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ASSERT(Contains(addr));
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ASSERT(Contains(addr + size) || (addr + size == end()));
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int prot = executable ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE;
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if (VirtualAlloc(address(), size, MEM_COMMIT, prot) == NULL) {
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return false;
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}
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return true;
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}
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} // namespace dart
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