blob: d1a9277741ad6bfaf55ac8364ed74158f6c3ec19 [file] [log] [blame]
// 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/globals.h"
#if defined(TARGET_OS_WINDOWS)
#include "vm/virtual_memory.h"
#include "platform/assert.h"
namespace dart {
uword VirtualMemory::page_size_ = 0;
void VirtualMemory::InitOnce() {
SYSTEM_INFO info;
GetSystemInfo(&info);
page_size_ = info.dwPageSize;
}
VirtualMemory* VirtualMemory::Reserve(intptr_t size) {
void* address = VirtualAlloc(NULL, size, MEM_RESERVE, PAGE_NOACCESS);
if (address == NULL) {
return NULL;
}
MemoryRegion region(address, size);
return new VirtualMemory(region, address);
}
VirtualMemory::~VirtualMemory() {
if (size() == 0) {
return;
}
// Since sub-segments are not freed, free the entire virtual segment
// here by passing the originally reserved pointer to VirtualFree.
ASSERT(reserved_pointer_ != NULL);
if (VirtualFree(reserved_pointer_, 0, MEM_RELEASE) == 0) {
FATAL("VirtualFree failed");
}
}
void VirtualMemory::FreeSubSegment(void* address, intptr_t size) {
// On Windows only the entire segment returned by VirtualAlloc
// can be freed. Therefore we will have to waste these unused
// virtual memory sub-segments.
}
bool VirtualMemory::Commit(uword addr, intptr_t size, bool executable) {
ASSERT(Contains(addr));
ASSERT(Contains(addr + size) || (addr + size == end()));
int prot = executable ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE;
if (VirtualAlloc(address(), size, MEM_COMMIT, prot) == NULL) {
return false;
}
return true;
}
bool VirtualMemory::Protect(Protection mode) {
DWORD prot = 0;
switch (mode) {
case kNoAccess:
prot = PAGE_NOACCESS;
break;
case kReadOnly:
prot = PAGE_READONLY;
break;
case kReadWrite:
prot = PAGE_READWRITE;
break;
case kReadExecute:
prot = PAGE_EXECUTE_READ;
break;
case kReadWriteExecute:
prot = PAGE_EXECUTE_READWRITE;
break;
}
DWORD old_prot = 0;
return VirtualProtect(address(), size(), prot, &old_prot);
}
} // namespace dart
#endif // defined(TARGET_OS_WINDOWS)