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// Copyright (c) 2021, 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 "platform/globals.h"
#if defined(DART_HOST_OS_WINDOWS)
#include "bin/virtual_memory.h"
#include "platform/assert.h"
#include "platform/utils.h"
namespace dart {
namespace bin {
uword VirtualMemory::page_size_ = 0;
intptr_t VirtualMemory::CalculatePageSize() {
SYSTEM_INFO info;
GetSystemInfo(&info);
const intptr_t page_size = info.dwPageSize;
ASSERT(page_size != 0);
ASSERT(Utils::IsPowerOfTwo(page_size));
return page_size;
}
VirtualMemory* VirtualMemory::Allocate(intptr_t size,
bool is_executable,
const char* name) {
ASSERT(Utils::IsAligned(size, PageSize()));
int prot = is_executable ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE;
void* address = VirtualAlloc(nullptr, size, MEM_RESERVE | MEM_COMMIT, prot);
if (address == nullptr) {
return nullptr;
}
return new VirtualMemory(address, size);
}
VirtualMemory::~VirtualMemory() {
if (address_ != nullptr) {
if (VirtualFree(address_, 0, MEM_RELEASE) == 0) {
FATAL("VirtualFree failed: Error code %d\n", GetLastError());
}
}
}
void VirtualMemory::Protect(void* address, intptr_t size, Protection mode) {
uword start_address = reinterpret_cast<uword>(address);
uword end_address = start_address + size;
uword page_address = Utils::RoundDown(start_address, PageSize());
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;
if (VirtualProtect(reinterpret_cast<void*>(page_address),
end_address - page_address, prot, &old_prot) == 0) {
FATAL("VirtualProtect failed %d\n", GetLastError());
}
}
} // namespace bin
} // namespace dart
#endif // defined(DART_HOST_OS_WINDOWS)