| // 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(HOST_OS_WINDOWS) |
| |
| #include "vm/virtual_memory.h" |
| |
| #include "platform/assert.h" |
| #include "vm/os.h" |
| |
| #include "vm/isolate.h" |
| |
| namespace dart { |
| |
| uword VirtualMemory::page_size_ = 0; |
| |
| void VirtualMemory::Init() { |
| SYSTEM_INFO info; |
| GetSystemInfo(&info); |
| page_size_ = info.dwPageSize; |
| } |
| |
| VirtualMemory* VirtualMemory::Allocate(intptr_t size, |
| bool is_executable, |
| const char* name) { |
| ASSERT(Utils::IsAligned(size, page_size_)); |
| int prot = is_executable ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE; |
| void* address = VirtualAlloc(NULL, size, MEM_RESERVE | MEM_COMMIT, prot); |
| if (address == NULL) { |
| return NULL; |
| } |
| MemoryRegion region(address, size); |
| return new VirtualMemory(region, region); |
| } |
| |
| VirtualMemory* VirtualMemory::AllocateAligned(intptr_t size, |
| intptr_t alignment, |
| bool is_executable, |
| const char* name) { |
| ASSERT(Utils::IsAligned(size, page_size_)); |
| ASSERT(Utils::IsAligned(alignment, page_size_)); |
| intptr_t reserved_size = size + alignment; |
| int prot = is_executable ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE; |
| void* address = VirtualAlloc(NULL, reserved_size, MEM_RESERVE, prot); |
| if (address == NULL) { |
| return NULL; |
| } |
| |
| void* aligned_address = reinterpret_cast<void*>( |
| Utils::RoundUp(reinterpret_cast<uword>(address), alignment)); |
| if (VirtualAlloc(aligned_address, size, MEM_COMMIT, prot) != |
| aligned_address) { |
| VirtualFree(address, reserved_size, MEM_RELEASE); |
| return NULL; |
| } |
| |
| MemoryRegion region(aligned_address, size); |
| MemoryRegion reserved(address, reserved_size); |
| return new VirtualMemory(region, reserved); |
| } |
| |
| VirtualMemory::~VirtualMemory() { |
| // Note that the size of the reserved region might be set to 0 by |
| // Truncate(0, true) but that does not actually release the mapping |
| // itself. The only way to release the mapping is to invoke VirtualFree |
| // with original base pointer and MEM_RELEASE. |
| if (!vm_owns_region()) { |
| return; |
| } |
| if (VirtualFree(reserved_.pointer(), 0, MEM_RELEASE) == 0) { |
| FATAL1("VirtualFree failed: Error code %d\n", GetLastError()); |
| } |
| } |
| |
| bool VirtualMemory::FreeSubSegment(void* address, |
| intptr_t size) { |
| if (VirtualFree(address, size, MEM_DECOMMIT) == 0) { |
| FATAL1("VirtualFree failed: Error code %d\n", GetLastError()); |
| } |
| return true; |
| } |
| |
| void VirtualMemory::Protect(void* address, intptr_t size, Protection mode) { |
| #if defined(DEBUG) |
| Thread* thread = Thread::Current(); |
| ASSERT((thread == nullptr) || thread->IsMutatorThread() || |
| thread->isolate()->mutator_thread()->IsAtSafepoint()); |
| #endif |
| 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) { |
| FATAL1("VirtualProtect failed %d\n", GetLastError()); |
| } |
| } |
| |
| } // namespace dart |
| |
| #endif // defined(HOST_OS_WINDOWS) |