| // Copyright 2012 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef V8_ALLOCATION_H_ |
| #define V8_ALLOCATION_H_ |
| |
| #include "include/v8-platform.h" |
| #include "src/base/compiler-specific.h" |
| #include "src/base/platform/platform.h" |
| #include "src/globals.h" |
| #include "src/v8.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| // This file defines memory allocation functions. If a first attempt at an |
| // allocation fails, these functions call back into the embedder, then attempt |
| // the allocation a second time. The embedder callback must not reenter V8. |
| |
| // Called when allocation routines fail to allocate, even with a possible retry. |
| // This function should not return, but should terminate the current processing. |
| V8_EXPORT_PRIVATE void FatalProcessOutOfMemory(const char* message); |
| |
| // Superclass for classes managed with new & delete. |
| class V8_EXPORT_PRIVATE Malloced { |
| public: |
| void* operator new(size_t size) { return New(size); } |
| void operator delete(void* p) { Delete(p); } |
| |
| static void* New(size_t size); |
| static void Delete(void* p); |
| }; |
| |
| template <typename T> |
| T* NewArray(size_t size) { |
| T* result = new (std::nothrow) T[size]; |
| if (result == nullptr) { |
| V8::GetCurrentPlatform()->OnCriticalMemoryPressure(); |
| result = new (std::nothrow) T[size]; |
| if (result == nullptr) FatalProcessOutOfMemory("NewArray"); |
| } |
| return result; |
| } |
| |
| template <typename T, |
| typename = typename std::enable_if<IS_TRIVIALLY_COPYABLE(T)>::type> |
| T* NewArray(size_t size, T default_val) { |
| T* result = reinterpret_cast<T*>(NewArray<uint8_t>(sizeof(T) * size)); |
| for (size_t i = 0; i < size; ++i) result[i] = default_val; |
| return result; |
| } |
| |
| template <typename T> |
| void DeleteArray(T* array) { |
| delete[] array; |
| } |
| |
| |
| // The normal strdup functions use malloc. These versions of StrDup |
| // and StrNDup uses new and calls the FatalProcessOutOfMemory handler |
| // if allocation fails. |
| V8_EXPORT_PRIVATE char* StrDup(const char* str); |
| char* StrNDup(const char* str, int n); |
| |
| |
| // Allocation policy for allocating in the C free store using malloc |
| // and free. Used as the default policy for lists. |
| class FreeStoreAllocationPolicy { |
| public: |
| INLINE(void* New(size_t size)) { return Malloced::New(size); } |
| INLINE(static void Delete(void* p)) { Malloced::Delete(p); } |
| }; |
| |
| |
| void* AlignedAlloc(size_t size, size_t alignment); |
| void AlignedFree(void *ptr); |
| |
| // Represents and controls an area of reserved memory. |
| class V8_EXPORT_PRIVATE VirtualMemory { |
| public: |
| // Empty VirtualMemory object, controlling no reserved memory. |
| VirtualMemory(); |
| |
| // Reserves virtual memory with size. |
| explicit VirtualMemory(size_t size, void* hint); |
| |
| // Reserves virtual memory containing an area of the given size that |
| // is aligned per alignment. This may not be at the position returned |
| // by address(). |
| VirtualMemory(size_t size, size_t alignment, void* hint); |
| |
| // Construct a virtual memory by assigning it some already mapped address |
| // and size. |
| VirtualMemory(void* address, size_t size) : address_(address), size_(size) {} |
| |
| // Releases the reserved memory, if any, controlled by this VirtualMemory |
| // object. |
| ~VirtualMemory(); |
| |
| // Returns whether the memory has been reserved. |
| bool IsReserved() const { return address_ != nullptr; } |
| |
| // Initialize or resets an embedded VirtualMemory object. |
| void Reset(); |
| |
| // Returns the start address of the reserved memory. |
| // If the memory was reserved with an alignment, this address is not |
| // necessarily aligned. The user might need to round it up to a multiple of |
| // the alignment to get the start of the aligned block. |
| void* address() const { |
| DCHECK(IsReserved()); |
| return address_; |
| } |
| |
| void* end() const { |
| DCHECK(IsReserved()); |
| return reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(address_) + |
| size_); |
| } |
| |
| // Returns the size of the reserved memory. The returned value is only |
| // meaningful when IsReserved() returns true. |
| // If the memory was reserved with an alignment, this size may be larger |
| // than the requested size. |
| size_t size() const { return size_; } |
| |
| // Commits real memory. Returns whether the operation succeeded. |
| bool Commit(void* address, size_t size, bool is_executable); |
| |
| // Uncommit real memory. Returns whether the operation succeeded. |
| bool Uncommit(void* address, size_t size); |
| |
| // Creates a single guard page at the given address. |
| bool Guard(void* address); |
| |
| // Releases the memory after |free_start|. Returns the bytes released. |
| size_t ReleasePartial(void* free_start); |
| |
| void Release(); |
| |
| // Assign control of the reserved region to a different VirtualMemory object. |
| // The old object is no longer functional (IsReserved() returns false). |
| void TakeControl(VirtualMemory* from); |
| |
| bool InVM(void* address, size_t size) { |
| return (reinterpret_cast<uintptr_t>(address_) <= |
| reinterpret_cast<uintptr_t>(address)) && |
| ((reinterpret_cast<uintptr_t>(address_) + size_) >= |
| (reinterpret_cast<uintptr_t>(address) + size)); |
| } |
| |
| private: |
| void* address_; // Start address of the virtual memory. |
| size_t size_; // Size of the virtual memory. |
| }; |
| |
| bool AllocVirtualMemory(size_t size, void* hint, VirtualMemory* result); |
| bool AlignedAllocVirtualMemory(size_t size, size_t alignment, void* hint, |
| VirtualMemory* result); |
| |
| // Generate a random address to be used for hinting mmap(). |
| V8_EXPORT_PRIVATE void* GetRandomMmapAddr(); |
| |
| } // namespace internal |
| } // namespace v8 |
| |
| #endif // V8_ALLOCATION_H_ |