CSimpleFixedSizedMemoryAllocator Class Reference
[Win32 Tools Library]
Detailed Description
A class that provides naive fixed sized memory allocation. Note that once the allocator has requested memory from the operating system it never returns it to the operating system, it simply keeps it around until another allocation request can use it. So, if you allocate 1000 1024 byte blocks and then free them all the allocator itself is still holding on to 1024000 bytes of memory. The allocator uses VirtualAlloc() to allocate the memory that it uses, this allows it to provide page aligned memory if requested to do so. It also means that internally it works in terms of multiples of the system's allocation granularity when allocating chunks of memory that it can slice up into blocks to return to the caller. Also, if you specify that you want page alignment and the memory block size that you're using is smaller than an exact page multiple then the difference between the block size and the next multiple of the page size will be 'wasted'.
Public Types | |
| enum | AllocationFlags { SizeInBytes = 0x00, SizeInPages = 0x01, SizeBitsMask = 0x0F, NoAlignment = 0x00, AlignOnPageSize = 0x10, AlignmentBitsMask = 0xF0 } |
| These flags are passed to the constructor of the allocator. SizeInBytes is the default flag and gives an allocator that allocates blocks of the specified size in bytes. Size in pages causes the allocator to treat your block size as a multiple of the system's page size, so by specifying this flag and a block size of 1 you are asking for a block that is the size of the system't memory page. You can OR the AlignOnPageSize flag with the SizeInBytes or SizeInPages flag to tell the allocator that you want each block that is allocated to be aligned on a page boundary. More... | |
Public Member Functions | |
| CSimpleFixedSizedMemoryAllocator (size_t blockSize, AllocationFlags allocationFlags=SizeInBytes) | |
| Create an allocator for memory blocks of the requested size. See AlocationFlags for details of how you can tune the allocators allocation strategy. | |
| CSimpleFixedSizedMemoryAllocator (const AllocationTuningParameters &tuningParams, size_t blockSize, AllocationFlags allocationFlags=SizeInBytes) | |
| Create an allocator for memory blocks of the requested size using the supplied allocation tuning parameters. See AlocationFlags for details of how you can tune the allocators allocation strategy. | |
| CSimpleFixedSizedMemoryAllocator (const CSimpleFixedSizedMemoryAllocator &rhs) | |
| ~CSimpleFixedSizedMemoryAllocator () override | |
| Destroys the allocator, note that any blocks that are still allocated when the allocator is destroyed are no longer usable as the underlying memory will be released back to the operating system. | |
| CSimpleFixedSizedMemoryAllocator & | operator= (const CSimpleFixedSizedMemoryAllocator &rhs) |
| size_t | GetAllocationSize () const override |
| Returns the size of the allocated blocks. | |
| void * | Allocate () override |
| Allocate a block of memory. | |
| void | Free (void *pMem) override |
| Release a block of memory back to the allocator for reuse. | |
Classes | |
| struct | AllocationTuningParameters |
Member Enumeration Documentation
| enum AllocationFlags |
These flags are passed to the constructor of the allocator. SizeInBytes is the default flag and gives an allocator that allocates blocks of the specified size in bytes. Size in pages causes the allocator to treat your block size as a multiple of the system's page size, so by specifying this flag and a block size of 1 you are asking for a block that is the size of the system't memory page. You can OR the AlignOnPageSize flag with the SizeInBytes or SizeInPages flag to tell the allocator that you want each block that is allocated to be aligned on a page boundary.
Constructor & Destructor Documentation
| CSimpleFixedSizedMemoryAllocator | ( | size_t | blockSize, | |
| AllocationFlags | allocationFlags = SizeInBytes | |||
| ) | [explicit] |
Create an allocator for memory blocks of the requested size. See AlocationFlags for details of how you can tune the allocators allocation strategy.
| CSimpleFixedSizedMemoryAllocator | ( | const AllocationTuningParameters & | tuningParams, | |
| size_t | blockSize, | |||
| AllocationFlags | allocationFlags = SizeInBytes | |||
| ) |
Create an allocator for memory blocks of the requested size using the supplied allocation tuning parameters. See AlocationFlags for details of how you can tune the allocators allocation strategy.
| CSimpleFixedSizedMemoryAllocator | ( | const CSimpleFixedSizedMemoryAllocator & | rhs | ) |
| ~CSimpleFixedSizedMemoryAllocator | ( | ) | [override] |
Destroys the allocator, note that any blocks that are still allocated when the allocator is destroyed are no longer usable as the underlying memory will be released back to the operating system.
Member Function Documentation
| CSimpleFixedSizedMemoryAllocator& operator= | ( | const CSimpleFixedSizedMemoryAllocator & | rhs | ) |
| size_t GetAllocationSize | ( | ) | const [override, virtual] |
| void * Allocate | ( | ) | [override, virtual] |
| void Free | ( | void * | pMem | ) | [override, virtual] |
