| 摘要 |
<p>A system and method for memory allocation from a heap comprising memory blocks of a uniform fixed size. Each memory block has a status bit. A binary status key stores a Boolean value indicating free memory. The heap is scanned in order until a sequence of a requested quantity of free contiguous memory blocks is found or NULL is returned. Each scanned free memory block is marked un-free by assigning its status bit to the logical negative of the binary status key. If the end of the heap is reached before a sequence of sufficient quantity is found, all reachable blocks are marked as free. The binary status key is flipped such that all memory blocks which were marked free are now un-free, and vice versa. Any memory block whose corresponding structure has become unreferenced is reclaimed for future use. The scan then continues from the beginning of the heap. In another embodiment, a memory allocation for a partitioned data structure from a heap of fixed-size memory blocks may be used. The quantity of memory blocks required to store a data structure is determined. The required quantity of the memory blocks, which may be noncontiguous, is allocated from the heap. The allocated memory blocks are linked in a list such that the components of the data structure are partitioned in the proper order across the allocated quantity of memory blocks.</p> |
