Heap Allocator used in some versions of C, derived from dlmalloc. Uses a Data Segment with brk() and sbrk() to manage memory
Allocating
ptmalloc slices off bits of the Data Segment for small allocations and uses mmap() for large allocations
Freeing
- ptmalloc checks its mutliple BIns (free lists) for their sizes
- When a Heap Chunk is freed, we don’t immediately want to Coalesce it, we move it to a Tcache Bin, Fast Bin or a Unsorted Bin if none of the others match
- Malloc waits to see if you immediately reuse this chunk, if not, it will sort it into a small or large bin