4 ms·

Seems interesting; but what happens when 1 thread allocates memory, passes it to another thread and ends? There does not seem to be a way to change ownership of

• maniccoder 10y ago
  Memory blocks are owned by the span (the page-aligned larger bucket of blocks) they belong to. While a span is in use (at least on block is allocated) it is indeed owned by the heap that allocates the block. When the span is completely freed, ownership is released. In your case, the block will be marked as free for allocation. If it is the last used block in that span, the span will eventually be returned to the global cache and reused by other heaps/threads when the owner thread ends. If the span is still used, it will remain in the heap until the heap is picked up by another thread. Heaps are reused as threads are joined and created (i.e number of allocated heaps are the maximum number of concurrent threads since process started). The worst case is that one thread allocates blocks, hands them off to other threads then ends, and that the process never creates additional threads. In this case, the spans will remain mapped and unused. I have planned to allow other threads to pick up and collect spans from unused heaps at some point to solve this.
  • ckok 10y ago
    that's pretty cool. Is there a way to track progress on reuse (like an issue I can follow)?
    • maniccoder 10y ago
      https://github.com/rampantpixels/rpmalloc/issues/6 https://github.com/rampantpixels/rpmalloc/issues/6