How to write a thread-safe and efficient, lock-free memory allocator in C?

Question

How to write a thread-safe and efficient, lock-free memory allocator in C? By efficient I mean:

1. Fast allocation & deallocation

2. Optimal memor

Answer 1

Depends on what you mean by efficiency. If my concern was to make things fast, then I would probably give each thread it's own separate memory pool to work with, and a custom 'malloc' that took memory from that pool. Of course, if my concern was speed, I would probably avoid allocation in the first place.

There is no one answer; you'll be balancing a range of concerns. It will be pretty much impossible to get a lock-free allocator, but you can either do the locking early and infrequently ( by allocating large pools for each thread ) or you can make the locks so small and tight that they must be correct.