Einsums BufferAllocator

This module contains an allocator that keeps track of how much memory has been allocated for buffers. The allocator is controlled by global configuration options.

See the API reference of this module for more details.

Interacting with the Allocator

To modify the allocator’s maximum size, set the string option “buffer-size” in the GlobalConfigMap to a memory string. A memory string is a number, possibly a decimal, followed by an optional prefix and unit. The understood prefixes are k, M, G, and T, all case insensitive. The units can either be B, W, or o, also case insensitive. The B and o units represent bytes, with the o provided for people who use the octet convention. The W unit represents words and are the size of size_t on the user’s system. On 64-bit systems, one word is generally eight bytes. The setting may be set in the program using the global option mentioned before or may be set on the command line using the –einsums:buffer-size option. The total amount of memory is shared among all processes, not on a per-process basis.

The BufferAllocator is a normal allocator. As such, it can be used in C++ containers and can be interacted with in the same way as other C++ allocators. Users must be careful when resizing allocations, though, as in order to resize an allocation, the full size of the final allocation will be requested before the original amount is freed, which can cause an out of memory exception. There are a few extra methods provided as well, though these are considered to be best for internal use.