Free a block fast path written carefully to prevent spilling on the stack

OS (small) page size

Segment belonging to a page

Get the block size of a page (special case for huge objects)

--------------------------------------------------------------------------- Helper functions ---------------------------------------------------------

Segment that contains the pointer Large aligned blocks may be aligned at N*MI_SEGMENT_SIZE (inside a huge segment > MI_SEGMENT_SIZE), and we need alig

Align upwards

Heap access

must be thread safe as it is called from stats_merge

Get the usable block size of a page without fixed padding. This may still include internal padding due to alignment and rounding up size classes.

Get the head of the list.

These are used by the statistics

Get the field index from a bit index.

----------------------------------------------------------- Page flags -----------------------------------------------------------

size of a segment

Quick page start for initialized pages

The bit mask for a given number of blocks at a specified bit index.

are there immediately available blocks, i.e. blocks available on the free list.

Return the end of the current chunk.

Return the end of the current chunk.

Safe multiply `count*size` into `total`; return `true` on overflow.

Unmap pages from virtual memory

Get the page containing the pointer

are all blocks in a page freed? note: needs up-to-date used count, (as the `xthread_free` list may not be empty). see `_mi_page_collect_free`.

Divide upwards: `s <= _mi_divide_up(s,d)*d < s+d`.

Get the span size class from page count

Clear the list.