The split managed one ordering constraint: arena_choose() had to be
defined before arena_choose_maybe_huge() but after the tsd/tcache
inlines it depends on. After the malloc_dispatch refactor moved the
heaviest tcache-pulling inlines out of arena_inlines_b.h, the
remaining arena-side inlines all belong together. The merged
arena_inlines.h explicitly includes jemalloc_internal_inlines_a.h
and tcache.h (previously transitively pulled).
arena_types.h + arena_structs.h + arena_externs.h merged into arena.h,
keeping the three logical sections (TYPES / STRUCTS / EXTERNS) with
explicit dividers. arena_inlines_a.h and arena_inlines_b.h stay
separate; arena_inlines_b.h now carries a comment explaining why
merging the two would reintroduce a real #include cycle through
tcache_inlines.h -> arena_choose (the asymmetric cycle-breaker).
arena_decay_constants.h (new): minimal header for
ARENA_DECAY_NTICKS_PER_UPDATE.
Fold historical *_types/_structs/_externs/_inlines splits where the
layering is no longer load-bearing.
- large_externs.h -> large.h: rename; it was a single-purpose
function-prototype file.
- background_thread_structs.h + background_thread_externs.h ->
background_thread.h: merge. background_thread_inlines.h stays
separate because it depends on arena_inlines_a.h.
- bin_types.h -> bin.h: BIN_SHARDS_MAX / N_BIN_SHARDS_DEFAULT join the
bin_t struct and the bin_dalloc_locked_info_t type. bin_inlines.h
stays separate so TUs that only need the bin_t type don't pull in
the tcache-flush inline closure. The two bin_stats_* helpers move
from bin.h into bin_inlines.h so all bin inlines live together.
- tsd_binshards.h (new): houses tsd_binshards_t and its zero
initializer. Lets tsd_internals.h pull it in for X-macro expansion
without dragging mutex.h -- mutex.h depends on TSD machinery, which
would form a cycle through bin.h.
jemalloc_internal_includes.h drops the references to the deleted/
merged headers.
Pull the tcache-aware routing helpers out of arena into a layer that
sits directly below the public malloc interface:
arena_malloc -> malloc_dispatch_malloc
arena_palloc -> malloc_dispatch_palloc
arena_ralloc -> malloc_dispatch_ralloc
arena_dalloc* -> malloc_dispatch_dalloc*
arena_sdalloc* -> malloc_dispatch_sdalloc*
arena_dalloc_promoted -> malloc_dispatch_dalloc_promoted
The new module (malloc_dispatch.h, malloc_dispatch_inlines.h,
src/malloc_dispatch.c) owns the tcache-vs-fall-through decision; the
only consumer is jemalloc_internal_inlines_c.h. arena keeps a narrower
arena_prof_demote() for the sampled-allocation demotion path.
Slobodan Predolac