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).
Two ordering gotchas this consolidation surfaced:
1. tsd_internals.h is included from tsd.h via tsd_generic.h, sometimes
long before arena.h is loaded (e.g. ckh.c includes ckh.h -> tsd.h
before jemalloc_internal_includes.h). TSD_INITIALIZER's expansion
in tsd_generic.h's function bodies references
ARENA_DECAY_NTICKS_PER_UPDATE, so it must already be defined.
Factor the constant into a new minimal header,
arena_decay_constants.h, that pulls nothing but jemalloc_preamble.h,
and include it from both arena.h and tsd_internals.h. arena_t is
still added as a forward decl in tsd_internals.h -- including
arena.h there would trigger arena_stats.h -> mutex.h -> tsd.h ->
re-entry into this very file.
2. extent_dss.h previously included arena_types.h for the arena_t
pointer type, but arena.h now includes extent_dss.h (it was a
STRUCTS-section dep). Forward-decl arena_t in extent_dss.h to
break that cycle.
Additional forward decls in tcache.h and large.h (arena_t *). These
were previously satisfied by the master include order loading
arena_types.h before everything else; with arena.h now in the EXTERNS
section, large.h and tcache.h are parsed earlier than arena.h, so
they need to declare arena_t themselves.
jemalloc_internal_externs.h's #include of arena_types.h was
vestigial -- the file uses no arena symbols. Dropped.
This mallctl accepts an arena_config_t structure which
can be used to customize the behavior of the arena.
Right now it contains extent_hooks and a new option,
metadata_use_hooks, which controls whether the extent
hooks are also used for metadata allocation.
The medata_use_hooks option has two main use cases:
1. In heterogeneous memory systems, to avoid metadata
being placed on potentially slower memory.
2. Avoiding virtual memory from being leaked as a result
of metadata allocation failure originating in an extent hook.
Added opt.background_thread to enable background threads, which handles purging
currently. When enabled, decay ticks will not trigger purging (which will be
left to the background threads). We limit the max number of threads to NCPUs.
When percpu arena is enabled, set CPU affinity for the background threads as
well.
The sleep interval of background threads is dynamic and determined by computing
number of pages to purge in the future (based on backlog).
malloc_conf does not reliably work with MSVC, which complains of
"inconsistent dll linkage", i.e. its inability to support the
application overriding malloc_conf when dynamically linking/loading.
Work around this limitation by adding test harness support for per test
shell script sourcing, and converting all tests to use MALLOC_CONF
instead of malloc_conf.
Move test extent hook code from the extent integration test into a
header, and normalize the out-of-band controls and introspection.
Also refactor the base unit test to use the header.
Add/rename related mallctls:
- Add stats.arenas.<i>.base .
- Rename stats.arenas.<i>.metadata to stats.arenas.<i>.internal .
- Add stats.arenas.<i>.resident .
Modify the arenas.extend mallctl to take an optional (extent_hooks_t *)
argument so that it is possible for all base allocations to be serviced
by the specified extent hooks.
This resolves#463.
Split purging into lazy and forced variants. Use the forced variant for
zeroing dss.
Add support for NULL function pointers as an opt-out mechanism for the
dalloc, commit, decommit, purge_lazy, purge_forced, split, and merge
fields of extent_hooks_t.
Add short-circuiting checks in large_ralloc_no_move_{shrink,expand}() so
that no attempt is made if splitting/merging is not supported.
This resolves#268.
