This is debug only and we keep it off the fast path. Moving it here simplifies
the internal logic.
This never tries to junk on regions that were shrunk via xallocx. I think this
is fine for two reasons:
- The shrunk-with-xallocx case is rare.
- We don't always do that anyway before this diff (it depends on the opt
settings and extent hooks in effect).
Make the event module to accept two event types, and pass around the event
context. Use bytes-based events to trigger tcache GC on deallocation, and get
rid of the tcache ticker.
Add options stats_interval and stats_interval_opts to allow interval based stats
printing. This provides an easy way to collect stats without code changes,
because opt.stats_print may not work (some binaries never exit).
This will eventually completely wrap the eset, and handle concurrency,
allocation, and deallocation. For now, we only pull out the mutex from the
eset.
Fold the tsd_state check onto the event threshold check. The fast threshold is
set to 0 when tsd switch to non-nominal.
The fast_threshold can be reset by remote threads, to refect the non nominal tsd
state change.
Develop new data structure and code logic for holding profiling
related information stored in the extent that may be needed after the
extent is released, which in particular is the case for the
reallocation code path (e.g. in `rallocx()` and `xallocx()`). The
data structure is a generalization of `prof_tctx_t`: we previously
only copy out the `prof_tctx` before the extent is released, but we
may be in need of additional fields. Currently the only additional
field is the allocation time field, but there may be more fields in
the future.
The restructuring also resolved a bug: `prof_realloc()` mistakenly
passed the new `ptr` to `prof_free_sampled_object()`, but passing in
the `old_ptr` would crash because it's already been released. Now
the essential profiling information is collectively copied out early
and safely passed to `prof_free_sampled_object()` after the extent is
released.
Specifically, the extent_arena_[g|s]et functions and the address randomization.
These are the only things that tie the extent struct itself to the arena code.
The -1 value of low_water indicates if the cache has been depleted and
refilled. Track the status explicitly in the tcache struct.
This allows the fast path to check if (cur_ptr > low_water), instead of >=,
which avoids reaching slow path when the last item is allocated.
With the cache bin metadata switched to pointers, ncached_max is usually
accessed and timed by sizeof(ptr). Store the results in tcache_bin_info for
direct access, and add a helper function for the ncached_max value.
