Make one call to prof_active_get_unlocked() per allocation event, and
use the result throughout the relevant functions that handle an
allocation event.  Also add a missing check in prof_realloc().  These
fixes protect allocation events against concurrent prof_active changes.

Fix xallocx() bugs related to the 'extra' parameter when specified as
non-zero.

Fix heap profiling to distinguish among otherwise identical sample sites
with interposed resets (triggered via the "prof.reset" mallctl).  This
bug could cause data structure corruption that would most likely result
in a segfault.

Fix TLS configuration such that it is enabled by default for platforms
on which it works correctly.  This regression was introduced by
ac5db020 (Make --enable-tls and
--enable-lazy-lock take precedence over configure.ac-hardcoded
defaults).

Fix chunk purge hook calls for in-place huge shrinking reallocation to
specify the old chunk size rather than the new chunk size.  This bug
caused no correctness issues for the default chunk purge function, but
was visible to custom functions set via the "arena.<i>.chunk_hooks"
mallctl.

This resolves #264.

Fix arenas_cache_cleanup() and arena_get_hard() to handle
allocation/deallocation within the application's thread-specific data
cleanup functions even after arenas_cache is torn down.

This is a more general fix that complements
45e9f66c (Fix arenas_cache_cleanup().).

Add JEMALLOC_CXX_THROW to the memalign() function prototype, in order to
match glibc and avoid compilation errors when including both
jemalloc/jemalloc.h and malloc.h in C++ code.

This change was unintentionally omitted from
ae93d6bf (Avoid function prototype
incompatibilities.).

Fix arenas_cache_cleanup() to handle allocation/deallocation within the
application's thread-specific data cleanup functions even after
arenas_cache is torn down.

This resolves #256.

Don't bitshift by negative amounts when encoding/decoding run sizes in
chunk header maps.  This affected systems with page sizes greater than 8
KiB.

Reported by Ingvar Hagelund <ingvar@redpill-linpro.com>.

Add the "arena.<i>.chunk_hooks" mallctl, which replaces and expands on
the "arena.<i>.chunk.{alloc,dalloc,purge}" mallctls.  The chunk hooks
allow control over chunk allocation/deallocation, decommit/commit,
purging, and splitting/merging, such that the application can rely on
jemalloc's internal chunk caching and retaining functionality, yet
implement a variety of chunk management mechanisms and policies.

Merge the chunks_[sz]ad_{mmap,dss} red-black trees into
chunks_[sz]ad_retained.  This slightly reduces how hard jemalloc tries
to honor the dss precedence setting; prior to this change the precedence
setting was also consulted when recycling chunks.

Fix chunk purging.  Don't purge chunks in arena_purge_stashed(); instead
deallocate them in arena_unstash_purged(), so that the dirty memory
linkage remains valid until after the last time it is used.

This resolves #176 and #201.

Fix typos ChangeLog

Fix size class overflow handling for malloc(), posix_memalign(),
memalign(), calloc(), and realloc() when profiling is enabled.

Remove an assertion that erroneously caused arena_sdalloc() to fail when
profiling was enabled.

This resolves #232.

Extract szad size quantization into {extent,run}_quantize(), and .
quantize szad run sizes to the union of valid small region run sizes and
large run sizes.

Refactor iteration in arena_run_first_fit() to use
run_quantize{,_first,_next(), and add support for padded large runs.

For large allocations that have no specified alignment constraints,
compute a pseudo-random offset from the beginning of the first backing
page that is a multiple of the cache line size.  Under typical
configurations with 4-KiB pages and 64-byte cache lines this results in
a uniform distribution among 64 page boundary offsets.

Add the --disable-cache-oblivious option, primarily intended for
performance testing.

This resolves #13.

This rename avoids installation collisions with the upstream gperftools.
Additionally, jemalloc's per thread heap profile functionality
introduced an incompatible file format, so it's now worthwhile to
clearly distinguish jemalloc's version of this script from the upstream
version.

This resolves #229.

However, unlike before it was removed do not force --enable-ivsalloc
when Darwin zone allocator integration is enabled, since the zone
allocator code uses ivsalloc() regardless of whether
malloc_usable_size() and sallocx() do.

This resolves #211.

Unless heap profiling is enabled, disable floating point code and don't
link with libm.  This, in combination with e.g. EXTRA_CFLAGS=-mno-sse on
x64 systems, makes it possible to completely disable floating point
register use.  Some versions of glibc neglect to save/restore
caller-saved floating point registers during dynamic lazy symbol
loading, and the symbol loading code uses whatever malloc the
application happens to have linked/loaded with, the result being
potential floating point register corruption.

Refactor the test harness to support three types of tests:
- unit: White box unit tests.  These tests have full access to all
  internal jemalloc library symbols.  Though in actuality all symbols
  are prefixed by jet_, macro-based name mangling abstracts this away
  from test code.
- integration: Black box integration tests.  These tests link with
  the installable shared jemalloc library, and with the exception of
  some utility code and configure-generated macro definitions, they have
  no access to jemalloc internals.
- stress: Black box stress tests.  These tests link with the installable
  shared jemalloc library, as well as with an internal allocator with
  symbols prefixed by jet_ (same as for unit tests) that can be used to
  allocate data structures that are internal to the test code.

Move existing tests into test/{unit,integration}/ as appropriate.

Split out internal parts of jemalloc_defs.h.in and put them in
jemalloc_internal_defs.h.in.  This reduces internals exposure to
applications that #include <jemalloc/jemalloc.h>.

Refactor jemalloc.h header generation so that a single header file
results, and the prototypes can be used to generate jet_ prototypes for
tests.  Split jemalloc.h.in into multiple parts (jemalloc_defs.h.in,
jemalloc_macros.h.in, jemalloc_protos.h.in, jemalloc_mangle.h.in) and
use a shell script to generate a unified jemalloc.h at configure time.

Change the default private namespace prefix from "" to "je_".

Add missing private namespace mangling.

Remove hard-coded private_namespace.h.  Instead generate it and
private_unnamespace.h from private_symbols.txt.  Use similar logic for
public symbols, which aids in name mangling for jet_ symbols.

Add test_warn() and test_fail().  Replace existing exit(1) calls with
test_fail() calls.

Fix a race condition in the "arenas.extend" mallctl that could lead to
internal data structure corruption.  The race could be hit if one
thread called the "arenas.extend" mallctl while another thread
concurrently triggered initialization of one of the lazily created
arenas.

Fix a Valgrind integration flaw that caused Valgrind warnings about
reads of uninitialized memory in internal zero-initialized data
structures (relevant to tcache and prof code).