Inline the heap sampling code that is executed for every allocation
event (regardless of whether a sample is taken).
Combine all prof TLS data into a single data structure, in order to
reduce the TLS lookup volume.
Add the "thread.allocated" and "thread.deallocated" mallctls, which can
be used to query the total number of bytes ever allocated/deallocated by
the calling thread.
Add s2u() and sa2u(), which can be used to compute the usable size that
will result from an allocation request of a particular size/alignment.
Re-factor ipalloc() to use sa2u().
Enhance the heap profiler to trigger samples based on usable size,
rather than request size. This has a subtle, but important, impact on
the accuracy of heap sampling. For example, previous to this change,
16- and 17-byte objects were sampled at nearly the same rate, but
17-byte objects actually consume 32 bytes each. Therefore it was
possible for the sample to be somewhat skewed compared to actual memory
usage of the allocated objects.
Fix a bug in leak context count reporting that tended to cause the
number of contexts to be underreported. The reported number of leaked
objects and bytes were not affected by this bug.
Add the R option to control whether cumulative heap profile data
are maintained. Add the T option to control the size of per thread
backtrace caches, primarily because when the R option is specified,
backtraces that no longer have allocations associated with them are
discarded as soon as no thread caches refer to them.
Use INT_MAX instead of MAX_INT in ALLOCM_ALIGN(), and #include
<limits.h> in order to get its definition.
Modify prof code related to hash tables to avoid aliasing warnings from
gcc 4.1.2 (gcc 4.4.0 and 4.4.3 do not warn).
Add allocm(), rallocm(), sallocm(), and dallocm(), which are a
functional superset of malloc(), calloc(), posix_memalign(),
malloc_usable_size(), and free().
Fix the libunwind version of prof_backtrace() to set the backtrace depth
for all possible code paths. This fixes the zero-length backtrace
problem when using libunwind.
When heap profiling is enabled but deactivated, there is no need to call
isalloc(ptr) in prof_{malloc,realloc}(). Avoid these calls, so that
profiling overhead under such conditions is negligible.
Initialize bt2cnt_tsd so that cleanup at thread exit actually happens.
Associate (prof_ctx_t *) with allocated objects, rather than
(prof_thr_cnt_t *). Each thread must always operate on its own
(prof_thr_cnt_t *), and an object may outlive the thread that allocated it.
Add the E/e options to control whether the application starts with
sampling active/inactive (secondary control to F/f). Add the
prof.active mallctl so that the application can activate/deactivate
sampling on the fly.
Make it possible to disable interval-triggered profile dumping, even if
profiling is enabled. This is useful if the user only wants a single
dump at exit, or if the application manually triggers profile dumps.
If the mean heap sampling interval is larger than one page, simulate
sampled small objects with large objects. This allows profiling context
pointers to be omitted for small objects. As a result, the memory
overhead for sampling decreases as the sampling interval is increased.
Fix a compilation error in the profiling code.
Add the --disable-prof-libgcc configure option, and add backtracing
based on libgcc, which is used by default.
Fix a bug in hash().
Fix various configuration-dependent compilation errors.
