Add support for sized deallocation.
This adds a new `sdallocx` function to the external API, allowing the
size to be passed by the caller. It avoids some extra reads in the
thread cache fast path. In the case where stats are enabled, this
avoids the work of calculating the size from the pointer.
An assertion validates the size that's passed in, so enabling debugging
will allow users of the API to debug cases where an incorrect size is
passed in.
The performance win for a contrived microbenchmark doing an allocation
and immediately freeing it is ~10%. It may have a different impact on a
real workload.
Closes #28
diff --git a/configure.ac b/configure.ac
index ce4af21..d221876 100644
--- a/configure.ac
+++ b/configure.ac
@@ -452,7 +452,7 @@
AC_PATH_PROG([LD], [ld], [false], [$PATH])
AC_PATH_PROG([AUTOCONF], [autoconf], [false], [$PATH])
-public_syms="malloc_conf malloc_message malloc calloc posix_memalign aligned_alloc realloc free mallocx rallocx xallocx sallocx dallocx nallocx mallctl mallctlnametomib mallctlbymib malloc_stats_print malloc_usable_size"
+public_syms="malloc_conf malloc_message malloc calloc posix_memalign aligned_alloc realloc free mallocx rallocx xallocx sallocx dallocx sdallocx nallocx mallctl mallctlnametomib mallctlbymib malloc_stats_print malloc_usable_size"
dnl Check for allocator-related functions that should be wrapped.
AC_CHECK_FUNC([memalign],