gc.c: malloc_usable_size

* gc.c (vm_xrealloc, vm_xfree): use malloc_usable_size() to obtain old
  size if available.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43760 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 16 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index bc4f94f0e1..908fdf9dac 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Nov 21 18:49:02 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* gc.c (vm_xrealloc, vm_xfree): use malloc_usable_size() to obtain old
+	  size if available.
+
 Thu Nov 21 18:47:29 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* lib/delegate.rb (SimpleDelegator#__getobj__): target object must be set.
diff --git a/configure.in b/configure.in
index a4080e1a00..ab0cea9905 100644
--- a/configure.in
+++ b/configure.in
@@ -1851,6 +1851,7 @@ AC_CHECK_FUNCS(llabs)
 AC_CHECK_FUNCS(lockf)
 AC_CHECK_FUNCS(log2)
 AC_CHECK_FUNCS(lstat)
+AC_CHECK_FUNCS(malloc_usable_size)
 AC_CHECK_FUNCS(mblen)
 AC_CHECK_FUNCS(memalign)
 AC_CHECK_FUNCS(memrchr)
diff --git a/gc.c b/gc.c
index 3c1c63d1d8..c15b19c44f 100644
--- a/gc.c
+++ b/gc.c
@@ -5553,6 +5553,10 @@ vm_xrealloc(rb_objspace_t *objspace, void *ptr, size_t new_size, size_t old_size
 	return 0;
     }
 
+#ifdef HAVE_MALLOC_USABLE_SIZE
+    old_size = malloc_usable_size(ptr);
+#endif
+
     vm_malloc_increase(objspace, new_size, old_size, FALSE);
 
 #if CALC_EXACT_MALLOC_SIZE
@@ -5587,7 +5591,13 @@ vm_xfree(rb_objspace_t *objspace, void *ptr, size_t old_size)
 	ATOMIC_SIZE_SUB(objspace->malloc_params.allocated_size, cem_oldsize);
 	ATOMIC_SIZE_DEC(objspace->malloc_params.allocations);
     }
+#endif
 
+#ifdef HAVE_MALLOC_USABLE_SIZE
+    old_size = malloc_usable_size(ptr);
+#endif
+
+#if CALC_EXACT_MALLOC_SIZE
     if (CALC_EXACT_MALLOC_SIZE_CHECK_OLD_SIZE && old_size > 0 && cem_oldsize - sizeof(size_t) != old_size) {
 	fprintf(stderr, "vm_xfree: old_size mismatch: expected %d, but %d\n", (int)(cem_oldsize-sizeof(size_t)), (int)old_size);
     }