tcmalloc-usable-size.diff

commit 2ec0bd00031a777237a24b7cd6a06b0f7f007430
Author: Joe Damato <[email protected]>
Date:   Wed Nov 18 16:22:06 2009 -0800

    add malloc_usable_size

diff --git a/configure.ac b/configure.ac
index 9db399a..12cc585 100644
--- a/configure.ac
+++ b/configure.ac
@@ -109,6 +109,7 @@ AC_HEADER_STDC
 # TODO(csilvers): we could remove a lot when WITH_CPU_PROFILER etc is "no".
 AC_CHECK_TYPES([__int64])       # defined in some windows platforms
 AC_CHECK_TYPES([struct mallinfo],,, [#include <malloc.h>])
+AC_CHECK_FUNCS(malloc_usable_size) # for getting the number of bytes allocated
 AC_CHECK_TYPES([Elf32_Versym],,, [#include <elf.h>])   # for vdso_support.h
 AC_CHECK_FUNCS(sbrk)            # for tcmalloc to get memory
 AC_CHECK_FUNCS(geteuid)         # for turning off services when run as root
@@ -143,6 +144,12 @@ AC_CHECK_DECLS([cfree,
                 #include <stdlib.h>
                 #include <malloc.h>])
 
+if test "$ac_cv_have_func_malloc_usable_size" = yes; then
+  AC_SUBST(ac_cv_have_func_malloc_usable_size, 1)
+else
+  AC_SUBST(ac_cv_have_func_malloc_usable_size, 0)
+fi
+
 if test "$ac_cv_type_struct_mallinfo" = yes; then
   AC_SUBST(ac_cv_have_struct_mallinfo, 1)   # google/tcmalloc.h needs this
 else
diff --git a/src/config.h.in b/src/config.h.in
index 18be9f3..861790a 100644
--- a/src/config.h.in
+++ b/src/config.h.in
@@ -114,6 +114,9 @@
 /* Define to 1 if the system has the type `struct mallinfo'. */
 #undef HAVE_STRUCT_MALLINFO
 
+/* Define to 1 if the system has the function malloc_usable_size.*/
+#undef HAVE_MALLOC_USABLE_SIZE
+
 /* Define to 1 if you have the <sys/prctl.h> header file. */
 #undef HAVE_SYS_PRCTL_H
 
diff --git a/src/google/tcmalloc.h.in b/src/google/tcmalloc.h.in
index 4937c62..0731f14 100644
--- a/src/google/tcmalloc.h.in
+++ b/src/google/tcmalloc.h.in
@@ -84,6 +84,7 @@ extern "C" {
 
   PERFTOOLS_DLL_DECL void tc_malloc_stats(void) __THROW;
   PERFTOOLS_DLL_DECL int tc_mallopt(int cmd, int value) __THROW;
+  PERFTOOLS_DLL_DECL size_t tc_malloc_usable_size(void *ptr) __THROW;
 #if @ac_cv_have_struct_mallinfo@
   PERFTOOLS_DLL_DECL struct mallinfo tc_mallinfo(void) __THROW;
 #endif
diff --git a/src/tcmalloc.cc b/src/tcmalloc.cc
index 5d634fa..a390dad 100644
--- a/src/tcmalloc.cc
+++ b/src/tcmalloc.cc
@@ -97,7 +97,7 @@
 #else
 #include <sys/types.h>
 #endif
-#if defined(HAVE_MALLOC_H) && defined(HAVE_STRUCT_MALLINFO)
+#if defined(HAVE_MALLOC_H) && (defined(HAVE_STRUCT_MALLINFO) || defined(HAVE_MALLOC_USABLE_SIZE))
 #include <malloc.h>                        // for struct mallinfo
 #endif
 #include <string.h>
@@ -211,6 +211,10 @@ extern "C" {
       ATTRIBUTE_SECTION(google_malloc);
   int tc_mallopt(int cmd, int value) __THROW
       ATTRIBUTE_SECTION(google_malloc);
+#ifdef HAVE_MALLOC_USABLE_SIZE
+  size_t tc_malloc_usable_size(void *ptr) __THROW
+      ATTRIBUTE_SECTION(google_malloc);
+#endif
 #ifdef HAVE_STRUCT_MALLINFO    // struct mallinfo isn't defined on freebsd
   struct mallinfo tc_mallinfo(void) __THROW
       ATTRIBUTE_SECTION(google_malloc);
@@ -266,6 +270,9 @@ extern "C" {
   int posix_memalign(void** r, size_t a, size_t s) __THROW
       ALIAS("tc_posix_memalign");
   void malloc_stats(void) __THROW                ALIAS("tc_malloc_stats");
+#ifdef HAVE_MALLOC_USABLE_SIZE
+  size_t malloc_usable_size(void *ptr) __THROW   ALIAS("tc_malloc_usable_size");
+#endif
   int mallopt(int cmd, int value) __THROW        ALIAS("tc_mallopt");
 #ifdef HAVE_STRUCT_MALLINFO
   struct mallinfo mallinfo(void) __THROW         ALIAS("tc_mallinfo");
@@ -297,6 +304,9 @@ extern "C" {
   }
   void malloc_stats(void) __THROW                { tc_malloc_stats();         }
   int mallopt(int cmd, int v) __THROW            { return tc_mallopt(cmd, v); }
+#ifdef HAVE_MALLOC_USABLE_SIZE
+  size_t malloc_usable_size(void *ptr) __THROW   { return tc_malloc_usable_size(ptr); }
+#endif
 #ifdef HAVE_STRUCT_MALLINFO
   struct mallinfo mallinfo(void) __THROW         { return tc_mallinfo();      }
 #endif
@@ -1062,6 +1072,30 @@ inline struct mallinfo do_mallinfo() {
 }
 #endif  // #ifndef HAVE_STRUCT_MALLINFO
 
+#ifdef HAVE_MALLOC_USABLE_SIZE
+inline size_t do_malloc_usable_size(void *ptr) {
+  if (ptr == NULL) return 0;
+  Span *span = NULL;
+  const PageID p = reinterpret_cast<uintptr_t>(ptr) >> kPageShift;
+  size_t cl = Static::pageheap()->GetSizeClassIfCached(p);
+  size_t alloc_size = Static::sizemap()->ByteSizeForClass(cl);
+
+  if (cl == 0) {
+    span = Static::pageheap()->GetDescriptor(p);
+    if (!span) {
+      return 0;
+    }
+    alloc_size = Static::sizemap()->ByteSizeForClass(span->sizeclass);
+  }
+
+  if (alloc_size == 0) {
+    return span->length << kPageShift;
+  }
+
+  return alloc_size;
+}
+#endif
+
 static SpinLock set_new_handler_lock(SpinLock::LINKER_INITIALIZED);
 
 inline void* cpp_alloc(size_t size, bool nothrow) {
@@ -1278,6 +1312,12 @@ extern "C" PERFTOOLS_DLL_DECL void tc_malloc_stats(void) __THROW {
   do_malloc_stats();
 }
 
+#ifdef HAVE_MALLOC_USABLE_SIZE
+extern "C" PERFTOOLS_DLL_DECL size_t tc_malloc_usable_size(void *ptr) __THROW {
+  return do_malloc_usable_size(ptr);
+}
+#endif
+
 extern "C" PERFTOOLS_DLL_DECL int tc_mallopt(int cmd, int value) __THROW {
   return do_mallopt(cmd, value);
 }