cleanup: make malloc_size_cb_func always defined

mysys/my_malloc.c

@@ -48,7 +48,6 @@ static inline size_t malloc_size_and_flag(void *p, my_bool *is_thread_specific)
 #define MALLOC_FIX_POINTER_FOR_FREE(p) (((char*) (p)) - MALLOC_PREFIX_SIZE)
 #endif /* SAFEMALLOC */
 
-static MALLOC_SIZE_CB malloc_size_cb_func= NULL;
 
 /**
   Inform application that memory usage has changed
@@ -59,17 +58,19 @@ static MALLOC_SIZE_CB malloc_size_cb_func= NULL;
 
   The type os size is long long, to be able to handle negative numbers to
   decrement the memory usage
+
+  @return 0 - ok
+          1 - failure, abort the allocation
 */
+static void dummy(long long size __attribute__((unused)),
+                  my_bool is_thread_specific __attribute__((unused)))
+{}
 
-static void update_malloc_size(long long size, my_bool is_thread_specific)
-{
-  if (malloc_size_cb_func)
-    malloc_size_cb_func(size, is_thread_specific);
-}
+static MALLOC_SIZE_CB update_malloc_size= dummy;
 
 void set_malloc_size_cb(MALLOC_SIZE_CB func)
 {
-  malloc_size_cb_func= func;
+  update_malloc_size= func ? func : dummy;
 }
     
     

sql/mysqld.cc

@@ -3989,7 +3989,7 @@ static void my_malloc_size_cb_func(long long size, my_bool is_thread_specific)
 {
   THD *thd= current_thd;
 
-  if (likely(is_thread_specific))  /* If thread specific memory */
+  if (is_thread_specific)  /* If thread specific memory */
   {
     /*
       When thread specfic is set, both mysqld_server_initialized and thd
@@ -4006,8 +4006,7 @@ static void my_malloc_size_cb_func(long long size, my_bool is_thread_specific)
   else if (likely(thd))
   {
     DBUG_PRINT("info", ("global thd memory_used: %lld  size: %lld",
-                        (longlong) thd->status_var.global_memory_used,
-                        size));
+                        (longlong) thd->status_var.global_memory_used, size));
     thd->status_var.global_memory_used+= size;
   }
   else