tal: optimize case where no (non-destructor) notifiers are used.
authorRusty Russell <rusty@rustcorp.com.au>
Mon, 3 Dec 2012 08:59:38 +0000 (19:29 +1030)
committerRusty Russell <rusty@rustcorp.com.au>
Mon, 3 Dec 2012 08:59:38 +0000 (19:29 +1030)
$ for i in `seq 10`; do ./samba-allocs talloc.dump --tal; done | stats.c --trim-outliers
Before:
Read 25998 nodes
Tal time:                2857988-2981158(2904324)ns
Tal_free time:           2417170-2582088(2470931)ns
Single tal_free time:    1551654-1609583(1575984)ns

After:
Read 25998 nodes
Tal time:                2780974-2901323(2839352)ns
Tal_free time:           2241725-2355309(2285165)ns
Single tal_free time:    1549908-1612485(1566609)ns

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
ccan/tal/tal.c

index 72518b249cb37dc719739ed59726d17bbc9a5a6c..c9006857e599e3cea89ef39418b2dd62b0274d1a 100644 (file)
@@ -70,6 +70,9 @@ static void *(*allocfn)(size_t size) = malloc;
 static void *(*resizefn)(void *, size_t size) = realloc;
 static void (*freefn)(void *) = free;
 static void (*errorfn)(const char *msg) = (void *)abort;
+static bool initialized = false;
+/* Count on non-destrutor notifiers; often stays zero. */
+static size_t notifiers = 0;
 
 static inline void COLD call_error(const char *msg)
 {
@@ -91,8 +94,6 @@ static struct children *ignore_destroying_bit(struct children *parent_child)
        return (void *)((size_t)parent_child & ~(size_t)1);
 }
 
-static bool initialized = false;
-
 /* This means valgrind can see leaks. */
 static void tal_cleanup(void)
 {
@@ -291,9 +292,10 @@ static struct notifier *add_notifier_property(struct tal_hdr *t,
        return prop;
 }
 
-static bool del_notifier_property(struct tal_hdr *t,
-                                 void (*fn)(tal_t *,
-                                            enum tal_notify_type, void *))
+static enum tal_notify_type del_notifier_property(struct tal_hdr *t,
+                                                 void (*fn)(tal_t *,
+                                                            enum tal_notify_type,
+                                                            void *))
 {
         struct prop_hdr **p;
 
@@ -306,12 +308,13 @@ static bool del_notifier_property(struct tal_hdr *t,
                        continue;
                n = (struct notifier *)*p;
                if (n->u.notifyfn == fn) {
+                       enum tal_notify_type types = n->types;
                        *p = (*p)->next;
                        freefn(n);
-                       return true;
+                       return types & ~NOTIFY_IS_DESTRUCTOR;
                }
         }
-        return false;
+        return 0;
 }
 
 static struct name *add_name_property(struct tal_hdr *t, const char *name)
@@ -405,7 +408,8 @@ void *tal_alloc_(const tal_t *ctx, size_t size, bool clear, const char *label)
                return NULL;
        }
        debug_tal(parent);
-       notify(parent, TAL_NOTIFY_ADD_CHILD, from_tal_hdr(debug_tal(child)));
+       if (notifiers)
+               notify(parent, TAL_NOTIFY_ADD_CHILD, from_tal_hdr(child));
        return from_tal_hdr(debug_tal(child));
 }
 
@@ -415,8 +419,9 @@ void *tal_free(const tal_t *ctx)
                struct tal_hdr *t;
                int saved_errno = errno;
                t = debug_tal(to_tal_hdr(ctx));
-               notify(ignore_destroying_bit(t->parent_child)->parent,
-                      TAL_NOTIFY_DEL_CHILD, ctx);
+               if (notifiers)
+                       notify(ignore_destroying_bit(t->parent_child)->parent,
+                              TAL_NOTIFY_DEL_CHILD, ctx);
                list_del(&t->list);
                del_tree(t, ctx);
                errno = saved_errno;
@@ -444,7 +449,8 @@ void *tal_steal_(const tal_t *new_parent, const tal_t *ctx)
                        return NULL;
                }
                debug_tal(newpar);
-               notify(t, TAL_NOTIFY_STEAL, new_parent);
+               if (notifiers)
+                       notify(t, TAL_NOTIFY_STEAL, new_parent);
         }
         return (void *)ctx;
 }
@@ -474,8 +480,12 @@ bool tal_add_notifier_(tal_t *ctx, enum tal_notify_type types,
        if (unlikely(!n))
                return false;
 
-       notify(t, TAL_NOTIFY_ADD_NOTIFIER, callback);
+       if (notifiers)
+               notify(t, TAL_NOTIFY_ADD_NOTIFIER, callback);
+
        n->types = types;
+       if (types != TAL_NOTIFY_FREE)
+               notifiers++;
        return true;
 }
 
@@ -483,12 +493,16 @@ bool tal_del_notifier_(tal_t *ctx,
                       void (*callback)(tal_t *, enum tal_notify_type, void *))
 {
        struct tal_hdr *t = debug_tal(to_tal_hdr(ctx));
-       bool ret;
+       enum tal_notify_type types;
 
-        ret = del_notifier_property(t, callback);
-       if (ret)
+        types = del_notifier_property(t, callback);
+       if (types) {
                notify(t, TAL_NOTIFY_DEL_NOTIFIER, callback);
-       return ret;
+               if (types != TAL_NOTIFY_FREE)
+                       notifiers--;
+               return true;
+       }
+       return false;
 }
 
 bool tal_del_destructor_(tal_t *ctx, void (*destroy)(void *me))
@@ -522,7 +536,8 @@ bool tal_set_name_(tal_t *ctx, const char *name, bool literal)
                return false;
 
        debug_tal(t);
-       notify(t, TAL_NOTIFY_RENAME, name);
+       if (notifiers)
+               notify(t, TAL_NOTIFY_RENAME, name);
        return true;
 }
 
@@ -635,9 +650,11 @@ bool tal_resize_(tal_t **ctxp, size_t size)
                        child->parent = t;
                }
                *ctxp = from_tal_hdr(debug_tal(t));
-               notify(t, TAL_NOTIFY_MOVE, from_tal_hdr(old_t));
+               if (notifiers)
+                       notify(t, TAL_NOTIFY_MOVE, from_tal_hdr(old_t));
        }
-       notify(t, TAL_NOTIFY_RESIZE, (void *)size);
+       if (notifiers)
+               notify(t, TAL_NOTIFY_RESIZE, (void *)size);
 
        return true;
 }