Re: [Qemu-devel] [PATCH v4 2/2] QOM: object_property_add() performance improvement

[Paolo Bonzini <pbonzini@redhat.com>]

On 27/07/2015 16:57, Andreas Färber wrote:
>> >  I am absolutely fine with absolutely anything. Suggest what you like and i'll change it.
> Paolo suggested ...-count on #qemu, but I would prefer ...-max or so, as
> the number could differ when some property gets deleted.

Yes, I agree -max is better.

I'm just asking myself whether this is really necessary.  Is the
automagic [*] really needed in this case?  Can it just do:

diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index b2f404a..19bfee1 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -415,19 +415,19 @@ static NamedGPIOList *qdev_get_named_gpio_list(DeviceState *dev,
 void qdev_init_gpio_in_named(DeviceState *dev, qemu_irq_handler handler,
                              const char *name, int n)
 {
-    int i;
+    int i, j;
     NamedGPIOList *gpio_list = qdev_get_named_gpio_list(dev, name);
-    char *propname = g_strdup_printf("%s[*]", name ? name : "unnamed-gpio-in");
 
     assert(gpio_list->num_out == 0 || !name);
     gpio_list->in = qemu_extend_irqs(gpio_list->in, gpio_list->num_in, handler,
                                      dev, n);
 
     for (i = gpio_list->num_in; i < gpio_list->num_in + n; i++) {
+        char *propname = g_strdup_printf("%s[%d]", name ? name : "unnamed-gpio-in", j++);
         object_property_add_child(OBJECT(dev), propname,
                                   OBJECT(gpio_list->in[i]), &error_abort);
+        g_free(propname);
     }
-    g_free(propname);
 
     gpio_list->num_in += n;
 }

?

Paolo

> On the other hand, since this is not a user-added property, using a
> reserved character such as '#' would avoid clashes with user-added
> properties, as long as tools handle accessing that property okay.