Commit 61b0e1c8 authored by Christian Persch's avatar Christian Persch Committed by Allison Karlitskaya
Browse files

Add G_SIGNAL_MUST_COLLECT

In some cases, signal arguments have to be collected, even if there are i
no signal handlers connected (e.g. for GVariant parameters, where collection
consumes a floating variant).

Based on a patch by Christian Persch.

Bug #643624.
parent c95ff4de
......@@ -1340,7 +1340,8 @@ g_signal_new (const gchar *signal_name,
/* optimize NOP emissions with NULL class handlers */
if (signal_id && G_TYPE_IS_INSTANTIATABLE (itype) && return_type == G_TYPE_NONE &&
class_offset && class_offset < MAX_TEST_CLASS_OFFSET)
class_offset && class_offset < MAX_TEST_CLASS_OFFSET &&
~signal_flags & G_SIGNAL_MUST_COLLECT)
{
SignalNode *node;
......@@ -1632,7 +1633,9 @@ g_signal_newv (const gchar *signal_name,
node->emission_hooks = NULL;
if (class_closure)
signal_add_class_closure (node, 0, class_closure);
else if (G_TYPE_IS_INSTANTIATABLE (itype) && return_type == G_TYPE_NONE)
else if (G_TYPE_IS_INSTANTIATABLE (itype) &&
return_type == G_TYPE_NONE &&
~signal_flags & G_SIGNAL_MUST_COLLECT)
{
/* optimize NOP emissions */
node->test_class_offset = TEST_CLASS_MAGIC;
......@@ -2913,7 +2916,7 @@ g_signal_emit_valist (gpointer instance,
GValue *param_values;
SignalNode *node;
guint i, n_params;
g_return_if_fail (G_TYPE_CHECK_INSTANCE (instance));
g_return_if_fail (signal_id > 0);
......@@ -2976,6 +2979,7 @@ g_signal_emit_valist (gpointer instance,
SIGNAL_LOCK ();
}
SIGNAL_UNLOCK ();
instance_and_params->g_type = 0;
g_value_init (instance_and_params, G_TYPE_FROM_INSTANCE (instance));
g_value_set_instance (instance_and_params, instance);
......
......@@ -108,6 +108,8 @@ typedef gboolean (*GSignalAccumulator) (GSignalInvocationHint *ihint,
* of as object methods which can be called generically by
* third-party code.
* @G_SIGNAL_NO_HOOKS: No emissions hooks are supported for this signal.
* @G_SIGNAL_MUST_COLLECT: Varargs signal emission will always collect the
* arguments, even if there are no signal handlers connected. Since 2.30.
*
* The signal flags are used to specify a signal's behaviour, the overall
* signal description outlines how especially the RUN flags control the
......@@ -121,14 +123,15 @@ typedef enum
G_SIGNAL_NO_RECURSE = 1 << 3,
G_SIGNAL_DETAILED = 1 << 4,
G_SIGNAL_ACTION = 1 << 5,
G_SIGNAL_NO_HOOKS = 1 << 6
G_SIGNAL_NO_HOOKS = 1 << 6,
G_SIGNAL_MUST_COLLECT = 1 << 7
} GSignalFlags;
/**
* G_SIGNAL_FLAGS_MASK:
*
* A mask for all #GSignalFlags bits.
*/
#define G_SIGNAL_FLAGS_MASK 0x7f
#define G_SIGNAL_FLAGS_MASK 0xff
/**
* GConnectFlags:
* @G_CONNECT_AFTER: whether the handler should be called before or after the
......
......@@ -9,6 +9,7 @@ TEST_PROGS += \
boxed \
enums \
param \
signals \
threadtests \
dynamictests \
binding \
......
#include <glib-object.h>
typedef struct _Test Test;
typedef struct _TestClass TestClass;
struct _Test
{
GObject parent_instance;
};
struct _TestClass
{
GObjectClass parent_class;
void (* variant_changed) (Test *, GVariant *);
};
static GType test_get_type (void);
G_DEFINE_TYPE (Test, test, G_TYPE_OBJECT)
static void
test_init (Test *test)
{
}
static void
test_class_init (TestClass *klass)
{
g_signal_new ("variant-changed-no-slot",
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST | G_SIGNAL_MUST_COLLECT,
0,
NULL, NULL,
g_cclosure_marshal_VOID__VARIANT,
G_TYPE_NONE,
1,
G_TYPE_VARIANT);
g_signal_new ("variant-changed",
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST | G_SIGNAL_MUST_COLLECT,
G_STRUCT_OFFSET (TestClass, variant_changed),
NULL, NULL,
g_cclosure_marshal_VOID__VARIANT,
G_TYPE_NONE,
1,
G_TYPE_VARIANT);
}
static void
test_variant_signal (void)
{
Test *test;
GVariant *v;
/* Tests that the signal emission consumes the variant,
* even if there are no handlers connected.
*/
test = g_object_new (test_get_type (), NULL);
v = g_variant_new_boolean (TRUE);
g_variant_ref (v);
g_assert (g_variant_is_floating (v));
g_signal_emit_by_name (test, "variant-changed-no-slot", v);
g_assert (!g_variant_is_floating (v));
g_variant_unref (v);
v = g_variant_new_boolean (TRUE);
g_variant_ref (v);
g_assert (g_variant_is_floating (v));
g_signal_emit_by_name (test, "variant-changed", v);
g_assert (!g_variant_is_floating (v));
g_variant_unref (v);
g_object_unref (test);
}
/* --- */
int
main (int argc,
char *argv[])
{
g_type_init ();
g_test_init (&argc, &argv, NULL);
g_test_add_func ("/gobject/signals/variant", test_variant_signal);
return g_test_run ();
}
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