gstreamer/gst/gstdeviceprovider.c
Matthew Waters 3d887c7f07 gst: don't use volatile to mean atomic
volatile is not sufficient to provide atomic guarantees and real atomics
should be used instead.  GCC 11 has started warning about using volatile
with atomic operations.

https://gitlab.gnome.org/GNOME/glib/-/merge_requests/1719

Discovered in https://gitlab.freedesktop.org/gstreamer/gst-plugins-good/-/issues/868

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/775>
2021-03-19 04:15:19 +00:00

879 lines
26 KiB
C

/* GStreamer
* Copyright (C) 2012 Olivier Crete <olivier.crete@collabora.com>
*
* gstdeviceprovider.c: Device probing and monitoring
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/**
* SECTION:gstdeviceprovider
* @title: GstDeviceProvider
* @short_description: A device provider
* @see_also: #GstDevice, #GstDeviceMonitor
*
* A #GstDeviceProvider subclass is provided by a plugin that handles devices
* if there is a way to programmatically list connected devices. It can also
* optionally provide updates to the list of connected devices.
*
* Each #GstDeviceProvider subclass is a singleton, a plugin should
* normally provide a single subclass for all devices.
*
* Applications would normally use a #GstDeviceMonitor to monitor devices
* from all relevant providers.
*
* Since: 1.4
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gst_private.h"
#include "gstdeviceprovider.h"
#include "gstelementmetadata.h"
#include "gstquark.h"
struct _GstDeviceProviderPrivate
{
GstBus *bus;
GMutex start_lock;
gint started_count;
GList *hidden_providers;
};
enum
{
PROVIDER_HIDDEN,
PROVIDER_UNHIDDEN,
LAST_SIGNAL
};
static guint gst_device_provider_signals[LAST_SIGNAL] = { 0 };
/* this is used in gstelementfactory.c:gst_element_register() */
GQuark __gst_deviceproviderclass_factory = 0;
static void gst_device_provider_class_init (GstDeviceProviderClass * klass);
static void gst_device_provider_init (GstDeviceProvider * element);
static void gst_device_provider_base_class_init (gpointer g_class);
static void gst_device_provider_dispose (GObject * object);
static void gst_device_provider_finalize (GObject * object);
static gpointer gst_device_provider_parent_class = NULL;
static gint private_offset = 0;
GType
gst_device_provider_get_type (void)
{
static gsize gst_device_provider_type = 0;
if (g_once_init_enter (&gst_device_provider_type)) {
GType _type;
static const GTypeInfo element_info = {
sizeof (GstDeviceProviderClass),
gst_device_provider_base_class_init,
NULL, /* base_class_finalize */
(GClassInitFunc) gst_device_provider_class_init,
NULL,
NULL,
sizeof (GstDeviceProvider),
0,
(GInstanceInitFunc) gst_device_provider_init,
NULL
};
_type = g_type_register_static (GST_TYPE_OBJECT, "GstDeviceProvider",
&element_info, G_TYPE_FLAG_ABSTRACT);
private_offset =
g_type_add_instance_private (_type, sizeof (GstDeviceProviderPrivate));
__gst_deviceproviderclass_factory =
g_quark_from_static_string ("GST_DEVICEPROVIDERCLASS_FACTORY");
g_once_init_leave (&gst_device_provider_type, _type);
}
return gst_device_provider_type;
}
static inline gpointer
gst_device_provider_get_instance_private (GstDeviceProvider * self)
{
return (G_STRUCT_MEMBER_P (self, private_offset));
}
static void
gst_device_provider_base_class_init (gpointer g_class)
{
GstDeviceProviderClass *klass = GST_DEVICE_PROVIDER_CLASS (g_class);
/* Copy the element details here so elements can inherit the
* details from their base class and classes only need to set
* the details in class_init instead of base_init */
klass->metadata =
klass->metadata ? gst_structure_copy (klass->metadata) :
gst_structure_new_empty ("metadata");
klass->factory = g_type_get_qdata (G_TYPE_FROM_CLASS (klass),
__gst_deviceproviderclass_factory);
}
static void
gst_device_provider_class_init (GstDeviceProviderClass * klass)
{
GObjectClass *gobject_class = (GObjectClass *) klass;
gst_device_provider_parent_class = g_type_class_peek_parent (klass);
if (private_offset != 0)
g_type_class_adjust_private_offset (klass, &private_offset);
gobject_class->dispose = gst_device_provider_dispose;
gobject_class->finalize = gst_device_provider_finalize;
gst_device_provider_signals[PROVIDER_HIDDEN] =
g_signal_new ("provider-hidden", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST, 0, NULL, NULL, NULL, G_TYPE_NONE, 1, G_TYPE_STRING);
gst_device_provider_signals[PROVIDER_UNHIDDEN] =
g_signal_new ("provider-unhidden", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_FIRST, 0, NULL, NULL, NULL, G_TYPE_NONE, 1, G_TYPE_STRING);
}
static void
gst_device_provider_init (GstDeviceProvider * provider)
{
provider->priv = gst_device_provider_get_instance_private (provider);
g_mutex_init (&provider->priv->start_lock);
provider->priv->started_count = 0;
provider->priv->bus = gst_bus_new ();
gst_bus_set_flushing (provider->priv->bus, TRUE);
}
static void
gst_device_provider_dispose (GObject * object)
{
GstDeviceProvider *provider = GST_DEVICE_PROVIDER (object);
gst_object_replace ((GstObject **) & provider->priv->bus, NULL);
GST_OBJECT_LOCK (provider);
g_list_free_full (provider->devices, (GDestroyNotify) gst_object_unparent);
provider->devices = NULL;
GST_OBJECT_UNLOCK (provider);
G_OBJECT_CLASS (gst_device_provider_parent_class)->dispose (object);
}
static void
gst_device_provider_finalize (GObject * object)
{
GstDeviceProvider *provider = GST_DEVICE_PROVIDER (object);
g_mutex_clear (&provider->priv->start_lock);
G_OBJECT_CLASS (gst_device_provider_parent_class)->finalize (object);
}
/**
* gst_device_provider_class_add_metadata:
* @klass: class to set metadata for
* @key: the key to set
* @value: the value to set
*
* Set @key with @value as metadata in @klass.
*
* Since: 1.4
*/
void
gst_device_provider_class_add_metadata (GstDeviceProviderClass * klass,
const gchar * key, const gchar * value)
{
g_return_if_fail (GST_IS_DEVICE_PROVIDER_CLASS (klass));
g_return_if_fail (key != NULL);
g_return_if_fail (value != NULL);
gst_structure_set ((GstStructure *) klass->metadata,
key, G_TYPE_STRING, value, NULL);
}
/**
* gst_device_provider_class_add_static_metadata:
* @klass: class to set metadata for
* @key: the key to set
* @value: (transfer full): the value to set
*
* Set @key with @value as metadata in @klass.
*
* Same as gst_device_provider_class_add_metadata(), but @value must be a static string
* or an inlined string, as it will not be copied. (GStreamer plugins will
* be made resident once loaded, so this function can be used even from
* dynamically loaded plugins.)
*
* Since: 1.4
*/
void
gst_device_provider_class_add_static_metadata (GstDeviceProviderClass * klass,
const gchar * key, const gchar * value)
{
GValue val = G_VALUE_INIT;
g_return_if_fail (GST_IS_DEVICE_PROVIDER_CLASS (klass));
g_return_if_fail (key != NULL);
g_return_if_fail (value != NULL);
g_value_init (&val, G_TYPE_STRING);
g_value_set_static_string (&val, value);
gst_structure_take_value ((GstStructure *) klass->metadata, key, &val);
}
/**
* gst_device_provider_class_set_metadata:
* @klass: class to set metadata for
* @longname: The long English name of the device provider. E.g. "File Sink"
* @classification: String describing the type of device provider, as an
* unordered list separated with slashes ('/'). See draft-klass.txt of the
* design docs
* for more details and common types. E.g: "Sink/File"
* @description: Sentence describing the purpose of the device provider.
* E.g: "Write stream to a file"
* @author: Name and contact details of the author(s). Use \n to separate
* multiple author metadata. E.g: "Joe Bloggs &lt;joe.blogs at foo.com&gt;"
*
* Sets the detailed information for a #GstDeviceProviderClass.
*
* > This function is for use in _class_init functions only.
*
* Since: 1.4
*/
void
gst_device_provider_class_set_metadata (GstDeviceProviderClass * klass,
const gchar * longname, const gchar * classification,
const gchar * description, const gchar * author)
{
g_return_if_fail (GST_IS_DEVICE_PROVIDER_CLASS (klass));
g_return_if_fail (longname != NULL && *longname != '\0');
g_return_if_fail (classification != NULL && *classification != '\0');
g_return_if_fail (description != NULL && *description != '\0');
g_return_if_fail (author != NULL && *author != '\0');
gst_structure_id_set ((GstStructure *) klass->metadata,
GST_QUARK (ELEMENT_METADATA_LONGNAME), G_TYPE_STRING, longname,
GST_QUARK (ELEMENT_METADATA_KLASS), G_TYPE_STRING, classification,
GST_QUARK (ELEMENT_METADATA_DESCRIPTION), G_TYPE_STRING, description,
GST_QUARK (ELEMENT_METADATA_AUTHOR), G_TYPE_STRING, author, NULL);
}
/**
* gst_device_provider_class_set_static_metadata:
* @klass: class to set metadata for
* @longname: (transfer full): The long English name of the element. E.g. "File Sink"
* @classification: (transfer full): String describing the type of element, as
* an unordered list separated with slashes ('/'). See draft-klass.txt of the
* design docs for more details and common types. E.g: "Sink/File"
* @description: (transfer full): Sentence describing the purpose of the
* element. E.g: "Write stream to a file"
* @author: (transfer full): Name and contact details of the author(s). Use \n
* to separate multiple author metadata. E.g: "Joe Bloggs &lt;joe.blogs at
* foo.com&gt;"
*
* Sets the detailed information for a #GstDeviceProviderClass.
*
* > This function is for use in _class_init functions only.
*
* Same as gst_device_provider_class_set_metadata(), but @longname, @classification,
* @description, and @author must be static strings or inlined strings, as
* they will not be copied. (GStreamer plugins will be made resident once
* loaded, so this function can be used even from dynamically loaded plugins.)
*
* Since: 1.4
*/
void
gst_device_provider_class_set_static_metadata (GstDeviceProviderClass * klass,
const gchar * longname, const gchar * classification,
const gchar * description, const gchar * author)
{
GstStructure *s = (GstStructure *) klass->metadata;
GValue val = G_VALUE_INIT;
g_return_if_fail (GST_IS_DEVICE_PROVIDER_CLASS (klass));
g_return_if_fail (longname != NULL && *longname != '\0');
g_return_if_fail (classification != NULL && *classification != '\0');
g_return_if_fail (description != NULL && *description != '\0');
g_return_if_fail (author != NULL && *author != '\0');
g_value_init (&val, G_TYPE_STRING);
g_value_set_static_string (&val, longname);
gst_structure_id_set_value (s, GST_QUARK (ELEMENT_METADATA_LONGNAME), &val);
g_value_set_static_string (&val, classification);
gst_structure_id_set_value (s, GST_QUARK (ELEMENT_METADATA_KLASS), &val);
g_value_set_static_string (&val, description);
gst_structure_id_set_value (s, GST_QUARK (ELEMENT_METADATA_DESCRIPTION),
&val);
g_value_set_static_string (&val, author);
gst_structure_id_take_value (s, GST_QUARK (ELEMENT_METADATA_AUTHOR), &val);
}
/**
* gst_device_provider_class_get_metadata:
* @klass: class to get metadata for
* @key: the key to get
*
* Get metadata with @key in @klass.
*
* Returns: (nullable): the metadata for @key.
*
* Since: 1.4
*/
const gchar *
gst_device_provider_class_get_metadata (GstDeviceProviderClass * klass,
const gchar * key)
{
g_return_val_if_fail (GST_IS_DEVICE_PROVIDER_CLASS (klass), NULL);
g_return_val_if_fail (key != NULL, NULL);
return gst_structure_get_string ((GstStructure *) klass->metadata, key);
}
/**
* gst_device_provider_get_metadata:
* @provider: provider to get metadata for
* @key: the key to get
*
* Get metadata with @key in @provider.
*
* Returns: the metadata for @key.
*
* Since: 1.14
*/
const gchar *
gst_device_provider_get_metadata (GstDeviceProvider * provider,
const gchar * key)
{
g_return_val_if_fail (GST_IS_DEVICE_PROVIDER (provider), NULL);
g_return_val_if_fail (key != NULL, NULL);
return
gst_device_provider_class_get_metadata (GST_DEVICE_PROVIDER_GET_CLASS
(provider), key);
}
/**
* gst_device_provider_get_devices:
* @provider: A #GstDeviceProvider
*
* Gets a list of devices that this provider understands. This may actually
* probe the hardware if the provider is not currently started.
*
* If the provider has been started, this will returned the same #GstDevice
* objedcts that have been returned by the #GST_MESSAGE_DEVICE_ADDED messages.
*
* Returns: (transfer full) (element-type GstDevice): a #GList of
* #GstDevice
*
* Since: 1.4
*/
GList *
gst_device_provider_get_devices (GstDeviceProvider * provider)
{
GstDeviceProviderClass *klass;
GList *devices = NULL;
gboolean started;
GList *item;
g_return_val_if_fail (GST_IS_DEVICE_PROVIDER (provider), NULL);
klass = GST_DEVICE_PROVIDER_GET_CLASS (provider);
g_mutex_lock (&provider->priv->start_lock);
started = (provider->priv->started_count > 0);
if (started) {
GST_OBJECT_LOCK (provider);
for (item = provider->devices; item; item = item->next)
devices = g_list_prepend (devices, gst_object_ref (item->data));
GST_OBJECT_UNLOCK (provider);
} else if (klass->probe) {
devices = klass->probe (provider);
for (item = devices; item; item = item->next)
if (g_object_is_floating (item->data))
g_object_ref_sink (item->data);
}
g_mutex_unlock (&provider->priv->start_lock);
return devices;
}
/**
* gst_device_provider_start:
* @provider: A #GstDeviceProvider
*
* Starts providering the devices. This will cause #GST_MESSAGE_DEVICE_ADDED
* and #GST_MESSAGE_DEVICE_REMOVED messages to be posted on the provider's bus
* when devices are added or removed from the system.
*
* Since the #GstDeviceProvider is a singleton,
* gst_device_provider_start() may already have been called by another
* user of the object, gst_device_provider_stop() needs to be called the same
* number of times.
*
* After this function has been called, gst_device_provider_get_devices() will
* return the same objects that have been received from the
* #GST_MESSAGE_DEVICE_ADDED messages and will no longer probe.
*
* Returns: %TRUE if the device providering could be started
*
* Since: 1.4
*/
gboolean
gst_device_provider_start (GstDeviceProvider * provider)
{
GstDeviceProviderClass *klass;
gboolean ret = FALSE;
g_return_val_if_fail (GST_IS_DEVICE_PROVIDER (provider), FALSE);
klass = GST_DEVICE_PROVIDER_GET_CLASS (provider);
g_mutex_lock (&provider->priv->start_lock);
if (provider->priv->started_count > 0) {
provider->priv->started_count++;
ret = TRUE;
goto started;
}
gst_bus_set_flushing (provider->priv->bus, FALSE);
if (klass->start) {
ret = klass->start (provider);
} else {
GList *devices = NULL, *item;
devices = klass->probe (provider);
for (item = devices; item; item = item->next) {
GstDevice *device = GST_DEVICE (item->data);
gboolean was_floating = g_object_is_floating (item->data);
gst_device_provider_device_add (provider, device);
if (!was_floating)
g_object_unref (item->data);
}
g_list_free (devices);
ret = TRUE;
}
if (ret) {
provider->priv->started_count++;
} else if (provider->priv->started_count == 0) {
gst_bus_set_flushing (provider->priv->bus, TRUE);
}
started:
g_mutex_unlock (&provider->priv->start_lock);
return ret;
}
/**
* gst_device_provider_stop:
* @provider: A #GstDeviceProvider
*
* Decreases the use-count by one. If the use count reaches zero, this
* #GstDeviceProvider will stop providering the devices. This needs to be
* called the same number of times that gst_device_provider_start() was called.
*
* Since: 1.4
*/
void
gst_device_provider_stop (GstDeviceProvider * provider)
{
GstDeviceProviderClass *klass;
g_return_if_fail (GST_IS_DEVICE_PROVIDER (provider));
klass = GST_DEVICE_PROVIDER_GET_CLASS (provider);
g_mutex_lock (&provider->priv->start_lock);
if (provider->priv->started_count == 1) {
gst_bus_set_flushing (provider->priv->bus, TRUE);
if (klass->stop)
klass->stop (provider);
GST_OBJECT_LOCK (provider);
g_list_free_full (provider->devices, (GDestroyNotify) gst_object_unparent);
provider->devices = NULL;
GST_OBJECT_UNLOCK (provider);
} else if (provider->priv->started_count < 1) {
g_critical
("Trying to stop a GstDeviceProvider %s which is already stopped",
GST_OBJECT_NAME (provider));
}
provider->priv->started_count--;
g_mutex_unlock (&provider->priv->start_lock);
}
/**
* gst_device_provider_get_factory:
* @provider: a #GstDeviceProvider to request the device provider factory of.
*
* Retrieves the factory that was used to create this device provider.
*
* Returns: (transfer none) (nullable): the #GstDeviceProviderFactory used for
* creating this device provider. no refcounting is needed.
*
* Since: 1.4
*/
GstDeviceProviderFactory *
gst_device_provider_get_factory (GstDeviceProvider * provider)
{
g_return_val_if_fail (GST_IS_DEVICE_PROVIDER (provider), NULL);
return GST_DEVICE_PROVIDER_GET_CLASS (provider)->factory;
}
/**
* gst_device_provider_can_provider:
* @provider: a #GstDeviceProvider
*
* If this function returns %TRUE, then the device provider can provider if
* devices are added or removed. Otherwise, it can only do static probing.
*
* Returns: %TRUE if the #GstDeviceProvider support providering, %FALSE otherwise
*/
gboolean
gst_device_provider_can_monitor (GstDeviceProvider * provider)
{
GstDeviceProviderClass *klass;
g_return_val_if_fail (GST_IS_DEVICE_PROVIDER (provider), FALSE);
klass = GST_DEVICE_PROVIDER_GET_CLASS (provider);
if (klass->start)
return TRUE;
else
return FALSE;
}
/**
* gst_device_provider_get_bus:
* @provider: a #GstDeviceProvider
*
* Gets the #GstBus of this #GstDeviceProvider
*
* Returns: (transfer full): a #GstBus
*
* Since: 1.4
*/
GstBus *
gst_device_provider_get_bus (GstDeviceProvider * provider)
{
g_return_val_if_fail (GST_IS_DEVICE_PROVIDER (provider), NULL);
return gst_object_ref (provider->priv->bus);
}
/**
* gst_device_provider_device_add:
* @provider: a #GstDeviceProvider
* @device: (transfer floating): a #GstDevice that has been added
*
* Posts a message on the provider's #GstBus to inform applications that
* a new device has been added.
*
* This is for use by subclasses.
*
* @device's reference count will be incremented, and any floating reference
* will be removed (see gst_object_ref_sink()).
*
* Since: 1.4
*/
void
gst_device_provider_device_add (GstDeviceProvider * provider,
GstDevice * device)
{
GstMessage *message;
g_return_if_fail (GST_IS_DEVICE_PROVIDER (provider));
g_return_if_fail (GST_IS_DEVICE (device));
if (!gst_object_set_parent (GST_OBJECT (device), GST_OBJECT (provider))) {
GST_WARNING_OBJECT (provider, "Could not parent device %p to provider,"
" it already has a parent", device);
return;
}
GST_OBJECT_LOCK (provider);
/* Take an additional reference so we can be sure nobody removed it from the
* provider in the meantime and we can safely emit the message */
gst_object_ref (device);
provider->devices = g_list_prepend (provider->devices, device);
GST_OBJECT_UNLOCK (provider);
message = gst_message_new_device_added (GST_OBJECT (provider), device);
gst_bus_post (provider->priv->bus, message);
gst_object_unref (device);
}
/**
* gst_device_provider_device_remove:
* @provider: a #GstDeviceProvider
* @device: a #GstDevice that has been removed
*
* Posts a message on the provider's #GstBus to inform applications that
* a device has been removed.
*
* This is for use by subclasses.
*
* Since: 1.4
*/
void
gst_device_provider_device_remove (GstDeviceProvider * provider,
GstDevice * device)
{
GstMessage *message;
GList *item;
g_return_if_fail (GST_IS_DEVICE_PROVIDER (provider));
g_return_if_fail (GST_IS_DEVICE (device));
GST_OBJECT_LOCK (provider);
item = g_list_find (provider->devices, device);
if (item) {
provider->devices = g_list_delete_link (provider->devices, item);
}
GST_OBJECT_UNLOCK (provider);
message = gst_message_new_device_removed (GST_OBJECT (provider), device);
g_signal_emit_by_name (device, "removed");
gst_bus_post (provider->priv->bus, message);
if (item)
gst_object_unparent (GST_OBJECT (device));
}
/**
* gst_device_provider_get_hidden_providers:
* @provider: a #GstDeviceProvider
*
* Get the provider factory names of the #GstDeviceProvider instances that
* are hidden by @provider.
*
* Returns: (transfer full) (array zero-terminated=1) (element-type gchar*):
* a list of hidden providers factory names or %NULL when
* nothing is hidden by @provider. Free with g_strfreev.
*
* Since: 1.6
*/
gchar **
gst_device_provider_get_hidden_providers (GstDeviceProvider * provider)
{
GList *walk;
guint i, len;
gchar **res = NULL;
g_return_val_if_fail (GST_IS_DEVICE_PROVIDER (provider), NULL);
GST_OBJECT_LOCK (provider);
len = g_list_length (provider->priv->hidden_providers);
if (len == 0)
goto done;
res = g_new (gchar *, len + 1);
for (i = 0, walk = provider->priv->hidden_providers; walk;
walk = g_list_next (walk), i++)
res[i] = g_strdup (walk->data);
res[i] = NULL;
done:
GST_OBJECT_UNLOCK (provider);
return res;
}
/**
* gst_device_provider_hide_provider:
* @provider: a #GstDeviceProvider
* @name: a provider factory name
*
* Make @provider hide the devices from the factory with @name.
*
* This function is used when @provider will also provide the devices reported
* by provider factory @name. A monitor should stop monitoring the
* device provider with @name to avoid duplicate devices.
*
* Since: 1.6
*/
void
gst_device_provider_hide_provider (GstDeviceProvider * provider,
const gchar * name)
{
GList *find;
const gchar *hidden_name = NULL;
g_return_if_fail (GST_IS_DEVICE_PROVIDER (provider));
g_return_if_fail (name != NULL);
GST_OBJECT_LOCK (provider);
find =
g_list_find_custom (provider->priv->hidden_providers, name,
(GCompareFunc) g_strcmp0);
if (find == NULL) {
hidden_name = name;
provider->priv->hidden_providers =
g_list_prepend (provider->priv->hidden_providers, g_strdup (name));
}
GST_OBJECT_UNLOCK (provider);
if (hidden_name)
g_signal_emit (provider, gst_device_provider_signals[PROVIDER_HIDDEN],
0, hidden_name);
}
/**
* gst_device_provider_unhide_provider:
* @provider: a #GstDeviceProvider
* @name: a provider factory name
*
* Make @provider unhide the devices from factory @name.
*
* This function is used when @provider will no longer provide the devices
* reported by provider factory @name. A monitor should start
* monitoring the devices from provider factory @name in order to see
* all devices again.
*
* Since: 1.6
*/
void
gst_device_provider_unhide_provider (GstDeviceProvider * provider,
const gchar * name)
{
GList *find;
gchar *unhidden_name = NULL;
g_return_if_fail (GST_IS_DEVICE_PROVIDER (provider));
g_return_if_fail (name != NULL);
GST_OBJECT_LOCK (provider);
find =
g_list_find_custom (provider->priv->hidden_providers, name,
(GCompareFunc) g_strcmp0);
if (find) {
unhidden_name = find->data;
provider->priv->hidden_providers =
g_list_delete_link (provider->priv->hidden_providers, find);
}
GST_OBJECT_UNLOCK (provider);
if (unhidden_name) {
g_signal_emit (provider,
gst_device_provider_signals[PROVIDER_UNHIDDEN], 0, unhidden_name);
g_free (unhidden_name);
}
}
/**
* gst_device_provider_device_changed:
* @device: (transfer none): the new version of @changed_device
* @changed_device: (transfer floating): the old version of the device that has been updated
*
* This function is used when @changed_device was modified into its new form
* @device. This will post a `DEVICE_CHANGED` message on the bus to let
* the application know that the device was modified. #GstDevice is immutable
* for MT. safety purposes so this is an "atomic" way of letting the application
* know when a device was modified.
*
* Since: 1.16
*/
void
gst_device_provider_device_changed (GstDeviceProvider * provider,
GstDevice * device, GstDevice * changed_device)
{
GList *dev_lst;
GstMessage *message;
g_return_if_fail (GST_IS_DEVICE_PROVIDER (provider));
g_return_if_fail (GST_IS_DEVICE (device));
g_return_if_fail (GST_IS_DEVICE (changed_device));
GST_OBJECT_LOCK (provider);
dev_lst = g_list_find (provider->devices, changed_device);
if (!dev_lst) {
GST_ERROR_OBJECT (provider,
"Trying to update a device we do not have in our own list!");
GST_OBJECT_UNLOCK (provider);
return;
}
if (!gst_object_set_parent (GST_OBJECT (device), GST_OBJECT (provider))) {
GST_OBJECT_UNLOCK (provider);
GST_WARNING_OBJECT (provider, "Could not parent device %p to provider,"
" it already has a parent", device);
return;
}
dev_lst->data = device;
GST_OBJECT_UNLOCK (provider);
message =
gst_message_new_device_changed (GST_OBJECT (provider), device,
changed_device);
gst_bus_post (provider->priv->bus, message);
gst_object_unparent (GST_OBJECT (changed_device));
}
/**
* gst_device_provider_is_started:
* @provider: a #GstDeviceProvider
*
* This function can be used to know if the @provider was successfully started.
*
* Since: 1.20
*/
gboolean
gst_device_provider_is_started (GstDeviceProvider * provider)
{
gboolean started = FALSE;
g_return_val_if_fail (GST_IS_DEVICE_PROVIDER (provider), FALSE);
g_mutex_lock (&provider->priv->start_lock);
started = provider->priv->started_count > 0;
g_mutex_unlock (&provider->priv->start_lock);
return started;
}