mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-11-25 19:21:06 +00:00
42 lines
2.2 KiB
Text
42 lines
2.2 KiB
Text
GstObject
|
|
=========
|
|
|
|
The base class for the entire GStreamer hierarchy is the GstObject. It is currently a bit of a hack caused by the
|
|
fact that GStreamer is built on top of GtkObject. GObject should help, if it's designed properly. Currently the
|
|
capabilities provided by GstObject are quite underutilized, this will be fixed with a refactoring of the
|
|
object system and a code cleanup at some point in the future. If nothing else, it serves as an easy check to see if a
|
|
given object belongs to GStreamer.
|
|
|
|
Parentage
|
|
---------
|
|
|
|
A pointer is available to store the current parent of the object. This one of the two fundamental requires for a
|
|
hierarchical system such as GStreamer (for the other, read up on GstBin). Three functions are provided: _set_parent(),
|
|
_get_parent(), and _unparent(). The third is required because there is an explicit check in _set_parent(): an object
|
|
must not already have a parent if you wish to set one. You must unparent the object first. This allows for new
|
|
additions later.
|
|
|
|
Refcounting
|
|
-----------
|
|
|
|
A reference count is kept for the object. When this is fully utilized, it will enable generic destruction of objects
|
|
by simply reducing the reference count to zero. GObject should provide these capabilities, however.
|
|
|
|
Locking
|
|
-------
|
|
|
|
The GstObject contains the necessary primitives to lock the object in a thread-safe manner. This will be used to
|
|
provide general thread-safety as needed. However, this lock is generic, i.e. it covers the whole object. Note that
|
|
this does *not* mean that no other thread can modify the object at the same time that the lock is held. It only means
|
|
that any two sections of code that obey the lock are guaranteed to not be running simultaneously.
|
|
|
|
This lock will ideally be used for parentage and refcounting, which is reasonable, since they are the only possible
|
|
things to protect in the GstObject.
|
|
|
|
Path Generation
|
|
---------------
|
|
|
|
Due to the base nature of the GstObject, it becomes the only reasonable place to put this particular function
|
|
(_get_path_string). It will generate a string describing the parent hierarchy of a given GstObject. Currently it is
|
|
forced to use several child-class-specific functions, because we do not properly use the base capabilities (parentage,
|
|
etc.) of GstObject properly.
|