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42 lines
2.2 KiB
Text
42 lines
2.2 KiB
Text
GstObject
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=========
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The base class for the entire GStreamer hierarchy is the GstObject. It is currently a bit of a hack caused by the
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fact that GStreamer is built on top of GtkObject. GObject should help, if it's designed properly. Currently the
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capabilities provided by GstObject are quite underutilized, this will be fixed with a refactoring of the
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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
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given object belongs to GStreamer.
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Parentage
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---------
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A pointer is available to store the current parent of the object. This one of the two fundamental requires for a
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hierarchical system such as GStreamer (for the other, read up on GstBin). Three functions are provided: _set_parent(),
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_get_parent(), and _unparent(). The third is required because there is an explicit check in _set_parent(): an object
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must not already have a parent if you wish to set one. You must unparent the object first. This allows for new
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additions later.
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Refcounting
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-----------
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A reference count is kept for the object. When this is fully utilized, it will enable generic destruction of objects
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by simply reducing the reference count to zero. GObject should provide these capabilities, however.
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Locking
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-------
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The GstObject contains the necessary primitives to lock the object in a thread-safe manner. This will be used to
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provide general thread-safety as needed. However, this lock is generic, i.e. it covers the whole object. Note that
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this does *not* mean that no other thread can modify the object at the same time that the lock is held. It only means
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that any two sections of code that obey the lock are guaranteed to not be running simultaneously.
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This lock will ideally be used for parentage and refcounting, which is reasonable, since they are the only possible
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things to protect in the GstObject.
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Path Generation
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---------------
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Due to the base nature of the GstObject, it becomes the only reasonable place to put this particular function
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(_get_path_string). It will generate a string describing the parent hierarchy of a given GstObject. Currently it is
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forced to use several child-class-specific functions, because we do not properly use the base capabilities (parentage,
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etc.) of GstObject properly.
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