Previously gst_buffer_list_foreach() could modify (drop or replace)
buffers in non-writable lists, which could cause all kinds of problems
if other code also has a reference to the list and assumes that it stays
the same.
https://bugzilla.gnome.org/show_bug.cgi?id=796692
Every container of miniobjects now needs to store itself as parent in
the child object, and remove itself again at a later time.
A miniobject is only writable if there is at most one parent, and that
parent is writable itself, and if the reference count of the miniobject
is 1.
GstBuffer (for memories), GstBufferList (for buffers) and GstSample (for
caps, buffer, bufferlist) was updated accordingly.
Without this it was possible to have e.g. a bufferlist with refcount 2
in two places, modifying the same buffer with refcount 1 at the same
time.
https://bugzilla.gnome.org/show_bug.cgi?id=796692
gst_buffer_list_new_sized(0) will cause an underflow in a calculation
which then makes it try to allocate huge amounts of memory, which
may lead to aborts.
https://bugzilla.gnome.org/show_bug.cgi?id=795758
We can now create and free a buffer list with one slice alloc/free
call in most cases, instead of one slice alloc/free for the list,
one slice alloc/free for the GArray, and one malloc/free for the
GArray array. In practice we know the max size of our buffer list
from the start, so can avoid reallocs.
https://bugzilla.gnome.org/show_bug.cgi?id=732284
Support for (nullable) was added to G-I at the same time as nullable
return values. Previous versions of G-I will not mark return values as
nullable, even when an (allow-none) annotation is present, so it is
not necessary to add (allow-none) annotations for compatibility with
older versions of G-I.
https://bugzilla.gnome.org/show_bug.cgi?id=730957
They are very confusing for people, and more often than not
also just not very accurate. Seeing 'last reviewed: 2005' in
your docs is not very confidence-inspiring. Let's just remove
those comments.
Move the locking methods from GstMemory to GstMiniObject.
Add a miniobject flag to enable LOCKABLE objects. LOCKABLE objects can
use the lock/unlock API to control the access to the object.
Add a minobject flag that allows you to lock an object in readonly mode.
Modify the _is_writable() method to check the shared counter for LOCKABLE
objects. This allows us to control writability separately from the refcount for
LOCKABLE objects.
So mini objects don't have to poke into the GstMiniObject part
of the structure. Saves lines of code, and seems slightly cleaner.
We don't have proper OO hierarchies or methods here after all.
The size field is used by subclasses to store the total allocated size of the
memory for this miniobject. Because miniobject doesn't really do anything with
this field we can move it to the subclasses.
When the foreach function told us to remove the buffer from the list, decrease
the length of the array or else we might read past the last item in the array.
Remove gst_mini_object_register() and add a GST_DEFINE_MINI_OBJECT macro to
define a _get_type() function for the boxed miniobject.
Remove a bunch of custom _get_type() functions and replace them with the
miniobject macro.
Rename some _init method to _priv_*_initialize() like the rest of them.
Inspired by patch from Johan Dahlin and see bug #657603
Adding a buffer to the end of a GstBufferList is supposed to be a fast
operation, but it was not since the iterator does not advance its
nextpointer when adding buffers and GList does not have a tail pointer.
Using a GQueue to store the buffers makes it easier to add buffers to
the end of the list and this operation will now be much more efficient.
Adding an entire GList of buffers using
gst_buffer_list_iterator_add_list() will however have to iterate over
the list being added to be able to update the tail pointer in the
GQueue.
