Add a new pad flag NEED_PARENT that ensures that the parent of a pad is
reffed and not NULL when the event, query and internal links functions
are called.
When a pad is added to an element automatically make sure the NEED_PARENT flag
is enabled.
Remove the getcaps function on the pad and use the CAPS query for
the same effect.
Add PROXY_CAPS to the pad flags. This instructs the default caps event and query
handlers to pass on the CAPS related queries and events. This simplifies a lot
of elements that passtrough caps negotiation.
Make two utility functions to proxy caps queries and aggregate the result. Needs
to use the pad forward function instead later.
Make the _query_peer_ utility functions use the gst_pad_peer_query() function to
make sure the probes are emited properly.
The fixate caps function was not used externally and we have vmethods in the
base classes where it is needed.
Update some docs.
simplify some fixate functions in the base classes. Also pass the untruncated
caps to the vmethod.
when we are flushing, don't store the event on the pad but simply return FALSE.
Don't deactivate the srcpad, we need it to be active in order to push the
caps. Downstream can change the scheduling mode of an active pad.
Make a new GstPadProbeInfo structure and pass this in the probe callback. This
allows us to add more things later and also allow the callback to replace or
modify the passed object.
Make a separate cookie to detect chancges in the list of probes and keeping
track of what hooks have been invoked yet.
Remove the requirement to have probes on srcpads in push mode and sinkpads in
pull mode.
Add some more debug.
Keep track of what callbacks got executed. If no callback is called and we are a
blocking pad, let the item pass. This allows you to block pads on selected
items only.
Explicitly have an UPSTREAM and DOWNSTREAM PadProbeType. This allows you to only
block the pad on upstream or downstream items.
Add convenience macros to only block on downstream/upstream items.
Better now than later in the cycle. These might come in handy:
sed -i -e 's/GstProbeReturn/GstPadProbeReturn/g' `git grep GstProbeReturn | sed -e 's/:.*//' | sort -u`
sed -i -e 's/GST_PROBE_/GST_PAD_PROBE_/g' `git grep GST_PROBE_ | sed -e 's/:.*//' | sort -u`
sed -i -e 's/GstProbeType/GstPadProbeType/g' `git grep GstProbeType | sed -e 's/:.*//' | sort -u`
If pushgin downstream returned a non-ok value (like GST_FLOW_WRONG_STATE),
we don't want to end up returning a different value (GST_FLOW_OK in this
case) if IDLE probes are present.
GstBuffer pointers can now be printed using GST_PTR_FORMAT. This is used
in the very useful GST_SCHEDULING debug logs in gstpad.c and allows for
easier and more information tracking of buffer progress through a
pipeline with just debug logging.
This allows the setcaps handler and notify::caps to link
the pad downstream and doesn't require hacks to always
provide a peer to the pad, like in decodebin2.
This reverts commit 2bfada5581.
Conflicts:
gst/gstpad.c
For 0.11 we want to enforce that only subsets of the pad
caps are allowed. This breaks backward compatibility for
some elements, which is why we only print a warning in
0.10.
Pads should only accept caps that are a subset of the pad caps, e.g.
they should accept only caps that have a non-empty intersection and
at least all fields of the pad caps.
Without this a pad that wants for example
"video/x-h264,stream-format=byte-stream"
will be happy to accept
"video/x-h264".
Make the acceptcaps function behave like all the other functions with a default
implementation. Don't try to chain up to the default implementation when it was
set to NULL explicitly but return FALSE instead.
Fix some docs
Remove gst_pad_get_negotiated_caps(), it does not realy do what it says,
gst_pad_get_current_caps() returns the currently negotiated caps on the pad
correctly.
Refactor calling the GETCAPS function and checks.
Move the filter code in one place.
When using fixed pad caps, get the currently configured caps and then fallback
to the GETCAPS function. We used to simply ignore the GETCAPS function, which
resulted in transform elements returning the template caps instead of doing the
caps transform.
Always forward all events in the default handler. Previously it used to not
forward caps events by default. It makes more sense to forward the caps events,
if the element is interested in the caps, it will implement an event handler to
retrieve the caps and then it can decide to forward or not. If the element has
no event handler, it probably just doesn't care about caps and it probably is
also not going to modify the data in a way that needs a caps change.
Rename gst_pad_dispatcher() to gst_pad_forward() and make it more useful by
iterating the internal links of a pad and handling resync properly.
Add a method gst_pad_event_forward() that unconditionally forwards an event to
all internally linked pads.
Update some pad code to use the new forward function.
Optimize linking by only releasing the pad locks when there are link functions
installed on the pads.
Add some G_LIKELY here and there.
Move error paths out of the main code flow.
Keep track of installed number of probes to shortcut emission.
Allow NULL callbacks, this is useful for blocking probes.
Improve probe selection based on the mask, an empty mask for the data or the
scheduling flags equals that all probes match.
Add some more debug info.
Don't check the flushing flag in the probe callback handler, this needs to be
done before calling the handler.
Fix blocking probes.
Fix unit tests
Make the PadBlock callback take a GstBlockType parameter to handle the different
kind of stages in the pad block. This provides for more backwards compatibility
in the pad block API.
Separate blocking and unblocking into different methods, only blocking can do a
callback, unblock is always immediately. Also removed synchronous blocking, it
can always be implemented with a callback.
Make pad block call the callback as soon as the pad is not in use. This makes it
possible to make sure that when the callback is called, no activity is happening
on the pad and that no activity will ever happen until the pad is unblocked
again. This makes pad blocking work when there is no dataflow or after EOS and
greatly helps dynamic pipelines.
Move the probe handling right where we wait on the pad block. The two are
related but not the same and the probe can eventually influence the pad
blocking as we'll se later.
Fix up some broken unit tests or tests that fail with the new behaviour.
Rework _push_event() a little so that it drops events on blocking pads.
Make sure that events are forwarded when we unblock.
Add counter on the pad to keep track of busy pads.
Implement a default buffer-list function in case the element doesn't implement
one.
Also pass buffer-lists to the have-data signal, this allows us to remove some
backward compatibility code.
Change the sticky event array so that it contains a pending and an active event.
Events on the sinkpad are copied to the pending array and after the eventfunc
returned TRUE, moved to the active event. This allows us to queue new events
like when we do per-pad offsets without removing the currently active event.
Remove the active argument from the gst_pad_get_sticky_event() method, the
pending events are not something we want to expose.
When linking pads and when copying a segment event from the sourc pad to the
sinkpad, apply the src and sinkpad offsets to the segment base. Make sure that
we only modify the event stored on the sinkpad and never the one on the source
pad.
When changing the pad offset, perform the segment copy with the updated offsets.
When pushing a segment event, apply the srcpad offset before sending the event
to the peer pad.
This part is missing the adjustment of the segment event on the sinkpad, which
is for a later patch.
Add methods to adjust the offset. This will be used to change the segment events
with an offset so that we can tweak the timing of the stream on a per-pad base.
First store the sticky event on the sinkpad in the inactive state, then check
for the flushing flag. We want to have the events on sinkpads at all times,
ready to be activated when the pad becomes active.
Make a function to call the eventfunc and perform a caps check when we are
dispatching a caps event.
This makes sure that all code paths correctly check that the caps are
acceptable before sending the caps to the eventfunction.
Update the design docs with some clear rules for how sticky events are
handled.
Reimplement the sticky tags, use a small structure to hold the event and its
current state (active or inactive).
Events on sinkpads only become active when the event function returned success
for the event.
When linking, only update events that are different.
Avoid making a copy of the event array, use the object lock to protect the event
array and release it only to call the event function. This will need to check
if something changed, later.
Disable a test in the unit test, it can't work yet.
gst_pad_template_get_caps(), gst_pad_get_pad_template_caps()
and gst_pad_get_pad_template() return a new reference of the
caps or template now and the return value needs to be
unreffed after usage.
This reverts commit cf4fbc005c.
This change did not improve the situation for bindings because
queries are usually created, then directly passed to a function
and not stored elsewhere, and the writability problem with
miniobjects usually happens with buffers or caps instead.
Resetting the result is not necessary when resyncing because
pads that previously got the event will be skipped and we
need to consider the results of the previous pushes.
Fix replace of caps events when linking: we need to unref the old ones.
Make sure we pass error values around.
Move backward compat code into the default handler for now.
Don't use the buffer caps for negotiation anymore but use the CAPS events.
Make the _set_caps method produce the CAPS event, add some backward
compatibility code to trigger the setcaps functions on src and sinkpads.
Remove all negotiation code from the chain functions.
Don't use the GST_PAD_CAPS variable anymore to store the caps but retrieve the
caps from the sticky event array.
Remove the context again, adding an extra layer of refcounting and object
creation to manage an array is too complicated and inefficient. Use a simple
array again.
Also implement event updates when calling gst_pad_chain() and
gst_event_send_event() directly.
Pass the context downstream when it got updated.
Have two ways of informing downstream of events, do a full context update when
the CONTEXT_PENDING flag is set and simply forward the event otherwise.
Set the CONTENT_PENDING flag when linking pads.
We don't need to old context anymore when updating the context of a pad.
If there is no custom getcaps function on a sink pad, then changes in
downstream caps will never be propagated, so there is no point in trying to
renegotiate the capabilities.
This reverts commit 9ef1346b1f.
Way to much for one commit and I'm not sure we want to get rid of the pad caps
just like that. It's nice to have the buffer and its type in onw nice bundle
without having to drag the complete context with it.
Resetting the result is not necessary when resyncing because
pads that previously got the event will be skipped and we
need to consider the results of the previous pushes.
Copy the sticky events from the srcpad to the sinkpad when linking pads. Set the
STICKY_PENDING flag to make sure that the sticky events are dispatched before
pushing the next buffer to the element.
Add the sticky flag to events and a sticky index.
Keep sticky events in an array on each pad.
Remove GST_EVENT_SRC(), it is causing refcycles with sticky events, was not used
and is not very interesting anyway.
Remove pad_alloc and all references. This can now be done more efficiently and
more flexible with the ALLOCATION query and the bufferpool objects. There is no
reverse negotiation yet but that will be done with an event later.
As GST_SCHEDULING reports when buffers pass through pads due to
gst_pad_push calls, they are a good way of tracking the progress of
buffers through pipelines. As such, adding output of the buffer pointers
to these messages allows tracking of specific buffers, easing debugging.
Check the sinkpad for the flushing state before calling the chainfunction on the
pad. We do this by checking the cache (which is also cleared on the srcpad when
the sink is set to flushing).
Fixes#641928
Make the _get_caps functions behave like the _get_caps_reffed variants and
remove the _reffed variants. This means that _get_caps doesn't return a writable
caps anymore and an explicit _make_writable() is needed before modifying the
caps.
There is no need to cache the peer chainfunction as we can just as efficiently
get to it from the peer object. Also not caching the chain function works better
because then we automatically get the new chainfunctions when they change.
Build the cache while we push data. When we don't have a cache, we run the
slowpath and collect cacheable properties. When all conditions are met, keep the
cached data around so that we can more efficiently push data around.
Otherwise the source will stay at NULL, the event is passed to the
peerpad via gst_pad_send_event() and then the peerpad is set as
source of the event instead of the originating pad.
A flush-stop event would make a pad unflushing, causing it
to start acting as an activated pad. This, for example,
could lead to the chain function being called when stuff
isn't initialized.
This could happend when setting qtdemux to NULL while a seek
was being handled in the upstream filesrc (in push mode).
This patch makes it check if it is activated before setting
it to unflushing.
This is the same behaviour as if we had a pad template caps of
GST_CAPS_ANY on any of the pads (i.e. the actual check will be done
during caps negotiation).
Instead just check that the caps intersect with the pad template.
The elements should properly accept/refuse the caps in setcaps().
Shaves off calling the default implementation of acceptcaps which does
an expensive gst_pad_get_caps() (so if you have 50 of those elements in
a row, you'd be doing factorial(50) gst_pad_get_caps...).
Does not break any module unit test and most apps work fine.
https://bugzilla.gnome.org/show_bug.cgi?id=622740
Since everything GstXML related has been deprecated, we can now skip the
libxml includes from the public headers when GST_DISABLE_DEPRECATED is
defined.
See #463435.
Pipeline serialisation to and from XML is horribly broken for all
but the most simple use cases, and will likely never be fixed.
Make sure everyone playing around with these tools is aware of
this, to avoid frustration. See countless bug reports in bugzilla.
Fixes bug #622685.
A pad is 'negotiable' when its container element is in a state greater
than GST_STATE_READY
API:gst_pad_is_negotiable
API:gst_pad_set_negotiable
API:GST_PAD_NEGOTIABLE
https://bugzilla.gnome.org/show_bug.cgi?id=618644
Just truncate and then fixate. We check for empty caps in the begin and a
fixate-func that empties a caps would be broken. It also helps lazy caps impl.
in bug 618853 by avoiding the gst_caps_get_size().
We need to check the pad caps on the srcpad as well as on the sinkpad. Revert
this commit as it removes the check on the srcpad and can leave the srcpad
unnegotiated (or negotiated with wrong caps)
This reverts commit 07dc1e5b49.
This check is not necesarry as we are not negotiating anymore. And it can
be wrong if upstream can't produce this caps anymore, but downstream can
process them fine.
When we unblock a pad with the same user_data, the destroy callback is not
called. This leads to refcounting leaks that cannot be avoided. Instead always
call the destroy notify whenever we install a new pad block.
In particular, this fixes a nasty pad leak in decodebin2.
Also update the unit test to have more accurate comments and test the required
behaviour.
The default gst_pad_fixate_caps() previously would only fixate each individual
struct. In case there are multiple structs, the resulting caps would still not
be fixed. In the spirit of how individual structs are fixated, this patch
changes gst_pad_fixate_caps() to remove all but the first struct.
Fixes#595886
There's not much point in using GST_DEBUG_FUNCPTR with GObject
virtual functions such as get_property, set_propery, finalize and
dispose, since they'll never be used by anyone anyway. Saves a
few bytes and possibly a tenth of a polar bear.
In most places in core and baseclasses we just need the caps to do caps-
intersections. In that case ref'ed caps are enough (no need to copy).
This patch also switches the code to use the new functions.
API: gst_pad_get_caps_refed(), gst_pad_peer_get_caps_refed()
Post the structure change messages on the sinkpads of the elements. This allows
us to catch unlinked pads earlier without ending up with inconsistent element
degrees.
The internal links function is deprecated since some time and
there already were GST_REMOVE_DEPRECATED markers in the source file,
now add them to the header too.
Fixes bug #592209.
This makes the generated code faster since:
* It won't have to read an undirect value (which will most likely be
outside of the L1/L2 cache)
* We know that value never changes (the compiler has no clue that it doesn't).
Move MT safety to main description (it does not belong to Return: or Since:
statement). Add a few missing return docs. Downgrade a normal comment froma doc
comment. Fix a doc header to only contain symbol name.
Reuse buffer code for bufferlists. Not sure if this measurably impacts performance
for the simple buffer case, if it does after doing some benchmarks, we can
decouple it later.
Fixes#572285
Post a stream-status message indicating that a new task was created so that the
application has a chance to change the properties of the task.
Fix unit test to take into account the new ref of the message.
Move the gst_pad_can_link() implementation from gstutils to gstpad and use
gst_pad_link_prepare() to make it work correctly and also check the caps.
Make the broken implementation in gstutils static.
Small cleanups in the _get_fixed_caps() function.
Fixes#575682.
Keep track of when a new callback is installed in the callback and call the new
callback in that case.
Add unit test for checking pad blocking.
Fixes#573823.
When de/activating a pad in pull mode the pad needs to de/activate the
peer pad it is connected to, failure to be able to do this in activation mode
is an error.
However if there is no peerpad, we can still deactivate the pad correctly and
assume the application will deactivate the unlinked peer pad eventually.
Fixes#574163.
Original commit message from CVS:
* gst/gstpad.c: (gst_pad_configure_src):
When we use gst_pad_alloc_buffer() without wanting to set the caps we
also don't need to check if the caps are compatible because the caller
presumably is going to perform its own custom checks. Fixes some cases
where basetransform elements would error out when it was not needed.
Original commit message from CVS:
* gst/gstpad.c: (gst_pad_get_range), (gst_pad_pull_range):
Revert a patch from 21 months ago that broke caps negotiation in pull
mode. Basically, having a buffer pass over a pad will trigger the
setcaps function when caps change, just like in push mode.
Original commit message from CVS:
Base on Patch by: Olivier Crete <tester at tester dot ca>
* gst/gstbin.c: (gst_bin_init), (gst_bin_add_func),
(gst_bin_remove_func), (update_degree),
(gst_bin_sort_iterator_new), (gst_bin_handle_message_func):
Keep track of pads that are being linked/unlinked and resync the state
changes.
* gst/gstpad.c: (gst_pad_get_direction),
(gst_pad_set_chain_function), (gst_pad_set_getrange_function),
(gst_pad_set_checkgetrange_function), (gst_pad_unlink),
(gst_pad_link_prepare), (gst_pad_link),
(gst_pad_event_default_dispatch), (gst_pad_chain), (gst_pad_push),
(gst_pad_check_pull_range), (gst_pad_get_range),
(gst_pad_pull_range):
Some code cleanups, use macros to check pad direction.
Don't need to take the lock on the pad direction.
Post structure change when pads are linked/unlinked.
Change some checks into _return_if_fail().
* tests/check/gst/gstbin.c:
(test_link_structure_change_state_changed_sync_cb),
(GST_START_TEST), (gst_bin_suite):
Add testcase for pad link/unlinke resync during a state change.
Fixes#510354.
Original commit message from CVS:
Patch by: Antoine Tremblay <hexa00 at gmail dot com>
* gst/gstpad.c: (gst_pad_link_check_compatible_unlocked):
Original patch by : Simon Descaries
Fix small refount leak in caps compatibility check.
Fixes#551676.
Original commit message from CVS:
* gst/gstpad.c: (add_unref_pad_to_list),
(gst_pad_get_internal_links_default):
Add fallback when calling the deprecated function on an element that
implements the new internal_link handler.
Original commit message from CVS:
Based on patch by: Olivier Crete <tester at tester dot ca>
* docs/gst/gstreamer-sections.txt:
* win32/common/libgstreamer.def:
* gst/gstpad.c: (gst_pad_init),
(gst_pad_set_iterate_internal_links_function),
(int_link_iter_data_free), (iterate_pad),
(gst_pad_iterate_internal_links_default),
(gst_pad_iterate_internal_links), (gst_pad_get_internal_links):
* gst/gstpad.h:
Add threadsafe replacement functions for getting internal links of an
element. Deprecate the old internal links functions.
API:GstPad::gst_pad_set_iterate_internal_links_function()
API:GstPad::GstPadIterIntLinkFunction
API:GstPad::gst_pad_iterate_internal_links()
API:GstPad::gst_pad_iterate_internal_links_default()
* gst/gstghostpad.c: (gst_proxy_pad_do_iterate_internal_links),
(gst_proxy_pad_init):
Implement threadsafe internal links.
* tests/check/elements/tee.c: (GST_START_TEST), (tee_suite):
Unit test for internal links on tee. See #549504.
Original commit message from CVS:
* gst/gstpad.c: (gst_pad_get_internal_links_default):
Make the internal links function less thread-unsafe and add some
comments, dunno why.
Original commit message from CVS:
* gst/gstpad.c: (gst_pad_acceptcaps_default),
(gst_pad_configure_src), (gst_pad_alloc_buffer_full):
Remove silly redundant debug.
Add some more debug info.
Clarify the docs regarding new caps received from pad_alloc.
Original commit message from CVS:
* gst/gstpad.c: (gst_pad_alloc_buffer_full):
Only sanity-check the buffer size if requested_caps == buffer_caps
(ie. don't take pad caps into account, they're not relevant here)
Original commit message from CVS:
* gst/gstpad.c: (gst_pad_event_default_dispatch):
The default event function on a sinkpad should return TRUE when
there are no internal links but should collect the return values from
the internal links otherwise.
Original commit message from CVS:
* gst/gstpad.c: (gst_pad_alloc_buffer_full):
Move size sanity check to the right place: downstream may return
a buffer with a smaller size if the buffer caps are different than
the requested ones, as may happen when doing reverse negotiation.
Original commit message from CVS:
* gst/gstpad.c: (gst_pad_buffer_alloc_unchecked):
Add sanity check to make sure we don't get smaller buffers
than requested (and fallback to normal buffer alloc if we do).
Original commit message from CVS:
* gst/gstconfig.h.in:
Add 'id' for example.
* gst/gstpad.c:
* gst/gstutils.c:
* plugins/elements/gstfdsink.c:
Link to signals. Doc and comment fixes.
Original commit message from CVS:
* gst/gstpad.c:
* tests/check/gst/gstpad.c:
Be sure that we have a new copy of the caps and not
reffed caps from a template
Original commit message from CVS:
* gst/gstpad.c: (gst_pad_dispose):
Really unlink the peer pad instead of setting the peer pointer to NULL
when we dispose the pad.
This correctly calls the unlink functions and makes sure that the peer
does not have a handle to invalid memory. See #504671.
* tests/check/gst/gstpad.c: (GST_START_TEST), (gst_pad_suite):
Add testsuite for above case.
Original commit message from CVS:
* docs/gst/gstreamer-sections.txt:
* gst/gstpad.c: (gst_pad_peer_query):
* gst/gstpad.h:
Add function to perform a query on the peer of a pad.
API: gst_pad_peer_query()
Original commit message from CVS:
* docs/design/part-TODO.txt:
Add some more TODO items
* gst/gstbin.c: (find_message), (gst_bin_change_state_func):
Improve debugging.
* gst/gstcaps.c: (gst_caps_intersect):
Optimize trivial intersection case between identical caps pointers.
* gst/gstelement.c: (gst_element_continue_state),
(gst_element_set_state_func):
* gst/gstpad.c:
Fix spelling and grammar mistakes.
Original commit message from CVS:
* gst/gstpad.c: (gst_pad_alloc_buffer_full), (gst_pad_push):
Show the caps change in the log to help spotting the case of not
exactly matching caps.
Original commit message from CVS:
* gst/gstpad.c: (gst_pad_get_caps_unlocked),
(gst_pad_acceptcaps_default), (gst_pad_configure_sink),
(gst_pad_configure_src):
Added simple version of improved caps checking. It was previously
assumed that a setcaps function would check the validity of the caps but
people prefer us to check caps against the template automatically.
Fixes#421543.
Original commit message from CVS:
* docs/faq/gst-uninstalled:
don't get empty paths on the PATH variables
* gst/gstpad.c (gst_pad_is_active, gst_pad_set_blocked_async):
Don't format for the uncommon terminal width of 84 characters.
Original commit message from CVS:
* gst/gstpad.c: (gst_pad_set_caps), (gst_pad_configure_sink),
(gst_pad_configure_src), (gst_pad_alloc_buffer_full),
(gst_pad_chain_unchecked), (gst_pad_push):
Revert last commit. This needs some more thoughts.
Original commit message from CVS:
* gst/gstpad.c: (gst_pad_set_caps), (gst_pad_alloc_buffer_full),
(gst_pad_chain_unchecked), (gst_pad_push):
Check in set_caps if the caps are compatible with the pad and remove
two functions that are redundant now. Fixes#421543.
Original commit message from CVS:
Patch by: <syrjala at sci dot fi>
* gst/gstpad.c: (gst_pad_alloc_buffer_full), (gst_pad_send_event):
Fix possible deadlock if pad eventfunc is not specified. Fixes#421177.
Improve debugging.
Original commit message from CVS:
* docs/design/draft-tagreading.txt:
* docs/random/ensonic/audiobaseclasses.txt:
Do some Architect work.
* gst/gstobject.c: (gst_object_set_name):
Add a WARNING.
* gst/gstpad.c:
Add docs that point from gst_pad_get_range to gst_pad_pull_range
Original commit message from CVS:
* docs/design/part-gstghostpad.txt:
* gst/gstghostpad.c: (gst_ghost_pad_dispose),
(gst_ghost_pad_new_full):
Make the ghostpad a parent of the internal pad again for better backward
compatibility. Don't write code that relies on this however.
* gst/gstpad.c: (gst_pad_activate_pull), (gst_pad_activate_push),
(gst_pad_link_check_hierarchy):
Require that parents should be GstElements in the hierarchy check.
Original commit message from CVS:
* docs/design/part-gstghostpad.txt:
* gst/gstghostpad.c: (gst_ghost_pad_class_init),
(gst_ghost_pad_internal_do_activate_push),
(gst_ghost_pad_internal_do_activate_pull),
(gst_ghost_pad_do_activate_push), (gst_ghost_pad_do_activate_pull),
(gst_ghost_pad_do_link), (gst_ghost_pad_dispose),
(gst_ghost_pad_new_full), (gst_ghost_pad_set_target):
Do not set the internal pad as a parent anymore so we can avoid
hierarchy linking errors when the ghostpad has no parent yet. This also
fixes failed activation because of unlinked internal pads, which in
turn fixes the impossible case where you have to activate a pad before
you can add it to a running element.
Also fix the docs.
* gst/gstpad.c: (pre_activate), (post_activate),
(gst_pad_set_active), (gst_pad_activate_pull),
(gst_pad_activate_push), (gst_pad_check_pull_range):
Add some more debug info.
Mark activation mode in pre_activate so that we don't try to activate in
endless loops. Fixes#385084.
