Commit 38100682 authored by Andy Wingo Wingo's avatar Andy Wingo Wingo
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gst/gstobject.h (GST_OBJECT_REFCOUNT_VALUE): Just use the int.

Original commit message from CVS:
2005-10-02  Andy Wingo  <wingo@pobox.com>

* gst/gstobject.h (GST_OBJECT_REFCOUNT_VALUE): Just use the int.
It is volatile, after all.

* docs/design/part-gstghostpad.txt: Flesh out activation with
ghost pads.

* gst/base/gstbasesrc.c (gst_base_src_init): Use
GST_DEBUG_FUNCPTR.
parent cfd31847
2005-10-02 Andy Wingo <wingo@pobox.com>
* gst/gstobject.h (GST_OBJECT_REFCOUNT_VALUE): Just use the int.
It is volatile, after all.
* docs/design/part-gstghostpad.txt: Flesh out activation with
ghost pads.
* gst/base/gstbasesrc.c (gst_base_src_init): Use
GST_DEBUG_FUNCPTR.
2005-10-02 Tim-Philipp Müller <tim at centricular dot net>
* configure.ac:
......
......@@ -5,7 +5,7 @@ Ghostpads
existing elements. They are used to expose internal element pads
on the complex element.
Some design requirements
Some design requirements
- Must look like a real GstPad on both sides.
- target of Ghostpad must be changeable
......@@ -50,7 +50,7 @@ Ghostpads
(--------------
(- X --------) |
(- X --------) |
| | |------)
| target *------------------> | sink |
|------------| |------)
......@@ -72,11 +72,11 @@ Ghostpads
5) link/unlink and activate functions are set up
on GstGhostPad.
(- X --------)
| |
(- X --------)
| |
| target *------>//
|------------|
|------------|
| internal *---->//
(------------)
......@@ -87,10 +87,10 @@ Ghostpads
gst_ghost_pad_set_target (char *name, GstPad *newtarget)
(- X --------)
| |
(- X --------)
| |
| target *------>//
|------------|
|------------|
| internal *---->//
(------------)
......@@ -98,12 +98,12 @@ Ghostpads
2) target is set to newtarget
(--------
(- X --------) |
(- X --------) |
| | |------)
| target *------------->| sink |
|------------| |------)
| internal *--->// (--------
(------------)
(------------)
* Setting target on an targetted unlinked ghostpad
......@@ -111,23 +111,23 @@ Ghostpads
gst_ghost_pad_set_target (char *name, GstPad *newtarget)
(--------
(- X --------) |
(- X --------) |
| | |------)
| target *------------->| sink |
|------------| |------)
| internal *--->// (--------
(------------)
(------------)
1) assert direction of newtarget == X direction
2) target is set to newtarget
(--------
(- X --------) |
(- X --------) |
| | |------)
| target *------------->| sink |
|------------| |------)
| internal *--->// (--------
(------------)
(------------)
* Linking a pad to an untargetted ghostpad:
......@@ -135,10 +135,10 @@ Ghostpads
gst_pad_link (src, X)
(- X --------)
| |
(- X --------)
| |
| target *------>//
|------------|
|------------|
| internal *---->//
(------------)
-------)
......@@ -157,12 +157,12 @@ Ghostpads
e) Y is activated in the same mode as X
f) core makes link from src to X
(- X --------)
| |
(- X --------)
| |
| target *----->//
>|------------|
(real pad link) / | internal * |
>|------------|
(real pad link) / | internal * |
/ (----------|-)
/ |
-------) / V
......@@ -178,12 +178,12 @@ Ghostpads
gst_pad_link (src, X)
(--------
(- X --------) |
(- X --------) |
| | |------)
| target *------------->| sink |
|------------| |------)
| internal *--->// (--------
(------------)
(------------)
-------)
|
(-----|
......@@ -202,7 +202,7 @@ Ghostpads
g) core makes link from src to X
(--------
(- X --------) |
(- X --------) |
| | |------)
| target *------------->| sink |
>|------------| >|------)
......@@ -221,12 +221,12 @@ Ghostpads
gst_ghost_pad_set_target (char *name, GstPad *newtarget)
(- X --------)
| |
(- X --------)
| |
| target *----->//
>|------------|
(real pad link) / | internal * |
>|------------|
(real pad link) / | internal * |
/ (----------|-)
/ |
-------) / V
......@@ -240,9 +240,9 @@ Ghostpads
2) X target is set to newtarget
3) Y (X internal) is linked to newtarget
(--------
(- X --------) |
(- X --------) |
| | |------)
| target *------------->| sink |
>|------------| >|------)
......@@ -256,14 +256,14 @@ Ghostpads
(-----| (----------)
-------)
* Setting target on targetted linked ghostpad:
gst_ghost_pad_set_target (char *name, GstPad *newtarget)
(--------
(- X --------) |
(- X --------) |
| | |------)
| target *------------->| sink |
>|------------| >|------)
......@@ -276,15 +276,15 @@ Ghostpads
| src |<-------------* target |
(-----| (----------)
-------)
1) assert direction of newtarget == X direction
2) Y and X target are unlinked
2) X target is set to newtarget
3) Y (X internal) is linked to newtarget
(--------
(- X --------) |
(- X --------) |
| | |------)
| target *------------->| sink |
>|------------| >|------)
......@@ -298,4 +298,105 @@ Ghostpads
(-----| (----------)
-------)
Activation
==========
Sometimes ghost pads should proxy activation functions. This thingie
attempts to explain how it should work in the different cases.
+---+ +----+ +----+ +----+
| A +-----+ B | | C |-------+ D |
+---+ +---=+ +=---+ +----+
+--=-----------------------------=-+
| +=---+ +----+ +----+ +---=+ |
| | a +---+ b ==== c +--+ d | |
| +----+ +----+ +----+ +----+ |
| |
+----------------------------------+
state change goes from right to left
<-----------------------------------------------------------
All of the labeled boxes are pads. The dashes (---) show pad links, and
the double-lines (===) are internal connections. The box around a, b, c,
and d is a bin. B and C are ghost pads, and a and d are proxy pads. The
arrow represents the direction of a state change algorithm. Not counting
the bin, there are three elements involved here -- the parent of D, the
parent of A, and the parent of b and c.
Now, in the state change from READY to PAUSED, assuming the pipeline
does not have a live source, all of the pads will end up activated at
the end. There are 4 possible activation modes:
1) AD and ab in PUSH, cd and CD in PUSH
2) AD and ab in PUSH, cd and CD in PULL
3) AD and ab in PULL, cd and CD in PUSH
4) AD and ab in PULL, cd and CD in PULL
When activating (1), the state change algorithm will first visit the
parent of D and activate D in push mode. Then it visits the bin. The bin
will first change the state of its child before activating its pads.
That means c will be activated in push mode. [*] At this point, d and C
should also be active in push mode, because it could be that activating
c in push mode starts a thread, which starts pushing to pads which
aren't ready yet. Then b is activated in push mode. Then, the bin
activates C in push mode, which should already be in push mode, so
nothing is done. It then activates B in push mode, which activates b in
push mode, but it's already there, then activates a in push mode as
well. The order of activating a and b does not matter in this case.
Then, finally, the state change algorithm moves to the parent of A,
activates A in push mode, and dataflow begins.
[*] Not yet implemented.
Activation mode (2) is implausible, so we can ignore it for now. That
leaves us with the rest.
(3) is the same as (1) until you get to activating b. Activating b will
proxy directly to activating a, which will activate B and A as well.
Then when the state change algorithm gets to B and A it sees that they
are already active, so it ignores them.
Similarly in (4), activating D will cause the activation of all of the
rest of the pads, in this order: C d c b a B A. Then when the state
change gets to the other elements they are already active, and in fact
data flow is already occuring.
So, from these scenarios, we can distill how ghost pad activation
functions should work:
Ghost source pads (e.g. C):
push:
called by: element state change handler
behavior: just return TRUE
pull:
called by: peer's activatepull
behavior: change the internal pad, which proxies to its peer e.g. C
changes d which changes c.
Internal sink pads (e.g. d):
push:
called by: nobody (doesn't seem possible)
behavior: n/a
pull:
called by: ghost pad
behavior: proxy to peer first
Internal src pads (e.g. a):
push:
called by: ghost pad
behavior: activate peer in push mode
pull:
called by: peer's activatepull
behavior: proxy to ghost pad, which proxies to its peer (e.g. a
calls B which calls A)
Ghost sink pads (e.g. B):
push:
called by: element state change handler
behavior: change the internal pad, which proxies to peer (e.g. B
changes a which changes b)
pull:
called by: internal pad
behavior: proxy to peer
......@@ -193,14 +193,19 @@ gst_base_src_init (GstBaseSrc * basesrc, gpointer g_class)
pad = gst_pad_new_from_template (pad_template, "src");
GST_DEBUG_OBJECT (basesrc, "setting functions on src pad");
gst_pad_set_activatepush_function (pad, gst_base_src_activate_push);
gst_pad_set_activatepull_function (pad, gst_base_src_activate_pull);
gst_pad_set_event_function (pad, gst_base_src_event_handler);
gst_pad_set_query_function (pad, gst_base_src_query);
gst_pad_set_checkgetrange_function (pad, gst_base_src_check_get_range);
gst_pad_set_getrange_function (pad, gst_base_src_get_range);
gst_pad_set_getcaps_function (pad, gst_base_src_getcaps);
gst_pad_set_setcaps_function (pad, gst_base_src_setcaps);
gst_pad_set_activatepush_function (pad,
GST_DEBUG_FUNCPTR (gst_base_src_activate_push));
gst_pad_set_activatepull_function (pad,
GST_DEBUG_FUNCPTR (gst_base_src_activate_pull));
gst_pad_set_event_function (pad,
GST_DEBUG_FUNCPTR (gst_base_src_event_handler));
gst_pad_set_query_function (pad, GST_DEBUG_FUNCPTR (gst_base_src_query));
gst_pad_set_checkgetrange_function (pad,
GST_DEBUG_FUNCPTR (gst_base_src_check_get_range));
gst_pad_set_getrange_function (pad,
GST_DEBUG_FUNCPTR (gst_base_src_get_range));
gst_pad_set_getcaps_function (pad, GST_DEBUG_FUNCPTR (gst_base_src_getcaps));
gst_pad_set_setcaps_function (pad, GST_DEBUG_FUNCPTR (gst_base_src_setcaps));
/* hold pointer to pad */
basesrc->srcpad = pad;
......
......@@ -66,7 +66,7 @@ typedef enum
#ifdef GST_HAVE_GLIB_2_8
#define GST_OBJECT_REFCOUNT(obj) (((GObject*)(obj))->ref_count)
#define GST_OBJECT_REFCOUNT_VALUE(obj) (g_atomic_int_get (&((GObject*)(obj))->ref_count))
#define GST_OBJECT_REFCOUNT_VALUE(obj) GST_OBJECT_REFCOUNT(obj)
#else
#define GST_OBJECT_REFCOUNT(obj) ((GST_OBJECT_CAST(obj))->refcount)
#define GST_OBJECT_REFCOUNT_VALUE(obj) (g_atomic_int_get (&(GST_OBJECT_CAST(obj))->refcount))
......
......@@ -193,14 +193,19 @@ gst_base_src_init (GstBaseSrc * basesrc, gpointer g_class)
pad = gst_pad_new_from_template (pad_template, "src");
GST_DEBUG_OBJECT (basesrc, "setting functions on src pad");
gst_pad_set_activatepush_function (pad, gst_base_src_activate_push);
gst_pad_set_activatepull_function (pad, gst_base_src_activate_pull);
gst_pad_set_event_function (pad, gst_base_src_event_handler);
gst_pad_set_query_function (pad, gst_base_src_query);
gst_pad_set_checkgetrange_function (pad, gst_base_src_check_get_range);
gst_pad_set_getrange_function (pad, gst_base_src_get_range);
gst_pad_set_getcaps_function (pad, gst_base_src_getcaps);
gst_pad_set_setcaps_function (pad, gst_base_src_setcaps);
gst_pad_set_activatepush_function (pad,
GST_DEBUG_FUNCPTR (gst_base_src_activate_push));
gst_pad_set_activatepull_function (pad,
GST_DEBUG_FUNCPTR (gst_base_src_activate_pull));
gst_pad_set_event_function (pad,
GST_DEBUG_FUNCPTR (gst_base_src_event_handler));
gst_pad_set_query_function (pad, GST_DEBUG_FUNCPTR (gst_base_src_query));
gst_pad_set_checkgetrange_function (pad,
GST_DEBUG_FUNCPTR (gst_base_src_check_get_range));
gst_pad_set_getrange_function (pad,
GST_DEBUG_FUNCPTR (gst_base_src_get_range));
gst_pad_set_getcaps_function (pad, GST_DEBUG_FUNCPTR (gst_base_src_getcaps));
gst_pad_set_setcaps_function (pad, GST_DEBUG_FUNCPTR (gst_base_src_setcaps));
/* hold pointer to pad */
basesrc->srcpad = pad;
......
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