Otherwise we're not guaranteed to read the very latest value that
another thread might've written in there when the pad was released, and
could instead work with an old value.
By passing NULL to `g_signal_new` instead of a marshaller, GLib will
actually internally optimize the signal (if the marshaller is available
in GLib itself) by also setting the valist marshaller. This makes the
signal emission a bit more performant than the regular marshalling,
which still needs to box into `GValue` and call libffi in case of a
generic marshaller.
Note that for custom marshallers, one would use
`g_signal_set_va_marshaller()` with the valist marshaller instead.
In gst_download_buffer_wait_for_data(), when a seek is made with
perform_seek_to_offset() the `qlock` is released temporarily. Therefore,
the flushing condition can be set during this period and should be
checked.
This was not being checked before, causing occasional deadlocks when
GST_DOWNLOAD_BUFFER_WAIT_ADD_CHECK() was called.
GST_DOWNLOAD_BUFFER_WAIT_ADD_CHECK() assumes that the caller has already
checked that we're not flushing before, since this is done when
acquiring the lock; so if we release it temporarily somewhere, we need
to check for flush again.
Without that check, the function would keep waiting for the condition
variable to be notified before checking for flushing condition again,
and that may very well never happen. This was reproduced when during pad
deactivation when running WebKit in gdb.
sync=TRUE implementation changes the latency query of a non-live
upstream into live, though it wrongly set the upstream max latency to 0.
As non-live sources won't loose data if we wait longer, this should have
been reported as have no max latency limite (-1).
In the hotdoc inspector for example, pads are instantiated with
g_object_new, other code paths to get/set properties already make
that check.
And update doc cache
There was a race where we could still get the pad event function
called when its private member were already unset, leading to
a segfault in the event handler:
```
0 gst_multi_queue_src_event (pad=<optimized out>, parent=<optimized out>, event=0x7f3ff0007600) at ../subprojects/gstreamer/plugins/elements/gstmultiqueue.c:2534
2534 ret = gst_pad_push_event (sq->sinkpad, event);
[Current thread is 1 (Thread 0x7f406c0258c0 (LWP 21925))]
(gdb) bt
0 0x00007f4062ec1399 in gst_multi_queue_src_event (pad=<optimized out>, parent=<optimized out>, event=0x7f3ff0007600 [GstEvent]) at ../subprojects/gstreamer/plugins/elements/gstmultiqueue.c:2534
1 0x00007f406b40f46d in gst_validate_pad_monitor_src_event_check (handler=0x7f4062ec1360 <gst_multi_queue_src_event>, event=0x7f3ff0007600 [GstEvent], parent=0x7f3fcc01f090 [GstMultiQueue|multiqueue167], pad_monitor=0x7f3fe809e7c0 [GstValidatePadMonitor|validatepadmonitor2213]) at ../subprojects/gst-devtools/validate/gst/validate/gst-validate-pad-monitor.c:2101
2 0x00007f406b40f46d in gst_validate_pad_monitor_src_event_func (pad=<optimized out>, parent=0x7f3fcc01f090 [GstMultiQueue|multiqueue167], event=0x7f3ff0007600 [GstEvent]) at ../subprojects/gst-devtools/validate/gst/validate/gst-validate-pad-monitor.c:2374
3 0x00007f406b904387 in gst_pad_send_event_unchecked (pad=pad@entry=0x7f3fdc027650 [GstPad|src_0], event=event@entry=0x7f3ff0007600 [GstEvent], type=<optimized out>, type@entry=GST_PAD_PROBE_TYPE_EVENT_UPSTREAM) at ../subprojects/gstreamer/gst/gstpad.c:5772
4 0x00007f406b90481b in gst_pad_push_event_unchecked (pad=pad@entry=0x7f4058182fc0 [GstPad|sink], event=event@entry=0x7f3ff0007600 [GstEvent], type=type@entry=GST_PAD_PROBE_TYPE_EVENT_UPSTREAM) at ../subprojects/gstreamer/gst/gstpad.c:5417
5 0x00007f406b90f016 in gst_pad_push_event (pad=0x7f4058182fc0 [GstPad|sink], event=event@entry=0x7f3ff0007600 [GstEvent]) at ../subprojects/gstreamer/gst/gstpad.c:5554
6 0x00007f406a1c99ba in gst_video_decoder_src_event_default (decoder=0x7f3fe81c6060 [GstTheoraDec|theoradec46], event=<optimized out>) at ../subprojects/gst-plugins-base/gst-libs/gst/video/gstvideodecoder.c:1532
7 0x00007f406b40f46d in gst_validate_pad_monitor_src_event_check (handler=0x7f406a1ca270 <gst_video_decoder_src_event>, event=0x7f3ff0007600 [GstEvent], parent=0x7f3fe81c6060 [GstTheoraDec|theoradec46], pad_monitor=0x7f4028163aa0 [GstValidatePadMonitor|validatepadmonitor2216]) at ../subprojects/gst-devtools/validate/gst/validate/gst-validate-pad-monitor.c:2101
8 0x00007f406b40f46d in gst_validate_pad_monitor_src_event_func (pad=<optimized out>, parent=0x7f3fe81c6060 [GstTheoraDec|theoradec46], event=0x7f3ff0007600 [GstEvent]) at ../subprojects/gst-devtools/validate/gst/validate/gst-validate-pad-monitor.c:2374
```
This make the GstSingleQueue a MiniObject, mainly so it is properly
refcounted.
This also make use of the GstMultiQueuePad class for srcpads which
is totally valid as srcpads and sinkpads share the same SingleQueue
object.
The `query` argument of gst_pad_query is "transfer none".
Query objects are "borrowed" by the pad query handlers and those
should never unref them.
This was leading to double freed queries in a very racy way with nested
GESTimelines.
Otherwise when seeking backwards we would keep the last_stop at the last
position we saw until playback passed the seek position again, and if
switching to the next pad happens in the meantime we would set the wrong
offset in the outgoing segment.
This URI is valid:
data:,;base64
(It encodes the literal string ";base64")
But would lead to a crash because the code assumed the semicolon would
be placed before the colon.
Quoting RFC 2396:
For resiliency, programs interpreting URI should treat upper case
letters as equivalent to lower case in scheme names (e.g., allow
"HTTP" as well as "http").
This seems to happen when another client is accessing the file at the
same time, and retrying after a short amount of time solves it.
Sometimes partial data is written at that point already but we have no
idea how much it is, or if what was written is correct (it sometimes
isn't) so we always first seek back to the current position and repeat
the whole failed write.
It happens at least on Linux and macOS on SMB/CIFS and NFS file systems.
Between write attempts that failed with EACCES we wait 10ms, and after
enough consecutive tries that failed with EACCES we simply time out.
In theory a valid EACCES for files to which we simply have no access
should've happened already during the call to open(), except for NFS
(see open(2)).
This can be enabled with the new max-transient-error-timeout property, and
a new o-sync boolean property was added to open the file in O_SYNC mode
as without that it's not guaranteed that we get EACCES for the actual
writev() call that failed but might only get it at a later time.
Fixes https://gitlab.freedesktop.org/gstreamer/gstreamer/issues/305
I copied `error-after` to make the `eos-after` property, but it turned
out there were some problems with that one, so this patch: adds
separate counters (so setting to NULL and reusing the element will
still work); clarifies the properties' min values; and reports an
error when both are set.
Using `num-buffers` can be unpredictable as buffer sizes are often
arbitrary (filesrc, multifilesrc, etc.). The `error-after` property on
`identity` is better but obviously reports an error afterwards. This
adds `eos-after` which does exactly the same thing but reports EOS
instead.
By doing so GL source elements can successfully reuse the GL context and display
of downstream elements. This change fixes an issue in playbin when using
gltestsrc where the context query made by the source element would fail and the
source element would create a second (useless) GLDisplay.
Allows determining from downstream what the expected bitrate of a stream
may be which is useful in queue2 for setting time based limits when
upstream does not provide timing information.
Implement bitrate query handling in queue2
https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/issues/60
If upstream is pushing buffers larger than our limits, only 1 buffer
is ever in the queue at a time. Once that single buffer has left the
queue, a 0% buffering message would be posted followed immediately by a
100% buffering message when the next buffer was inserted into the queue
a very short time later. As per the recommendations, This would result
in the application pausing for a short while causing the appearance of
a short stutter.
The first step of a solution involves not posting a buffering message if
there is still data waiting on the sink pad for insertion into the queue.
This successfully drops the 0% messages from being posted however a
message is still posted on each transition to 100% when the new buffer
arrives resulting in a string of 100% buffering messages. We silence
these by storing the last posted buffering percentage and only posting a
new message when it is different from or last posted message.
Since we use full signed running times, we no longer need to clamp
the buffer time.
This avoids having the position of single queues not advancing for
buffers that are out of segment and never waking up non-linked
streams (resulting in an apparent "deadlock").
If we ever get a GST_FLOW_EOS from downstream, we might retry
pushing new data. But if pushing that data doesn't return a
GstFlowReturn (such as pushing events), we would end up returning
the previous GstFlowReturn (i.e. EOS).
Not properly resetting it would cause cases where queue2 would
stop pushing on the first GstEvent stored (even if there is more
data contained within).
Otherwise we write out the SYNC_AFTER buffer immediately, and the
previously queued up buffers afterwards which then breaks the order of
data.
Also add various debug output.
fflush() has no effect because we use writev() directly, so fsync()
should be used instead which is actually flushing the kernel-side
buffers.
As a next step, a non-line-buffered buffering mode is to be added.
https://bugzilla.gnome.org/show_bug.cgi?id=794173
Otherwise downstream will consider the pipeline not live if the active
pad is live, even though some inactive pads might be live and might
require a non-zero latency configuration.
https://bugzilla.gnome.org/show_bug.cgi?id=796901
And make use of it in the typefind element. It's useful to distinguish
between the different errors why typefinding can fail, and especially to
not consider GST_FLOW_FLUSHING as an actual error.
https://bugzilla.gnome.org/show_bug.cgi?id=796894
