This applies to the ones of the appsink, appsrc and bus. If we would
store a strong reference then they would keep alive the underlying
object forever even if their pipeline disappeared in the meantime.
Like this e.g. the bus stream would start returning None once the bus
was destroyed, similar to how other channels are working in Rust.
Previously it was not thread-safe to change them and could lead to
crashes but with 1.16.3 it is now.
Unsetting the bus sync handler before 1.16.3 will have no effect at all,
setting a new bus sync handler or appsink/src callbacks will panic.
This partially reverts 2f88dc6576
This is racy and can cause the consumer of the messages to never be
woken up anymore:
1. Waker is stored because no message on the bus
2. Sync handler is called, waker is woken up
3. Bus is polled again and no message is on it (yet),
new waker is registered
4. Bus stores the message from 2. in its queue (after
the sync handler has returned BusSyncReply::Pass)
5. No new message ever appears on the bus because all
this happened for the very last message
Fixes https://gitlab.freedesktop.org/gstreamer/gstreamer-rs/issues/235
There are different implementations and signatures for `get_pollfd` depending
on whether the target platform is unix or windows. When generating the doc,
we need both implementations to appear regardless of the target platform. This
commit is inspired by the way Rust `std` library deals with `process::Command`
OS dependent variants
(https://doc.rust-lang.org/std/process/struct.Command.html#impl-CommandExt).
Documentation can't be accurate though as we can't use the`std::os::windows`
on `unix` and vice versa. As a workaround a fake fd class matching the other
platform is declared.
This could be further enhanced once `#[doc(cfg(...))]` is stabilized
(https://github.com/rust-lang/rust/issues/43781) by declaring `#[doc(cfg(unix))]`
or `#[doc(cfg(windows))]` instead of the hard coded comments `This is supported
on **Windows/Unix** only`. Unfortunately, these comments disappear when
generating will `--all-features` because they are not part of the documentation
in the gir file.
