The TaskQueuePacedSender today has some inefficiencies:
* Enqueuing a packet will trigger a MaybeProcessPackets() call, but it
won't actually run immediately even if it should - instead it will
schedule a new call in at least 1ms. This incurs delays and extra
CPU overhead.
* Sometimes thread wakeups are scheduled simply in order to do
book-keeping: ProcessPackets() will be called when the media debt has
gone down to 0 even if there is no packet in the queue, in order to
check if we should send padding.
This CL fixes that by called ProcessPackets() immediately if it is
actually time to do so, and by immediately determining when padding
should be sent without having a separate call to drain media debt.
Bug: webrtc:10809
Change-Id: I4870e86e6de2ce4197463fd5b788ad4717fc7177
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/172842
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Commit-Queue: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31010}
be152f5f9e