No longer hide errors while queueing tasks on the main thread. This
requires creating two types of `TaskSource`s: one for the main thread
and one that can be sent to other threads. This makes queueing a bit
more efficient on the main thread and more importantly, no longer hides
task queue errors.
Fixes#25688.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Mukilan Thiyagarajan <mukilan@igalia.com>
This is a simplification of the internal `TaskQueue` API that moves the
`TaskManager` to the `GlobalScope` itself. In addition, the handling of
cancellers is moved to the `TaskManager` as well. This means that no
arguments other than the `task` are necessary for queueing tasks, which
makes the API a lot easier to use and cleaner.
`TaskSource` now also keeps a copy of the canceller with it, so that
they always know the proper way to cancel any tasks queued on them.
There is one complication here. The event loop `sender` for dedicated
workers is constantly changing as it is set to `None` when not handling
messages. This is because this sender keeps a handle to the main
thread's `Worker` object, preventing garbage collection while any
messages are still in flight or being handled. This change allows
setting the `sender` on the `TaskManager` to `None` to allow proper
garbabge collection.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>