Since the event loop has a very specifically scoped lifetime, we can't
ensure that it outlives threads that hold a reference to it without
blocking the thread that owns it. In order to make threads use the
event loop safely, we now have an atomically ref-counted
WeakEventLoopReference class that can be passed off to threads to
safely post events/callbacks to it.
Another possibility was to use an RWLock per event loop that each
thread holds a read lock on, while ~EventLoop() uses a write lock to
block and prevent it being destroyed until all its threads exit.
However, media data providers don't receive a signal to exit due to the
GC heap being intentionally leaked, so the process never actually
exits. It would be possible to specifically drop the reference to
PlaybackManager in HTMLMediaElement in order to make those data
providers die on their own, but that doesn't help prevent this problem
in other cases where it may arise.
.. and make travis run it.
I renamed check-license-headers.sh to check-style.sh and expanded it so
that it now also checks for the presence of "#pragma once" in .h files.
It also checks the presence of a (single) blank line above and below the
"#pragma once" line.
I also added "#pragma once" to all the files that need it: even the ones
we are not check.
I also added/removed blank lines in order to make the script not fail.
I also ran clang-format on the files I modified.
The kernel was already using the UDP prefix, and the TCP LibCore classes
are also uppercased. Let's rename for consistency.
Also order the LibCore Makefile alphabetically, because everywhere else
seems to be doing that :)
