After we've been hit by Large File Support problems several times in
the past week (which only occur on 32 bit platforms, which I don't
have), this is yet another attempt to fix the issue.
Added the "fd_util" library, which attempts to use the new thread-safe
Linux system calls pipe2(), accept4() and the options O_CLOEXEC,
SOCK_CLOEXEC. Without these, it falls back to FD_CLOEXEC, which is
not thread safe.
This is particularly important for the "pipe" output plugin (and
others, such as JACK/PulseAudio), because we were heavily leaking file
descriptors to child processes.
On both locations, the result of write() can be ignored safely. In
event_pipe_emit_fast(), that can only be "EAGAIN", which means that
the pipe buffer is full - no further notification required. In
client_init(), that would be a fatal connection error, which would be
caught by the next event.
This patch fixes gcc warnings.
This updates the copyright header to all be the same, which is
pretty much an update of where to mail request for a copy of the GPL
and the years of the MPD project. This also puts all committers under
'The Music Player Project' umbrella. These entries should go
individually in the AUTHORS file, for consistancy.
There is only one location using PIPE_EVENT_SIGNAL: to synchronize
player_command() with player_command_finished(). Use the "notify"
library instead of the event_pipe here.
event_pipe_emit_fast() is aimed for use in signal handlers: it doesn't
lock the mutex, and doesn't log on error. That makes it potentially
lossy, but for its intended use, that does not matter.
Make the event_pipe (formerly main_notify) send/receive a set of
events, with a callback for each one.
The default event PIPE_EVENT_SIGNAL does not have a callback. It
is still there for waking up the main thread, when it is waiting for
the player thread.
We are going to migrate away from the concept of notifying the main
thread. There should be events sent to it instead. This patch starts
a series to implement that.
