This is just a more convenient way to start IPC client scripts per mpv
instance.
Does not work on Windows, although it could if the subprocess and IPC
parts are implemented (and I guess .exe/.bat suffixes are required).
Also untested whether it builds on Windows. A lot of other things are
untested too, so don't complain.
The previous method for this sucked: for every launched detached
process, it started a thread, which then would leak if the launched
process didn't end before the player uninitialized. This was very racy
(although I bet the race condition wouldn't trigger in a 100 years), and
wasteful (threads aren't a cheap resource).
Implement it for POSIX directly. posix_spawn() has no direct support for
this, so we need to do it ourselves with fork(). We could probably do it
without fork(), and attempt to collect the PID in another thread. But
then we'd either have a waiting thread again, or we'd need to do an
unsafe waitpid(-1, ...) call. (POSIX process management sucks so badly,
how did they even manage this. Hopefully I'm just missing something, but
I'm not.) So now we depend on both posix_spawn() _and_ fork(), isn't it
fun?
Also call setsid(), to essentially detach the child process from the
terminal. (Otherwise it can receive various signals from the terminal,
which is probably not what you want.) posix_spawn() adds
POSIX_SPAWN_SETSID in newer POSIX releases, but we don't want to rely on
this yet.
The posix_spawnp() call is duplicated, but this is better than somehow
trying to unify the code paths.
Only somewhat tested, so enjoy the bugs.
Introduce mp_subprocess() and related definitions. This is a bit more
flexible than the old stuff. This may or may not be used for a more
complicated feature that involves starting processes, and which would
require more control.
Only port subprocess-posix.c to this API. The player still uses the
"old" API, so for win32 and dummy implementations, the new API is simply
not available, while for POSIX, the old APIs are emulated on top of the
new one. I'm hoping the win32 code can be ported as well, so the ifdefs
in subprocess.c can be dropped, and the player can (if convenient or
needed) use the new API.
In a bunch of cases, we emulate highly platform specific APIs on a
higher level across all OSes, such as IPC, terminal, subprocess
handling, and more. We have source files for each OS, and they implement
all the same mpv internal API.
Selecting which source file to use on an OS can be tricky, because there
is partially overlapping and emulated APIs (consider Cygwin on Windows).
Add a pick_first_matching_dep() function to make this slightly easier
and more structured.
Also add dummy backends in some cases, to deal with APIs not being
available.
Clarify the Windows dependency identifiers, as these are the most
confusing.
This covers source files which were added in mplayer2 and mpv times
only, and where all code is covered by LGPL relicensing agreements.
There are probably more files to which this applies, but I'm being
conservative here.
A file named ao_sdl.c exists in MPlayer too, but the mpv one is a
complete rewrite, and was added some time after the original ao_sdl.c
was removed. The same applies to vo_sdl.c, for which the SDL2 API is
radically different in addition (MPlayer supports SDL 1.2 only).
common.c contains only code written by me. But common.h is a strange
case: although it originally was named mp_common.h and exists in MPlayer
too, by now it contains only definitions written by uau and me. The
exceptions are the CONTROL_ defines - thus not changing the license of
common.h yet.
codec_tags.c contained once large tables generated from MPlayer's
codecs.conf, but all of these tables were removed.
From demux_playlist.c I'm removing a code fragment from someone who was
not asked; this probably could be done later (see commit 15dccc37).
misc.c is a bit complicated to reason about (it was split off mplayer.c
and thus contains random functions out of this file), but actually all
functions have been added post-MPlayer. Except get_relative_time(),
which was written by uau, but looks similar to 3 different versions of
something similar in each of the Unix/win32/OSX timer source files. I'm
not sure what that means in regards to copyright, so I've just moved it
into another still-GPL source file for now.
screenshot.c once had some minor parts of MPlayer's vf_screenshot.c, but
they're all gone.
wm4
Ben Boeckel