We don't want m_config uninitialization to call random change callbacks.
This happens at the end of mp_destroy(), when almost everything else is
already destroyed, and the change callbacks would probably trigger UB
all over the place.
The change callbacks could be trigger by m_config_restore_backups(),
which is just used as a cheap way to free the remaining state. The worst
is that this depends on which options may still have been part of this
"backup" state, which depends on user input.
Probably never a practical problem, since the backup state is most
likely guaranteed to be empty before uninit is performed, but still.
Instead of making m_config a special-case, it more or less uses the
underlying m_config_cache/m_config_shadow APIs properly. This makes the
player core a (relatively) equivalent user of the core option API. In
particular, this means that other threads can change core options with
m_config_cache_write_opt() calls (before this commit, this merely led to
diverging option values).
An important change is that before this commit, mpctx->opts contained
the "master copy" of all option data. Now it's just another copy of the
option data, and the shadow copy is considered the master. This is why
whenever mpctx->opts is written, the change needs to be copied to the
master (thus why this commits add a bunch of m_config_notify... calls).
If another thread (e.g. a VO) changes an option, async_change_cb is now
invoked, which funnels the change notification through the player's
layers.
The new self_notification parameter on mp_option_change_callback is so
that m_config_notify... doesn't trigger recursion, and it's used in
cases where the change was already "processed". It's still needed to
trigger libmpv property updates. (I considered using an extra
m_config_cache for that, but it'd only cause problems with no
advantages.)
I think the recent changes actually forgot to send libmpv property
updates in some cases. This should fix this anyway. In some cases,
property updates are reworked, and the potential for bugs should be
lower (probably).
The primary point of this change is to allow external updates, for
example by a VO writing the fullscreen option if the window state is
changed by the window manager (rather than mpv changing it). This is not
used yet, but the following commits will.
Goes in line with the recent changes to always checking for option value
changes. The player core will use this to determine whether it should
send additional change events.
Just an implementation detail that can be cleaned up now. Internally,
m_config maintains a tree of m_sub_options structs, except for the root
it was not defined explicitly. GLOBAL_CONFIG was a hack to get access to
it anyway. Define it explicitly instead.
The original MPlayer m_config was essentially only responsible for
handling some command line parsing details, handling profiles, and
file-local options. And then there's the new mpv stuff (that stuff was
regretfully written by me), which is mostly associated with making
things thread-safe (includes things like making it all library-safe,
instead of stuffing all option data into global variables).
This commit tries to separate them some more. For example,
m_config_shadow (the thread-safe thing) now does not need access to
m_config anymore. m_config can hopefully be reduced to handling only the
"old" mplayer-derived mechanisms.
This will allow any other threads to write to the global option data in
a safe way.
The typical example for this is the fullscreen option, which needs to be
written by VO (or even some other thing running completely separate from
the main thread). We have a complicated and annoying contraption which
gets the value updated on the main thread, and this function will help
get rid of it.
As of this commit, this doesn't really work yet, because he main thread
uses its own weird copy of the option data.
This adds m_config_cache_get_next_changed() and the change_flags field
in m_config_cache. Both can be used to determine whether specific
options changed (rather than the entire sub-group).
Not sure if I'm very happy with that. The former rather compact
update_options() is now a bit of a mess, because it needs to be
incremental. m_config_cache_get_next_changed() will not be too nice to
use, and change_flags still relies on global "allocation" of change
flags (see UPDATE_* defines in m_option.h). If C weren't such a
primitive language that smells like grandpa, it would be nice to define
per-option change callbacks or so.
This compares options by value to determine whether they have changed.
This makes it slower in theory, but in practice it probably doesn't
matter (options are rarely changed after initialization). The
alternative would have been per-option change counters (wastes too much
memory; not a practical problem but too ugly), or keep all
m_config_caches in a global list and have bitmaps with per-option change
bits (sounds complicated). I guess the current way is OK.
Technically, this changes semantics slightly by ignoring setting an
option to the same value. Technically this wasn't a no-op, although the
effect was almost almost no-op. Some code would actually become cleaner
by ignoring such redundant change events, and them being no-op is
probably also what the user would normally assume.
Create a separate struct for internal fields of m_config_cache, so API
users can't just mess with stuff they shouldn't access.
Move the ts field out of m_config_data, so we don't need unnecessary
atomics in one case.
This is just preparation, and shouldn't change any behavior.
The previous bunch of commits made this unnecessary, so this should be
a purely internal change with no user impact.
This may or may not open the way to future improvements. Even if not,
at least the property/option interaction should now be much less buggy.
Options marked with this flag were changed to strictly read-only after
initialization (mpv_initialize() in the client API, after option parsing
and config file loading with the CLI player).
This used to be necessary, because there was a single option struct that
could be accessed by multiple threads. For example, --config-dir sets
MPOpts.force_configdir, which was read whenever anything accessed the
mpv config dir (which could be on different threads, e.g. font
initialization tries to lookup fonts.conf from an arbitrary thread).
This isn't needed anymore, because threads now access these in a thread
safe way. In the case of --config-dir, the path is actually just copied
on init.
This M_OPT_FIXED mechanism is thus not strictly needed anymore. It still
prevents writing to some options that cannot take effect at runtime, but
even that can be dropped. In general, all mpv options can be changed any
time at runtime, even if they never take effect, and there's no need to
make an exception for a very low number of options. So just get rid of
it.
In 2017, we lowered this to debug level. But I think setting options is
important enough that it should be logged even in verbose, at least
compared to all the other dumb noise.
This might be reduced again if verbose logging becomes much cleaner.
It seems using multiple prefixes for an option isn't supported out of
laziness (and shouldn't, because what the fuck). So assert() on this.
(Unfortunately this prefix nonsense is still needed. Especially AO and
VO options use this through the options_prefix field.)
A previous commit changed m_config so that it always creates the shadow
thing, and the function's only remaining purpose was to initialize
mpv_global. It makes much more sense to do that at the caller, and it's
only 1 line of code too.
m_config has a m_config_option array, that is used for all option
access. The code maintaining shadow copies also tried to make use of it,
and did so by "cleverly" assigning each m_sub_options run a slice of
that array. But actually it's much simpler to, you know, directly access
the damn options.
This helps separation m_config and the general option code slightly.
Still seems to work after a superficial test, good enough.
This is good because a private thing is not so public anymore, and it's
also preparation for further changes.
Some tricky memory management issues: m_config_data (i.e. config->data)
now depends on m_config_shadow, instead of m_config. In particular,
free_option_data() accesses the m_config_shadow.groups array. Obviously
it must be freed before m_config_shadow.
Move the comments documenting exported functions to the header. It looks
like the header is the preferred place for that (although I don't really
appreciate headers where you lose the overview because of all the
documentation comments). Add comments to some undocumented prototypes.
This was one of those "shouldn't exist" type of functions that could
access internals that were supposed to be isolated away, but some code
needed to access it anyway.
It looks like the last use of it went away in 2016, shortly after it was
introduced.
Or at least I hope it's theoretical. This function is supposed to unset
any old listeners for the given cache, and the code works only if
there's at most 1. Add a defense break to avoid UB if there's more than
one, and add an assert() to check the assumption that there's at most
one.
The added comment is unrelated.
C11 can access atomic variables normally (in which case they use the
strictest memory access semantics). But the mpv stdatomic wrapper for
C99 compilers does not allow it, because it couldn't give any
guarantees. This means we always need to access them with atomic macros.
While we're at, use relaxed semantics for the m_config_cache field,
since because it's accessed from a single thread only (essentially
used in a non-atomic way). Switch the comparison arguments to make the
formatting look slightly less weird.
Although the new code actually fires update notifications only when
needed, m_config_cache_update() itself returned a rather coarse change
value, which could indicate change even if none of the cached options
were changed. On top of that, some code (like vo_gpu) calls the update
function on every frame, which would reconfigure the renderer even on
unrelated option changes.
Options with dynamic memory allocations (such as strings) require some
care. They need to be fully copied on initialization, and if a static
default value was declared, we must not free that value either.
Instead of going through the entire thing even for simple types like
integers, really run it only for options with dynamic allocations. To
distinguish types which use dynamic allocations, we can use the fact
that they require a free callback (otherwise they would leak). As a
result initialization of simple types becomes chaper, and the init
function does nothing at all if src==dst for a simple type.
(It's funny how mplayer had M_OPT_TYPE_DYNAMIC since 2002, until we
replaced it by the same heuristic as used here in commit 3bb134969e.
It's also funny how the new check was used only for some asserts, and
finally removed in commit 7539928c1c. I guess at this time I felt like
having uniform code was more important than pointless
micro-optimizations.)
The src==NULL case is removed because it can't happen.
Actually rewrite most of the option management code. This affects how
options are allocated, and how thread-safe access to them is done.
One thing that is nicer is that creating m_config_cache does not need to
ridiculously recreate and store the entire option list again. Instead,
option metadata and option storage are now separated. m_config contains
the metadata, and m_config_data all or parts of the actual option
values. (m_config_cache simply uses the metadata part of m_config, which
is immutable after creation.)
The mentioned hack was introduced in commit 1a2319f3e4, and is the
global state around g_group_mutex. Although it was "benign" global
state, it's good that it's finally removed.
For some reason shadow_offset is a int16_t variable (to save some space
or something), which means the static part of the entire option list
must be below 32KB. This is fine, but still add a check against
overflows. (Currently it's 3.6KB. This does not include dynamic
allocations like strings.)
Most options starting with --no-<name> are automatically translated to
--<name>=no. Make the code slightly nicer by using a flag instead of
explicitly comparing option types. Also fix an issue that made the
option parser print nonsense error messages for if --no-... was used for
options which don't support it.
There is some craziness here: the function allocates m_config_cache,
which in turn allocates the actual option struct, which is what the
function returns. The user would expect to be able to use talloc_free()
to deallocate everything. Of course this didn't work, because the
returned pointer is not the root parent in the talloc tree.
But with some additional talloc craziness, this can be fixed. We
rearrange the parent pointers such that freeing the option struct will
free m_config_cache first, which uninits the contents in the option
struct, but fortunately not the option struct itself.
This change should simplify API use on the caller side, and reduce
surprises.
mp_read_option_raw() should not print the deprecation warning if the
option is deprecated. This change also means you can't pass an alias
to the function, but all existing uses should be fine.
This is part of trying to get rid of --af-defaults, and the af
resample filter.
It requires a complicated mechanism to set the defaults on the resample
filter for backwards compatibility.
Remove them from the big MPOpts struct and move them to their sub
structs. In the places where their fields are used, create a private
copy of the structs, instead of accessing the semi-deprecated global
option struct instance (mpv_global.opts) directly.
This actually makes accessing these options finally thread-safe. They
weren't even if they should have for years. (Including some potential
for undefined behavior when e.g. the OSD font was changed at runtime.)
This is mostly transparent. All options get moved around, but most users
of the options just need to access a different struct (changing sd.opts
to a different type changes a lot of uses, for example).
One thing which has to be considered and could cause potential
regressions is that the new option copies must be explicitly updated.
sub_update_opts() takes care of this for example.
Another thing is that writing to the option structs manually won't work,
because the changes won't be propagated to other copies. Apparently the
only affected case is the implementation of the sub-step command, which
tries to change sub_delay. Handle this one explicitly (osd_changed()
doesn't need to be called anymore, because changing the option triggers
UPDATE_OSD, and updates the OSD as a consequence). The way the option
value is propagated is rather hacky, but for now this will do.
I've decided that MP_TRACE means “noisy spam per frame”, whereas
MP_DBG just means “more verbose debugging messages than MSGL_V”.
Basically, MSGL_DBG shouldn't create spam per frame like it currently
does, and MSGL_V should make sense to the end-user and provide mostly
additional informational output.
MP_DBG is basically what I want to make the new default for --log-file,
so the cut-off point for MP_DBG is if we probably want to know if for
debugging purposes but the user most likely doesn't care about on the
terminal.
Also, the debug callbacks for libass and ffmpeg got bumped in their
verbosity levels slightly, because being external components they're a
bit less relevant to mpv debugging, and a bit too over-eager in what
they consider to be relevant information.
I exclusively used the "try it on my machine and remove messages from
MSGL_* until it does what I want it to" approach of refactoring, so
YMMV.
We want e.g. --opengl-shaders-append=foo to resolve to the new option,
all while printing an option name. --opengl-shader is a similar case.
These options are special, because they apply "actions" on actual
options by specifying a suffix. So the alias/deprecation handling has to
be part of resolving the actual option from prefix and suffix.
So far, we had a thread-safe way to read options, but no option update
notification mechanism. Everything was funneled though the main thread's
central mp_option_change_callback() function. For example, if the
panscan options were changed, the function called vo_control() with
VOCTRL_SET_PANSCAN to manually notify the VO thread of updates. This
worked, but's pretty inconvenient. Most of these problems come from the
fact that MPlayer was written as a single-threaded program.
This commit works towards a more flexible mechanism. It adds an update
callback to m_config_cache (the thing that is already used for
thread-safe access of global options).
This alone would still be rather inconvenient, at least in context of
VOs. Add another mechanism on top of it that uses mp_dispatch_queue, and
takes care of some annoying synchronization issues. We extend
mp_dispatch_queue itself to make this easier and slightly more
efficient.
As a first application, use this to reimplement certain VO scaling and
renderer options. The update_opts() function translates these to the
"old" VOCTRLs, though.
An annoyingly subtle issue is that m_config_cache's destructor now
releases pending notifications, and must be released before the
associated dispatch queue. Otherwise, it could happen that option
updates during e.g. VO destruction queue or run stale entries, which is
not expected.
Rather untested. The singly-linked list code in dispatch.c is probably
buggy, and I bet some aspects about synchronization are not entirely
sane.
This is really obnoxious. --include parses into the default profile, but
when used on the command line, it did never get applied. So we have to
apply it when the exact conditions for this are met.
Fixes#4673.
Remove the various redundant m_config_set_option* calls, rename the
remaining one to m_config_set_option_cli(), and merge the
m_config_parse_option() function.
These are not "really" separate actions, but on the command line they're
obserable as such. So it would be a good idea to list them too.
Adds about 117 options (holy fuck).
This affects options like --vf or --display-tags. These used a "*"
suffix to match all options starting with a specific name, and handled
the rest in the option parser. Change this to remove the "*" special
case, and require every option parser to declare a list of allowed
suffixes via m_option_type.actions.
The new way is conceptually simpler, because we don't have to account
for the "*" in a bunch of places anymore, and instead everything is
centrally handled in the CLI part of the option parser, where it's
actually needed.
It automatically enables suffixes like -add for a bunch of other
stringlist options.
