The select() in the main event loop blocks now (saving us many
unnecessary wakeups). This interacted badly with the threads
that were trying to wakeup the main task via
pthread_cond_signal() since the main task was not blocked
on a condition variable, but on select().
So now if we detect a need to wakeup the player, we write
to a pipe which select() is watching instead of blindly
calling pthread_cond_signal().
git-svn-id: https://svn.musicpd.org/mpd/trunk@7347 09075e82-0dd4-0310-85a5-a0d7c8717e4f
Try to only include headers which are really needed. We should
particularly check all "headers including other headers". The
long-term goal is to have a manageable, small API for plugins
(decoders, output) without so many mpd internals cluttering the
namespace.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7319 09075e82-0dd4-0310-85a5-a0d7c8717e4f
Less global variables: at any invocation of decoder_sleep(), we have a
reference to the DecoderControl anyway, so we should pass it. This
costs less than having to call getPlayerData() in every tiny
function. Maybe some day we will be able to have multiple decoders at
the same time...
git-svn-id: https://svn.musicpd.org/mpd/trunk@7316 09075e82-0dd4-0310-85a5-a0d7c8717e4f
"end" is not being used anymore, since we moved most OutputBuffer
struct accesses into methods.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7314 09075e82-0dd4-0310-85a5-a0d7c8717e4f
Don't be mean with integer sizes. Although we will probably never
have more than 32k buffered chunks, we should use 32 bit integers for
addressing them. We do not save very much (some of the saved space is
eaten by alignment anyway), but we save at least one assembler
instruction for converting short to int.
This change requires some more explicit casts, because gcc was less
picky when comparing short with a full int.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7313 09075e82-0dd4-0310-85a5-a0d7c8717e4f
First patch without camelCase ;)
output_buffer_skip() lets us eliminate advanceOutputBufferTo(), and
removes yet another external OutputBuffer struct access.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7312 09075e82-0dd4-0310-85a5-a0d7c8717e4f
Second patch to make OutputBuffer self-contained: since OutputBuffer
now knows its own size, we do not need the global variable
"buffered_chunks" anymore.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7311 09075e82-0dd4-0310-85a5-a0d7c8717e4f
calculateCrossFadeChunks() still returns int, although the caller uses
it as an unsigned value. Since the function body checks for negative
values, it is safe to cast to unsigned.
crossFade() takes signed parameters, although it callers pass unsigned
integers. Change declaration to unsigned.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7291 09075e82-0dd4-0310-85a5-a0d7c8717e4f
The code paths which return from the functions all have to call
quitDecode(). If we simply break instead of calling quitDecode()
explicitly, this function gets called in the last line of this
function anyway.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7278 09075e82-0dd4-0310-85a5-a0d7c8717e4f
The multi-line expression which calculates sizeToTime is hard to read,
partly because "cb->audioFormat." is too long. Create a separate
inline function in audio.h for that.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7277 09075e82-0dd4-0310-85a5-a0d7c8717e4f
Moved the decision whether to cross-fade the current song to
calculateCrossFadeChunks(). This simplifies the function
decoderParent() and eliminates one layer of indentation.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7276 09075e82-0dd4-0310-85a5-a0d7c8717e4f
Similar to the crossFade() patch: pass chunk objects to playChunk(),
simplify decodeParent() by removing clutter.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7275 09075e82-0dd4-0310-85a5-a0d7c8717e4f
To unify the decoderParent() main loop some more, use it to wait for
the decoder to change the song. Only one single processDecodeInput()
caller left after this patch.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7273 09075e82-0dd4-0310-85a5-a0d7c8717e4f
When there are not enough decode cross-fade chunks in the buffer yet,
the current code does busy-wait, which will delay the decoder even
more. sleep instead, expecting the decoder to wake us up.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7272 09075e82-0dd4-0310-85a5-a0d7c8717e4f
Calling crossFade() with the chunk objects is easier than unrolling
all the chunk properties manually, and decodeParent() can really use
more of these simplifications.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7271 09075e82-0dd4-0310-85a5-a0d7c8717e4f
To make access to OutputBuffer easier, move everything which belongs
to a chunk into its own structure, namely OutputBufferChunk.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7269 09075e82-0dd4-0310-85a5-a0d7c8717e4f
Hiding OutputBuffer internals, again. We get an extra assertion in
return.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7267 09075e82-0dd4-0310-85a5-a0d7c8717e4f
The variable "quit" can be removed, since its only setter can use
"break" instead, just like the other code paths.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7266 09075e82-0dd4-0310-85a5-a0d7c8717e4f
The variables "nextChunk" and "crossFadeChunks" are only used when
doCrossFade==1. This means that we do not have to reset these as long
as doCrossFade!=1.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7265 09075e82-0dd4-0310-85a5-a0d7c8717e4f
The cross-fade check is still very complicated whenever it uses
OutputBuffer internals. Greatly simplify another check by introducing
outputBufferRelative().
git-svn-id: https://svn.musicpd.org/mpd/trunk@7264 09075e82-0dd4-0310-85a5-a0d7c8717e4f
Another "don't use OutputBuffer internals" patch. This ignores the
copied "end" value, but I do not think that has ever been a real
issue.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7263 09075e82-0dd4-0310-85a5-a0d7c8717e4f
decoderParent() uses a lot of OutputBuffer internals to see whether
cross-fading should be started. Move these checks to outputBuffer.c,
which also simplifies decoderParent().
git-svn-id: https://svn.musicpd.org/mpd/trunk@7262 09075e82-0dd4-0310-85a5-a0d7c8717e4f
Declare the variables "test" and "fadePosition" in the scope where
they are really used. This removes some of the clutter in the
function decodeParent().
git-svn-id: https://svn.musicpd.org/mpd/trunk@7261 09075e82-0dd4-0310-85a5-a0d7c8717e4f
Eliminating some duplicated and. This also decreases the number of
lines calling processDecodeInput().
git-svn-id: https://svn.musicpd.org/mpd/trunk@7260 09075e82-0dd4-0310-85a5-a0d7c8717e4f
I have spent some time to understand decodeParent(), which does a lot
of obfuscated magic... I find it useful to help others to also
understand it, so I wrote a few comments.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7259 09075e82-0dd4-0310-85a5-a0d7c8717e4f
Another patch indended to improve the CPP macro hell. This enlarges
the function decodeParent(), but it cannot be converted into a
standalone function easily, because it references so many local
variables.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7258 09075e82-0dd4-0310-85a5-a0d7c8717e4f
clearOutputBuffer() also resets currentChunk; this might resolve a
theoretical bug.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7257 09075e82-0dd4-0310-85a5-a0d7c8717e4f
dc->start cannot be true after the loop, because it was the loop
condition. dc->start could have been set by another thread between
the while loop and the if, but I suspect this is not the case the
author intended, so we just remove the dc->start check.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7256 09075e82-0dd4-0310-85a5-a0d7c8717e4f
In my opinion, the code becomes more readable when we explicitly check
"==NOERROR" instead of an implicit 0 check.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7255 09075e82-0dd4-0310-85a5-a0d7c8717e4f
Macros are ugly, and multi-line macros are even more ugly. This patch
converts processDecodeInput() to a C function. The disadvantage may
be that the function does not have access to the caller's local
variables, which might be regarded as an advantage on the other hand.
For this reason, we have to pass variable references. This costs a
tiny bit of performance, but it's worth eliminating this monster
macro, and further patches will optimize this cost down.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7254 09075e82-0dd4-0310-85a5-a0d7c8717e4f
The block after "if" breaks out of the loop. To make the code a
little bit more readable, don't write the rest in an "else" block,
since this code path does not break.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7251 09075e82-0dd4-0310-85a5-a0d7c8717e4f
The method availableOutputBuffer() calculates how many chunks are in
use. This simplifies code which needs this information, and it can
run without knowing OutputBuffer internals. The function knows how to
calculate this when begin>end; this might have been a bug in
decodeParent(), which does not.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7250 09075e82-0dd4-0310-85a5-a0d7c8717e4f
After the previous patch, it is clear that the loop in
advanceOutputBufferTo() can be replaced with a simple assignment.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7249 09075e82-0dd4-0310-85a5-a0d7c8717e4f
The parameter "currentChunkSent" is not used and can be dropped.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7248 09075e82-0dd4-0310-85a5-a0d7c8717e4f
It is way more complicated than it should be; and
locking it for thread-safety is too difficult.
[merged r7183 from branches/ew]
git-svn-id: https://svn.musicpd.org/mpd/trunk@7241 09075e82-0dd4-0310-85a5-a0d7c8717e4f
I initially started to do a heavy rewrite that changed the way processes
communicated, but that was too much to do at once. So this change only
focuses on replacing the player and decode processes with threads and
using condition variables instead of polling in loops; so the changeset
itself is quiet small.
* The shared output buffer variables will still need locking
to guard against race conditions. So in this effect, we're probably
just as buggy as before. The reduced context-switching overhead of
using threads instead of processes may even make bugs show up more or
less often...
* Basic functionality appears to be working for playing local (and NFS)
audio, including:
play, pause, stop, seek, previous, next, and main playlist editing
* I haven't tested HTTP streams yet, they should work.
* I've only tested ALSA and Icecast. ALSA works fine, Icecast
metadata seems to get screwy at times and breaks song
advancement in the playlist at times.
* state file loading works, too (after some last-minute hacks with
non-blocking wakeup functions)
* The non-blocking (*_nb) variants of the task management functions are
probably overused. They're more lenient and easier to use because
much of our code is still based on our previous polling-based system.
* It currently segfaults on exit. I haven't paid much attention
to the exit/signal-handling routines other than ensuring it
compiles. At least the state file seems to work. We don't
do any cleanups of the threads on exit, yet.
* Update is still done in a child process and not in a thread.
To do this in a thread, we'll need to ensure it does proper
locking and communication with the main thread; but should
require less memory in the end because we'll be updating
the database "in-place" rather than updating a copy and
then bulk-loading when done.
* We're more sensitive to bugs in 3rd party libraries now.
My plan is to eventually use a master process which forks()
and restarts the child when it dies:
locking and communication with the main thread; but should
require less memory in the end because we'll be updating
the database "in-place" rather than updating a copy and
then bulk-loading when done.
* We're more sensitive to bugs in 3rd party libraries now.
My plan is to eventually use a master process which forks()
and restarts the child when it dies:
master - just does waitpid() + fork() in a loop
\- main thread
\- decoder thread
\- player thread
At the beginning of every song, the main thread will set
a dirty flag and update the state file. This way, if we
encounter a song that triggers a segfault killing the
main thread, the master will start the replacement main
on the next song.
* The main thread still wakes up every second on select()
to check for signals; which affects power management.
[merged r7138 from branches/ew]
git-svn-id: https://svn.musicpd.org/mpd/trunk@7240 09075e82-0dd4-0310-85a5-a0d7c8717e4f
Do explicit casts before comparing signed with unsigned. The one in
log.c actually fixes another warning: in the expanded macro, there may
be a check "logLevel>=0", which is always true.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7230 09075e82-0dd4-0310-85a5-a0d7c8717e4f
Use unsigned integers in decoderParent() for chunk numbers which
cannot be negative.
git-svn-id: https://svn.musicpd.org/mpd/trunk@7226 09075e82-0dd4-0310-85a5-a0d7c8717e4f
