Much of the existing code queries all three variables sequentially.
Since only one of them can be set at a time, this can be optimized and
unified by merging all of them into one enum variable.  Later, the
"command" checks can be expressed in a "switch" statement.

pc->errored_song is already set by decodeParent() in the player thread
when we set dc->error; no need to set it in the decoder thread.

Since pc->current_song denotes the song which the decoder should use
next, we should move it to DecoderControl.  This removes one internal
PlayerControl struct access from the decoder code.

Also add pc.next_song, which is manipulated by the playlist code, and
gets copied to dc.next_song as soon as the decoder is started.

Include only headers which are really required.  This speeds up
compilation and helps detect cross-layer accesses.

Also enable -Wunused-parameter - this forces us to add the gcc
"unused" attribute to a lot of parameters (mostly library callback
functions), but it's worth it during code refactorizations.

Previously, it was not possible to check for e.g. "-std=c99".

Fix a "unused argument" warning, and several warnings regarding void
pointer calculation.

Fix a "signed/unsigned comparison warning", and several void pointer
math warnings.

* Correctly define the following CPP directives:
  HAVE_FAAD_BUFLEN_FUNCS
  HAVE_MP4AUDIOSPECIFICCONFIG

* link against libwavpack correctly in bs

* fix include path for the mpd config.h for mp4ff

git-svn-id: https://svn.musicpd.org/mpd/trunk@7399 09075e82-0dd4-0310-85a5-a0d7c8717e4f

git-svn-id: https://svn.musicpd.org/mpd/trunk@7398 09075e82-0dd4-0310-85a5-a0d7c8717e4f

If nothing has been read from the input stream, we don't have to
rewind it.

git-svn-id: https://svn.musicpd.org/mpd/trunk@7397 09075e82-0dd4-0310-85a5-a0d7c8717e4f

The variable "to_read" is never modified except in the last iteration
of the while loop.  This means the while condition will never become
false, as the body will break before that may be checked.

git-svn-id: https://svn.musicpd.org/mpd/trunk@7396 09075e82-0dd4-0310-85a5-a0d7c8717e4f

Start using it in the HTTP code

git-svn-id: https://svn.musicpd.org/mpd/trunk@7395 09075e82-0dd4-0310-85a5-a0d7c8717e4f

git-svn-id: https://svn.musicpd.org/mpd/trunk@7394 09075e82-0dd4-0310-85a5-a0d7c8717e4f

This institutes the usage of a separate thread to buffer HTTP
input.  It is basically practice code for using the ringbuffer
code which I plan on reusing for the OutputBuffer as well as
further input buffering for disk (networked filesystems over
WAN, laptops on battery, etc).

Each readFromInputStream() call on an HTTP stream can take
several seconds to complete, short reads are avoided.

A single-threaded solution for systems supporting large enough
SO_RCVBUF values should also be possible and will likely be done
in the future; but this lock-free(except when full/empty)
ringbuffer is cool :)

git-svn-id: https://svn.musicpd.org/mpd/trunk@7393 09075e82-0dd4-0310-85a5-a0d7c8717e4f

git-svn-id: https://svn.musicpd.org/mpd/trunk@7392 09075e82-0dd4-0310-85a5-a0d7c8717e4f

We'll be using pipes when waiting for I/O, and condition
variables at other times.

git-svn-id: https://svn.musicpd.org/mpd/trunk@7391 09075e82-0dd4-0310-85a5-a0d7c8717e4f

This will allow both the reader and writer threads to
reset the ringbuffer in a thread-safe fashion.

git-svn-id: https://svn.musicpd.org/mpd/trunk@7390 09075e82-0dd4-0310-85a5-a0d7c8717e4f

This will eliminate unnecessary calls to ringbuf_{read,write}_space

git-svn-id: https://svn.musicpd.org/mpd/trunk@7389 09075e82-0dd4-0310-85a5-a0d7c8717e4f

Makes code easier to read and modularize

git-svn-id: https://svn.musicpd.org/mpd/trunk@7388 09075e82-0dd4-0310-85a5-a0d7c8717e4f

The auth code also has some ugly usages of string generation
which I will eventually replace with something nicer...

git-svn-id: https://svn.musicpd.org/mpd/trunk@7387 09075e82-0dd4-0310-85a5-a0d7c8717e4f

This piece of code is from the JACK Audio Connection Kit
(trimmed down a bit for better readability).

The vector functions now reuse the common iovec struct used by
writev/readv instead of reinventing an identical but
differently-named struct.

From the comments:
> ISO/POSIX C version of Paul Davis's lock free ringbuffer C++ code.
> This is safe for the case of one read thread and one write thread.

License is LGPL 2.1 or later

git-svn-id: https://svn.musicpd.org/mpd/trunk@7386 09075e82-0dd4-0310-85a5-a0d7c8717e4f

vectored I/O will be useful with our ring buffer lib

git-svn-id: https://svn.musicpd.org/mpd/trunk@7385 09075e82-0dd4-0310-85a5-a0d7c8717e4f

git-svn-id: https://svn.musicpd.org/mpd/trunk@7382 09075e82-0dd4-0310-85a5-a0d7c8717e4f

Initialize audioOutput->data with NULL in jack_initDriver().
Previously, this was never initialized, although the other functions
relied on it being NULL prior to jack_openDevice().

This patch addresses bug 0001641[1].  In contrast to the patch provided
by the bug reporter, it moves the initialization before the "!param"
check.

[1] - http://musicpd.org/mantis/view.php?id=1641

git-svn-id: https://svn.musicpd.org/mpd/trunk@7375 09075e82-0dd4-0310-85a5-a0d7c8717e4f

This patch was taken from
http://bugzilla.livna.org/show_bug.cgi?id=1987 and addresses bug
0001693[1]

[1] - http://musicpd.org/mantis/view.php?id=1693

git-svn-id: https://svn.musicpd.org/mpd/trunk@7374 09075e82-0dd4-0310-85a5-a0d7c8717e4f

git-svn-id: https://svn.musicpd.org/mpd/trunk@7373 09075e82-0dd4-0310-85a5-a0d7c8717e4f

git-svn-id: https://svn.musicpd.org/mpd/trunk@7372 09075e82-0dd4-0310-85a5-a0d7c8717e4f

Streaming was broken, beacuse the stream URL was never copied to
path_max_fs.

[ew: replaced strcpy with pathcpy_trunc for ease of auditing]

git-svn-id: https://svn.musicpd.org/mpd/trunk@7371 09075e82-0dd4-0310-85a5-a0d7c8717e4f

git-svn-id: https://svn.musicpd.org/mpd/trunk@7370 09075e82-0dd4-0310-85a5-a0d7c8717e4f

git-svn-id: https://svn.musicpd.org/mpd/trunk@7369 09075e82-0dd4-0310-85a5-a0d7c8717e4f

Dealing with autotools is too painful when having
to deal with multiple build environments and
configurations.

git-svn-id: https://svn.musicpd.org/mpd/trunk@7368 09075e82-0dd4-0310-85a5-a0d7c8717e4f

git-svn-id: https://svn.musicpd.org/mpd/trunk@7367 09075e82-0dd4-0310-85a5-a0d7c8717e4f

During the decoder thread main loop, dc.state must be
DECODE_STATE_STOP.  Explicitly assigning it after the "dc.stop" check
is redundant.

git-svn-id: https://svn.musicpd.org/mpd/trunk@7366 09075e82-0dd4-0310-85a5-a0d7c8717e4f

The function wait_main_task() is racy: if the function
wakeup_via_cond() sees the mutex is locked just before
wait_main_task() executes pthread_cond_wait(), the main thread blocks
forever.

Work around this issue by adding a "pending" flag just like in my
notify.c code.  A standards-compliant solution should be implemented
later.

git-svn-id: https://svn.musicpd.org/mpd/trunk@7365 09075e82-0dd4-0310-85a5-a0d7c8717e4f

In lazy mode (previously the default), outputBuffer.c only wakes up
the player when it was previously empty.  That caused a deadlock when
the player was waiting for buffered_before_play, since the decoder
wouldn't wake up the player when buffered_before_play was reached.  In
non-lazy mode, always wake up the player when a new chunk was decoded.

git-svn-id: https://svn.musicpd.org/mpd/trunk@7364 09075e82-0dd4-0310-85a5-a0d7c8717e4f

When we are in an input plugin, dc.current_song should already be
set.  Use it instead of pc.current_song.

git-svn-id: https://svn.musicpd.org/mpd/trunk@7363 09075e82-0dd4-0310-85a5-a0d7c8717e4f

git-svn-id: https://svn.musicpd.org/mpd/trunk@7362 09075e82-0dd4-0310-85a5-a0d7c8717e4f

git-svn-id: https://svn.musicpd.org/mpd/trunk@7361 09075e82-0dd4-0310-85a5-a0d7c8717e4f

git-svn-id: https://svn.musicpd.org/mpd/trunk@7360 09075e82-0dd4-0310-85a5-a0d7c8717e4f