It can cause excessively long interrupt outages if moving a larger
buffer and disrupt audio where DMA is not at a higher interrupt priority
such as FIQ.
Some targets, like Gigabeat S, have very low audio interrupt latency
requirements and will even channel swap if they are missed. Pictureflow
will make the issue very obvious. Even then, moves could take
milliseconds or more depending on the buffer size which is far too long
for any target.
Change-Id: I8e7817213e901da67c36b7eb25d7cb1c1e3ba802
Reviewed-on: http://gerrit.rockbox.org/472
Reviewed-by: Michael Sevakis <jethead71@rockbox.org>
Tested-by: Michael Sevakis <jethead71@rockbox.org>
Buffers are not allocated and thread is not created until the first
call where voice is required.
Adds a different callback (sync_callback) to buflib so that other
sorts of synchonization are possible, such as briefly locking-out the
PCM callback for a buffer move. It's sort of a messy addition but it
is needed so voice decoding won't have to be stopped when its buffer
is moved.
Change-Id: I4d4d8c35eed5dd15fb7ee7df9323af3d036e92b3
* shrinking now considers freespace just before the alloc-to-be-shrinked,
that means less (or sometimes none at all) is taken from the audio buffer.
* core_available() now searches for the best free space, instead of simply the end,
i.e. it will not return 0 if the audio buffer is allocated and there's free space
before it. It also runs a compaction to ensure maximum contiguous memory.
audio_buffer_available() is also enhanced. It now considers the 256K reserve buffer,
and returns free buflib space instead if the audio buffer is short.
This all fixes the root problem of FS#12344 (Sansa Clip+: PANIC occurred when
dircache is enabled), that alloced from the audio buffer, even if it was very
short and buflib had many more available as free space before it.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@31006 a1c6a512-1295-4272-9138-f99709370657
This makes accessing the buffers with core_get_data() from
interrupt context safe, other buflib functions aren't really safe (yet).
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30736 a1c6a512-1295-4272-9138-f99709370657
Handles are allocated at the end, growing downwards.
The tiny allocations from r30478 broke buflib, since it was assumed that the only shrinkable allocation (the audiobuffer) is the very last allocation.
The tiny allocations however fit into the reserve buffer for new handles, breaking the above assumption, and they can't shrink to make room for handles.
Now, move any allocations before audiobuf (or shrink audiobuf like before) to make room for handles. This also unifies some duplicated code.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30486 a1c6a512-1295-4272-9138-f99709370657
* Enhance allocation function comments to better state the return value and what an invalid value is
* Change clients to check for "< 0" instead of "<= 0" or "== 0"
* Return -1 or -2 depending on the exact failure in buflib_alloc_ex.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30469 a1c6a512-1295-4272-9138-f99709370657
This enables the ability to allocate (and free) memory dynamically
without fragmentation, through compaction. This means allocations can move
and fragmentation be reduced. Most changes are preparing Rockbox for this,
which many times means adding a move callback which can temporarily disable
movement when the corresponding code is in a critical section.
For now, the audio buffer allocation has a central role, because it's the one
having allocated most. This buffer is able to shrink itself, for which it
needs to stop playback for a very short moment. For this,
audio_buffer_available() returns the size of the audio buffer which can
possibly be used by other allocations because the audio buffer can shrink.
lastfm scrobbling and timestretch can now be toggled at runtime without
requiring a reboot.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30381 a1c6a512-1295-4272-9138-f99709370657
The buflib memory allocator is handle based and can free and
compact, move or resize memory on demand. This allows to effeciently
allocate memory dynamically without an MMU, by avoiding fragmentation
through memory compaction.
This patch adds the buflib library to the core, along with
convinience wrappers to omit the context parameter. Compaction is
not yet enabled, but will be in a later patch. Therefore, this acts as a
replacement for buffer_alloc/buffer_get_buffer() with the benifit of a debug
menu.
See buflib.h for some API documentation.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30380 a1c6a512-1295-4272-9138-f99709370657
