Traditionally, many of ALSA library functions are supposed to be
thread-unsafe, and applications are required to take care of thread
safety by themselves. However, people never be careful enough, and
almost all applications fail in this regard.
This patch is an attempt to harden the thread safety in exported PCM
functions in a simplistic way: just wrap some of exported functions
with the pthread mutex of each PCM object. Not all API functions are
wrapped by the mutex since it doesn't make sense. Instead, the
patchset covers only the functions that may be likely called
concurrently. The supposedly thread-safe API functions are marked in
the document.
For achieving the feature, two new fields are added snd_pcm_t when the
option is enabled: thread_safe and lock. The former indicates that
the plugin is thread-safe that doesn't need this workaround and the
latter is the pthread mutex. Currently only hw plugin have
thread_safe=1. So, the most of real-time sensitive apps won't be
influenced by this patchset.
Although the patch covers most of PCM ops, a few snd_pcm_fast_ops are
left without the extra mutex locking: namely, the ones that may have
blocking behavior, i.e. resume, drain, readi, writei, readn and
writen. These are supposed to handle own locking in the callbacks.
Also, if anyone wants to disable this new thread-safe API feature, it
can be still turned off via --disable-thread-safety configure option.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
There are strange "!" added before snd_config_get_id() return value
checks in a couple of places in pcm_route.c. This essentially makes
the result always positive, making checks bogus.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The PCM route plugin can assign the destination value from average of
multiple sources with attenuation. This requires the read of each
channel value, sums and writes the resultant value in the requested
format.
Currently, get_labels is used for reading source values while
put32_labels is used for writing the dest value. This is, however,
a buggy implementation; get_labels gives the value as is only with
endianness and signedness conversions, but put32_labels assumes that
the value is normalized to 32bit int and it shifts down to the dest
format. In addition, the current code lacks get_labels entries for
the 24bit formats, as Shengjiu Wang spotted out.
For fixing these bugs, this patch replaces the read with
get32_labels and use always 64bit int for sum. This simplifies the
code a lot and drops many lines.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
So far, use_getput flag is set only when the src or dest format is
24bit physical width. But, also 18 and 20 bit physical width formats
should set the flag, too. This patch makes the check broader to cover
all 3 bytes formats.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Now all PCM plugins do support the proper timestamp type or pass it
over slaves. The internal monotonic flag is dropped and replaced with
tstamp_type in all places.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This patch fixes a bug where the slave pcm was not correctly closed
on some error conditions, such as not finding a matching chmap.
Reported-by: Raymond Yau <superquad.vortex2@gmail.com>
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This reverts commit 5b72e3d530.
With the previous fixes, it's no longer needed as a workaround for
regression with PulseAudio.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
An uninitialized chmap pointer value is assigned in
_snd_pcm_route_open(). Add NULL initializations appropriately, and
also avoid the possible invalid access of NULL pcmp pointer.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This should fix the problem where the old route syntax can no longer
be opened.
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
When find_matching_chmap() returns an error for the non-matching
chmap, the caller, snd_pcm_route_open(), also returns an error
although it shouldn't be handled as the fatal error. This results in
the probe error with PulseAudio and it gives no real output in the
end.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
It means we need to initialize this order:
1) Read the ttable to figure out which channels are present
2) Open slave pcm and find a matching chmap
3) Determine size of ttable (this can now depend on the chmap)
4) Read ttable coefficients
5) At prepare time, select the matching chmap
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Instead of writing e g "0" and "1", one can now write "FL" and "FR" instead.
E g:
ttable.0.FL 1
ttable.1.FR 1
ttable.2.LFE 1
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Instead of passing ambiguous integer array, define snd_pcm_chmap_t and
snd_pcm_chmap_query_t so that user can understand more easily which
element is for what.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This makes it possible to write them to .data.rel.ro or to .rodata if
there is no relocation involved (arrays of character arrays).
Signed-off-by: Diego E. 'Flameeyes' Pettenò <flameeyes@gmail.com>
This ensures they are emitted in .data.rel.ro rather than .data.rel,
which should make a nice difference when using prelink.
Signed-off-by: Diego E. 'Flameeyes' Pettenò <flameeyes@gmail.com>
- added link/unlink/link_fd fast_ops callbacks
- moved code from snd_pcm_link to pcm_hw.c
- moved "empty" routines pointing to slave to pcm_generic.c
- introduced snd_pcm_generic_t
- added poll_events to main pcm structure
- added poll_revents callback to pcm->ops structure
- fixed snd_pcm_wait() - call revents function and enhanced
error code reporting
DMIX plugin:
- more complete code (works at least for one instance)
- still no "mix" code (it's silent)
- added backward compatibility for older non-compatible functions
- added --with-compat-rc3 to configure script to build library
backwards compatible with 0.9.0rc3
- added symbol versioning like libc.so.6
- ALSA_0.9 - alsa base
- ALSA_0.9.0rc4 - first set of new functions (snd_pcm_hw_params_*)
Added undo callbacks for snd_pcm_plugin based plugins.
- helpers when mmap_commit proceed only a partial transfer
Fixes to avail_update implementation in pcm_hw.c.
- changed snd_config_get_id function to follow semantic of other get functions
- added snd_config_test_id
- added runtime pointer type (not persistent)
- added snd_config_make_pointer, snd_config_set_pointer, snd_config_get_pointer
- added type/contents checking for callback functions
- changed 'void *private_data' to 'snd_config_t *private_data'
- renamed card_strtype functions to card_driver
Control:
- fixed passing parameters to snd_ctl_async
Async handlers:
- added public snd_async_handler_get_signo function
Documentation:
- moved all documentation to source files
