Iwai-san,
On Jul 3 2018 22:59, twischer@de.adit-jv.com wrote:
From: Timo Wischer twischer@de.adit-jv.com
This function can be called without calling snd_pcm_avail_update().
The call to snd_pcm_avail_update() can take some time. Therefore some developers would not like to call it from a real-time context (e.g. from JACK client context).
Signed-off-by: Timo Wischer twischer@de.adit-jv.com
diff --git a/include/pcm_ioplug.h b/include/pcm_ioplug.h index c1310e3..b16fc8b 100644 --- a/include/pcm_ioplug.h +++ b/include/pcm_ioplug.h @@ -235,6 +235,9 @@ int snd_pcm_ioplug_set_param_list(snd_pcm_ioplug_t *io, int type, unsigned int n int snd_pcm_ioplug_set_state(snd_pcm_ioplug_t *ioplug, snd_pcm_state_t state);
/* calucalte the available frames */ +snd_pcm_uframes_t snd_pcm_ioplug_avail(const snd_pcm_ioplug_t * const ioplug,
const snd_pcm_uframes_t hw_ptr,const snd_pcm_uframes_t appl_ptr);diff --git a/src/pcm/pcm_ioplug.c b/src/pcm/pcm_ioplug.c index 4d44ae2..6d52c27 100644 --- a/src/pcm/pcm_ioplug.c +++ b/src/pcm/pcm_ioplug.c @@ -1221,6 +1221,21 @@ int snd_pcm_ioplug_set_state(snd_pcm_ioplug_t *ioplug, snd_pcm_state_t state)
- \param ioplug the ioplug handle
- \param hw_ptr hardware pointer in frames
- \param appl_ptr application pointer in frames
- \return available frames for the application
- */
+snd_pcm_uframes_t snd_pcm_ioplug_avail(const snd_pcm_ioplug_t * const ioplug,
const snd_pcm_uframes_t hw_ptr,const snd_pcm_uframes_t appl_ptr)+{
- return __snd_pcm_avail(ioplug->pcm, hw_ptr, appl_ptr);
+}
+/**
- \brief Get the available frames. This function can be used to calculate the
- the available frames before calling #snd_pcm_avail_update()
- \param ioplug the ioplug handle
- \param hw_ptr hardware pointer in frames
*/ snd_pcm_uframes_t snd_pcm_ioplug_hw_avail(const snd_pcm_ioplug_t * const ioplug,
- \param appl_ptr application pointer in frames
- \return available frames for the hardware
@@ -1230,8 +1245,9 @@ snd_pcm_uframes_t snd_pcm_ioplug_hw_avail(const snd_pcm_ioplug_t * const ioplug, /* available data/space which can be transferred by the user * application */
- const snd_pcm_uframes_t user_avail = __snd_pcm_avail(ioplug->pcm,
hw_ptr, appl_ptr);
const snd_pcm_uframes_t user_avail = snd_pcm_ioplug_avail(ioplug,
hw_ptr,appl_ptr);if (user_avail > ioplug->pcm->buffer_size) { /* there was an Xrun */
I have a question about maintenance policy of this library to update version script for GNU Linker (ld) when introducing new symbols. The version script is not updated since node name as 'ALSA_0.9.7'. The newly intduced symbol, 'snd_pcm_ioplug_hw_avail' is in node name of 'ALSA_0.9'.
``` $ readelf -s src/.libs/libasound.so.2.0.0 | grep snd_pcm_ioplug_hw_avail 1254: 000000000009bfe0 40 FUNC GLOBAL DEFAULT 13 snd_pcm_ioplug_hw_avail@@ALSA_0.9 3840: 000000000009bfe0 40 FUNC GLOBAL DEFAULT 13 snd_pcm_ioplug_hw_avail ```
The last node name is 'ALSA_1.1.6':
``` $ tail -n 10 src/Versions.in global:
@SYMBOL_PREFIX@alsa_lisp_*; } ALSA_0.9.5;
ALSA_1.1.6 { global:
@SYMBOL_PREFIX@snd_dlopen; } ALSA_0.9.7; ```
Practically this brings no issue, but theoretically the newly introduced symbol should be in a new node name next to ALSA_1.1.6. I'm not so strict in this point, but it's better to decide maintenance policy (because I've added some APIs in recent years).
Regards
Takashi Sakamoto