main motivation for adding the callback is to use it to enable operation on mmaped buffer before user access for pcm_file plugin

support for MMAP read access with masking by data from input file is not implemented for pcm_file plugin, by adding this callback implementing such feature can be done by rewriting next continuous portion of buffer on each mmap_begin call

plugins like softvol use pcm_plugin interface and overwrite the buffer by looping around it in avail_update callback, this patch hopes to simplify the task by adding new api callback, removing the need for rewriting pcm_file (to use pcm_plugin callbacks) and careful checking when looping around whole mmaped buffer

Signed-off-by: Adam Miartus amiartus@de.adit-jv.com Reviewed-by: Timo Wischer twischer@de.adit-jv.com

diff --git a/src/pcm/pcm.c b/src/pcm/pcm.c index 3a71d79..323926e 100644 --- a/src/pcm/pcm.c +++ b/src/pcm/pcm.c @@ -7129,7 +7129,13 @@ int __snd_pcm_mmap_begin(snd_pcm_t *pcm, const snd_pcm_channel_area_t **areas, snd_pcm_uframes_t f; snd_pcm_uframes_t avail; const snd_pcm_channel_area_t *xareas; + assert(pcm && areas && offset && frames); + + if (pcm->fast_ops->mmap_begin) + return pcm->fast_ops->mmap_begin(pcm->fast_op_arg, areas, offset, frames); + + /* fallback for plugins that do not specify new callback */ xareas = snd_pcm_mmap_areas(pcm); if (xareas == NULL) return -EBADFD; diff --git a/src/pcm/pcm_dmix.c b/src/pcm/pcm_dmix.c index 274726e..96049e0 100644 --- a/src/pcm/pcm_dmix.c +++ b/src/pcm/pcm_dmix.c @@ -990,6 +990,7 @@ static const snd_pcm_fast_ops_t snd_pcm_dmix_fast_ops = { .poll_descriptors = snd_pcm_direct_poll_descriptors, .poll_descriptors_count = NULL, .poll_revents = snd_pcm_dmix_poll_revents, + .mmap_begin = NULL, };

/** diff --git a/src/pcm/pcm_dshare.c b/src/pcm/pcm_dshare.c index b75809c..328ef83 100644 --- a/src/pcm/pcm_dshare.c +++ b/src/pcm/pcm_dshare.c @@ -667,6 +667,7 @@ static const snd_pcm_fast_ops_t snd_pcm_dshare_fast_ops = { .poll_descriptors = snd_pcm_direct_poll_descriptors, .poll_descriptors_count = NULL, .poll_revents = snd_pcm_direct_poll_revents, + .mmap_begin = NULL, };

/** diff --git a/src/pcm/pcm_dsnoop.c b/src/pcm/pcm_dsnoop.c index 58b1e53..5b9d9f5 100644 --- a/src/pcm/pcm_dsnoop.c +++ b/src/pcm/pcm_dsnoop.c @@ -544,6 +544,7 @@ static const snd_pcm_fast_ops_t snd_pcm_dsnoop_fast_ops = { .poll_descriptors = snd_pcm_direct_poll_descriptors, .poll_descriptors_count = NULL, .poll_revents = snd_pcm_direct_poll_revents, + .mmap_begin = NULL, };

/** diff --git a/src/pcm/pcm_file.c b/src/pcm/pcm_file.c index dcaa41d..10d227b 100644 --- a/src/pcm/pcm_file.c +++ b/src/pcm/pcm_file.c @@ -773,6 +773,7 @@ static const snd_pcm_fast_ops_t snd_pcm_file_fast_ops = { .poll_descriptors = snd_pcm_generic_poll_descriptors, .poll_revents = snd_pcm_generic_poll_revents, .htimestamp = snd_pcm_generic_htimestamp, + .mmap_begin = NULL, };

/** diff --git a/src/pcm/pcm_generic.h b/src/pcm/pcm_generic.h index dfbe21a..683e60b 100644 --- a/src/pcm/pcm_generic.h +++ b/src/pcm/pcm_generic.h @@ -161,4 +161,3 @@ snd_pcm_chmap_query_t **snd_pcm_generic_query_chmaps(snd_pcm_t *pcm); snd_pcm_chmap_t *snd_pcm_generic_get_chmap(snd_pcm_t *pcm); int snd_pcm_generic_set_chmap(snd_pcm_t *pcm, const snd_pcm_chmap_t *map); int snd_pcm_generic_may_wait_for_avail_min(snd_pcm_t *pcm, snd_pcm_uframes_t avail); - diff --git a/src/pcm/pcm_hooks.c b/src/pcm/pcm_hooks.c index 4416d36..14396fa 100644 --- a/src/pcm/pcm_hooks.c +++ b/src/pcm/pcm_hooks.c @@ -200,6 +200,7 @@ static const snd_pcm_fast_ops_t snd_pcm_hooks_fast_ops = { .poll_descriptors = snd_pcm_generic_poll_descriptors, .poll_revents = snd_pcm_generic_poll_revents, .may_wait_for_avail_min = snd_pcm_generic_may_wait_for_avail_min, + .mmap_begin = NULL, };

/** diff --git a/src/pcm/pcm_hw.c b/src/pcm/pcm_hw.c index 91370a8..8ee1d69 100644 --- a/src/pcm/pcm_hw.c +++ b/src/pcm/pcm_hw.c @@ -1481,6 +1481,7 @@ static const snd_pcm_fast_ops_t snd_pcm_hw_fast_ops = { .poll_descriptors = NULL, .poll_descriptors_count = NULL, .poll_revents = NULL, + .mmap_begin = NULL, };

static const snd_pcm_fast_ops_t snd_pcm_hw_fast_ops_timer = { @@ -1512,6 +1513,7 @@ static const snd_pcm_fast_ops_t snd_pcm_hw_fast_ops_timer = { .poll_descriptors = snd_pcm_hw_poll_descriptors, .poll_descriptors_count = snd_pcm_hw_poll_descriptors_count, .poll_revents = snd_pcm_hw_poll_revents, + .mmap_begin = NULL, };

/** diff --git a/src/pcm/pcm_ioplug.c b/src/pcm/pcm_ioplug.c index a437ca3..3e19499 100644 --- a/src/pcm/pcm_ioplug.c +++ b/src/pcm/pcm_ioplug.c @@ -940,6 +940,7 @@ static const snd_pcm_fast_ops_t snd_pcm_ioplug_fast_ops = { .poll_descriptors_count = snd_pcm_ioplug_poll_descriptors_count, .poll_descriptors = snd_pcm_ioplug_poll_descriptors, .poll_revents = snd_pcm_ioplug_poll_revents, + .mmap_begin = NULL, };

#endif /* !DOC_HIDDEN */ diff --git a/src/pcm/pcm_local.h b/src/pcm/pcm_local.h index d52229d..d5726eb 100644 --- a/src/pcm/pcm_local.h +++ b/src/pcm/pcm_local.h @@ -184,6 +184,7 @@ typedef struct { int (*poll_descriptors)(snd_pcm_t *pcm, struct pollfd *pfds, unsigned int space); /* locked */ int (*poll_revents)(snd_pcm_t *pcm, struct pollfd *pfds, unsigned int nfds, unsigned short *revents); /* locked */ int (*may_wait_for_avail_min)(snd_pcm_t *pcm, snd_pcm_uframes_t avail); + int (*mmap_begin)(snd_pcm_t *pcm, const snd_pcm_channel_area_t **areas, snd_pcm_uframes_t *offset, snd_pcm_uframes_t *frames); /* locked */ } snd_pcm_fast_ops_t;

struct _snd_pcm { diff --git a/src/pcm/pcm_meter.c b/src/pcm/pcm_meter.c index 20b4187..28bb578 100644 --- a/src/pcm/pcm_meter.c +++ b/src/pcm/pcm_meter.c @@ -548,6 +548,7 @@ static const snd_pcm_fast_ops_t snd_pcm_meter_fast_ops = { .poll_descriptors = snd_pcm_generic_poll_descriptors, .poll_revents = snd_pcm_generic_poll_revents, .may_wait_for_avail_min = snd_pcm_generic_may_wait_for_avail_min, + .mmap_begin = NULL, };

/** diff --git a/src/pcm/pcm_mmap_emul.c b/src/pcm/pcm_mmap_emul.c index 009cebb..6fa5fe6 100644 --- a/src/pcm/pcm_mmap_emul.c +++ b/src/pcm/pcm_mmap_emul.c @@ -401,6 +401,7 @@ static const snd_pcm_fast_ops_t snd_pcm_mmap_emul_fast_ops = { .poll_descriptors_count = snd_pcm_generic_poll_descriptors_count, .poll_revents = snd_pcm_generic_poll_revents, .may_wait_for_avail_min = snd_pcm_generic_may_wait_for_avail_min, + .mmap_begin = NULL, };

#ifndef DOC_HIDDEN diff --git a/src/pcm/pcm_multi.c b/src/pcm/pcm_multi.c index 53c414d..069d224 100644 --- a/src/pcm/pcm_multi.c +++ b/src/pcm/pcm_multi.c @@ -1042,6 +1042,7 @@ static const snd_pcm_fast_ops_t snd_pcm_multi_fast_ops = { .poll_descriptors = snd_pcm_multi_poll_descriptors, .poll_revents = snd_pcm_multi_poll_revents, .may_wait_for_avail_min = snd_pcm_multi_may_wait_for_avail_min, + .mmap_begin = NULL, };

/** diff --git a/src/pcm/pcm_null.c b/src/pcm/pcm_null.c index 1d81548..e6fa049 100644 --- a/src/pcm/pcm_null.c +++ b/src/pcm/pcm_null.c @@ -361,6 +361,7 @@ static const snd_pcm_fast_ops_t snd_pcm_null_fast_ops = { .avail_update = snd_pcm_null_avail_update, .mmap_commit = snd_pcm_null_mmap_commit, .htimestamp = snd_pcm_generic_real_htimestamp, + .mmap_begin = NULL, };

/** diff --git a/src/pcm/pcm_plugin.c b/src/pcm/pcm_plugin.c index ea60eb9..0714d2c 100644 --- a/src/pcm/pcm_plugin.c +++ b/src/pcm/pcm_plugin.c @@ -646,6 +646,7 @@ const snd_pcm_fast_ops_t snd_pcm_plugin_fast_ops = { .poll_descriptors = snd_pcm_generic_poll_descriptors, .poll_revents = snd_pcm_generic_poll_revents, .may_wait_for_avail_min = snd_pcm_plugin_may_wait_for_avail_min, + .mmap_begin = NULL, };

#endif diff --git a/src/pcm/pcm_rate.c b/src/pcm/pcm_rate.c index 5dc8a92..f29739b 100644 --- a/src/pcm/pcm_rate.c +++ b/src/pcm/pcm_rate.c @@ -1217,6 +1217,7 @@ static const snd_pcm_fast_ops_t snd_pcm_rate_fast_ops = { .poll_descriptors = snd_pcm_generic_poll_descriptors, .poll_revents = snd_pcm_rate_poll_revents, .may_wait_for_avail_min = snd_pcm_plugin_may_wait_for_avail_min, + .mmap_begin = NULL, };

static const snd_pcm_ops_t snd_pcm_rate_ops = { diff --git a/src/pcm/pcm_share.c b/src/pcm/pcm_share.c index 5a540c4..b803a82 100644 --- a/src/pcm/pcm_share.c +++ b/src/pcm/pcm_share.c @@ -1346,6 +1346,7 @@ static const snd_pcm_fast_ops_t snd_pcm_share_fast_ops = { .avail_update = snd_pcm_share_avail_update, .htimestamp = snd_pcm_share_htimestamp, .mmap_commit = snd_pcm_share_mmap_commit, + .mmap_begin = NULL, };

/** diff --git a/src/pcm/pcm_shm.c b/src/pcm/pcm_shm.c index 26a27a5..a18720f 100644 --- a/src/pcm/pcm_shm.c +++ b/src/pcm/pcm_shm.c @@ -629,6 +629,7 @@ static const snd_pcm_fast_ops_t snd_pcm_shm_fast_ops = { .avail_update = snd_pcm_shm_avail_update, .mmap_commit = snd_pcm_shm_mmap_commit, .htimestamp = snd_pcm_shm_htimestamp, + .mmap_begin = NULL, };

static int make_local_socket(const char *filename)