mirrors/pulseaudio
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/pulseaudio/pulseaudio.git synced 2025-11-09 13:29:59 -05:00
Code Issues Projects Releases Packages Wiki Activity Actions

pstream: Support memfd blocks transport

Browse source 
Now that we have the necessary infrastructure to memexport and
mempimport a memfd memblock, extend that support higher up in the
chain with pstreams.

A PA endpoint can now _transparently_ send a memfd memblock to the
other end by simply calling pa_pstream_send_memblock() – provided
the block's memfd pool was earlier registered with the pstream.

If the pipe does not support memfd transfers, we fall back to
sending the block's full data instead of just its reference.

** Further details:

A single pstream connection usually transfers blocks from multiple
pools including the server's srbchannel mempool, the client's
audio data mempool, and the server's global core mempool.

If these mempools are memfd-backed, we now require registering
them with the pstream before sending any blocks they cover. This
is done to minimize fd passing overhead and avoid fd leaks.

Moreover, to support all these pools without hard-coding their
number or nature in the Pulse communication protocol itself, a new
REGISTER_MEMFD_SHMID command is introduced. That command can be
sent _anytime_ during the pstream's lifetime and is used for
creating on demand SHM ID to memfd mappings.

Suggested-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
This commit is contained in:
Ahmed S. Darwish 2016-03-13 01:12:18 +02:00 • committed by David Henningsson
parent ee2db62277
commit 27d0a3b388
17 changed files with 455 additions and 76 deletions
Download patch file Download diff file Expand all files Collapse all files

30
src/pulsecore/pdispatch.c
View file

@ -195,6 +195,10 @@ static const char *command_names[PA_COMMAND_MAX] = {
/* BOTH DIRECTIONS */
[PA_COMMAND_ENABLE_SRBCHANNEL] = "ENABLE_SRBCHANNEL",
[PA_COMMAND_DISABLE_SRBCHANNEL] = "DISABLE_SRBCHANNEL",
/* Supported since protocol v31 (9.0) */
/* BOTH DIRECTIONS */
[PA_COMMAND_REGISTER_MEMFD_SHMID] = "REGISTER_MEMFD_SHMID",
};
#endif
@ -219,7 +223,7 @@ struct pa_pdispatch {
PA_LLIST_HEAD(struct reply_info, replies);
pa_pdispatch_drain_cb_t drain_callback;
void *drain_userdata;
const pa_cmsg_ancil_data *ancil_data;
pa_cmsg_ancil_data *ancil_data;
bool use_rtclock;
};
@ -289,7 +293,7 @@ static void run_action(pa_pdispatch *pd, struct reply_info *r, uint32_t command,
pa_pdispatch_unref(pd);
}
int pa_pdispatch_run(pa_pdispatch *pd, pa_packet *packet, const pa_cmsg_ancil_data *ancil_data, void *userdata) {
int pa_pdispatch_run(pa_pdispatch *pd, pa_packet *packet, pa_cmsg_ancil_data *ancil_data, void *userdata) {
uint32_t tag, command;
pa_tagstruct *ts = NULL;
int ret = -1;
@ -448,18 +452,24 @@ const pa_creds * pa_pdispatch_creds(pa_pdispatch *pd) {
return NULL;
}
const int * pa_pdispatch_fds(pa_pdispatch *pd, int *nfd) {
/* Should be called only once during the dispatcher lifetime
*
* If the returned ancillary data contains any fds, caller maintains sole
* responsibility of closing them down using pa_cmsg_ancil_data_close_fds() */
pa_cmsg_ancil_data *pa_pdispatch_take_ancil_data(pa_pdispatch *pd) {
pa_cmsg_ancil_data *ancil;
pa_assert(pd);
pa_assert(PA_REFCNT_VALUE(pd) >= 1);
pa_assert(nfd);
if (pd->ancil_data) {
*nfd = pd->ancil_data->nfd;
return pd->ancil_data->fds;
}
ancil = pd->ancil_data;
*nfd = 0;
return NULL;
/* iochannel guarantees us that nfd will always be capped */
if (ancil)
pa_assert(ancil->nfd <= MAX_ANCIL_DATA_FDS);
pd->ancil_data = NULL;
return ancil;
}
#endif