[pulseaudio-discuss] [PATCH] pipe-sink: new option "use_existing_fifo"

[Samo Pogačnik]

Allow usage of an already existing fifo (named pipe) upon module
load. Also, the fifo is not going to be removed upon module unload,
if "use_existing_fifo" option has been enabled.
---
 src/modules/module-pipe-sink.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/src/modules/module-pipe-sink.c b/src/modules/module-pipe-sink.c
index fe2af70..eafc3f7 100644
--- a/src/modules/module-pipe-sink.c
+++ b/src/modules/module-pipe-sink.c
@@ -62,6 +62,7 @@ PA_MODULE_USAGE(
         "channels=<number of channels> "
         "channel_map=<channel map> "
         "use_system_clock_for_timing=<yes or no> "
+        "use_existing_fifo=<yes or no> "
 );
 
 #define DEFAULT_FILE_NAME "fifo_output"
@@ -91,6 +92,7 @@ struct userdata {
     pa_usec_t timestamp;
 
     bool use_system_clock_for_timing;
+    bool use_existing_fifo;
 };
 
 static const char* const valid_modargs[] = {
@@ -102,6 +104,7 @@ static const char* const valid_modargs[] = {
     "channels",
     "channel_map",
     "use_system_clock_for_timing",
+    "use_existing_fifo",
     NULL
 };
 
@@ -442,6 +445,11 @@ int pa__init(pa_module *m) {
         goto fail;
     }
 
+    if (pa_modargs_get_value_boolean(ma, "use_existing_fifo", &u->use_existing_fifo) < 0) {
+        pa_log("Failed to parse use_existing_fifo argument.");
+        goto fail;
+    }
+
     if (pa_thread_mq_init(&u->thread_mq, m->core->mainloop, u->rtpoll) < 0) {
         pa_log("pa_thread_mq_init() failed.");
         goto fail;
@@ -452,8 +460,10 @@ int pa__init(pa_module *m) {
     u->filename = pa_runtime_path(pa_modargs_get_value(ma, "file", DEFAULT_FILE_NAME));
 
     if (mkfifo(u->filename, 0666) < 0) {
-        pa_log("mkfifo('%s'): %s", u->filename, pa_cstrerror(errno));
-        goto fail;
+        int errno_save = errno;
+        pa_log("mkfifo('%s'): %s", u->filename, pa_cstrerror(errno_save));
+        if (!u->use_existing_fifo || errno_save != EEXIST)
+            goto fail;
     }
     if ((u->fd = pa_open_cloexec(u->filename, O_RDWR, 0)) < 0) {
         pa_log("open('%s'): %s", u->filename, pa_cstrerror(errno));
@@ -584,7 +594,8 @@ void pa__done(pa_module *m) {
         pa_rtpoll_free(u->rtpoll);
 
     if (u->filename) {
-        unlink(u->filename);
+        if (!u->use_existing_fifo)
+            unlink(u->filename);
         pa_xfree(u->filename);
     }
 
-- 
2.7.4

regards, Samo