[pulseaudio-discuss] [PATCH v2] pipe-source: suspend source when no writers connected to fifo
Raman Shyshniou
rommer at ibuffed.com
Thu Feb 8 16:58:44 UTC 2018
Make pipe-source suspended if all writers closed fifo.
Source will be automatically unsuspended if any data will
be written to pipe and suspended again when last writer
closed fifo.
---
src/modules/module-pipe-source.c | 114 +++++++++++++++++++++++++++++++++++++--
1 file changed, 109 insertions(+), 5 deletions(-)
diff --git a/src/modules/module-pipe-source.c b/src/modules/module-pipe-source.c
index f8284c1..927fa89 100644
--- a/src/modules/module-pipe-source.c
+++ b/src/modules/module-pipe-source.c
@@ -62,6 +62,18 @@ PA_MODULE_USAGE(
#define DEFAULT_FILE_NAME "/tmp/music.input"
#define DEFAULT_SOURCE_NAME "fifo_input"
+struct pipe_source_msg {
+ pa_msgobject parent;
+};
+
+typedef struct pipe_source_msg pipe_source_msg;
+PA_DEFINE_PRIVATE_CLASS(pipe_source_msg, pa_msgobject);
+
+enum {
+ PIPE_SOURCE_SUSPEND,
+ PIPE_SOURCE_RESUME,
+};
+
struct userdata {
pa_core *core;
pa_module *module;
@@ -71,7 +83,10 @@ struct userdata {
pa_thread_mq thread_mq;
pa_rtpoll *rtpoll;
+ pipe_source_msg *msg;
+
char *filename;
+ int corkfd;
int fd;
pa_memchunk memchunk;
@@ -90,6 +105,37 @@ static const char* const valid_modargs[] = {
NULL
};
+/* Called from main context */
+static int pipe_source_process_msg(
+ pa_msgobject *o,
+ int code,
+ void *data,
+ int64_t offset,
+ pa_memchunk *chunk) {
+
+ struct userdata *u = (struct userdata *) data;
+
+ pa_assert(u);
+
+ switch (code) {
+ case PIPE_SOURCE_SUSPEND:
+ pa_log_debug("Suspending source %s because no writers left", u->source->name);
+ pa_source_suspend(u->source, true, PA_SUSPEND_APPLICATION);
+ break;
+
+ case PIPE_SOURCE_RESUME:
+ pa_log_debug("Resuming source %s because writer connected", u->source->name);
+ pa_source_suspend(u->source, false, PA_SUSPEND_APPLICATION);
+ break;
+
+ default:
+ pa_assert_not_reached();
+ }
+
+ return 0;
+}
+
+/* Called from thread context */
static int source_process_msg(
pa_msgobject *o,
int code,
@@ -135,8 +181,15 @@ static void thread_func(void *userdata) {
pollfd = pa_rtpoll_item_get_pollfd(u->rtpoll_item, NULL);
+ /* Writer connected */
+ if (u->corkfd >= 0 && pollfd->revents & POLLIN) {
+ pa_asyncmsgq_post(pa_thread_mq_get()->outq, PA_MSGOBJECT(u->msg), PIPE_SOURCE_RESUME, u, 0, NULL, NULL);
+ pa_assert_se(pa_close(u->corkfd) == 0);
+ u->corkfd = -1;
+ }
+
/* Try to read some data and pass it on to the source driver */
- if (u->source->thread_info.state == PA_SOURCE_RUNNING && pollfd->revents) {
+ if (u->source->thread_info.state == PA_SOURCE_RUNNING && pollfd->revents & POLLIN) {
ssize_t l;
void *p;
@@ -151,8 +204,6 @@ static void thread_func(void *userdata) {
l = pa_read(u->fd, (uint8_t*) p + u->memchunk.index, pa_memblock_get_length(u->memchunk.memblock) - u->memchunk.index, &read_type);
pa_memblock_release(u->memchunk.memblock);
- pa_assert(l != 0); /* EOF cannot happen, since we opened the fifo for both reading and writing */
-
if (l < 0) {
if (errno == EINTR)
@@ -162,6 +213,11 @@ static void thread_func(void *userdata) {
goto fail;
}
+ } else if (l == 0) {
+
+ /* Nothing to read */
+ pollfd->revents = 0;
+
} else {
u->memchunk.length = (size_t) l;
@@ -178,7 +234,7 @@ static void thread_func(void *userdata) {
}
/* Hmm, nothing to do. Let's sleep */
- pollfd->events = (short) (u->source->thread_info.state == PA_SOURCE_RUNNING ? POLLIN : 0);
+ pollfd->events = (short) ((u->source->thread_info.state == PA_SOURCE_RUNNING || u->corkfd >= 0) ? POLLIN : 0);
if ((ret = pa_rtpoll_run(u->rtpoll)) < 0)
goto fail;
@@ -188,6 +244,29 @@ static void thread_func(void *userdata) {
pollfd = pa_rtpoll_item_get_pollfd(u->rtpoll_item, NULL);
+ /* Last writer disconnected but data may still be in the buffer */
+ if (pollfd->revents & POLLHUP) {
+ int l = 0;
+
+#ifdef FIONREAD
+ ioctl(u->fd, FIONREAD, &l);
+#endif
+
+ if (!l && u->corkfd < 0) {
+ /* Suspend source */
+ pa_asyncmsgq_post(pa_thread_mq_get()->outq, PA_MSGOBJECT(u->msg), PIPE_SOURCE_SUSPEND, u, 0, NULL, NULL);
+
+ /* Open fifo for writing to stop POLLHUP spam */
+ if ((u->corkfd = pa_open_cloexec(u->filename, O_WRONLY, 0)) < 0) {
+ pa_log("open('%s'): %s", u->filename, pa_cstrerror(errno));
+ goto fail;
+ }
+ }
+
+ /* Ignore POOLHUP anyway */
+ pollfd->revents &= ~POLLHUP;
+ }
+
if (pollfd->revents & ~POLLIN) {
pa_log("FIFO shutdown.");
goto fail;
@@ -212,6 +291,7 @@ int pa__init(pa_module *m) {
pa_modargs *ma;
struct pollfd *pollfd;
pa_source_new_data data;
+ int rwfd;
pa_assert(m);
@@ -238,17 +318,35 @@ int pa__init(pa_module *m) {
goto fail;
}
+ u->corkfd = -1;
+
+ if (!(u->msg = pa_msgobject_new(pipe_source_msg)))
+ goto fail;
+
+ u->msg->parent.process_msg = pipe_source_process_msg;
+
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;
}
- if ((u->fd = pa_open_cloexec(u->filename, O_RDWR, 0)) < 0) {
+
+ /* Open fifo for read and write first, so the next open for read-only
+ will be succeded immediately */
+ if ((rwfd = pa_open_cloexec(u->filename, O_RDWR, 0)) < 0) {
+ pa_log("open('%s'): %s", u->filename, pa_cstrerror(errno));
+ goto fail;
+ }
+
+ if ((u->fd = pa_open_cloexec(u->filename, O_RDONLY, 0)) < 0) {
pa_log("open('%s'): %s", u->filename, pa_cstrerror(errno));
+ pa_assert_se(pa_close(rwfd) == 0);
goto fail;
}
+ pa_assert_se(pa_close(rwfd) == 0);
+
pa_make_fd_nonblock(u->fd);
if (fstat(u->fd, &st) < 0) {
@@ -360,6 +458,12 @@ void pa__done(pa_module *m) {
pa_xfree(u->filename);
}
+ if (u->msg)
+ pa_xfree(u->msg);
+
+ if (u->corkfd >= 0)
+ pa_assert_se(pa_close(u->corkfd) == 0);
+
if (u->fd >= 0)
pa_assert_se(pa_close(u->fd) == 0);
--
1.8.3.1
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