[pulseaudio-discuss] [PATCH v7] pipe-source: implement autosuspend option

Raman Shyshniou rommer at ibuffed.com
Mon Feb 19 15:01:09 UTC 2018


Currently the pipe-source will remain running even if no
writer is connected and therefore no data is produced.
This patch adds the autosuspend=<bool> option to prevent this.
Source will stay suspended if no writer is connected.
This option is enabled by default.
---
 src/modules/module-pipe-source.c | 279 ++++++++++++++++++++++++++++++---------
 1 file changed, 215 insertions(+), 64 deletions(-)

diff --git a/src/modules/module-pipe-source.c b/src/modules/module-pipe-source.c
index f8284c1..c1a1e9c 100644
--- a/src/modules/module-pipe-source.c
+++ b/src/modules/module-pipe-source.c
@@ -33,6 +33,7 @@
 #include <sys/filio.h>
 #endif
 
+#include <pulse/rtclock.h>
 #include <pulse/xmalloc.h>
 
 #include <pulsecore/core-error.h>
@@ -57,11 +58,24 @@ PA_MODULE_USAGE(
         "format=<sample format> "
         "rate=<sample rate> "
         "channels=<number of channels> "
-        "channel_map=<channel map>");
+        "channel_map=<channel map> "
+        "autosuspend=<boolean>");
 
 #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;
@@ -71,12 +85,14 @@ struct userdata {
     pa_thread_mq thread_mq;
     pa_rtpoll *rtpoll;
 
+    pipe_source_msg *msg;
+    pa_usec_t timestamp;
+    bool autosuspend;
+    size_t pipe_size;
+
     char *filename;
+    int corkfd;
     int fd;
-
-    pa_memchunk memchunk;
-
-    pa_rtpoll_item *rtpoll_item;
 };
 
 static const char* const valid_modargs[] = {
@@ -87,9 +103,41 @@ static const char* const valid_modargs[] = {
     "rate",
     "channels",
     "channel_map",
+    "autosuspend",
     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", 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,
@@ -101,17 +149,30 @@ static int source_process_msg(
 
     switch (code) {
 
+        case PA_SOURCE_MESSAGE_SET_STATE:
+
+            if (u->source->thread_info.state == PA_SOURCE_SUSPENDED || u->source->thread_info.state == PA_SOURCE_INIT) {
+                if (PA_SOURCE_IS_OPENED(PA_PTR_TO_UINT(data)))
+                    u->timestamp = pa_rtclock_now();
+            }
+
+            break;
+
         case PA_SOURCE_MESSAGE_GET_LATENCY: {
-            size_t n = 0;
+            int64_t latency;
+
+            latency = PA_CLIP_SUB((int64_t)pa_rtclock_now(), (int64_t)u->timestamp);
 
 #ifdef FIONREAD
-            int l;
+            if (u->corkfd < 0) {
+                int l;
 
-            if (ioctl(u->fd, FIONREAD, &l) >= 0 && l > 0)
-                n = (size_t) l;
+                if (ioctl(u->fd, FIONREAD, &l) >= 0 && l > 0)
+                    latency += pa_bytes_to_usec((uint64_t)l, &u->source->sample_spec);
+            }
 #endif
 
-            *((int64_t*) data) = pa_bytes_to_usec(n, &u->source->sample_spec);
+            *((int64_t*) data) = latency;
             return 0;
         }
     }
@@ -121,7 +182,11 @@ static int source_process_msg(
 
 static void thread_func(void *userdata) {
     struct userdata *u = userdata;
+    pa_rtpoll_item *rtpoll_item;
+    struct pollfd *pollfd;
+    pa_memchunk chunk;
     int read_type = 0;
+    size_t fs;
 
     pa_assert(u);
 
@@ -129,68 +194,135 @@ static void thread_func(void *userdata) {
 
     pa_thread_mq_install(&u->thread_mq);
 
+    fs = pa_frame_size(&u->source->sample_spec);
+
+    pa_memchunk_reset(&chunk);
+    chunk.memblock = pa_memblock_new(u->core->mempool, u->pipe_size);
+
+    rtpoll_item = NULL;
+    pollfd = NULL;
+
+    u->timestamp = pa_rtclock_now();
+
+    /* Close our writer here to suspend source if no writers left */
+    pa_assert_se(pa_close(u->corkfd) == 0);
+    u->corkfd = -1;
+
     for (;;) {
         int ret;
-        struct pollfd *pollfd;
 
-        pollfd = pa_rtpoll_item_get_pollfd(u->rtpoll_item, NULL);
+        if (chunk.length) {
+            /* We have a pending data, let's stop polling pipe.
+             * Setting up pollfd->events = 0 is not enough to stop
+             * POLLHUP spam if all writers are closed pipe.
+             * We need to stop polling pipe completely */
+            if (rtpoll_item) {
+                pa_rtpoll_item_free(rtpoll_item);
+                rtpoll_item = NULL;
+            }
+        } else {
+            /* We have no pending data, let's start polling pipe */
+            if (rtpoll_item == NULL) {
+                rtpoll_item = pa_rtpoll_item_new(u->rtpoll, PA_RTPOLL_NEVER, 1);
+                pollfd = pa_rtpoll_item_get_pollfd(rtpoll_item, NULL);
+                pollfd->events = POLLIN;
+                pollfd->fd = u->fd;
+            }
+        }
 
-        /* Try to read some data and pass it on to the source driver */
-        if (u->source->thread_info.state == PA_SOURCE_RUNNING && pollfd->revents) {
-            ssize_t l;
-            void *p;
+        if ((ret = pa_rtpoll_run(u->rtpoll)) < 0)
+            goto fail;
 
-            if (!u->memchunk.memblock) {
-                u->memchunk.memblock = pa_memblock_new(u->core->mempool, pa_pipe_buf(u->fd));
-                u->memchunk.index = u->memchunk.length = 0;
-            }
+        if (ret == 0)
+            goto finish;
 
-            pa_assert(pa_memblock_get_length(u->memchunk.memblock) > u->memchunk.index);
+        if (rtpoll_item) {
+            pollfd = pa_rtpoll_item_get_pollfd(rtpoll_item, NULL);
 
-            p = pa_memblock_acquire(u->memchunk.memblock);
-            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);
+            if (pollfd->revents & ~(POLLIN | POLLHUP)) {
+                pa_log("FIFO shutdown.");
+                goto fail;
+            }
+        } else
+            pollfd = NULL;
 
-            pa_assert(l != 0); /* EOF cannot happen, since we opened the fifo for both reading and writing */
+        /* Try to read some data if there are any events */
+        if (pollfd && pollfd->revents) {
+            ssize_t l;
+            void *p;
 
-            if (l < 0) {
+            pa_assert(chunk.index < fs);
 
-                if (errno == EINTR)
-                    continue;
-                else if (errno != EAGAIN) {
-                    pa_log("Failed to read data from FIFO: %s", pa_cstrerror(errno));
-                    goto fail;
-                }
+            p = pa_memblock_acquire(chunk.memblock);
+            l = pa_read(u->fd, (uint8_t *) p + chunk.index, pa_memblock_get_length(chunk.memblock) - chunk.index, &read_type);
+            pa_memblock_release(chunk.memblock);
 
-            } else {
+            if (l > 0) {
+                chunk.length = (size_t) l;
+                u->timestamp = pa_rtclock_now();
 
-                u->memchunk.length = (size_t) l;
-                pa_source_post(u->source, &u->memchunk);
-                u->memchunk.index += (size_t) l;
+                if (u->corkfd >= 0) {
+                    if (u->autosuspend)
+                        pa_asyncmsgq_post(pa_thread_mq_get()->outq, PA_MSGOBJECT(u->msg), PIPE_SOURCE_RESUME, u, 0, NULL, NULL);
 
-                if (u->memchunk.index >= pa_memblock_get_length(u->memchunk.memblock)) {
-                    pa_memblock_unref(u->memchunk.memblock);
-                    pa_memchunk_reset(&u->memchunk);
+                    pa_assert_se(pa_close(u->corkfd) == 0);
+                    u->corkfd = -1;
+                }
+            } else if (l == 0) {
+                /* Writer was disconnected: discard unalligned data tail */
+                chunk.index = 0;
+
+                if (u->corkfd < 0) {
+                    if (u->autosuspend)
+                        pa_asyncmsgq_post(pa_thread_mq_get()->outq, PA_MSGOBJECT(u->msg), PIPE_SOURCE_SUSPEND, u, 0, NULL, NULL);
+
+                    if ((u->corkfd = pa_open_cloexec(u->filename, O_WRONLY, 0)) < 0) {
+                        pa_log("open('%s'): %s", u->filename, pa_cstrerror(errno));
+                        goto fail;
+                    }
                 }
+            } else {
+                if (errno == EINTR || errno == EAGAIN)
+                    continue;
 
-                pollfd->revents = 0;
+                pa_log("Failed to read data from FIFO: %s", pa_cstrerror(errno));
+                goto fail;
             }
         }
 
-        /* Hmm, nothing to do. Let's sleep */
-        pollfd->events = (short) (u->source->thread_info.state == PA_SOURCE_RUNNING ? POLLIN : 0);
+        /* Post pending data.
+         * Let's keep frame boundaries */
+        if (PA_SOURCE_IS_OPENED(u->source->thread_info.state)) {
+            size_t total_len = chunk.index + chunk.length;
+            size_t frames = total_len / fs;
+            size_t tail = total_len % fs;
 
-        if ((ret = pa_rtpoll_run(u->rtpoll)) < 0)
-            goto fail;
+            if (frames > 0) {
+                pa_memblock *memblock;
 
-        if (ret == 0)
-            goto finish;
+                memblock = pa_memblock_new(u->core->mempool, u->pipe_size);
+                chunk.length = frames * fs;
+                chunk.index = 0;
 
-        pollfd = pa_rtpoll_item_get_pollfd(u->rtpoll_item, NULL);
+                if (tail) {
+                    void *src, *dst;
 
-        if (pollfd->revents & ~POLLIN) {
-            pa_log("FIFO shutdown.");
-            goto fail;
+                    dst = pa_memblock_acquire(memblock);
+                    src = pa_memblock_acquire(chunk.memblock);
+
+                    memcpy(dst, (uint8_t *) src + chunk.length, tail);
+
+                    pa_memblock_release(chunk.memblock);
+                    pa_memblock_release(memblock);
+                }
+
+                pa_source_post(u->source, &chunk);
+                pa_memblock_unref(chunk.memblock);
+                chunk.memblock = memblock;
+            }
+
+            chunk.index = tail;
+            chunk.length = 0;
         }
     }
 
@@ -201,6 +333,11 @@ fail:
     pa_asyncmsgq_wait_for(u->thread_mq.inq, PA_MESSAGE_SHUTDOWN);
 
 finish:
+    if (rtpoll_item)
+        pa_rtpoll_item_free(rtpoll_item);
+
+    pa_memblock_unref(chunk.memblock);
+
     pa_log_debug("Thread shutting down");
 }
 
@@ -210,7 +347,6 @@ int pa__init(pa_module *m) {
     pa_sample_spec ss;
     pa_channel_map map;
     pa_modargs *ma;
-    struct pollfd *pollfd;
     pa_source_new_data data;
 
     pa_assert(m);
@@ -230,7 +366,6 @@ int pa__init(pa_module *m) {
     m->userdata = u = pa_xnew0(struct userdata, 1);
     u->core = m->core;
     u->module = m;
-    pa_memchunk_reset(&u->memchunk);
     u->rtpoll = pa_rtpoll_new();
 
     if (pa_thread_mq_init(&u->thread_mq, m->core->mainloop, u->rtpoll) < 0) {
@@ -238,13 +373,31 @@ int pa__init(pa_module *m) {
         goto fail;
     }
 
+    if (!(u->msg = pa_msgobject_new(pipe_source_msg)))
+        goto fail;
+
+    u->msg->parent.process_msg = pipe_source_process_msg;
+
+    u->autosuspend = true;
+
+    if (pa_modargs_get_value_boolean(ma, "autosuspend", &u->autosuspend) < 0) {
+        pa_log("Failed to parse autosuspend argument.");
+        goto fail;
+    }
+
     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) {
+
+    if ((u->corkfd = 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));
         goto fail;
     }
@@ -289,12 +442,10 @@ int pa__init(pa_module *m) {
 
     pa_source_set_asyncmsgq(u->source, u->thread_mq.inq);
     pa_source_set_rtpoll(u->source, u->rtpoll);
-    pa_source_set_fixed_latency(u->source, pa_bytes_to_usec(pa_pipe_buf(u->fd), &u->source->sample_spec));
 
-    u->rtpoll_item = pa_rtpoll_item_new(u->rtpoll, PA_RTPOLL_NEVER, 1);
-    pollfd = pa_rtpoll_item_get_pollfd(u->rtpoll_item, NULL);
-    pollfd->fd = u->fd;
-    pollfd->events = pollfd->revents = 0;
+    u->pipe_size = pa_pipe_buf(u->fd);
+    u->pipe_size = PA_MIN(pa_mempool_block_size_max(u->core->mempool), u->pipe_size);
+    pa_source_set_fixed_latency(u->source, pa_bytes_to_usec(u->pipe_size, &u->source->sample_spec));
 
     if (!(u->thread = pa_thread_new("pipe-source", thread_func, u))) {
         pa_log("Failed to create thread.");
@@ -346,12 +497,6 @@ void pa__done(pa_module *m) {
     if (u->source)
         pa_source_unref(u->source);
 
-    if (u->memchunk.memblock)
-        pa_memblock_unref(u->memchunk.memblock);
-
-    if (u->rtpoll_item)
-        pa_rtpoll_item_free(u->rtpoll_item);
-
     if (u->rtpoll)
         pa_rtpoll_free(u->rtpoll);
 
@@ -360,6 +505,12 @@ 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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