shmsink: Port to ShmPipe

3 files changed, 367 insertions, 261 deletions

diff --git a/gst/shm/gstshm.h b/gst/shm/gstshm.h
deleted file mode 100644
index 601cfde0a..000000000
--- a/gst/shm/gstshm.h
+++ /dev/null
@@ -1,64 +0,0 @@
-
-/* GStreamer
- * Copyright (C) <2009> Collabora Ltd
- *  @author: Olivier Crete <olivier.crete@collabora.co.uk
- * Copyright (C) <2009> Nokia Inc
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Library General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Library General Public License for more details.
- *
- * You should have received a copy of the GNU Library General Public
- * License along with this library; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 02111-1307, USA.
- */
-
-#ifndef __GST_SHM_H__
-#define __GST_SHM_H__
-
-#include <gst/gst.h>
-#include <semaphore.h>
-
-G_BEGIN_DECLS
-#define GST_SHM_MAX_CAPS_LENGTH (1024)
-#define SHM_LOCK(shm)   sem_wait (&(shm)->mutex);
-#define SHM_UNLOCK(shm) sem_post (&(shm)->mutex);
-#define GST_SHM_CAPS_BUFFER(shm) ((shm)->data)
-#define GST_SHM_BUFFER(shm) ((shm)->data+(shm)->caps_size)
-    struct GstShmHeader
-{
-  sem_t notification;
-  sem_t mutex;
-
-  guint caps_gen;
-  guint buffer_gen;
-
-  gint caps_size;
-  gint buffer_size;
-
-  guint flags;
-
-  GstClockTime timestamp;
-  GstClockTime duration;
-
-  guint64 offset;
-  guint64 offset_end;
-
-  gboolean eos;
-
-  gchar data[0];
-  /*
-   * gchar caps_buffer[caps_size];
-   * gchar buffer[buffer_size];
-   */
-};
-
-G_END_DECLS
-#endif /* __GST_SHM_H__ */
diff --git a/gst/shm/gstshmsink.c b/gst/shm/gstshmsink.c
index 48332e60d..9a0233b25 100644
--- a/gst/shm/gstshmsink.c
+++ b/gst/shm/gstshmsink.c
@@ -25,21 +25,16 @@
 #endif
 
 #include "gstshmsink.h"
-#include "gstshm.h"
 
 #include <gst/gst.h>
 
-#include <sys/mman.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <errno.h>
 #include <string.h>
-#include <unistd.h>
-#include <semaphore.h>
 
 /* signals */
 enum
 {
+  SIGNAL_CLIENT_CONNECTED,
+  SIGNAL_CLIENT_DISCONNECTED,
   LAST_SIGNAL
 };
 
@@ -47,12 +42,25 @@ enum
 enum
 {
   PROP_0,
-  PROP_SHM_NAME,
-  PROP_PERMS
+  PROP_SOCKET_PATH,
+  PROP_PERMS,
+  PROP_SHM_SIZE,
+  PROP_WAIT_FOR_CONNECTION
 };
 
+struct GstShmClient
+{
+  ShmClient *client;
+  GstPollFD pollfd;
+};
+
+#define DEFAULT_SIZE ( 256 * 1024 )
+#define DEFAULT_WAIT_FOR_CONNECTION (TRUE)
+#define DEFAULT_PERMS (S_IRWXU | S_IRWXG)
+
 
 GST_DEBUG_CATEGORY_STATIC (shmsink_debug);
+#define GST_CAT_DEFAULT shmsink_debug
 
 static const GstElementDetails gst_shm_sink_details =
 GST_ELEMENT_DETAILS ("Shared Memory Sink",
@@ -67,21 +75,25 @@ static GstStaticPadTemplate sinktemplate = GST_STATIC_PAD_TEMPLATE ("sink",
 
 GST_BOILERPLATE (GstShmSink, gst_shm_sink, GstBaseSink, GST_TYPE_BASE_SINK);
 
+static void gst_shm_sink_finalize (GObject * object);
 static void gst_shm_sink_set_property (GObject * object, guint prop_id,
     const GValue * value, GParamSpec * pspec);
 static void gst_shm_sink_get_property (GObject * object, guint prop_id,
     GValue * value, GParamSpec * pspec);
 
-static GstStateChangeReturn gst_shm_sink_change_state (GstElement * element,
-    GstStateChange transition);
-
 static gboolean gst_shm_sink_start (GstBaseSink * bsink);
 static gboolean gst_shm_sink_stop (GstBaseSink * bsink);
-static gboolean gst_shm_sink_set_caps (GstBaseSink * bsink, GstCaps * caps);
 static GstFlowReturn gst_shm_sink_render (GstBaseSink * bsink, GstBuffer * buf);
+static GstFlowReturn gst_shm_sink_buffer_alloc (GstBaseSink * sink,
+    guint64 offset, guint size, GstCaps * caps, GstBuffer ** out_buf);
+
 static gboolean gst_shm_sink_event (GstBaseSink * bsink, GstEvent * event);
+static gboolean gst_shm_sink_unlock (GstBaseSink * bsink);
+static gboolean gst_shm_sink_unlock_stop (GstBaseSink * bsink);
 
-// static guint gst_shm_sink_signals[LAST_SIGNAL] = { 0 };
+static gpointer pollthread_func (gpointer data);
+
+static guint signals[LAST_SIGNAL] = { 0 };
 
 static void
 gst_shm_sink_base_init (gpointer g_class)
@@ -98,8 +110,10 @@ gst_shm_sink_base_init (gpointer g_class)
 static void
 gst_shm_sink_init (GstShmSink * self, GstShmSinkClass * g_class)
 {
-  self->fd = -1;
-  self->shm_area = MAP_FAILED;
+  self->cond = g_cond_new ();
+  self->size = DEFAULT_SIZE;
+  self->wait_for_connection = DEFAULT_WAIT_FOR_CONNECTION;
+  self->perms = DEFAULT_PERMS;
 }
 
 static void
@@ -113,33 +127,64 @@ gst_shm_sink_class_init (GstShmSinkClass * klass)
   gstelement_class = (GstElementClass *) klass;
   gstbasesink_class = (GstBaseSinkClass *) klass;
 
+  gobject_class->finalize = gst_shm_sink_finalize;
   gobject_class->set_property = gst_shm_sink_set_property;
   gobject_class->get_property = gst_shm_sink_get_property;
 
-  gstelement_class->change_state = gst_shm_sink_change_state;
-
-  gstbasesink_class->start = gst_shm_sink_start;
-  gstbasesink_class->stop = gst_shm_sink_stop;
-  gstbasesink_class->set_caps = gst_shm_sink_set_caps;
-  gstbasesink_class->render = gst_shm_sink_render;
-  gstbasesink_class->event = gst_shm_sink_event;
-
-  g_object_class_install_property (gobject_class, PROP_SHM_NAME,
-      g_param_spec_string ("shm-name",
-          "Name of the shared memory area",
-          "The name of the shared memory area that the source can read from",
-          NULL, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+  gstbasesink_class->start = GST_DEBUG_FUNCPTR (gst_shm_sink_start);
+  gstbasesink_class->stop = GST_DEBUG_FUNCPTR (gst_shm_sink_stop);
+  gstbasesink_class->render = GST_DEBUG_FUNCPTR (gst_shm_sink_render);
+  gstbasesink_class->event = GST_DEBUG_FUNCPTR (gst_shm_sink_event);
+  gstbasesink_class->unlock = GST_DEBUG_FUNCPTR (gst_shm_sink_unlock);
+  gstbasesink_class->unlock_stop = GST_DEBUG_FUNCPTR (gst_shm_sink_unlock_stop);
+  gstbasesink_class->buffer_alloc =
+      GST_DEBUG_FUNCPTR (gst_shm_sink_buffer_alloc);
+
+  g_object_class_install_property (gobject_class, PROP_SOCKET_PATH,
+      g_param_spec_string ("socket-path",
+          "Path to the control socket",
+          "The path to the control socket used to control the shared memory"
+          " transport", NULL, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
 
   g_object_class_install_property (gobject_class, PROP_PERMS,
       g_param_spec_uint ("perms",
           "Permissions on the shm area",
           "Permissions to set on the shm area",
-          0, 07777, S_IRWXU | S_IRWXG,
-          G_PARAM_CONSTRUCT | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+          0, 07777, DEFAULT_PERMS, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
+  g_object_class_install_property (gobject_class, PROP_SHM_SIZE,
+      g_param_spec_uint ("shm-size",
+          "Size of the shm area",
+          "Size of the shared memory area",
+          0, G_MAXUINT, DEFAULT_SIZE,
+          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
+  g_object_class_install_property (gobject_class, PROP_WAIT_FOR_CONNECTION,
+      g_param_spec_boolean ("wait-for-connection",
+          "Wait for a connection until rendering",
+          "Block the stream until the shm pipe is connected",
+          DEFAULT_WAIT_FOR_CONNECTION,
+          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
+  signals[SIGNAL_CLIENT_CONNECTED] = g_signal_new ("client-connected",
+      GST_TYPE_SHM_SINK, G_SIGNAL_RUN_LAST, 0, NULL, NULL,
+      g_cclosure_marshal_VOID__INT, G_TYPE_NONE, 1, G_TYPE_INT);
+
+  signals[SIGNAL_CLIENT_DISCONNECTED] = g_signal_new ("client-disconnected",
+      GST_TYPE_SHM_SINK, G_SIGNAL_RUN_LAST, 0, NULL, NULL,
+      g_cclosure_marshal_VOID__INT, G_TYPE_NONE, 1, G_TYPE_INT);
 
   GST_DEBUG_CATEGORY_INIT (shmsink_debug, "shmsink", 0, "Shared Memory Sink");
 }
 
+static void
+gst_shm_sink_finalize (GObject * object)
+{
+  GstShmSink *self = GST_SHM_SINK (object);
+
+  g_cond_free (self->cond);
+}
+
 /*
  * Set the value of a property for the server sink.
  */
@@ -150,19 +195,34 @@ gst_shm_sink_set_property (GObject * object, guint prop_id,
   GstShmSink *self = GST_SHM_SINK (object);
 
   switch (prop_id) {
-    case PROP_SHM_NAME:
+    case PROP_SOCKET_PATH:
       GST_OBJECT_LOCK (object);
-      g_free (self->shm_name);
-      self->shm_name = g_value_dup_string (value);
+      g_free (self->socket_path);
+      self->socket_path = g_value_dup_string (value);
       GST_OBJECT_UNLOCK (object);
       break;
     case PROP_PERMS:
+      GST_OBJECT_LOCK (object);
       self->perms = g_value_get_uint (value);
-      if (self->fd >= 0)
-        if (fchmod (self->fd, g_value_get_uint (value)))
-          GST_WARNING_OBJECT (self,
-              "Could not set permissions %o on shm area: %s",
-              g_value_get_uint (value), strerror (errno));
+      sp_writer_setperms_shm (self->pipe, self->perms);
+      GST_OBJECT_UNLOCK (object);
+      break;
+    case PROP_SHM_SIZE:
+      GST_OBJECT_LOCK (object);
+      if (sp_writer_resize (self->pipe, g_value_get_uint (value)) < 0)
+        GST_DEBUG_OBJECT (self,
+            "Resize shared memory area from %u to %u bytes");
+      else
+        GST_WARNING_OBJECT (self,
+            "Could not resize shared memory area from %u to %u bytes");
+      self->size = g_value_get_uint (value);
+      GST_OBJECT_UNLOCK (object);
+      break;
+    case PROP_WAIT_FOR_CONNECTION:
+      GST_OBJECT_LOCK (object);
+      self->wait_for_connection = g_value_get_boolean (value);
+      GST_OBJECT_UNLOCK (object);
+      g_cond_broadcast (self->cond);
       break;
     default:
       break;
@@ -175,22 +235,29 @@ gst_shm_sink_get_property (GObject * object, guint prop_id,
 {
   GstShmSink *self = GST_SHM_SINK (object);
 
+  GST_OBJECT_LOCK (object);
+
   switch (prop_id) {
-    case PROP_SHM_NAME:
-      GST_OBJECT_LOCK (object);
-      g_value_set_string (value, self->shm_name);
-      GST_OBJECT_UNLOCK (object);
+    case PROP_SOCKET_PATH:
+      g_value_set_string (value, self->socket_path);
       break;
     case PROP_PERMS:
       self->perms = g_value_get_uint (value);
-      if (self->fd >= 0)
-        fchmod (self->fd, g_value_get_uint (value));
+      if (self->pipe)
+        sp_writer_setperms_shm (self->pipe, self->perms);
+      break;
+    case PROP_SHM_SIZE:
+      g_value_set_uint (value, self->size);
+      break;
+    case PROP_WAIT_FOR_CONNECTION:
+      g_value_set_boolean (value, self->wait_for_connection);
       break;
-
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
   }
+
+  GST_OBJECT_UNLOCK (object);
 }
 
 
@@ -199,62 +266,44 @@ static gboolean
 gst_shm_sink_start (GstBaseSink * bsink)
 {
   GstShmSink *self = GST_SHM_SINK (bsink);
-  g_return_val_if_fail (self->fd == -1, FALSE);
 
-  GST_OBJECT_LOCK (self);
-  if (!self->shm_name) {
-    GST_OBJECT_UNLOCK (self);
-    GST_ERROR_OBJECT (self, "Must set the name of the shm area first");
+  self->stop = FALSE;
+
+  if (!self->socket_path) {
     GST_ELEMENT_ERROR (self, RESOURCE, OPEN_READ_WRITE,
-        ("One must specify the name of the shm area"),
-        ("shm-name property not set"));
+        ("Could not open socket."), (NULL));
     return FALSE;
   }
 
-  self->fd = shm_open (self->shm_name, O_RDWR | O_CREAT | O_TRUNC, self->perms);
+  self->pipe = sp_writer_create (self->socket_path, self->size, self->perms);
 
-  if (self->fd < 0) {
-    GST_OBJECT_UNLOCK (self);
-    GST_ERROR_OBJECT (self, "Could not open shm area: %s", strerror (errno));
+  if (!self->pipe) {
     GST_ELEMENT_ERROR (self, RESOURCE, OPEN_READ_WRITE,
-        ("Could not open the shm area"),
-        ("shm_open failed (%d): %s", errno, strerror (errno)));
+        ("Could not open socket."), (NULL));
     return FALSE;
   }
-  self->opened_name = g_strdup (self->shm_name);
 
-  GST_OBJECT_UNLOCK (self);
+  self->poll = gst_poll_new (TRUE);
+  gst_poll_fd_init (&self->serverpollfd);
+  self->serverpollfd.fd = sp_get_fd (self->pipe);
+  gst_poll_add_fd (self->poll, &self->serverpollfd);
+  gst_poll_fd_ctl_read (self->poll, &self->serverpollfd, TRUE);
 
-  self->shm_area_len = sizeof (struct GstShmHeader);
+  self->pollthread = g_thread_create (pollthread_func, self, TRUE, NULL);
 
-  if (ftruncate (self->fd, self->shm_area_len)) {
-    GST_ERROR_OBJECT (self,
-        "Could not make shm area large enough for header: %s",
-        strerror (errno));
-    gst_shm_sink_stop (bsink);
-    GST_ELEMENT_ERROR (self, RESOURCE, OPEN_READ_WRITE,
-        ("Could not resize memory area"),
-        ("ftruncate failed (%d): %s", errno, strerror (errno)));
-    return FALSE;
-  }
+  if (!self->pollthread)
+    goto thread_error;
 
-  self->shm_area = mmap (NULL, self->shm_area_len, PROT_READ | PROT_WRITE,
-      MAP_SHARED, self->fd, 0);
+  return TRUE;
 
-  if (self->shm_area == MAP_FAILED) {
-    GST_ERROR_OBJECT (self, "Could not map shm area");
-    GST_ELEMENT_ERROR (self, RESOURCE, OPEN_READ_WRITE,
-        ("Could not map memory area"),
-        ("mmap failed (%d): %s", errno, strerror (errno)));
-    gst_shm_sink_stop (bsink);
-    return FALSE;
-  }
+thread_error:
 
-  memset (self->shm_area, 0, self->shm_area_len);
-  g_assert (sem_init (&self->shm_area->notification, 1, 0) == 0);
-  g_assert (sem_init (&self->shm_area->mutex, 1, 1) == 0);
+  sp_close (self->pipe);
+  self->pipe = NULL;
+  gst_poll_free (self->poll);
 
-  return TRUE;
+  GST_ELEMENT_ERROR (self, CORE, THREAD, ("Could not srart thread"), (NULL));
+  return FALSE;
 }
 
 
@@ -263,124 +312,226 @@ gst_shm_sink_stop (GstBaseSink * bsink)
 {
   GstShmSink *self = GST_SHM_SINK (bsink);
 
-  if (self->fd >= 0)
-    close (self->fd);
-  self->fd = -1;
+  self->stop = TRUE;
+  gst_poll_set_flushing (self->poll, TRUE);
 
-  if (self->opened_name) {
-    shm_unlink (self->opened_name);
-    g_free (self->opened_name);
-    self->opened_name = NULL;
+  g_thread_join (self->pollthread);
+  self->pollthread = NULL;
+
+  GST_DEBUG_OBJECT (self, "Stopping");
+
+  while (self->clients) {
+    struct GstShmClient *client = self->clients->data;
+    self->clients = g_list_remove (self->clients, client);
+    sp_writer_close_client (self->pipe, client->client);
+    g_signal_emit (self, signals[SIGNAL_CLIENT_DISCONNECTED], 0,
+        client->pollfd.fd);
+    g_slice_free (struct GstShmClient, client);
   }
 
-  if (self->shm_area != MAP_FAILED)
-    munmap (self->shm_area, self->shm_area_len);
-  self->shm_area_len = 0;
-  self->shm_area = MAP_FAILED;
+  gst_poll_free (self->poll);
+  self->poll = NULL;
+
+  sp_close (self->pipe);
+  self->pipe = NULL;
 
   return TRUE;
 }
 
-static gboolean
-gst_shm_sink_set_caps (GstBaseSink * bsink, GstCaps * caps)
+static GstFlowReturn
+gst_shm_sink_render (GstBaseSink * bsink, GstBuffer * buf)
 {
   GstShmSink *self = GST_SHM_SINK (bsink);
+  int rv;
 
-  self->caps_gen++;
+  GST_OBJECT_LOCK (self);
+  while (self->wait_for_connection && !self->clients) {
+    g_cond_wait (self->cond, GST_OBJECT_GET_LOCK (self));
+    if (self->unlock) {
+      GST_OBJECT_UNLOCK (self);
+      return GST_FLOW_WRONG_STATE;
+    }
+  }
 
-  return TRUE;
-}
+  rv = sp_writer_send_buf (self->pipe, (char *) GST_BUFFER_DATA (buf),
+      GST_BUFFER_SIZE (buf));
 
-static gboolean
-resize_area (GstShmSink * self, size_t desired_length)
-{
-  if (desired_length <= self->shm_area_len)
-    return TRUE;
+  if (rv == -1) {
+    ShmBlock *block = NULL;
+    gchar *shmbuf = NULL;
+    while ((block = sp_writer_alloc_block (self->pipe,
+                GST_BUFFER_SIZE (buf))) == NULL) {
+      g_cond_wait (self->cond, GST_OBJECT_GET_LOCK (self));
+      if (self->unlock) {
+        GST_OBJECT_UNLOCK (self);
+        return GST_FLOW_WRONG_STATE;
+      }
+    }
+    while (self->wait_for_connection && !self->clients) {
+      g_cond_wait (self->cond, GST_OBJECT_GET_LOCK (self));
+      if (self->unlock) {
+        sp_writer_free_block (block);
+        GST_OBJECT_UNLOCK (self);
+        return GST_FLOW_WRONG_STATE;
+      }
+    }
 
-  SHM_UNLOCK (self->shm_area);
 
-  if (munmap (self->shm_area, self->shm_area_len)) {
-    GST_ERROR_OBJECT (self, "Could not unmap shared area");
-    GST_ELEMENT_ERROR (self, RESOURCE, OPEN_READ_WRITE,
-        ("Could not unmap memory area"),
-        ("munmap failed (%d): %s", errno, strerror (errno)));
-    return FALSE;
-  }
-  if (ftruncate (self->fd, desired_length)) {
-    GST_ERROR_OBJECT (self, "Could not resize shared area");
-    GST_ELEMENT_ERROR (self, RESOURCE, OPEN_READ_WRITE,
-        ("Could not resize memory area"),
-        ("ftruncate failed (%d): %s", errno, strerror (errno)));
-    return FALSE;
+    shmbuf = sp_writer_block_get_buf (block);
+    memcpy (shmbuf, GST_BUFFER_DATA (buf), GST_BUFFER_SIZE (buf));
+    sp_writer_send_buf (self->pipe, shmbuf, GST_BUFFER_SIZE (buf));
+    sp_writer_free_block (block);
   }
-  self->shm_area = mmap (NULL, desired_length, PROT_READ | PROT_WRITE,
-      MAP_SHARED, self->fd, 0);
-  self->shm_area_len = desired_length;
 
-  if (self->shm_area == MAP_FAILED) {
-    self->shm_area = NULL;
-    GST_ERROR_OBJECT (self, "Could not remap shared area");
-    GST_ELEMENT_ERROR (self, RESOURCE, OPEN_READ_WRITE,
-        ("Could not map memory area"),
-        ("mmap failed (%d): %s", errno, strerror (errno)));
-    return FALSE;
-  }
+  GST_OBJECT_UNLOCK (self);
 
-  SHM_LOCK (self->shm_area);
+  return GST_FLOW_OK;
+}
 
-  return TRUE;
+void
+gst_shm_sink_free_buffer (gpointer data)
+{
+  ShmBlock *block = data;
+  sp_writer_free_block (block);
 }
 
 static GstFlowReturn
-gst_shm_sink_render (GstBaseSink * bsink, GstBuffer * buf)
+gst_shm_sink_buffer_alloc (GstBaseSink * sink, guint64 offset, guint size,
+    GstCaps * caps, GstBuffer ** out_buf)
 {
-  GstShmSink *self = GST_SHM_SINK (bsink);
+  GstShmSink *self = GST_SHM_SINK (sink);
+  GstBuffer *buffer;
+  ShmBlock *block = NULL;
+  gpointer buf = NULL;
 
-  g_return_val_if_fail (self->shm_area != MAP_FAILED, GST_FLOW_ERROR);
+  GST_OBJECT_LOCK (self);
+  block = sp_writer_alloc_block (self->pipe, size);
+  if (block)
+    buf = sp_writer_block_get_buf (block);
+  GST_OBJECT_UNLOCK (self);
 
-  SHM_LOCK (self->shm_area);
+  if (block) {
+    buffer = gst_buffer_new ();
+    GST_BUFFER_DATA (buffer) = buf;
+    GST_BUFFER_MALLOCDATA (buffer) = (guint8 *) block;
+    GST_BUFFER_FREE_FUNC (buffer) =
+        GST_DEBUG_FUNCPTR (gst_shm_sink_free_buffer);
+    GST_BUFFER_SIZE (buffer) = size;
+    GST_LOG_OBJECT (self,
+        "Allocated buffer of %lu bytes from shared memory at %p", size, buf);
+  } else {
+    buffer = gst_buffer_new_and_alloc (size);
+    GST_LOG_OBJECT (self, "Not enough shared memory for buffer of %lu bytes, "
+        "allocating using standard allocator", size);
+  }
 
-  if (self->caps_gen != self->shm_area->caps_gen) {
-    gchar *caps_str =
-        gst_caps_to_string (GST_PAD_CAPS (GST_BASE_SINK_PAD (bsink)));
-    guint caps_size = strlen (caps_str) + 1;
+  GST_BUFFER_OFFSET (buffer) = offset;
+  gst_buffer_set_caps (buffer, caps);
 
-    if (!resize_area (self, sizeof (struct GstShmHeader) +
-            caps_size + GST_BUFFER_SIZE (buf))) {
-      g_free (caps_str);
-      return GST_FLOW_ERROR;
-    }
+  *out_buf = buffer;
 
-    self->shm_area->caps_size = caps_size;
+  return GST_FLOW_OK;
+}
 
-    memcpy (GST_SHM_CAPS_BUFFER (self->shm_area), caps_str, caps_size);
-    g_free (caps_str);
+static gpointer
+pollthread_func (gpointer data)
+{
+  GstShmSink *self = GST_SHM_SINK (data);
+  GList *item;
 
-    self->shm_area->caps_gen = self->caps_gen;
-  } else {
-    if (!resize_area (self, sizeof (struct GstShmHeader) +
-            self->shm_area->caps_size + GST_BUFFER_SIZE (buf)))
-      return GST_FLOW_ERROR;
-  }
+  while (!self->stop) {
 
-  memcpy (GST_SHM_BUFFER (self->shm_area), GST_BUFFER_DATA (buf),
-      GST_BUFFER_SIZE (buf));
+    if (gst_poll_wait (self->poll, GST_CLOCK_TIME_NONE) < 0)
+      return NULL;
 
-  self->shm_area->buffer_size = GST_BUFFER_SIZE (buf);
-  self->shm_area->buffer_gen++;
+    if (self->stop)
+      return NULL;
 
-  self->shm_area->timestamp = GST_BUFFER_TIMESTAMP (buf);
-  self->shm_area->duration = GST_BUFFER_DURATION (buf);
-  self->shm_area->offset = GST_BUFFER_OFFSET (buf);
-  self->shm_area->offset_end = GST_BUFFER_OFFSET_END (buf);
-  self->shm_area->flags = GST_BUFFER_FLAGS (buf) & (GST_BUFFER_FLAG_DISCONT |
-      GST_BUFFER_FLAG_GAP | GST_BUFFER_FLAG_DELTA_UNIT);
+    if (gst_poll_fd_has_closed (self->poll, &self->serverpollfd)) {
+      GST_ELEMENT_ERROR (self, RESOURCE, READ, ("Failed read from shmsink"),
+          ("Control socket has closed"));
+      return NULL;
+    }
 
-  sem_post (&self->shm_area->notification);
+    if (gst_poll_fd_has_error (self->poll, &self->serverpollfd)) {
+      GST_ELEMENT_ERROR (self, RESOURCE, READ, ("Failed to read from shmsink"),
+          ("Control socket has error"));
+      return NULL;
+    }
 
-  SHM_UNLOCK (self->shm_area);
+    if (gst_poll_fd_can_read (self->poll, &self->serverpollfd)) {
+      ShmClient *client;
+      struct GstShmClient *gclient;
+
+      GST_OBJECT_LOCK (self);
+      client = sp_writer_accept_client (self->pipe);
+      GST_OBJECT_UNLOCK (self);
+
+      if (!client) {
+        GST_ELEMENT_ERROR (self, RESOURCE, READ,
+            ("Failed to read from shmsink"),
+            ("Control socket returns wrong data"));
+        return NULL;
+      }
+
+      gclient = g_slice_new (struct GstShmClient);
+      gclient->client = client;
+      gst_poll_fd_init (&gclient->pollfd);
+      gclient->pollfd.fd = sp_writer_get_client_fd (client);
+      gst_poll_add_fd (self->poll, &gclient->pollfd);
+      gst_poll_fd_ctl_read (self->poll, &gclient->pollfd, TRUE);
+      self->clients = g_list_prepend (self->clients, gclient);
+      g_signal_emit (self, signals[SIGNAL_CLIENT_CONNECTED], 0,
+          gclient->pollfd.fd);
+    }
 
-  return GST_FLOW_OK;
+  again:
+    for (item = self->clients; item; item = item->next) {
+      struct GstShmClient *gclient = item->data;
+
+      if (gst_poll_fd_has_closed (self->poll, &gclient->pollfd)) {
+        GST_WARNING_OBJECT (self, "One client is gone, closing");
+        goto close_client;
+      }
+
+      if (gst_poll_fd_has_error (self->poll, &gclient->pollfd)) {
+        GST_WARNING_OBJECT (self, "One client fd has error, closing");
+        goto close_client;
+      }
+
+      if (gst_poll_fd_can_read (self->poll, &gclient->pollfd)) {
+        int rv;
+
+        GST_OBJECT_LOCK (self);
+        rv = sp_writer_recv (self->pipe, gclient->client);
+        GST_OBJECT_UNLOCK (self);
+
+        if (rv < 0) {
+          GST_WARNING_OBJECT (self, "One client has read error,"
+              " closing (retval: %d errno: %d)", rv, errno);
+          goto close_client;
+        }
+      }
+      continue;
+    close_client:
+      GST_OBJECT_LOCK (self);
+      sp_writer_close_client (self->pipe, gclient->client);
+      GST_OBJECT_UNLOCK (self);
+
+      gst_poll_remove_fd (self->poll, &gclient->pollfd);
+      self->clients = g_list_remove (self->clients, gclient);
+
+      g_signal_emit (self, signals[SIGNAL_CLIENT_DISCONNECTED], 0,
+          gclient->pollfd.fd);
+      g_slice_free (struct GstShmClient, gclient);
+
+      goto again;
+    }
+
+    g_cond_broadcast (self->cond);
+  }
+
+  return NULL;
 }
 
 static gboolean
@@ -388,33 +539,42 @@ gst_shm_sink_event (GstBaseSink * bsink, GstEvent * event)
 {
   GstShmSink *self = GST_SHM_SINK (bsink);
 
-  g_return_val_if_fail (self->shm_area != MAP_FAILED, FALSE);
-
-  if (GST_EVENT_TYPE (event) == GST_EVENT_EOS) {
-    SHM_LOCK (self->shm_area);
-    self->shm_area->eos = TRUE;
-    SHM_UNLOCK (self->shm_area);
+  switch (GST_EVENT_TYPE (event)) {
+    case GST_EVENT_EOS:
+      GST_OBJECT_LOCK (self);
+      while (sp_writer_pending_writes (self->pipe) && !self->unlock)
+        g_cond_wait (self->cond, GST_OBJECT_GET_LOCK (self));
+      GST_OBJECT_UNLOCK (self);
+      break;
+    default:
+      break;
   }
 
   return TRUE;
 }
 
-static GstStateChangeReturn
-gst_shm_sink_change_state (GstElement * element, GstStateChange transition)
+
+static gboolean
+gst_shm_sink_unlock (GstBaseSink * bsink)
 {
-  GstShmSink *self = GST_SHM_SINK (element);
-
-  switch (transition) {
-    case GST_STATE_CHANGE_READY_TO_PAUSED:
-      g_return_val_if_fail (self->shm_area != MAP_FAILED,
-          GST_STATE_CHANGE_FAILURE);
-      SHM_LOCK (self->shm_area);
-      self->shm_area->eos = FALSE;
-      SHM_UNLOCK (self->shm_area);
-      break;
-    default:
-      break;
-  }
+  GstShmSink *self = GST_SHM_SINK (bsink);
 
-  return GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
+  GST_OBJECT_LOCK (self);
+  self->unlock = TRUE;
+  GST_OBJECT_UNLOCK (self);
+
+  g_cond_broadcast (self->cond);
+  return TRUE;
+}
+
+static gboolean
+gst_shm_sink_unlock_stop (GstBaseSink * bsink)
+{
+  GstShmSink *self = GST_SHM_SINK (bsink);
+
+  GST_OBJECT_LOCK (self);
+  self->unlock = FALSE;
+  GST_OBJECT_UNLOCK (self);
+
+  return TRUE;
 }
diff --git a/gst/shm/gstshmsink.h b/gst/shm/gstshmsink.h
index 0475e1daa..bc6da74bc 100644
--- a/gst/shm/gstshmsink.h
+++ b/gst/shm/gstshmsink.h
@@ -25,6 +25,8 @@
 #include <gst/gst.h>
 #include <gst/base/gstbasesink.h>
 
+#include "shmpipe.h"
+
 G_BEGIN_DECLS
 #define GST_TYPE_SHM_SINK \
   (gst_shm_sink_get_type())
@@ -43,16 +45,24 @@ struct _GstShmSink
 {
   GstBaseSink element;
 
-  gchar *shm_name;
+  gchar *socket_path;
 
-  int fd;
-  struct GstShmHeader *shm_area;
-  size_t shm_area_len;
-  gchar *opened_name;
+  ShmPipe *pipe;
 
   guint perms;
+  guint size;
+
+  GList *clients;
+
+  GThread *pollthread;
+  GstPoll *poll;
+  GstPollFD serverpollfd;
+
+  gboolean wait_for_connection;
+  gboolean stop;
+  gboolean unlock;
 
-  guint caps_gen;
+  GCond *cond;
 };
 
 struct _GstShmSinkClass