dvbsrc: Add timeout property and use GstPoll instead of poll

This allows to use much higher timeout values because GstPoll
is interruptible and keeps the number of wakeups during signal
loss lower.

Fixes bug #608171.

sys/dvb/gstdvbsrc.c

@@ -87,7 +87,8 @@ enum
   ARG_DVBSRC_HIERARCHY_INF,
   ARG_DVBSRC_TUNE,
   ARG_DVBSRC_INVERSION,
-  ARG_DVBSRC_STATS_REPORTING_INTERVAL
+  ARG_DVBSRC_STATS_REPORTING_INTERVAL,
+  ARG_DVBSRC_TIMEOUT,
 };
 
 #define DEFAULT_ADAPTER 0
@@ -106,6 +107,7 @@ enum
 #define DEFAULT_HIERARCHY HIERARCHY_1
 #define DEFAULT_INVERSION INVERSION_ON
 #define DEFAULT_STATS_REPORTING_INTERVAL 100
+#define DEFAULT_TIMEOUT 1000000 /* 1 second */
 
 #define DEFAULT_BUFFER_SIZE 8192        /* not a property */
 
@@ -444,6 +446,11 @@ gst_dvbsrc_class_init (GstDvbSrcClass * klass)
           "stats-reporting-interval",
           "The number of reads before reporting frontend stats",
           0, G_MAXUINT, DEFAULT_STATS_REPORTING_INTERVAL, G_PARAM_READWRITE));
+
+  g_object_class_install_property (gobject_class, ARG_DVBSRC_TIMEOUT,
+      g_param_spec_uint64 ("timeout", "Timeout",
+          "Post a message after timeout microseconds (0 = disabled)", 0,
+          G_MAXUINT64, DEFAULT_TIMEOUT, G_PARAM_READWRITE));
 }
 
 /* initialize the new element
@@ -488,6 +495,7 @@ gst_dvbsrc_init (GstDvbSrc * object, GstDvbSrcClass * klass)
   object->stats_interval = DEFAULT_STATS_REPORTING_INTERVAL;
 
   object->tune_mutex = g_mutex_new ();
+  object->timeout = DEFAULT_TIMEOUT;
 }
 
 
@@ -625,10 +633,12 @@ gst_dvbsrc_set_property (GObject * _object, guint prop_id,
       object->stats_interval = g_value_get_uint (value);
       object->stats_counter = 0;
       break;
+    case ARG_DVBSRC_TIMEOUT:
+      object->timeout = g_value_get_uint64 (value);
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
   }
-
 }
 
 static void
@@ -689,6 +699,9 @@ gst_dvbsrc_get_property (GObject * _object, guint prop_id,
     case ARG_DVBSRC_STATS_REPORTING_INTERVAL:
       g_value_set_uint (value, object->stats_interval);
       break;
+    case ARG_DVBSRC_TIMEOUT:
+      g_value_set_uint64 (value, object->timeout);
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
   }
@@ -888,80 +901,62 @@ gst_dvbsrc_plugin_init (GstPlugin * plugin)
 }
 
 static GstBuffer *
-read_device (int fd, int adapter_number, int frontend_number, int size,
+gst_dvbsrc_read_device (GstDvbSrc * object, int size)
-    GstDvbSrc * object)
 {
-  int count = 0;
+  gint count = 0;
-  struct pollfd pfd[1];
+  gint ret_val = 0;
-  int ret_val = 0;
-  guint attempts = 0;
-  const int TIMEOUT = 100;
-
   GstBuffer *buf = gst_buffer_new_and_alloc (size);
+  GstClockTime timeout = object->timeout * GST_USECOND;
 
   g_return_val_if_fail (GST_IS_BUFFER (buf), NULL);
 
-  if (fd < 0) {
+  if (object->fd_dvr < 0)
     return NULL;
-  }
 
-  pfd[0].fd = fd;
+  while (count < size) {
-  pfd[0].events = POLLIN;
+    ret_val = gst_poll_wait (object->poll, timeout);
+    GST_LOG_OBJECT (object, "select returned %d", ret_val);
+    if (G_UNLIKELY (ret_val < 0)) {
+      if (errno == EBUSY)
+        goto stopped;
+      else
+        goto select_error;
+    } else if (G_UNLIKELY (ret_val == 0)) {
+      /* timeout, post element message */
+      gst_element_post_message (GST_ELEMENT_CAST (object),
+          gst_message_new_element (GST_OBJECT (object),
+              gst_structure_empty_new ("dvb-read-failure")));
+    } else {
+      int nread =
+          read (object->fd_dvr, GST_BUFFER_DATA (buf) + count, size - count);
 
-  while (count < size && !object->need_unlock) {
+      if (G_UNLIKELY (nread < 0)) {
-    ret_val = poll (pfd, 1, TIMEOUT);
+        GST_WARNING_OBJECT
-    if (ret_val > 0) {
+            (object,
-      if (pfd[0].revents & POLLIN) {
+            "Unable to read from device: /dev/dvb/adapter%d/dvr%d (%d)",
-        int tmp = 0;
+            object->adapter_number, object->frontend_number, errno);
-
-        tmp = read (fd, GST_BUFFER_DATA (buf) + count, size - count);
-        if (tmp < 0) {
-          GST_WARNING
-              ("Unable to read from device: /dev/dvb/adapter%d/dvr%d (%d)",
-              adapter_number, frontend_number, errno);
-          attempts += 1;
-          if (attempts % 10 == 0) {
-            GST_WARNING
-                ("Unable to read from device after %u attempts: /dev/dvb/adapter%d/dvr%d",
-                attempts, adapter_number, frontend_number);
-          }
-
-        } else
-          count = count + tmp;
-      } else {
-        GST_LOG ("revents = %d\n", pfd[0].revents);
-      }
-    } else if (ret_val == 0) {  // poll timeout
-      attempts += 1;
-      GST_INFO ("Reading from device /dev/dvb/adapter%d/dvr%d timedout (%d)",
-          adapter_number, frontend_number, attempts);
-
-      if (attempts % 10 == 0) {
-        GST_WARNING
-            ("Unable to read after %u attempts from device: /dev/dvb/adapter%d/dvr%d (%d)",
-            attempts, adapter_number, frontend_number, errno);
         gst_element_post_message (GST_ELEMENT_CAST (object),
             gst_message_new_element (GST_OBJECT (object),
                 gst_structure_empty_new ("dvb-read-failure")));
-
+      } else
-      }
+        count = count + nread;
-    } else if (errno == -EINTR) {       // poll interrupted
-      if (attempts % 50 == 0) {
-        gst_buffer_unref (buf);
-        return NULL;
-      };
     }
-
-  }
-
-  if (!count) {
-    gst_buffer_unref (buf);
-    return NULL;
   }
 
   GST_BUFFER_SIZE (buf) = count;
   GST_BUFFER_TIMESTAMP (buf) = GST_CLOCK_TIME_NONE;
   return buf;
+
+stopped:
+  GST_DEBUG_OBJECT (object, "stop called");
+  gst_buffer_unref (buf);
+  return NULL;
+
+select_error:
+  GST_ELEMENT_ERROR (object, RESOURCE, READ, (NULL),
+      ("select error %d: %s (%d)", ret_val, g_strerror (errno), errno));
+  gst_buffer_unref (buf);
+  return NULL;
 }
 
 static GstFlowReturn
@@ -984,8 +979,7 @@ gst_dvbsrc_create (GstPushSrc * element, GstBuffer ** buf)
   if (object->fd_dvr > -1) {
     /* --- Read TS from DVR device --- */
     GST_DEBUG_OBJECT (object, "Reading from DVR device");
-    *buf = read_device (object->fd_dvr, object->adapter_number,
+    *buf = gst_dvbsrc_read_device (object, buffer_size);
-        object->frontend_number, buffer_size, object);
     if (*buf != NULL) {
       GstCaps *caps;
 
@@ -994,11 +988,6 @@ gst_dvbsrc_create (GstPushSrc * element, GstBuffer ** buf)
       caps = gst_pad_get_caps (GST_BASE_SRC_PAD (object));
       gst_buffer_set_caps (*buf, caps);
       gst_caps_unref (caps);
-    } else {
-      GST_DEBUG_OBJECT (object, "Failed to read from device");
-      gst_element_post_message (GST_ELEMENT_CAST (object),
-          gst_message_new_element (GST_OBJECT (object),
-              gst_structure_empty_new ("dvb-read-failure")));
     }
 
     if (object->stats_interval != 0 &&
@@ -1062,7 +1051,19 @@ gst_dvbsrc_start (GstBaseSrc * bsrc)
     close (src->fd_frontend);
     return FALSE;
   }
-  src->need_unlock = FALSE;
+  if (!(src->poll = gst_poll_new (TRUE))) {
+    GST_ELEMENT_ERROR (src, RESOURCE, OPEN_READ_WRITE, (NULL),
+        ("could not create an fdset: %s (%d)", g_strerror (errno), errno));
+    /* unset filters also */
+    gst_dvbsrc_unset_pes_filters (src);
+    close (src->fd_frontend);
+    return FALSE;
+  } else {
+    gst_poll_fd_init (&src->poll_fd_dvr);
+    src->poll_fd_dvr.fd = src->fd_dvr;
+    gst_poll_add_fd (src->poll, &src->poll_fd_dvr);
+    gst_poll_fd_ctl_read (src->poll, &src->poll_fd_dvr, TRUE);
+  }
 
   return TRUE;
 }
@@ -1073,6 +1074,11 @@ gst_dvbsrc_stop (GstBaseSrc * bsrc)
   GstDvbSrc *src = GST_DVBSRC (bsrc);
 
   gst_dvbsrc_close_devices (src);
+  if (src->poll) {
+    gst_poll_free (src->poll);
+    src->poll = NULL;
+  }
+
   return TRUE;
 }
 
@@ -1081,7 +1087,7 @@ gst_dvbsrc_unlock (GstBaseSrc * bsrc)
 {
   GstDvbSrc *src = GST_DVBSRC (bsrc);
 
-  src->need_unlock = TRUE;
+  gst_poll_set_flushing (src->poll, TRUE);
   return TRUE;
 }
 
@@ -1090,7 +1096,7 @@ gst_dvbsrc_unlock_stop (GstBaseSrc * bsrc)
 {
   GstDvbSrc *src = GST_DVBSRC (bsrc);
 
-  src->need_unlock = FALSE;
+  gst_poll_set_flushing (src->poll, FALSE);
   return TRUE;
 }
 

sys/dvb/gstdvbsrc.h

@@ -52,6 +52,8 @@ G_BEGIN_DECLS
     int fd_frontend;
     int fd_dvr;
     int fd_filters[MAX_FILTERS];
+    GstPoll *poll;
+    GstPollFD poll_fd_dvr;
 
     guint16 pids[MAX_FILTERS];
     unsigned int freq;
@@ -68,11 +70,11 @@ G_BEGIN_DECLS
     int transmission_mode;
     int hierarchy_information;
     int inversion;
+    guint64 timeout;
 
     GstDvbSrcPol pol;
     guint stats_interval;
     guint stats_counter;
-    gboolean need_unlock;
   };
 
   struct _GstDvbSrcClass