Provide and use convenience functions to remove some copy-pasted code

18 files changed, 107 insertions, 211 deletions

diff --git a/backends/alsa/alsa-backend.c b/backends/alsa/alsa-backend.c
index 3d62380..fb045ec 100644
--- a/backends/alsa/alsa-backend.c
+++ b/backends/alsa/alsa-backend.c
@@ -219,12 +219,8 @@ alsa_backend_close (MateMixerBackend *backend)
 
     g_source_destroy (alsa->priv->timeout_source);
 
-    if (alsa->priv->devices != NULL) {
-        g_list_free_full (alsa->priv->devices, g_object_unref);
-        alsa->priv->devices = NULL;
-    }
-
-    free_stream_list (alsa);
+    _mate_mixer_clear_object_list (&alsa->priv->devices);
+    _mate_mixer_clear_object_list (&alsa->priv->streams);
 
     g_clear_object (&alsa->priv->default_device);
     g_hash_table_remove_all (alsa->priv->devices_ids);
@@ -605,12 +601,7 @@ set_default_device (AlsaBackend *alsa, AlsaDevice *device)
 static void
 free_stream_list (AlsaBackend *alsa)
 {
-    if (alsa->priv->streams == NULL)
-        return;
-
-    g_list_free_full (alsa->priv->streams, g_object_unref);
-
-    alsa->priv->streams = NULL;
+    _mate_mixer_clear_object_list (&alsa->priv->streams);
 }
 
 static gint
diff --git a/backends/alsa/alsa-device.c b/backends/alsa/alsa-device.c
index 2064f79..c18d143 100644
--- a/backends/alsa/alsa-device.c
+++ b/backends/alsa/alsa-device.c
@@ -22,7 +22,9 @@
 #include <glib/gi18n.h>
 #include <glib-object.h>
 #include <alsa/asoundlib.h>
+
 #include <libmatemixer/matemixer.h>
+#include <libmatemixer/matemixer-private.h>
 
 #include "alsa-compat.h"
 #include "alsa-constants.h"
@@ -155,8 +157,6 @@ static void               get_switch_info           (snd_mixer_elem_t
 
 static void               close_mixer               (AlsaDevice                 *device);
 
-static void               free_stream_list          (AlsaDevice                 *device);
-
 static void
 alsa_device_class_init (AlsaDeviceClass *klass)
 {
@@ -208,7 +208,7 @@ alsa_device_dispose (GObject *object)
     g_clear_object (&device->priv->input);
     g_clear_object (&device->priv->output);
 
-    free_stream_list (device);
+    _mate_mixer_clear_object_list (&device->priv->streams);
 
     G_OBJECT_CLASS (alsa_device_parent_class)->dispose (object);
 }
@@ -339,7 +339,7 @@ alsa_device_close (AlsaDevice *device)
     /* Make each stream remove its controls and switches */
     if (alsa_stream_has_controls_or_switches (device->priv->input) == TRUE) {
         alsa_stream_remove_all (device->priv->input);
-        free_stream_list (device);
+        _mate_mixer_clear_object_list (&device->priv->streams);
 
         g_signal_emit_by_name (G_OBJECT (device),
                                "stream-removed",
@@ -348,7 +348,7 @@ alsa_device_close (AlsaDevice *device)
 
     if (alsa_stream_has_controls_or_switches (device->priv->output) == TRUE) {
         alsa_stream_remove_all (device->priv->output);
-        free_stream_list (device);
+        _mate_mixer_clear_object_list (&device->priv->streams);
 
         g_signal_emit_by_name (G_OBJECT (device),
                                "stream-removed",
@@ -475,7 +475,7 @@ add_element (AlsaDevice *device, AlsaStream *stream, AlsaElement *element)
     }
 
     if (add_stream == TRUE) {
-        free_stream_list (device);
+        _mate_mixer_clear_object_list (&device->priv->streams);
 
         /* Pretend the stream has just been created now that we have added
          * the first control */
@@ -755,7 +755,7 @@ remove_elements_by_name (AlsaDevice *device, const gchar *name)
     if (alsa_stream_remove_elements (device->priv->input, name) == TRUE) {
         /* Removing last stream element "removes" the stream */
         if (alsa_stream_has_controls_or_switches (device->priv->input) == FALSE) {
-            free_stream_list (device);
+            _mate_mixer_clear_object_list (&device->priv->streams);
             g_signal_emit_by_name (G_OBJECT (device),
                                    "stream-removed",
                                    MATE_MIXER_STREAM (device->priv->input));
@@ -765,7 +765,7 @@ remove_elements_by_name (AlsaDevice *device, const gchar *name)
     if (alsa_stream_remove_elements (device->priv->output, name) == TRUE) {
         /* Removing last stream element "removes" the stream */
         if (alsa_stream_has_controls_or_switches (device->priv->output) == FALSE) {
-            free_stream_list (device);
+            _mate_mixer_clear_object_list (&device->priv->streams);
             g_signal_emit_by_name (G_OBJECT (device),
                                    "stream-removed",
                                    MATE_MIXER_STREAM (device->priv->output));
@@ -1122,15 +1122,3 @@ close_mixer (AlsaDevice *device)
      device->priv->handle = NULL;
      snd_mixer_close (handle);
 }
-
-static void
-free_stream_list (AlsaDevice *device)
-{
-    /* This function is called each time the stream list changes */
-    if (device->priv->streams == NULL)
-        return;
-
-    g_list_free_full (device->priv->streams, g_object_unref);
-
-    device->priv->streams = NULL;
-}
diff --git a/backends/alsa/alsa-stream.c b/backends/alsa/alsa-stream.c
index 7e9c89f..9c642fb 100644
--- a/backends/alsa/alsa-stream.c
+++ b/backends/alsa/alsa-stream.c
@@ -17,6 +17,7 @@
 
 #include <glib.h>
 #include <glib-object.h>
+
 #include <libmatemixer/matemixer.h>
 #include <libmatemixer/matemixer-private.h>
 
@@ -78,14 +79,8 @@ alsa_stream_dispose (GObject *object)
 
     stream = ALSA_STREAM (object);
 
-    if (stream->priv->controls != NULL) {
-        g_list_free_full (stream->priv->controls, g_object_unref);
-        stream->priv->controls = NULL;
-    }
-    if (stream->priv->switches != NULL) {
-        g_list_free_full (stream->priv->switches, g_object_unref);
-        stream->priv->switches = NULL;
-    }
+    _mate_mixer_clear_object_list (&stream->priv->controls);
+    _mate_mixer_clear_object_list (&stream->priv->switches);
 
     G_OBJECT_CLASS (alsa_stream_parent_class)->dispose (object);
 }
diff --git a/backends/alsa/alsa-switch.c b/backends/alsa/alsa-switch.c
index c2a95ca..7ea9e71 100644
--- a/backends/alsa/alsa-switch.c
+++ b/backends/alsa/alsa-switch.c
@@ -86,10 +86,7 @@ alsa_switch_dispose (GObject *object)
 
     swtch = ALSA_SWITCH (object);
 
-    if (swtch->priv->options != NULL) {
-        g_list_free_full (swtch->priv->options, g_object_unref);
-        swtch->priv->options = NULL;
-    }
+    _mate_mixer_clear_object_list (&swtch->priv->options);
 
     G_OBJECT_CLASS (alsa_switch_parent_class)->dispose (object);
 }
diff --git a/backends/oss/oss-backend.c b/backends/oss/oss-backend.c
index 5795e7c..bf5af37 100644
--- a/backends/oss/oss-backend.c
+++ b/backends/oss/oss-backend.c
@@ -267,12 +267,8 @@ oss_backend_close (MateMixerBackend *backend)
     if (oss->priv->timeout_source_default != NULL)
         g_source_destroy (oss->priv->timeout_source_default);
 
-    if (oss->priv->devices != NULL) {
-        g_list_free_full (oss->priv->devices, g_object_unref);
-        oss->priv->devices = NULL;
-    }
-
-    free_stream_list (oss);
+    _mate_mixer_clear_object_list (&oss->priv->devices);
+    _mate_mixer_clear_object_list (&oss->priv->streams);
 
     g_clear_object (&oss->priv->default_device);
     g_hash_table_remove_all (oss->priv->devices_paths);
@@ -388,7 +384,7 @@ read_device (OssBackend *oss, const gchar *path)
      * device's polling facility should handle this by itself.
      */
     if (g_hash_table_contains (oss->priv->devices_paths, path) == TRUE) {
-        close (fd);
+        g_close (fd, NULL);
         return TRUE;
     }
 
@@ -398,8 +394,7 @@ read_device (OssBackend *oss, const gchar *path)
     device = oss_device_new (bname, label, path, fd);
     g_free (bname);
     g_free (label);
-
-    close (fd);
+    g_close (fd, NULL);
 
     if G_LIKELY (device != NULL) {
         if (oss_device_open (device) == TRUE) {
@@ -717,12 +712,7 @@ set_default_device_index (OssBackend *oss, guint index, gboolean fallback)
 static void
 free_stream_list (OssBackend *oss)
 {
-    if (oss->priv->streams == NULL)
-        return;
-
-    g_list_free_full (oss->priv->streams, g_object_unref);
-
-    oss->priv->streams = NULL;
+    _mate_mixer_clear_object_list (&oss->priv->streams);
 }
 
 static gint
diff --git a/backends/oss/oss-device.c b/backends/oss/oss-device.c
index 582c837..d11555d 100644
--- a/backends/oss/oss-device.c
+++ b/backends/oss/oss-device.c
@@ -368,8 +368,7 @@ oss_device_close (OssDevice *device)
     if (device->priv->poll_tag_restore != 0)
         g_source_remove (device->priv->poll_tag_restore);
 
-    close (device->priv->fd);
-    device->priv->fd = -1;
+    _mate_mixer_clear_fd (&device->priv->fd);
 
     g_signal_emit (G_OBJECT (device), signals[CLOSED], 0);
 }
diff --git a/backends/oss/oss-stream-control.c b/backends/oss/oss-stream-control.c
index bcb73fe..f826f62 100644
--- a/backends/oss/oss-stream-control.c
+++ b/backends/oss/oss-stream-control.c
@@ -206,11 +206,7 @@ oss_stream_control_close (OssStreamControl *control)
 {
     g_return_if_fail (OSS_IS_STREAM_CONTROL (control));
 
-    if (control->priv->fd == -1)
-        return;
-
-    close (control->priv->fd);
-    control->priv->fd = -1;
+    _mate_mixer_clear_fd (&control->priv->fd);
 }
 
 static guint
diff --git a/backends/oss/oss-stream.c b/backends/oss/oss-stream.c
index 7727dad..63c8481 100644
--- a/backends/oss/oss-stream.c
+++ b/backends/oss/oss-stream.c
@@ -18,6 +18,7 @@
 #include <glib.h>
 #include <glib/gi18n.h>
 #include <glib-object.h>
+
 #include <libmatemixer/matemixer.h>
 #include <libmatemixer/matemixer-private.h>
 
@@ -75,14 +76,8 @@ oss_stream_dispose (GObject *object)
 
     stream = OSS_STREAM (object);
 
-    if (stream->priv->controls != NULL) {
-        g_list_free_full (stream->priv->controls, g_object_unref);
-        stream->priv->controls = NULL;
-    }
-    if (stream->priv->switches != NULL) {
-        g_list_free_full (stream->priv->switches, g_object_unref);
-        stream->priv->switches = NULL;
-    }
+    _mate_mixer_clear_object_list (&stream->priv->controls);
+    _mate_mixer_clear_object_list (&stream->priv->switches);
 
     g_clear_object (&stream->priv->swtch);
 
@@ -250,9 +245,7 @@ oss_stream_remove_all (OssStream *stream)
 
     if (stream->priv->swtch != NULL) {
         oss_switch_close (stream->priv->swtch);
-
-        g_list_free_full (stream->priv->switches, g_object_unref);
-        stream->priv->switches = NULL;
+        _mate_mixer_clear_object_list (&stream->priv->switches);
 
         g_signal_emit_by_name (G_OBJECT (stream),
                                "switch-removed",
diff --git a/backends/oss/oss-switch.c b/backends/oss/oss-switch.c
index 87ffb90..5ce3012 100644
--- a/backends/oss/oss-switch.c
+++ b/backends/oss/oss-switch.c
@@ -78,10 +78,7 @@ oss_switch_dispose (GObject *object)
 
     swtch = OSS_SWITCH (object);
 
-    if (swtch->priv->options != NULL) {
-        g_list_free_full (swtch->priv->options, g_object_unref);
-        swtch->priv->options = NULL;
-    }
+    _mate_mixer_clear_object_list (&swtch->priv->options);
 
     G_OBJECT_CLASS (oss_switch_parent_class)->dispose (object);
 }
@@ -206,11 +203,7 @@ oss_switch_close (OssSwitch *swtch)
 {
     g_return_if_fail (OSS_IS_SWITCH (swtch));
 
-    if (swtch->priv->fd == -1)
-        return;
-
-    close (swtch->priv->fd);
-    swtch->priv->fd = -1;
+    _mate_mixer_clear_fd (&swtch->priv->fd);
 }
 
 static gboolean
diff --git a/backends/pulse/pulse-backend.c b/backends/pulse/pulse-backend.c
index 88926be..71f6fa0 100644
--- a/backends/pulse/pulse-backend.c
+++ b/backends/pulse/pulse-backend.c
@@ -205,10 +205,6 @@ static void             remove_source_output                (PulseBackend
                                                              PulseSource                      *source,
                                                              guint                             index);
 
-static void             free_list_devices                   (PulseBackend                     *pulse);
-static void             free_list_streams                   (PulseBackend                     *pulse);
-static void             free_list_ext_streams               (PulseBackend                     *pulse);
-
 static gboolean         compare_stream_names                (gpointer                          key,
                                                              gpointer                          value,
                                                              gpointer                          user_data);
@@ -469,9 +465,9 @@ pulse_backend_close (MateMixerBackend *backend)
         g_clear_object (&pulse->priv->connection);
     }
 
-    free_list_devices (pulse);
-    free_list_streams (pulse);
-    free_list_ext_streams (pulse);
+    _mate_mixer_clear_object_list (&pulse->priv->devices_list);
+    _mate_mixer_clear_object_list (&pulse->priv->streams_list);
+    _mate_mixer_clear_object_list (&pulse->priv->ext_streams_list);
 
     g_hash_table_remove_all (pulse->priv->devices);
     g_hash_table_remove_all (pulse->priv->sinks);
@@ -776,7 +772,7 @@ on_connection_card_info (PulseConnection    *connection,
                              GUINT_TO_POINTER (info->index),
                              device);
 
-        free_list_devices (pulse);
+        _mate_mixer_clear_object_list (&pulse->priv->devices_list);
         g_signal_emit_by_name (G_OBJECT (pulse),
                                "device-added",
                                MATE_MIXER_DEVICE (device));
@@ -798,7 +794,7 @@ on_connection_card_removed (PulseConnection *connection,
     g_object_ref (device);
     g_hash_table_remove (pulse->priv->devices, GUINT_TO_POINTER (index));
 
-    free_list_devices (pulse);
+    _mate_mixer_clear_object_list (&pulse->priv->devices_list);
     g_signal_emit_by_name (G_OBJECT (pulse),
                            "device-removed",
                            MATE_MIXER_DEVICE (device));
@@ -826,7 +822,7 @@ on_connection_sink_info (PulseConnection    *connection,
                              GUINT_TO_POINTER (info->index),
                              stream);
 
-        free_list_streams (pulse);
+        _mate_mixer_clear_object_list (&pulse->priv->streams_list);
 
         if (device != NULL) {
             pulse_device_add_stream (device, stream);
@@ -859,7 +855,7 @@ on_connection_sink_removed (PulseConnection *connection,
     g_object_ref (stream);
     g_hash_table_remove (pulse->priv->sinks, GUINT_TO_POINTER (idx));
 
-    free_list_streams (pulse);
+    _mate_mixer_clear_object_list (&pulse->priv->streams_list);
 
     device = pulse_stream_get_device (stream);
     if (device != NULL) {
@@ -963,7 +959,7 @@ on_connection_source_info (PulseConnection      *connection,
                              GUINT_TO_POINTER (info->index),
                              stream);
 
-        free_list_streams (pulse);
+        _mate_mixer_clear_object_list (&pulse->priv->streams_list);
 
         if (device != NULL) {
             pulse_device_add_stream (device, stream);
@@ -994,9 +990,9 @@ on_connection_source_removed (PulseConnection *connection,
         return;
 
     g_object_ref (stream);
-
     g_hash_table_remove (pulse->priv->sources, GUINT_TO_POINTER (idx));
-    free_list_streams (pulse);
+
+    _mate_mixer_clear_object_list (&pulse->priv->streams_list);
 
     device = pulse_stream_get_device (stream);
     if (device != NULL) {
@@ -1105,7 +1101,7 @@ on_connection_ext_stream_info (PulseConnection                  *connection,
                              g_strdup (info->name),
                              ext);
 
-        free_list_ext_streams (pulse);
+        _mate_mixer_clear_object_list (&pulse->priv->ext_streams_list);
 
         g_signal_emit_by_name (G_OBJECT (pulse),
                                "stored-control-added",
@@ -1146,7 +1142,7 @@ on_connection_ext_stream_loaded (PulseConnection *connection, PulseBackend *puls
         g_object_ref (G_OBJECT (ext));
         g_hash_table_iter_remove (&iter);
 
-        free_list_ext_streams (pulse);
+        _mate_mixer_clear_object_list (&pulse->priv->ext_streams_list);
         g_signal_emit_by_name (G_OBJECT (pulse),
                                "stored-control-removed",
                                MATE_MIXER_STORED_CONTROL (ext));
@@ -1228,39 +1224,6 @@ remove_source_output (PulseBackend *pulse, PulseSource *source, guint index)
     g_hash_table_remove (pulse->priv->source_output_map, GUINT_TO_POINTER (index));
 }
 
-static void
-free_list_devices (PulseBackend *pulse)
-{
-    if (pulse->priv->devices_list == NULL)
-        return;
-
-    g_list_free_full (pulse->priv->devices_list, g_object_unref);
-
-    pulse->priv->devices_list = NULL;
-}
-
-static void
-free_list_streams (PulseBackend *pulse)
-{
-    if (pulse->priv->streams_list == NULL)
-        return;
-
-    g_list_free_full (pulse->priv->streams_list, g_object_unref);
-
-    pulse->priv->streams_list = NULL;
-}
-
-static void
-free_list_ext_streams (PulseBackend *pulse)
-{
-    if (pulse->priv->ext_streams_list == NULL)
-        return;
-
-    g_list_free_full (pulse->priv->ext_streams_list, g_object_unref);
-
-    pulse->priv->ext_streams_list = NULL;
-}
-
 static gboolean
 compare_stream_names (gpointer key, gpointer value, gpointer user_data)
 {
diff --git a/backends/pulse/pulse-device-switch.c b/backends/pulse/pulse-device-switch.c
index 4bd32ce..e8ba092 100644
--- a/backends/pulse/pulse-device-switch.c
+++ b/backends/pulse/pulse-device-switch.c
@@ -79,10 +79,8 @@ pulse_device_switch_dispose (GObject *object)
 
     swtch = PULSE_DEVICE_SWITCH (object);
 
-    if (swtch->priv->profiles != NULL) {
-        g_list_free_full (swtch->priv->profiles, g_object_unref);
-        swtch->priv->profiles = NULL;
-    }
+    _mate_mixer_clear_object_list (&swtch->priv->profiles);
+
     G_OBJECT_CLASS (pulse_device_switch_parent_class)->dispose (object);
 }
 
diff --git a/backends/pulse/pulse-device.c b/backends/pulse/pulse-device.c
index c65f304..8735071 100644
--- a/backends/pulse/pulse-device.c
+++ b/backends/pulse/pulse-device.c
@@ -78,8 +78,6 @@ static const GList *    pulse_device_list_switches (MateMixerDevice    *mmd);
 static void             pulse_device_load          (PulseDevice        *device,
                                                     const pa_card_info *info);
 
-static void             free_list_streams          (PulseDevice        *device);
-
 static void
 pulse_device_class_init (PulseDeviceClass *klass)
 {
@@ -198,13 +196,10 @@ pulse_device_dispose (GObject *object)
 
     g_clear_object (&device->priv->connection);
     g_clear_object (&device->priv->pswitch);
+    g_clear_pointer (&device->priv->pswitch_list, g_list_free);
 
-    free_list_streams (device);
+    _mate_mixer_clear_object_list (&device->priv->streams_list);
 
-    if (device->priv->pswitch_list != NULL) {
-        g_list_free (device->priv->pswitch_list);
-        device->priv->pswitch_list = NULL;
-    }
     G_OBJECT_CLASS (pulse_device_parent_class)->dispose (object);
 }
 
@@ -284,7 +279,7 @@ pulse_device_add_stream (PulseDevice *device, PulseStream *stream)
                          g_strdup (name),
                          g_object_ref (stream));
 
-    free_list_streams (device);
+    _mate_mixer_clear_object_list (&device->priv->streams_list);
 
     g_signal_emit_by_name (G_OBJECT (device),
                            "stream-added",
@@ -304,7 +299,7 @@ pulse_device_remove_stream (PulseDevice *device, PulseStream *stream)
     g_object_ref (stream);
     g_hash_table_remove (device->priv->streams, name);
 
-    free_list_streams (device);
+    _mate_mixer_clear_object_list (&device->priv->streams_list);
     g_signal_emit_by_name (G_OBJECT (device),
                            "stream-removed",
                            MATE_MIXER_STREAM (stream));
@@ -428,14 +423,3 @@ pulse_device_load (PulseDevice *device, const pa_card_info *info)
         g_object_unref (profile);
     }
 }
-
-static void
-free_list_streams (PulseDevice *device)
-{
-    if (device->priv->streams_list == NULL)
-        return;
-
-    g_list_free_full (device->priv->streams_list, g_object_unref);
-
-    device->priv->streams_list = NULL;
-}
diff --git a/backends/pulse/pulse-port-switch.c b/backends/pulse/pulse-port-switch.c
index 1f4ce67..c024d03 100644
--- a/backends/pulse/pulse-port-switch.c
+++ b/backends/pulse/pulse-port-switch.c
@@ -79,10 +79,8 @@ pulse_port_switch_dispose (GObject *object)
 
     swtch = PULSE_PORT_SWITCH (object);
 
-    if (swtch->priv->ports != NULL) {
-        g_list_free_full (swtch->priv->ports, g_object_unref);
-        swtch->priv->ports = NULL;
-    }
+    _mate_mixer_clear_object_list (&swtch->priv->ports);
+
     G_OBJECT_CLASS (pulse_port_switch_parent_class)->dispose (object);
 }
 
diff --git a/backends/pulse/pulse-sink.c b/backends/pulse/pulse-sink.c
index 9edf185..c698d02 100644
--- a/backends/pulse/pulse-sink.c
+++ b/backends/pulse/pulse-sink.c
@@ -54,8 +54,6 @@ G_DEFINE_TYPE (PulseSink, pulse_sink, PULSE_TYPE_STREAM);
 static const GList *pulse_sink_list_controls (MateMixerStream *mms);
 static const GList *pulse_sink_list_switches (MateMixerStream *mms);
 
-static void         free_list_controls       (PulseSink       *sink);
-
 static void
 pulse_sink_class_init (PulseSinkClass *klass)
 {
@@ -99,13 +97,10 @@ pulse_sink_dispose (GObject *object)
 
     g_clear_object (&sink->priv->control);
     g_clear_object (&sink->priv->pswitch);
+    g_clear_pointer (&sink->priv->pswitch_list, g_list_free);
 
-    free_list_controls (sink);
+    _mate_mixer_clear_object_list (&sink->priv->inputs_list);
 
-    if (sink->priv->pswitch_list != NULL) {
-        g_list_free (sink->priv->pswitch_list);
-        sink->priv->pswitch_list = NULL;
-    }
     G_OBJECT_CLASS (pulse_sink_parent_class)->dispose (object);
 }
 
@@ -207,7 +202,7 @@ pulse_sink_add_input (PulseSink *sink, const pa_sink_input_info *info)
                              GUINT_TO_POINTER (info->index),
                              input);
 
-        free_list_controls (sink);
+        _mate_mixer_clear_object_list (&sink->priv->inputs_list);
 
         g_signal_emit_by_name (G_OBJECT (sink),
                                "control-added",
@@ -233,7 +228,7 @@ pulse_sink_remove_input (PulseSink *sink, guint32 index)
     g_object_ref (input);
     g_hash_table_remove (sink->priv->inputs, GUINT_TO_POINTER (index));
 
-    free_list_controls (sink);
+    _mate_mixer_clear_object_list (&sink->priv->inputs_list);
     g_signal_emit_by_name (G_OBJECT (sink),
                            "control-removed",
                            MATE_MIXER_STREAM_CONTROL (input));
@@ -292,14 +287,3 @@ pulse_sink_list_switches (MateMixerStream *mms)
 
     return PULSE_SINK (mms)->priv->pswitch_list;
 }
-
-static void
-free_list_controls (PulseSink *sink)
-{
-    if (sink->priv->inputs_list == NULL)
-        return;
-
-    g_list_free_full (sink->priv->inputs_list, g_object_unref);
-
-    sink->priv->inputs_list = NULL;
-}
diff --git a/backends/pulse/pulse-source.c b/backends/pulse/pulse-source.c
index 6393743..1c4e01a 100644
--- a/backends/pulse/pulse-source.c
+++ b/backends/pulse/pulse-source.c
@@ -53,8 +53,6 @@ G_DEFINE_TYPE (PulseSource, pulse_source, PULSE_TYPE_STREAM);
 static const GList *pulse_source_list_controls (MateMixerStream *mms);
 static const GList *pulse_source_list_switches (MateMixerStream *mms);
 
-static void         free_list_controls         (PulseSource     *source);
-
 static void
 pulse_source_class_init (PulseSourceClass *klass)
 {
@@ -96,13 +94,10 @@ pulse_source_dispose (GObject *object)
 
     g_clear_object (&source->priv->control);
     g_clear_object (&source->priv->pswitch);
+    g_clear_pointer (&source->priv->pswitch_list, g_list_free);
 
-    free_list_controls (source);
+    _mate_mixer_clear_object_list (&source->priv->outputs_list);
 
-    if (source->priv->pswitch_list != NULL) {
-        g_list_free (source->priv->pswitch_list);
-        source->priv->pswitch_list = NULL;
-    }
     G_OBJECT_CLASS (pulse_source_parent_class)->dispose (object);
 }
 
@@ -203,7 +198,7 @@ pulse_source_add_output (PulseSource *source, const pa_source_output_info *info)
                              GUINT_TO_POINTER (info->index),
                              output);
 
-        free_list_controls (source);
+        _mate_mixer_clear_object_list (&source->priv->outputs_list);
 
         g_signal_emit_by_name (G_OBJECT (source),
                                "control-added",
@@ -229,7 +224,7 @@ pulse_source_remove_output (PulseSource *source, guint32 index)
     g_object_ref (output);
     g_hash_table_remove (source->priv->outputs, GUINT_TO_POINTER (index));
 
-    free_list_controls (source);
+    _mate_mixer_clear_object_list (&source->priv->outputs_list);
     g_signal_emit_by_name (G_OBJECT (source),
                            "control-removed",
                            MATE_MIXER_STREAM_CONTROL (output));
@@ -279,14 +274,3 @@ pulse_source_list_switches (MateMixerStream *mms)
 
     return PULSE_SOURCE (mms)->priv->pswitch_list;
 }
-
-static void
-free_list_controls (PulseSource *source)
-{
-    if (source->priv->outputs_list == NULL)
-        return;
-
-    g_list_free_full (source->priv->outputs_list, g_object_unref);
-
-    source->priv->outputs_list = NULL;
-}
diff --git a/libmatemixer/matemixer-private.h b/libmatemixer/matemixer-private.h
index 37c430d..8976de8 100644
--- a/libmatemixer/matemixer-private.h
+++ b/libmatemixer/matemixer-private.h
@@ -32,6 +32,12 @@
 
 G_BEGIN_DECLS
 
+const GList *_mate_mixer_list_modules (void);
+
+/* =======================================================================
+ * Convenience macros and functions to be used from modules
+ * =======================================================================
+ */
 #define MATE_MIXER_IS_LEFT_CHANNEL(c)                   \
     ((c) == MATE_MIXER_CHANNEL_FRONT_LEFT ||            \
      (c) == MATE_MIXER_CHANNEL_BACK_LEFT ||             \
@@ -106,10 +112,11 @@ G_BEGIN_DECLS
 #define MATE_MIXER_CHANNEL_MASK_HAS_FRONT(m)        ((m) & MATE_MIXER_CHANNEL_MASK_FRONT)
 #define MATE_MIXER_CHANNEL_MASK_HAS_BACK(m)         ((m) & MATE_MIXER_CHANNEL_MASK_BACK)
 
-const GList *_mate_mixer_list_modules        (void);
+guint32 _mate_mixer_create_channel_mask (MateMixerChannelPosition *positions,
+                                         guint                     n) G_GNUC_PURE;
 
-guint32      _mate_mixer_create_channel_mask (MateMixerChannelPosition *positions,
-                                              guint                     n) G_GNUC_PURE;
+void    _mate_mixer_clear_fd            (gint                     *fd);
+void    _mate_mixer_clear_object_list   (GList                   **list);
 
 G_END_DECLS
 
diff --git a/libmatemixer/matemixer-stream-toggle.c b/libmatemixer/matemixer-stream-toggle.c
index 70c829e..12582cb 100644
--- a/libmatemixer/matemixer-stream-toggle.c
+++ b/libmatemixer/matemixer-stream-toggle.c
@@ -199,13 +199,9 @@ mate_mixer_stream_toggle_dispose (GObject *object)
 
     toggle = MATE_MIXER_STREAM_TOGGLE (object);
 
-    if (toggle->priv->options != NULL) {
-        g_list_free (toggle->priv->options);
-        toggle->priv->options = NULL;
-    }
-
     g_clear_object (&toggle->priv->on);
     g_clear_object (&toggle->priv->off);
+    g_clear_pointer (&toggle->priv->options, g_list_free);
 
     G_OBJECT_CLASS (mate_mixer_stream_toggle_parent_class)->dispose (object);
 }
diff --git a/libmatemixer/matemixer.c b/libmatemixer/matemixer.c
index 1c09c7b..826c43b 100644
--- a/libmatemixer/matemixer.c
+++ b/libmatemixer/matemixer.c
@@ -18,6 +18,7 @@
 #include "config.h"
 
 #include <glib.h>
+#include <glib/gstdio.h>
 #include <glib-object.h>
 #include <gmodule.h>
 
@@ -141,6 +142,45 @@ _mate_mixer_create_channel_mask (MateMixerChannelPosition *positions, guint n)
     return mask;
 }
 
+/**
+ * _mate_mixer_clear_fd:
+ * @fd: a pointer to a file descriptor
+ *
+ * Closes the file descriptor if it is open and sets the pointer to -1.
+ */
+void
+_mate_mixer_clear_fd (gint *fd)
+{
+    g_return_if_fail (fd != NULL);
+
+    if (*fd == -1)
+        return;
+
+    g_close (*fd, NULL);
+
+    *fd = -1;
+}
+
+/**
+ * _mate_mixer_clear_object_list:
+ * @list: a pointer to a GList *
+ *
+ * Calls g_object_unref() on each item of the list, frees the list and
+ * sets the pointer to %NULL.
+ */
+void
+_mate_mixer_clear_object_list (GList **list)
+{
+    g_return_if_fail (list != NULL);
+
+    if (*list == NULL)
+        return;
+
+    g_list_free_full (*list, g_object_unref);
+
+   *list = NULL;
+}
+
 static void
 load_modules (void)
 {