X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Flibudev%2Flibudev-enumerate.c;h=a945758e3820088d4f2441e44acb9874805c55b4;hp=4725912c362add46dbe511f61c5afb69cb09f848;hb=3cbd5f6be191a4e71fc85d8b893e96d6d65bf792;hpb=33502ffe2eb7b56cdd018a4fb6830d7828519fad

diff --git a/src/libudev/libudev-enumerate.c b/src/libudev/libudev-enumerate.c
index 4725912c3..a945758e3 100644
--- a/src/libudev/libudev-enumerate.c
+++ b/src/libudev/libudev-enumerate.c
@@ -65,7 +65,9 @@ struct udev_enumerate {
  * udev_enumerate_new:
  * @udev: udev library context
  *
- * Returns: an enumeration context
+ * Create an enumeration context to scan /sys.
+ *
+ * Returns: an enumeration context.
  **/
 _public_ struct udev_enumerate *udev_enumerate_new(struct udev *udev)
 {
@@ -109,16 +111,18 @@ _public_ struct udev_enumerate *udev_enumerate_ref(struct udev_enumerate *udev_e
  *
  * Drop a reference of an enumeration context. If the refcount reaches zero,
  * all resources of the enumeration context will be released.
+ *
+ * Returns: the passed enumeration context if it has still an active reference, or #NULL otherwise.
  **/
-_public_ void udev_enumerate_unref(struct udev_enumerate *udev_enumerate)
+_public_ struct udev_enumerate *udev_enumerate_unref(struct udev_enumerate *udev_enumerate)
 {
         unsigned int i;
 
         if (udev_enumerate == NULL)
-                return;
+                return NULL;
         udev_enumerate->refcount--;
         if (udev_enumerate->refcount > 0)
-                return;
+                return udev_enumerate;
         udev_list_cleanup(&udev_enumerate->sysattr_match_list);
         udev_list_cleanup(&udev_enumerate->sysattr_nomatch_list);
         udev_list_cleanup(&udev_enumerate->subsystem_match_list);
@@ -132,13 +136,16 @@ _public_ void udev_enumerate_unref(struct udev_enumerate *udev_enumerate)
                 free(udev_enumerate->devices[i].syspath);
         free(udev_enumerate->devices);
         free(udev_enumerate);
+        return NULL;
 }
 
 /**
  * udev_enumerate_get_udev:
  * @udev_enumerate: context
  *
- * Returns: the udev library context.
+ * Get the udev library context.
+ *
+ * Returns: a pointer to the context.
  */
 _public_ struct udev *udev_enumerate_get_udev(struct udev_enumerate *udev_enumerate)
 {
@@ -243,7 +250,9 @@ static size_t devices_delay_later(struct udev *udev, const char *syspath)
  * udev_enumerate_get_list_entry:
  * @udev_enumerate: context
  *
- * Returns: the first entry of the sorted list of device paths.
+ * Get the first entry of the sorted list of device paths.
+ *
+ * Returns: a udev_list_entry.
  */
 _public_ struct udev_list_entry *udev_enumerate_get_list_entry(struct udev_enumerate *udev_enumerate)
 {
@@ -321,6 +330,8 @@ _public_ struct udev_list_entry *udev_enumerate_get_list_entry(struct udev_enume
  * @udev_enumerate: context
  * @subsystem: filter for a subsystem of the device to include in the list
  *
+ * Match only devices belonging to a certain kernel subsystem.
+ *
  * Returns: 0 on success, otherwise a negative error value.
  */
 _public_ int udev_enumerate_add_match_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
@@ -339,6 +350,8 @@ _public_ int udev_enumerate_add_match_subsystem(struct udev_enumerate *udev_enum
  * @udev_enumerate: context
  * @subsystem: filter for a subsystem of the device to exclude from the list
  *
+ * Match only devices not belonging to a certain kernel subsystem.
+ *
  * Returns: 0 on success, otherwise a negative error value.
  */
 _public_ int udev_enumerate_add_nomatch_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
@@ -358,6 +371,8 @@ _public_ int udev_enumerate_add_nomatch_subsystem(struct udev_enumerate *udev_en
  * @sysattr: filter for a sys attribute at the device to include in the list
  * @value: optional value of the sys attribute
  *
+ * Match only devices with a certain /sys device attribute.
+ *
  * Returns: 0 on success, otherwise a negative error value.
  */
 _public_ int udev_enumerate_add_match_sysattr(struct udev_enumerate *udev_enumerate, const char *sysattr, const char *value)
@@ -377,6 +392,8 @@ _public_ int udev_enumerate_add_match_sysattr(struct udev_enumerate *udev_enumer
  * @sysattr: filter for a sys attribute at the device to exclude from the list
  * @value: optional value of the sys attribute
  *
+ * Match only devices not having a certain /sys device attribute.
+ *
  * Returns: 0 on success, otherwise a negative error value.
  */
 _public_ int udev_enumerate_add_nomatch_sysattr(struct udev_enumerate *udev_enumerate, const char *sysattr, const char *value)
@@ -416,6 +433,8 @@ exit:
  * @property: filter for a property of the device to include in the list
  * @value: value of the property
  *
+ * Match only devices with a certain property.
+ *
  * Returns: 0 on success, otherwise a negative error value.
  */
 _public_ int udev_enumerate_add_match_property(struct udev_enumerate *udev_enumerate, const char *property, const char *value)
@@ -434,6 +453,8 @@ _public_ int udev_enumerate_add_match_property(struct udev_enumerate *udev_enume
  * @udev_enumerate: context
  * @tag: filter for a tag of the device to include in the list
  *
+ * Match only devices with a certain tag.
+ *
  * Returns: 0 on success, otherwise a negative error value.
  */
 _public_ int udev_enumerate_add_match_tag(struct udev_enumerate *udev_enumerate, const char *tag)
@@ -503,6 +524,8 @@ _public_ int udev_enumerate_add_match_is_initialized(struct udev_enumerate *udev
  * @udev_enumerate: context
  * @sysname: filter for the name of the device to include in the list
  *
+ * Match only devices with a given /sys device name.
+ *
  * Returns: 0 on success, otherwise a negative error value.
  */
 _public_ int udev_enumerate_add_match_sysname(struct udev_enumerate *udev_enumerate, const char *sysname)
@@ -867,6 +890,9 @@ static int scan_devices_all(struct udev_enumerate *udev_enumerate)
  * udev_enumerate_scan_devices:
  * @udev_enumerate: udev enumeration context
  *
+ * Scan /sys for all devices which match the given filters. No matches
+ * will return all currently available devices.
+ *
  * Returns: 0 on success, otherwise a negative error value.
  **/
 _public_ int udev_enumerate_scan_devices(struct udev_enumerate *udev_enumerate)
@@ -890,6 +916,8 @@ _public_ int udev_enumerate_scan_devices(struct udev_enumerate *udev_enumerate)
  * udev_enumerate_scan_subsystems:
  * @udev_enumerate: udev enumeration context
  *
+ * Scan /sys for all kernel subsystems, including buses, classes, drivers.
+ *
  * Returns: 0 on success, otherwise a negative error value.
  **/
 _public_ int udev_enumerate_scan_subsystems(struct udev_enumerate *udev_enumerate)