Make the media_device refcounted to manage its life time.
Signed-off-by: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
---
src/main.c | 21 ++++---
src/mediactl.c | 172 ++++++++++++++++++++++++++++++++++++++++-----------------
src/mediactl.h | 84 +++++++++++++++-------------
3 files changed, 180 insertions(+), 97 deletions(-)
diff --git a/src/main.c b/src/main.c
index 4a27c8c..8b48fde 100644
--- a/src/main.c
+++ b/src/main.c
@@ -329,15 +329,20 @@ int main(int argc, char **argv)
if (parse_cmdline(argc, argv))
return EXIT_FAILURE;
- /* Open the media device and enumerate entities, pads and links. */
+ media = media_device_new(media_opts.devname);
+ if (media == NULL) {
+ printf("Failed to create media device\n");
+ goto out;
+ }
+
if (media_opts.verbose)
- media = media_open_debug(
- media_opts.devname,
+ media_debug_set_handler(media,
(void (*)(void *, ...))fprintf, stdout);
- else
- media = media_open(media_opts.devname);
- if (media == NULL) {
- printf("Failed to open %s\n", media_opts.devname);
+
+ /* Enumerate entities, pads and links. */
+ ret = media_device_enumerate(media);
+ if (ret < 0) {
+ printf("Failed to enumerate %s (%d)\n", media_opts.devname,
ret);
goto out;
}
@@ -446,7 +451,7 @@ int main(int argc, char **argv)
out:
if (media)
- media_close(media);
+ media_device_unref(media);
return ret ? EXIT_FAILURE : EXIT_SUCCESS;
}
diff --git a/src/mediactl.c b/src/mediactl.c
index 57cf86b..c71d4e1 100644
--- a/src/mediactl.c
+++ b/src/mediactl.c
@@ -101,6 +101,42 @@ struct media_entity *media_get_entity_by_id(struct
media_device *media,
return NULL;
}
+/*
-----------------------------------------------------------------------------
+ * Open/close
+ */
+
+static int media_device_open(struct media_device *media)
+{
+ int ret;
+
+ if (media->fd != -1)
+ return 0;
+
+ media_dbg(media, "Opening media device %s\n", media->devnode);
+
+ media->fd = open(media->devnode, O_RDWR);
+ if (media->fd < 0) {
+ ret = -errno;
+ media_dbg(media, "%s: Can't open media device %s\n",
+ __func__, media->devnode);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void media_device_close(struct media_device *media)
+{
+ if (media->fd != -1) {
+ close(media->fd);
+ media->fd = -1;
+ }
+}
+
+/*
-----------------------------------------------------------------------------
+ * Link setup
+ */
+
int media_setup_link(struct media_device *media,
struct media_pad *source,
struct media_pad *sink,
@@ -111,6 +147,10 @@ int media_setup_link(struct media_device *media,
unsigned int i;
int ret;
+ ret = media_device_open(media);
+ if (ret < 0)
+ goto done;
+
for (i = 0; i < source->entity->num_links; i++) {
link = &source->entity->links[i];
@@ -123,7 +163,8 @@ int media_setup_link(struct media_device *media,
if (i == source->entity->num_links) {
media_dbg(media, "%s: Link not found\n", __func__);
- return -ENOENT;
+ ret = -ENOENT;
+ goto done;
}
/* source pad */
@@ -142,12 +183,18 @@ int media_setup_link(struct media_device *media,
if (ret == -1) {
media_dbg(media, "%s: Unable to setup link (%s)\n",
__func__, strerror(errno));
- return -errno;
+ ret = -errno;
+ goto done;
}
link->flags = ulink.flags;
link->twin->flags = ulink.flags;
- return 0;
+
+ ret = 0;
+
+done:
+ media_device_close(media);
+ return ret;
}
int media_reset_links(struct media_device *media)
@@ -425,6 +472,58 @@ static int media_enum_entities(struct media_device *media)
return ret;
}
+int media_device_enumerate(struct media_device *media)
+{
+ int ret;
+
+ if (media->entities)
+ return 0;
+
+ ret = media_device_open(media);
+ if (ret < 0)
+ return ret;
+
+ ret = ioctl(media->fd, MEDIA_IOC_DEVICE_INFO, &media->info);
+ if (ret < 0) {
+ media_dbg(media, "%s: Unable to retrieve media device "
+ "information for device %s (%s)\n", __func__,
+ media->devnode, strerror(errno));
+ ret = -errno;
+ goto done;
+ }
+
+ media_dbg(media, "Enumerating entities\n");
+
+ ret = media_enum_entities(media);
+ if (ret < 0) {
+ media_dbg(media,
+ "%s: Unable to enumerate entities for device %s
(%s)\n",
+ __func__, media->devnode, strerror(-ret));
+ goto done;
+ }
+
+ media_dbg(media, "Found %u entities\n", media->entities_count);
+ media_dbg(media, "Enumerating pads and links\n");
+
+ ret = media_enum_links(media);
+ if (ret < 0) {
+ media_dbg(media,
+ "%s: Unable to enumerate pads and linksfor device
%s\n",
+ __func__, media->devnode);
+ goto done;
+ }
+
+ ret = 0;
+
+done:
+ media_device_close(media);
+ return ret;
+}
+
+/*
-----------------------------------------------------------------------------
+ * Create/destroy
+ */
+
static void media_debug_default(void *ptr, ...)
{
}
@@ -442,9 +541,7 @@ void media_debug_set_handler(struct media_device *media,
}
}
-struct media_device *media_open_debug(
- const char *name, void (*debug_handler)(void *, ...),
- void *debug_priv)
+struct media_device *media_device_new(const char *devnode)
{
struct media_device *media;
int ret;
@@ -453,65 +550,33 @@ struct media_device *media_open_debug(
if (media == NULL)
return NULL;
- media_debug_set_handler(media, debug_handler, debug_priv);
-
- media_dbg(media, "Opening media device %s\n", name);
+ media->fd = -1;
+ media->refcount = 1;
- media->fd = open(name, O_RDWR);
- if (media->fd < 0) {
- media_close(media);
- media_dbg(media, "%s: Can't open media device %s\n",
- __func__, name);
- return NULL;
- }
+ media_debug_set_handler(media, NULL, NULL);
- ret = ioctl(media->fd, MEDIA_IOC_DEVICE_INFO, &media->info);
- if (ret < 0) {
- media_dbg(media, "%s: Unable to retrieve media device "
- "information for device %s (%s)\n", __func__,
- name, strerror(errno));
- media_close(media);
- return NULL;
- }
-
- media_dbg(media, "Enumerating entities\n");
-
- ret = media_enum_entities(media);
-
- if (ret < 0) {
- media_dbg(media,
- "%s: Unable to enumerate entities for device %s
(%s)\n",
- __func__, name, strerror(-ret));
- media_close(media);
- return NULL;
- }
-
- media_dbg(media, "Found %u entities\n", media->entities_count);
- media_dbg(media, "Enumerating pads and links\n");
-
- ret = media_enum_links(media);
- if (ret < 0) {
- media_dbg(media,
- "%s: Unable to enumerate pads and linksfor device
%s\n",
- __func__, name);
- media_close(media);
+ media->devnode = strdup(devnode);
+ if (media->devnode == NULL) {
+ media_device_unref(media);
return NULL;
}
return media;
}
-struct media_device *media_open(const char *name)
+struct media_device *media_device_ref(struct media_device *media)
{
- return media_open_debug(name, NULL, NULL);
+ media->refcount++;
+ return media;
}
-void media_close(struct media_device *media)
+void media_device_unref(struct media_device *media)
{
unsigned int i;
- if (media->fd != -1)
- close(media->fd);
+ media->refcount--;
+ if (media->refcount > 0)
+ return;
for (i = 0; i < media->entities_count; ++i) {
struct media_entity *entity = &media->entities[i];
@@ -523,9 +588,14 @@ void media_close(struct media_device *media)
}
free(media->entities);
+ free(media->devnode);
free(media);
}
+/*
-----------------------------------------------------------------------------
+ * Parsing
+ */
+
struct media_pad *media_parse_pad(struct media_device *media,
const char *p, char **endp)
{
diff --git a/src/mediactl.h b/src/mediactl.h
index 2296fe2..34e7487 100644
--- a/src/mediactl.h
+++ b/src/mediactl.h
@@ -54,6 +54,8 @@ struct media_entity {
struct media_device {
int fd;
+ int refcount;
+ char *devnode;
struct media_device_info info;
struct media_entity *entities;
unsigned int entities_count;
@@ -66,61 +68,67 @@ struct media_device {
(media)->debug_handler((media)->debug_priv, __VA_ARGS__)
/**
- * @brief Set a handler for debug messages.
- * @param media - device instance.
- * @param debug_handler - debug message handler
- * @param debug_priv - first argument to debug message handler
+ * @brief Create a new media device.
+ * @param devnode - device node path.
*
- * Set a handler for debug messages that will be called whenever
- * debugging information is to be printed. The handler expects an
- * fprintf-like function.
+ * Create a media device instance for the given device node and return it. The
+ * device node is not accessed by this function, device node access errors will
+ * not be caught and reported here. The media device needs to be enumerated
+ * before it can be accessed, see media_device_enumerate().
+ *
+ * Media devices are reference-counted, see media_device_ref() and
+ * media_device_unref() for more information.
+ *
+ * @return A pointer to the new media device or NULL if memory cannot be
+ * allocated.
*/
-void media_debug_set_handler(
- struct media_device *media, void (*debug_handler)(void *, ...),
- void *debug_priv);
+struct media_device *media_device_new(const char *devnode);
/**
- * @brief Open a media device with debugging enabled.
- * @param name - name (including path) of the device node.
- * @param debug_handler - debug message handler
- * @param debug_priv - first argument to debug message handler
- *
- * Open the media device referenced by @a name and enumerate entities, pads and
- * links.
+ * @brief Take a reference to the device.
+ * @param media - device instance.
*
- * Calling media_open_debug() instead of media_open() is equivalent to
- * media_open() and media_debug_set_handler() except that debugging is
- * also enabled during media_open().
+ * Media devices are reference-counted. Taking a reference to a device prevents
+ * it from being freed until all references are released. The reference count
is
+ * initialized to 1 when the device is created.
*
- * @return A pointer to a newly allocated media_device structure instance on
- * success and NULL on failure. The returned pointer must be freed with
- * media_close when the device isn't needed anymore.
+ * @return A pointer to @a media.
*/
-struct media_device *media_open_debug(
- const char *name, void (*debug_handler)(void *, ...),
- void *debug_priv);
+struct media_device *media_device_ref(struct media_device *media);
/**
- * @brief Open a media device.
- * @param name - name (including path) of the device node.
+ * @brief Release a reference to the device.
+ * @param media - device instance.
*
- * Open the media device referenced by @a name and enumerate entities, pads and
- * links.
+ * Release a reference to the media device. When the reference count reaches 0
+ * this function frees the device.
+ */
+void media_device_unref(struct media_device *media);
+
+/**
+ * @brief Set a handler for debug messages.
+ * @param media - device instance.
+ * @param debug_handler - debug message handler
+ * @param debug_priv - first argument to debug message handler
*
- * @return A pointer to a newly allocated media_device structure instance on
- * success and NULL on failure. The returned pointer must be freed with
- * media_close when the device isn't needed anymore.
+ * Set a handler for debug messages that will be called whenever
+ * debugging information is to be printed. The handler expects an
+ * fprintf-like function.
*/
-struct media_device *media_open(const char *name);
+void media_debug_set_handler(
+ struct media_device *media, void (*debug_handler)(void *, ...),
+ void *debug_priv);
/**
- * @brief Close a media device.
+ * @brief Enumerate the device topology
* @param media - device instance.
*
- * Close the @a media device instance and free allocated resources. Access to
the
- * device instance is forbidden after this function returns.
+ * Enumerate the media device entities, pads and links. Calling this function
is
+ * mandatory before accessing the media device contents.
+ *
+ * @return Zero on success or a negative error code on failure.
*/
-void media_close(struct media_device *media);
+int media_device_enumerate(struct media_device *media);
/**
* @brief Locate the pad at the other end of a link.
--
1.8.3.2
--
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