From bc72e1332cfc81e166c83c90ad63b4b648f19867 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Tue, 31 Jul 2012 13:10:44 +0200 Subject: Split media_device creation and opening Make the media_device refcounted to manage its life time. Signed-off-by: Laurent Pinchart Acked-by: Hans Verkuil Acked-by: Sakari Ailus --- src/main.c | 21 ++++--- src/mediactl.c | 171 ++++++++++++++++++++++++++++++++++++++++----------------- src/mediactl.h | 84 +++++++++++++++------------- 3 files changed, 179 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 7b18ca7..2b054e9 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 */ @@ -143,12 +184,17 @@ int media_setup_link(struct media_device *media, ret = -errno; media_dbg(media, "%s: Unable to setup link (%s)\n", __func__, strerror(errno)); - return ret; + 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) @@ -427,6 +473,58 @@ 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) { + ret = -errno; + media_dbg(media, "%s: Unable to retrieve media device " + "information for device %s (%s)\n", __func__, + media->devnode, strerror(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, ...) { } @@ -444,9 +542,7 @@ 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; @@ -455,65 +551,33 @@ struct media_device *media_open_debug( if (media == NULL) return NULL; - media_debug_set_handler(media, debug_handler, debug_priv); + media->fd = -1; + media->refcount = 1; - media_dbg(media, "Opening media device %s\n", name); + media_debug_set_handler(media, NULL, NULL); - 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; - } - - 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]; @@ -525,9 +589,14 @@ 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. -- cgit v1.2.3