diff options
Diffstat (limited to 'src/libcamera/media_device.cpp')
| -rw-r--r-- | src/libcamera/media_device.cpp | 29 |
1 files changed, 15 insertions, 14 deletions
diff --git a/src/libcamera/media_device.cpp b/src/libcamera/media_device.cpp index eef348e3..b1cc37e8 100644 --- a/src/libcamera/media_device.cpp +++ b/src/libcamera/media_device.cpp @@ -40,10 +40,9 @@ LOG_DEFINE_CATEGORY(MediaDevice) * instance. * * The instance is created with an empty media graph. Before performing any - * other operation, it must be opened with the open() function and the media - * graph populated by calling populate(). Instances of MediaEntity, MediaPad and - * MediaLink are created to model the media graph, and stored in a map indexed - * by object id. + * other operation, it must be populate by calling populate(). Instances of + * MediaEntity, MediaPad and MediaLink are created to model the media graph, + * and stored in a map indexed by object id. * * The graph is valid once successfully populated, as reported by the valid() * function. It can be queried to list all entities(), or entities can be @@ -51,12 +50,6 @@ LOG_DEFINE_CATEGORY(MediaDevice) * entity to entity through pads and links as exposed by the corresponding * classes. * - * An open media device will keep an open file handle for the underlying media - * controller device node. It can be closed at any time with a call to close(). - * This will not invalidate the media graph and all cached media objects remain - * valid and can be accessed normally. The device can then be later reopened if - * needed to perform other operations that interact with the device node. - * * Media device can be claimed for exclusive use with acquire(), released with * release() and tested with busy(). This mechanism is aimed at pipeline * managers to claim media devices they support during enumeration. @@ -66,8 +59,8 @@ LOG_DEFINE_CATEGORY(MediaDevice) * \brief Construct a MediaDevice * \param[in] deviceNode The media device node path * - * Once constructed the media device is invalid, and must be opened and - * populated with open() and populate() before the media graph can be queried. + * Once constructed the media device is invalid, and must be populated with + * populate() before the media graph can be queried. */ MediaDevice::MediaDevice(const std::string &deviceNode) : deviceNode_(deviceNode), fd_(-1), valid_(false), acquired_(false) @@ -92,7 +85,8 @@ MediaDevice::~MediaDevice() * busy() function. * * Once claimed the device shall be released by its user when not needed anymore - * by calling the release() function. + * by calling the release() function. Acquiring the media device opens a file + * descriptor to the device which is kept open until release() is called. * * Exclusive access is only guaranteed if all users of the media device abide by * the device claiming mechanism, as it isn't enforced by the media device @@ -107,15 +101,22 @@ bool MediaDevice::acquire() if (acquired_) return false; + if (open()) + return false; + acquired_ = true; return true; } /** - * \fn MediaDevice::release() * \brief Release a device previously claimed for exclusive use * \sa acquire(), busy() */ +void MediaDevice::release() +{ + close(); + acquired_ = false; +} /** * \fn MediaDevice::busy() |