As reported in issue 6302, playing a stream that causes gstreamer to error at
start can cause a crash. The problem occurs when the MoodbarPipeline receives a
pad-added signal after it has handled an error callback. In the error callback,
the builder_ is freed. In the pad-added handler (NewPadCallback), this object
is accessed.
This change adds a running_ flag that is set when the pipeline is started and
cleared on an error, end of stream, or object destruction. We check this flag at
the beginning of NewPadCallback. For sanity sake, we also check the builder_
pointer before dereferencing. Note that checking the state of the pipeline
wasn't an option since the pipeline is in the process of changing states during
the pad-added callback and gst_element_get_state wants to block during a state
change.
This solution is not complete as there are still some syncronization issues.
With this specific situation, the error and new pad callbacks appear to always
occur on the same thread, but that's probably not true for all error conditions.
The object is also destroyed by a different thread, so it may be possible that a
callback can occur at the wrong time during or after the deletion of the object.
See https://github.com/clementine-player/Clementine/issues/6302
There is a small chance that a device lister is able to discover and add a
previously known device before it is added by the database loader thread.
In this case, copy the data that is user-settable to the existing DeviceInfo
object and destroy the object created from the database query.
This adds and utilizes a new FindEquivalentDevice method that compares the
device unique IDs. This could probably be made more robust as the unique
IDs for some listers may change. However, this is a problem with the database
storage implementation in general.
When DeviceManager initializes, it creates a thread to load device information
from the database. Part of this process includes use of QPixMap for icons which
produced a warning message:
22:32:53.763 WARN unknown QPixmap: It is not safe to use pixmaps outside the GUI thread
In addition, the device is added to the view using beginInsertRows and
endInsertRows. This could contend with a device added by a lister signaling
PhysicalDeviceAdded.
To solve these problems, this change moves the icon loading and insertion to the
main thread. LoadAllDevices reads the data from the database and creates the
DeviceInfo object, then sends a signal to the main thread. In the signal
handler, the icon is loaded and the device is added to the master list and view.
When unmounting a device, the ConnectedDevice object is destroyed. The
FileSystemDevice destructor waits on its worker thread. If a scan is in
progress, this will block until completion.
There is an existing Stop method in the LibraryWatcher class that is intended to
stop long running operations. To fix, or at least significantly shorten this
hang, we'll call this before waiting for the thread to exit. Also add a
stop_requested check in the cover art scan.
In addition, add a call to Stop in the Library destructor, which has a similar
usage.
Currently, the failure to connect to an MTP device results in the UI displaying
an open device that appears empty. This change introduces a method
ConnectedDevice::ConnectAsync() that is expected to handle any connecting tasks
that could block asynchronously. Upon completion, this emits a ConnectFinished
signal that indicates success or failure. The row in the UI is only updated
after the successful response is received. Upon failure, DeviceManager will
clean up and the row in UI is left in the pre-connect state.
Currently, only the MtpDevice utilizes this mechanism. All other devices use a
default implementation that immediately reports success.
In 1.37.2, gvfs switched to URIs that remain consistent across USB device
re-enumerations. This removed the usb bus and device numbers from the URI. In
the case that these values aren't found in the URI, try to parse Unix device
name property and pass results as query params on the URL. Pay attention to
these params in MtpConnection.
See gvfs commits 3a7bb06b and efc76d0c for reference.
* Qt5::Test is not required in the global QT_LIBRARIES definition
* Qt5::DBus had already been optional, drop bogus pkgconfig search
This partially reverts commit 4321ecf7d26c5eed577a97d230786bb9f56ea37f.
* Find X11 only once, in root CMakeLists.txt
Since we have HAVE_X11, use HAVE_X11 in cmake.
