C++17 introduces helper variable templates for type traits, allowing
shortening std::is_foo<T>::value to std::is_foo_v<T>. Use them through
the code base.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
We build libcamera with -Wno-unused-parameter and this doesn't cause
much issue internally. However, it prevents catching unused parameters
in inline functions defined in public headers. This can lead to
compilation warnings for applications compiled without
-Wno-unused-parameter.
To catch those issues, remove -Wno-unused-parameter and fix all the
related warnings with [[maybe_unused]].
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
C++14 introduced useful type traits helpers named std::*_t as aliases to
std::*<...>::type. Use them to simplify the code.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
The slots list is touched from most of the Signal template functions. In
order to prepare for thread-safety, move handling of the list to a small
number of non-template functions in the SignalBase class.
This incidently fixes a bug in signal disconnection handling where the
signal wasn't removed from the object's signals list, as pointed out by
the signals unit test.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Most of the bound method classes are named with a BoundMethod prefix,
except for BoundMemberMethod and BoundStaticMethod. Rename them to
BoundMethodMember and BoundMethodStatic respectively to make the code
more coherent.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
The bound method implementation is restricted to binding to void methods
as return values are not supported. This complicates usage of bound
methods, as non-void methods used a slots or Object::invokeMethod()
targets need to be wrapped in a void method. Simplify this by supporting
arbitrary return types and ignoring the return value.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
To make the BoundMethod classes more generic, replace direct access to
private member from Signal classes with accessors or helper functions.
This allows removal of friend statements from the BoundMethod classes.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Move the Slot* classes to bound_method.{h,cpp} and rename them to
Bound*Method*. They will be reused to implement asynchronous method
invocation similar to cross-thread signal delivery.
This is only a move and rename, no functional changes are included.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
gcc complains that the recently template specialisation of the
SlotBase::match() method is invalid as it is in a non-namespace scope.
Luckily this can easily be fixed by removing the specialisation for the
fully specialised implementation. As an additional safety measure, using
std::enable_if<!std::is_same<Object, T>> on the template implementation
ensures that it will never be called for an Object instance.
Fixes: 56c2e65300 ("libcamera: signal: Fix Object handling in multiple inheritance cases")
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
The SlotBase implementation stores the receiver object pointer as a void
pointer internally. The pointer is then cast back to an Object pointer
when the receiver object class derives from Object. When the receiver is
an object that inherits from both the Object class and other classes,
the Object data members may not be stored at the beginning of the object
memory. The cast back to an Object pointer is thus incorrect.
Fix this by casting the receiver object pointer to an Object pointer
where the type of the receiver object is known, and pass it along with
the receiver void pointer to the SlotBase class. The SlotBase class
stores both pointers internally, and doesn't need the isObject_ field
anymore as the same information is obtained from checking if the Object
pointer is null.
To avoid confusing the two pointers, use the same naming scheme through
the whole implementation: "obj" points to a receiver object as an
unknown type, and "object" to the receiver object cast to an Object. The
latter is null when the receiver object doesn't inherit from the Object
class.
To further clarify the code, remove direct access to the SlotBase "obj"
and "object" fields as much as possible. They are replaced by two new
methods :
- SlotBase::disconnect() to disconnect a signal from the slot's receiver
object
- SlotBase::match() to test if an object pointer matches the slot
The match() method is a template method with a specialisation for the
Object type, to compare either the obj or the object pointer depending
on the type of the parameter. This is required as the Object destructor
calls the SignalBase::disconnect() method for signal connected to the
object, and passes a pointer to Object to that method, while the actual
object may have a different address due to the issue explained above.
The pointer must thus be compared with the stored Object pointer in that
case, not to the pointer to the receiver object.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Allow signals to cross thread boundaries by posting them to the
recipient through messages instead of calling the slot directly when the
recipient lives in a different thread.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
When a signal is connected to a member function slot, the slot is not
disconnected when the slot object is deleted. This can lead to calling a
member function of a deleted object if the signal isn't disconnected
manually by the slot object's destructor.
Make signal handling easier by implementing a base Object class that
tracks all connected signals and disconnects from them automatically
when the object is deleted, using template specialization resolution in
the Signal class.
As inheriting from the Object class may to a too harsh requirement for
Signal usage in applications, keep the existing behaviour working if the
slot doesn't inherit from the Object class. We may reconsider this later
and require all slot objects to inherit from the Object class.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Use static_cast<>() instead of reinterpret_cast<>() to perform
downcasts, as reinterpret_cast<>() isn't meant (and guaranteed to be
safe) for that purpose.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Introduce a Signal class that allows connecting event sources (signals)
to event listeners (slots) without adding any boilerplate code usually
associated with the observer or listener design patterns.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
