The \Q_OBJECT macro has been removed but using Q_OBJECT in the file
would erroneously trigger automoc. Avoid the issue by moving
the snippet into its own file.
Task-number: QTBUG-89505
Pick-to: 6.0
Change-Id: I6630ff4bfcbf33eae348ac3d92aae1878dc573ea
Reviewed-by: Paul Wicking <paul.wicking@qt.io>
When an eager binding triggers a setBinding call, we end up with a
special kind of binding loop:
setBinding() -> evaluate -> notifyObserver
^ |
| /
----------------------------
We now catch set condition, and set the binding status to BindingLoop
(with a distinct description).
Task-number: QTBUG-87153
Task-number: QTBUG-87733
Pick-to: 6.0
Change-Id: I9f9915797d82eab820fc279baceaf89d7e5a3f4a
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
The QPropertyBindingSourceLocation is only useful for C++ bindings; for
QML bindings we store the binding location in the V4 function. As the
QML binding needs to store some additional information for error
handling, we allow that memory to be reused by putting it into a union
with an array of byte.
Moreover, we use some of the space to store a callback pointer, which
gets called when an error occurs during binding evaluation. That
callback is only called when we know that the binding actually was set
up from the QML engine, in which case a bitflag is set.
Task-number: QTBUG-87733
Change-Id: I4387a4bd59d4d1ccfe75756ce81f4608319e0490
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
The QPropertyAlias example did not compile and comments were out of
sync with code. This patch fixes both.
Pick-to: 6.0
Change-Id: I5717f8df99f4936d0bcbae8df7d2d17e8086951d
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
The comments in the QProperty examples slightly mismatched the
implementation. This patch fixes it.
Pick-to: 6.0
Change-Id: I03cfb35c024fad8ea4eaa5d5db220e1907f06bc3
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
The intention was always that you can define properties that do
not require a changed signal. But having to explicitly pass
a nullptr as signal parameter into the macro is ugly, so
use the cool QT_OVERLOADED_MACRO to make it optional.
Pick-to: 6.0
Change-Id: I0ce366d043850f983c968d73c544d89933c48df9
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Avoid spurious bindings by resetting the binding state before calling
the setter of eager properties.
Fixes: QTBUG-88999
Pick-to: 6.0
Change-Id: I1e3b5662307d906598335a21d306be9c606529d4
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
The logic in notify() was doing quite a bit more work than
it needed to. By inserting a dummy node after the current one instead of
replacing it, we can avoid half of the data shuffling that has been
happening and also don't need a back pointer when executing the
notification.
Also avoid calling a semi expensive destructor of QPropertyObserver.
Reduces the overhead of notify() by ~30%.
Change-Id: I7ce16bcf9cd9c4368c18bf875fc959223452fd4f
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
(cherry picked from commit e8ef871e3522f340b4efe32382af7e35ef908665)
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Save a function call in the common case where we don't have a binding
This makes a rather large performance difference for setters that do
not have a binding.
Change-Id: I140f29790f6fe868721a33b9fad37205e547b8e9
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
(cherry picked from commit c63901c5f3195596eb81e5f5ae5483ca5a0b6d35)
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
No need to do function calls for the case where we return immediately
after checking a boolean.
Change-Id: I3e449850a10fcf82acb843cce6da6dfd98de32ad
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
(cherry picked from commit e165f416a752398079590161a18255f9a0058a3e)
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
They are not needed and removing it can simplify the code in some places
and avoid a couple of masking operations.
Change-Id: I0e4241a2784026aa89deed35f408b094e89a11a0
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
(cherry picked from commit b1be6e6e6f355bfcb0c3814516f6009c91d2de89)
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
In many cases, it only derefs and does nothing else. Inline the fast
code path.
Change-Id: Ib605c385c1683f7833f7189c84d6cf4eb5b0e59e
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
(cherry picked from commit eda4c29eb26dab32e22040bdda0b9b9109b1408b)
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
And inline the fast checks inside the methods in QBindingStorage.
This allows QObjectBindableProperty and friends to inline all the
fast checks and almost completely eliminates the overhead for property
accesses when no bindings are being used.
Read and write times of QObject based properties when no bindings
are being used:
Read Write
Old style property: 3.8ns 7.3ns
QObjectBindableProperty (no notification): 4.5ns 4.3ns
QObjectBindableProperty (with signal): 4.5ns 7.6ns
QObjectBindableProperty (inline accessors): 3.2ns 3.4ns
Numbers without this patch:
Old style property: 3.8ns 7.9ns
QObjectBindableProperty (no notification): 7.2ns 7.7ns
QObjectBindableProperty (with signal): 7.2ns 16.0ns
QObjectBindableProperty (inline accessors): 6.3ns 6.7ns
Change-Id: Ifd1fa3a489c3be8b1468c0b88af547aac397f412
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
(cherry picked from commit 98c82fb445acf45cc4c4bc86a5adda43358127bf)
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
This ensurse that we do not do dobule notifications in setValue.
Moerover we avoid needless notifications in markDirtyAndNotifyObservers
when the value did not change. Lastly, if the value did actually change,
we pass that information along to notify, so that we do not evaluate the
eager property twice.
Fixes a test-case which errorneously relied on the old behavior, and
adds a new test which verifies that the fix works.
Change-Id: I8ec6fa2fe8611565dfc603ceab3ba5f92999b26c
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
std::function as a type is rather unfortunate for us, as its SSO buffer
makes it rather large, and we can ensure that the function is never
empty.
Considering that we do need to allocate memory for
QPropertyBindingPrivate anyway, we can get rid of the SSO buffer and
instead coalesce the allocations (similar to how std::make_shared works).
The memory looks then like
[--QPropertyBindingPrivate--][Functor]
and QPropertyBindingPrivate can get a pointer to the functor via
reinterpret_cast<std::byte>(this)+sizeof(QPropertyBindingPrivate).
To actually do anything with the functor, we do however need a "vtable"
which describes how we can call, destroy and move the functor. This is
done by creating a constexpr struct of function pointers, and storing a
pointer to it in QPropertyBindingPrivate.
As a consequence of those changes, we cannot use QESDP anymore, as we
now have to carefully deallocate the buffer we used for both the
QPropertyBindingPrivate and the functor. We introduce a custom
refcounting pointer for that. While we're at it, we make the refcount
non-atomic, as bindings do not work across threads to begin with.
Moreover, we can now make the class non-virtual, as that was only needed
to hack around limitations of QESDP in the context of exported symbols.
Change-Id: Idc5507e4c120e28df5bd5aea717fe69f15e540dc
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Produced error in my GCC 7.5 on Ubuntu 18:
error: ‘nodiscard’ attribute applied to ‘QPropertyObserverNodeProtector<<anonymous> >::QPropertyObserverNodeProtector(QPropertyObserver*&)’ with void return type [-Werror=attributes]
Q_REQUIRED_RESULT QPropertyObserverNodeProtector(QPropertyObserver *&observer)
Change-Id: Ic1f6c4f502bb4d5c764686d5521b92f655592bb2
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
And not its constructor, as GCC at least doesn't like that.
Change-Id: I4aada7ca7135dd9c599980640588e7c98d398171
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
No need to default initialize the std::function and source location.
Change-Id: I7d840376b16e7257386a4787dd06b7956fe37576
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
As propertyobservers can execute arbitrarily complex code, they can also
modify the obsever list in multiple ways. To protect against list
corruption resulting from this, we introduce a protection scheme which
makes the list resilient against modification.
A detailed description of the scheme can be found as a comment in
QPropertyObserverPointer::notify.
Task-number: QTBUG-87153
Change-Id: I9bb49e457165ddc1e4c8bbdf3d3c9fbf5ff27e94
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
ChangeHandler's evaluated the binding to detect if the value actually
changed. This is a valid strategy for lazy bindings, but eager bindings
were already evaluated at that point, and thus the change would not be
detected.
Change the binding loop test, so that there isn't a fixpoint in the
binding loop, and we can still detect it. Changing the binding loop
detection code to deal with this case is left as an exercise for the
future.
Change-Id: Ia5d9ce2cd98a5780e69c993b5824024eb186c154
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
The semantics are not very intuitive, and it opens a can of worms
with regards to what should happen with observers that observe
that property.
Change-Id: I6fb00b7693904b968224cc87d098bbd0ea776ba3
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
In the internal hash map implementation, we have to ensure that the
index is in the interval [0, size - 1].
Moreover, in setBinding we have to refetch the binding storage in case a
reallocation happened.
Change-Id: I11c6264f16537699c8908b647e2355a39ce87648
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Before we had the option of eager evaluation, we were able to use the
dirty flag to detect whether we are recursing. However, eager properties
will lead to a evaluateIfDirtyAndReturnTrueIfValueChanged call, and that
in turn will clear the dirty flag.
Introduce a new member to detect that situation, and set the bindings
error state to BindingLoop if we detect that kind of loop.
Change-Id: If40b93221848bd9e9422502318d992fad95b0b74
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Add a compatibility property class that makes porting to the new
property system as simple as possible.
Binding evaluation for those compat properties is eager, as we
do not control possible side effects of the code in the existing
setters.
Change-Id: Ic56347abb49e40631ec73e88c6d40d4bdb05ca29
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Make it possible to evaluate the binding but write the result into
a different memory location. This will help support compat properties,
where the setter does a lot of additional work.
Change-Id: Ib60220eb629e3dcb5c0d7004b693e92290dfabe5
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Add Q_OBJECT_BINDABLE_PROPERTY() macro that can be used to define
a bindable property inside QObject.
The macro and the class behind it creates storage for a property
that is bindable inside a QObject or QObjectPrivate. The property
only uses as much space as the data contained, ie. it has no
storage overhead, as long as no bindings are being used.
Bindings are being stored and looked up in the QBindingStorage
associated with the owning object.
Change-Id: I1dadd7bddbad6fbf10cfa791d6461574b9db82dd
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Simplify the data structure. We only need one pointer for either
the static callback or a bindingWrapper, so don't share it
with the dependency observer array.
Also ensure we reset the propertyDataPtr and clear the observers
when the binding gets removed from a property.
Change-Id: I4c1e7ec7823c3ef12c63d6f758b757e7bac60cae
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
QBindingStorage is a class that can store a set of binding objects
for the properties of a QObject. This will get used to reduce the
memory overhead of the property system when adding bindable properties
to QObject based classes.
The binding storage has a pointer to the TLS entry containing the
currently evaluating binding. Like that we avoid repeated TLS
lookups and reduce the overhead of the property system to one
pointer lookup and one compare for the case that properties
aren't being used.
Each QObject now owns one binding storage object, that can be used to
store binding data for properties that members of the QObject.
Change-Id: I27427c03c2ba281f072e074be96147bdbcaac246
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reorder source code to make the follow-up work easier. Also clean up
retrieving the pointer to the aliased property.
Make setSource(QPropertyBindingData) public, it'll be needed later on.
Change-Id: I784fdceac8722c7df756b2d7c35e08c7ab3a2074
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Add an empty QUntypedPropertyData class. This allows making
a couple of places where the system is currently using a
void * more type safe.
Also add a QPropertyData<T> as an intermediate class between
QUntypedPropertyData and QProperty. This class will get used
in a future commit to simplify storing property data separately
from the possible binding data.
Also simplify the static observer handling a bit by always
passing it a pointer to the QUntypedPropertyData instead of
some other void * that could point to anything.
Change-Id: I1f8144ea717815b1bc6f034d1ac883c13af5aaf8
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
And all related functionality. This is being replaced by
Q_BINDABLE_PROPERTY and Q_OBJECT_BINDABLE_PROPERTY in the
next few commits. The new infrastructure coming will play
nicer along with the existing property system.
Commented out some autotests, that will get reimplemented
with the updated infrastructure.
Change-Id: I50c30bd4d5c6c6b6471f8eb93870e27d86f5a009
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Rename QPropertyBase to QPropertyBindingData, as it contains the
data related to bindings. The new name fits better, as the data
can now also live somewhere else than the data strored in the
property.
Change-Id: I489efb86ad2e0bad2740c9d1aa74506fe103d343
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Since we will be storing property data differently in most cases,
having this special case would create too many additional complications.
Change-Id: I27042b0730559bb375d8e3c07324398403a9885d
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Generalize some methods taking a QProperty<T>,
so that they can work with other types that
implement the QProperty interface as well.
This removes some duplication between QProperty and
QNotifiedProperty. It also makes it possible to
create private property classes that store their
data in a different place.
Change-Id: I4b1ae8589cb9a76be59e63206044dcf2244163c2
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Now that QMetaType is not refcounted anymore, we can and should
pass it by value.
Change-Id: I848db65070713762f548ca949097c27783aacad4
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
We can end up in a situation where a (soon to be destroyed) observer is
owned by a binding which is about to be deleted. If in that situation
the binding is destroyed first, we end up with a dangling pointer
and ensuing memory corruption. Instead, we now first transfer the
ownership of the observer and only destroy the binding afterwards.
Fixes: QTBUG-85824
Change-Id: I721c0319281ada981ae7896bd2e02e9a0cc901b8
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
And mark some methods as inline.
Performance is critical for our new property system. Compiling
it in one unit makes it possible for the compiler to do a much
better job at inlining and generating optimized code.
Improves performance of binding evaluations by another 20%.
Change-Id: I5a2aa93c74d2b68418b0a9d2e34d8199bb71e3ad
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Avoid any QVariant or type dependent code in the cpp files.
Instead, let the binding wrapper determine if the value
has changed and return true/false accordingly.
This required also some reworking of the guard mechanism
for notified properties, where the guard function wrapper
now calls first the binding evaluation function and then
passes the result to the guard.
Change-Id: I350d07a508ccc0c5db7054a0efa4f270b6a78ec3
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
There's no point in returning a usually empty error when
evaluating bindings, adding overhead to the regular code
path.
Instead, the error can be set on the currently evaluating
binding if required. This streamlines the functor used to
wrap the binding and should thus expand to less code and
execute faster in the regular case.
To achieve this, expose a pointer to the currently evaluating
binding in the private API (as QtQml needs it to be able to
report errors).
The error case now requires one additional TLS lookup, but
we don't really care about performance in that case anyway.
Change-Id: Iecb450e765244930a41d813fcf8eb4013957a6a3
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Remove location(). The method would always return an empty value. If you need the location,
the binding itself has it.
Remove setDescription() and require that the description gets passed
in the constructor. Never create a d pointer if type is NoError, so we
can quickly check for it inline.
Change-Id: I7eb8a94786281069d6ea2d82567c09aa50c52ef6
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Store a pointer to the TLS in the BingingEvaluationState. Like this,
we can save us one TLS lookup in the destructor. Shaves off a couple
of percent during binding evaluation.
Change-Id: Idc9dc5b0ea202aaeb68cdc063700b8e4968753dc
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Improves performance of binding evaluation by ~20% for
simple C++ bindings by simplifying and inlining the code
that clears the array of property observers.
Change-Id: I829ac1895f1673367d737944d950360015a5b435
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
A guard callback is a predicate which takes the new value set by
setValue or computed as the result of a binding expression. If it
returns false, the value is discarded and the old value is kept.
Note that due to lazyness, when setting a binding, we still notify
everyone as the binding is only evaluated on demand, and the guard can
thus only run when someone actually queries the value.
Note further that a guard is allowed to modify the value that is passed
to it (e.g. to clamp it to a certain range).
Task-number: QTBUG-85032
Change-Id: I3551e4357fe5780fb75da80bf8be208ec152dc2a
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Check at compile time whether the static callback takes an argument
(which has to be of the same time as the type of the property). If so,
retrieve the old value and pass it to the callback.
Change-Id: Ib1c4c9e05b826b6be492b03f66fa72ad015963ee
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
A common pattern in Qt Quick will be QProperty members that are
connected to a callback that needs to perform something when the value
changes, for example emitting a compatibility signal or marking scene
graph node data dirty.
To make such a pattern more efficient, a new QNotifiedProperty type is
introduced that offers the same API as QProperty<T>, with two changes:
(1) The template instantiation not only takes the property type as
parameter but also a callback pointer-to-member.
(2) Since that member itself cannot be called without an instance
and to avoid storing an instance pointer permanently, the API for
setBinding and setValue are adjusted to also take the instance
pointer. For the former it gets stored in the binding, for the
latter it is used to invoke the callback after setting the new
value.
Change-Id: I85cc1d1d1c0472164c4ae87808cfdc0d0b1475e1
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Fabian Kosmale
Andreas Buhr
Lars Knoll
Topi Reinio
Andrei Golubev
Simon Hausmann