Move all the QProperty related code into one compilation unit

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>

1 files changed, 162 insertions, 3 deletions

diff --git a/src/corelib/kernel/qproperty_p.h b/src/corelib/kernel/qproperty_p.h
index 7b9d7c207f..159c652657 100644
--- a/src/corelib/kernel/qproperty_p.h
+++ b/src/corelib/kernel/qproperty_p.h
@@ -52,20 +52,35 @@
 //
 
 #include <qglobal.h>
+#include <qproperty.h>
+
 #include <qvarlengtharray.h>
+#include <qscopedpointer.h>
+#include <vector>
 
-#include "qproperty.h"
 
 QT_BEGIN_NAMESPACE
 
+// Keep all classes related to QProperty in one compilation unit. Performance of this code is crucial and
+// we need to allow the compiler to inline where it makes sense.
+
 // This is a helper "namespace"
 struct Q_AUTOTEST_EXPORT QPropertyBasePointer
 {
     const QtPrivate::QPropertyBase *ptr = nullptr;
 
-    QPropertyBindingPrivate *bindingPtr() const;
+    QPropertyBindingPrivate *bindingPtr() const
+    {
+        if (ptr->d_ptr & QtPrivate::QPropertyBase::BindingBit)
+            return reinterpret_cast<QPropertyBindingPrivate*>(ptr->d_ptr & ~QtPrivate::QPropertyBase::FlagMask);
+        return nullptr;
+    }
 
-    void setObservers(QPropertyObserver *observer);
+    void setObservers(QPropertyObserver *observer)
+    {
+        observer->prev = reinterpret_cast<QPropertyObserver**>(&(ptr->d_ptr));
+        ptr->d_ptr = (reinterpret_cast<quintptr>(observer) & ~QtPrivate::QPropertyBase::FlagMask);
+    }
     void addObserver(QPropertyObserver *observer);
     void setFirstObserver(QPropertyObserver *observer);
     QPropertyObserverPointer firstObserver() const;
@@ -114,6 +129,150 @@ struct BindingEvaluationState
     BindingEvaluationState **currentState = nullptr;
 };
 
+class Q_CORE_EXPORT QPropertyBindingPrivate : public QSharedData
+{
+private:
+    friend struct QPropertyBasePointer;
+
+    using ObserverArray = std::array<QPropertyObserver, 4>;
+
+    // QSharedData is 4 bytes. Use the padding for the bools as we need 8 byte alignment below.
+    bool dirty = false;
+    bool updating = false;
+    bool hasStaticObserver = false;
+    bool isBool = false;
+
+    QUntypedPropertyBinding::BindingEvaluationFunction evaluationFunction;
+
+    QPropertyObserverPointer firstObserver;
+    union {
+        ObserverArray inlineDependencyObservers;
+        struct {
+            void *staticObserver;
+            QtPrivate::QPropertyObserverCallback staticObserverCallback;
+            QtPrivate::QPropertyGuardFunction staticGuardCallback;
+        };
+    };
+    QScopedPointer<std::vector<QPropertyObserver>> heapObservers;
+
+    void *propertyDataPtr = nullptr;
+
+    QPropertyBindingSourceLocation location;
+    QPropertyBindingError error;
+
+    QMetaType metaType;
+
+public:
+    // public because the auto-tests access it, too.
+    size_t dependencyObserverCount = 0;
+
+    QPropertyBindingPrivate(const QMetaType &metaType, QUntypedPropertyBinding::BindingEvaluationFunction evaluationFunction,
+                            const QPropertyBindingSourceLocation &location)
+        : isBool(metaType.id() == QMetaType::Bool)
+        , evaluationFunction(std::move(evaluationFunction))
+        , inlineDependencyObservers() // Explicit initialization required because of union
+        , location(location)
+        , metaType(metaType)
+    {}
+    virtual ~QPropertyBindingPrivate();
+
+    void setDirty(bool d) { dirty = d; }
+    void setProperty(void *propertyPtr) { propertyDataPtr = propertyPtr; }
+    void setStaticObserver(void *observer, QtPrivate::QPropertyObserverCallback callback,
+                           QtPrivate::QPropertyGuardFunction guardCallback)
+    {
+        if (observer) {
+            if (!hasStaticObserver) {
+                if (dependencyObserverCount > 0) {
+                    if (!heapObservers)
+                        heapObservers.reset(new std::vector<QPropertyObserver>());
+                    for (size_t i = 0, end = qMin(dependencyObserverCount, inlineDependencyObservers.size()); i < end; ++i)
+                        heapObservers->push_back(std::move(inlineDependencyObservers[i]));
+                }
+                inlineDependencyObservers.~ObserverArray();
+            }
+
+            hasStaticObserver = true;
+            staticObserver = observer;
+            staticObserverCallback = callback;
+            staticGuardCallback = guardCallback;
+        } else if (hasStaticObserver) {
+            hasStaticObserver = false;
+            new (&inlineDependencyObservers) ObserverArray();
+            for (size_t i = 0, end = qMin(dependencyObserverCount, inlineDependencyObservers.size()); i < end; ++i) {
+                inlineDependencyObservers[i] = std::move(heapObservers->back());
+                heapObservers->pop_back();
+            }
+        }
+    }
+    void prependObserver(QPropertyObserverPointer observer) {
+        observer.ptr->prev = const_cast<QPropertyObserver **>(&firstObserver.ptr);
+        firstObserver = observer;
+    }
+
+    QPropertyObserverPointer takeObservers()
+    {
+        auto observers = firstObserver;
+        firstObserver.ptr = nullptr;
+        return observers;
+    }
+
+    void clearDependencyObservers() {
+        if (!hasStaticObserver) {
+            for (size_t i = 0; i < qMin(dependencyObserverCount, inlineDependencyObservers.size()); ++i) {
+                QPropertyObserverPointer p{&inlineDependencyObservers[i]};
+                p.unlink();
+            }
+        }
+        if (heapObservers)
+            heapObservers->clear();
+        dependencyObserverCount = 0;
+    }
+    QPropertyObserverPointer allocateDependencyObserver() {
+        if (!hasStaticObserver && dependencyObserverCount < inlineDependencyObservers.size()) {
+            ++dependencyObserverCount;
+            return {&inlineDependencyObservers[dependencyObserverCount - 1]};
+        }
+        ++dependencyObserverCount;
+        if (!heapObservers)
+            heapObservers.reset(new std::vector<QPropertyObserver>());
+        return {&heapObservers->emplace_back()};
+    }
+
+    QPropertyBindingSourceLocation sourceLocation() const { return location; }
+    QPropertyBindingError bindingError() const { return error; }
+    QMetaType valueMetaType() const { return metaType; }
+
+    void unlinkAndDeref();
+
+    void markDirtyAndNotifyObservers();
+    bool evaluateIfDirtyAndReturnTrueIfValueChanged();
+
+    static QPropertyBindingPrivate *get(const QUntypedPropertyBinding &binding)
+    { return binding.d.data(); }
+
+    void setError(QPropertyBindingError &&e)
+    { error = std::move(e); }
+
+    static QPropertyBindingPrivate *currentlyEvaluatingBinding();
+};
+
+inline void QPropertyBasePointer::setFirstObserver(QPropertyObserver *observer)
+{
+    if (auto *binding = bindingPtr()) {
+        binding->firstObserver.ptr = observer;
+        return;
+    }
+    ptr->d_ptr = reinterpret_cast<quintptr>(observer) | (ptr->d_ptr & QtPrivate::QPropertyBase::FlagMask);
+}
+
+inline QPropertyObserverPointer QPropertyBasePointer::firstObserver() const
+{
+    if (auto *binding = bindingPtr())
+        return binding->firstObserver;
+    return {reinterpret_cast<QPropertyObserver*>(ptr->d_ptr & ~QtPrivate::QPropertyBase::FlagMask)};
+}
+
 QT_END_NAMESPACE
 
 #endif // QPROPERTY_P_H