diff options
author | J-P Nurmi <jpnurmi@qt.io> | 2017-12-11 21:49:53 +0100 |
---|---|---|
committer | J-P Nurmi <jpnurmi@qt.io> | 2017-12-12 14:39:48 +0000 |
commit | d9e740d2ccf8c1d3caacfcd95537718048e3a7ba (patch) | |
tree | d6a5cd642183974e1947275dee199270d3141310 /src/quicktemplates2/qquickdeferredexecute.cpp | |
parent | 64a01ff5b5d1eaadb1e60013673ac25459b79e14 (diff) |
Migitate the performance regression caused by deferred execution
458eb65f7 introduced a performance regression. Before 458eb65f7, qmlbench
delegates_button.qml results were around 40 frames on a TX1. After 458eb65f,
it dropped to 32. This patch is unfortunately not able to bring it on the
original level, but at least improves the results to 37.
For QQuickText, it is extremely important that implicitWidth() gets called
before the component is completed, to avoid doing implicit size calculation
multiple times. Deferred execution caused a performance regression by creating
contentItem in "one go". We need to split the deferred execution to two parts
so that bindings get first setup, and later enabled upon completion. This way,
we utilize QQuickText's performance optimization for implicit size calculation.
Task-number: QTBUG-50992
Change-Id: I4bf00af71b6d7dbf1d4b58b00fe547c6c321f8ed
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>
Diffstat (limited to 'src/quicktemplates2/qquickdeferredexecute.cpp')
-rw-r--r-- | src/quicktemplates2/qquickdeferredexecute.cpp | 29 |
1 files changed, 25 insertions, 4 deletions
diff --git a/src/quicktemplates2/qquickdeferredexecute.cpp b/src/quicktemplates2/qquickdeferredexecute.cpp index 7ec4e8e8..802ed3d0 100644 --- a/src/quicktemplates2/qquickdeferredexecute.cpp +++ b/src/quicktemplates2/qquickdeferredexecute.cpp @@ -36,6 +36,7 @@ #include "qquickdeferredexecute_p_p.h" +#include <QtCore/qhash.h> #include <QtQml/qqmlengine.h> #include <QtQml/private/qqmldata_p.h> #include <QtQml/private/qqmlcomponent_p.h> @@ -45,6 +46,15 @@ QT_BEGIN_NAMESPACE namespace QtQuickPrivate { +typedef QHash<uint, QQmlComponentPrivate::DeferredState *> DeferredStates; + +static inline uint qHash(QObject *object, const QString &propertyName) +{ + return ::qHash(object) + ::qHash(propertyName); +} + +Q_GLOBAL_STATIC(DeferredStates, deferredStates) + static void beginDeferred(QQmlEnginePrivate *enginePriv, const QQmlProperty &property, QQmlComponentPrivate::DeferredState *deferredState) { QObject *object = property.object(); @@ -89,20 +99,31 @@ static void beginDeferred(QQmlEnginePrivate *enginePriv, const QQmlProperty &pro } } -void executeDeferred(QObject *object, const QString &property) +void beginDeferred(QObject *object, const QString &property) { QQmlData *data = QQmlData::get(object); if (data && !data->deferredData.isEmpty() && !data->wasDeleted(object)) { QQmlEnginePrivate *ep = QQmlEnginePrivate::get(data->context->engine); - QQmlComponentPrivate::DeferredState state; - beginDeferred(ep, QQmlProperty(object, property), &state); + QQmlComponentPrivate::DeferredState *state = new QQmlComponentPrivate::DeferredState; + beginDeferred(ep, QQmlProperty(object, property), state); // Release deferred data for those compilation units that no longer have deferred bindings data->releaseDeferredData(); - QQmlComponentPrivate::completeDeferred(ep, &state); + deferredStates()->insert(qHash(object, property), state); + } +} + +void completeDeferred(QObject *object, const QString &property) +{ + QQmlData *data = QQmlData::get(object); + QQmlComponentPrivate::DeferredState *state = deferredStates()->take(qHash(object, property)); + if (data && state && !data->wasDeleted(object)) { + QQmlEnginePrivate *ep = QQmlEnginePrivate::get(data->context->engine); + QQmlComponentPrivate::completeDeferred(ep, state); } + delete state; } } // QtQuickPrivate |