Infrastructure for supporting multiple profilers in qqmlprofilerservice

The concepts of "global" and "engine" profilers are introduced. Profilers
can either be attached to specific QML engines and run in their threads
or they can be unspecific global profilers running in arbitrary threads.

Change-Id: I3862fc65c07ccb33a1ca08cd2425e4079d3ffc02
Reviewed-by: Kai Koehne <kai.koehne@digia.com>

1 files changed, 109 insertions, 0 deletions

diff --git a/src/qml/debugger/qqmlabstractprofileradapter.cpp b/src/qml/debugger/qqmlabstractprofileradapter.cpp
new file mode 100644
index 0000000000..b5962657b1
--- /dev/null
+++ b/src/qml/debugger/qqmlabstractprofileradapter.cpp
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+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qqmlabstractprofileradapter_p.h"
+
+QT_BEGIN_NAMESPACE
+
+/*!
+ * \class QQmlAbstractProfilerAdapter
+ * Abstract base class for all adapters between profilers and the QQmlProfilerService. Adapters have
+ * to retrieve profiler-specific data and convert it to the format sent over the wire. Adapters must
+ * live in the QDebugServer thread but the actual profilers can live in different threads. The
+ * recommended way to deal with this is passing the profiling data through a signal/slot connection.
+ */
+
+/*!
+ * \fn void QQmlAbstractProfilerAdapter::dataReady(QQmlAbstractProfilerAdapter *)
+ * Signals that data has been extracted from the profiler and is readily available in the adapter.
+ * The primary data representation is in satellite's format. It should be transformed and deleted
+ * on the fly with sendMessages.
+ */
+
+/*!
+ * \fn void QQmlAbstractProfilerAdapter::dataRequested()
+ * Signals that data has been requested by the \c QQmlProfilerService. This signal should be
+ * connected to a slot in the profiler and the profiler should then transfer its currently available
+ * profiling data to the adapter as soon as possible.
+ */
+
+/*!
+ * \fn qint64 QQmlAbstractProfilerAdapter::sendMessages(qint64 until, QList<QByteArray> &messages)
+ * Append the messages up to the timestamp \a until, chronologically sorted, to \a messages. Keep
+ * track of the messages already sent and with each subsequent call to this method start with the
+ * first one not yet sent. Messages that have been sent can be deleted. When new data from the
+ * profiler arrives the information about the last sent message must be reset. Return the timestamp
+ * of the next message after \a until or \c -1 if there is no such message.
+ * The profiler service keeps a list of adapters, sorted by time of next message and keeps querying
+ * the first one to send messages up to the time of the second one. Like that we get chronologically
+ * sorted messages and can occasionally post the messages to exploit parallelism and save memory.
+ */
+
+/*!
+ * \fn qint64 QQmlAbstractProfilerAdapter::startProfiling()
+ * Emits either \c profilingEnabled() or \c profilingEnabledWhileWaiting(), depending on \c waiting.
+ * If the profiler's thread is waiting for an initial start signal we can emit the signal over a
+ * \c Qt::DirectConnection to avoid the delay of the event loop.
+ */
+void QQmlAbstractProfilerAdapter::startProfiling()
+{
+    if (waiting)
+        emit profilingEnabledWhileWaiting();
+    else
+        emit profilingEnabled();
+    running = true;
+}
+
+/*!
+ * \fn qint64 QQmlAbstractProfilerAdapter::stopProfiling()
+ * Emits either \c profilingDisabled() or \c profilingDisabledWhileWaiting(), depending on
+ * \c waiting. If the profiler's thread is waiting for an initial start signal we can emit the
+ * signal over a \c Qt::DirectConnection to avoid the delay of the event loop.
+ */
+void QQmlAbstractProfilerAdapter::stopProfiling() {
+    if (waiting)
+        emit profilingDisabledWhileWaiting();
+    else
+        emit profilingDisabled();
+    running = false;
+}
+
+QT_END_NAMESPACE