| /**************************************************************************** |
| ** |
| ** Copyright (C) 2016 The Qt Company Ltd. |
| ** Contact: https://www.qt.io/licensing/ |
| ** |
| ** This file is part of the QtConcurrent 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 |
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| ** GNU Lesser General Public License Usage |
| ** Alternatively, this file may be used under the terms of the GNU Lesser |
| ** General Public License version 3 as published by the Free Software |
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| ** packaging of this file. Please review the following information to |
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| ** |
| ** GNU General Public License Usage |
| ** Alternatively, this file may be used under the terms of the GNU |
| ** General Public License version 2.0 or (at your option) the GNU General |
| ** Public license version 3 or any later version approved by the KDE Free |
| ** Qt Foundation. The licenses are as published by the Free Software |
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| ** information to ensure the GNU General Public License requirements will |
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| ** |
| ** $QT_END_LICENSE$ |
| ** |
| ****************************************************************************/ |
| |
| #include "qtconcurrentiteratekernel.h" |
| |
| #include <qdeadlinetimer.h> |
| #include "private/qfunctions_p.h" |
| |
| |
| #if !defined(QT_NO_CONCURRENT) || defined(Q_CLANG_QDOC) |
| |
| QT_BEGIN_NAMESPACE |
| |
| enum { |
| TargetRatio = 100, |
| MedianSize = 7 |
| }; |
| |
| static qint64 getticks() |
| { |
| return QDeadlineTimer::current(Qt::PreciseTimer).deadlineNSecs(); |
| } |
| |
| static double elapsed(qint64 after, qint64 before) |
| { |
| return double(after - before); |
| } |
| |
| namespace QtConcurrent { |
| |
| /*! |
| \class QtConcurrent::Median |
| \inmodule QtConcurrent |
| \internal |
| */ |
| |
| /*! |
| \class QtConcurrent::MedianDouble |
| \inmodule QtConcurrent |
| \internal |
| */ |
| |
| /*! |
| \class QtConcurrent::BlockSizeManager |
| \inmodule QtConcurrent |
| \internal |
| */ |
| |
| /*! |
| \class QtConcurrent::BlockSizeManagerV2 |
| \inmodule QtConcurrent |
| \internal |
| */ |
| |
| /*! |
| \class QtConcurrent::ResultReporter |
| \inmodule QtConcurrent |
| \internal |
| */ |
| |
| /*! \fn bool QtConcurrent::selectIteration(std::bidirectional_iterator_tag) |
| \internal |
| */ |
| |
| /*! \fn bool QtConcurrent::selectIteration(std::forward_iterator_tag) |
| \internal |
| */ |
| |
| /*! \fn bool QtConcurrent::selectIteration(std::random_access_iterator_tag) |
| \internal |
| */ |
| |
| /*! |
| \class QtConcurrent::IterateKernel |
| \inmodule QtConcurrent |
| \internal |
| */ |
| |
| /*! \internal |
| |
| */ |
| BlockSizeManager::BlockSizeManager(int iterationCount) |
| : maxBlockSize(iterationCount / (QThreadPool::globalInstance()->maxThreadCount() * 2)), |
| beforeUser(0), afterUser(0), |
| controlPartElapsed(MedianSize), userPartElapsed(MedianSize), |
| m_blockSize(1) |
| { } |
| |
| // Records the time before user code. |
| void BlockSizeManager::timeBeforeUser() |
| { |
| if (blockSizeMaxed()) |
| return; |
| |
| beforeUser = getticks(); |
| controlPartElapsed.addValue(elapsed(beforeUser, afterUser)); |
| } |
| |
| // Records the time after user code and adjust the block size if we are spending |
| // to much time in the for control code compared with the user code. |
| void BlockSizeManager::timeAfterUser() |
| { |
| if (blockSizeMaxed()) |
| return; |
| |
| afterUser = getticks(); |
| userPartElapsed.addValue(elapsed(afterUser, beforeUser)); |
| |
| if (controlPartElapsed.isMedianValid() == false) |
| return; |
| |
| if (controlPartElapsed.median() * TargetRatio < userPartElapsed.median()) |
| return; |
| |
| m_blockSize = qMin(m_blockSize * 2, maxBlockSize); |
| |
| #ifdef QTCONCURRENT_FOR_DEBUG |
| qDebug() << QThread::currentThread() << "adjusting block size" << controlPartElapsed.median() << userPartElapsed.median() << m_blockSize; |
| #endif |
| |
| // Reset the medians after adjusting the block size so we get |
| // new measurements with the new block size. |
| controlPartElapsed.reset(); |
| userPartElapsed.reset(); |
| } |
| |
| int BlockSizeManager::blockSize() |
| { |
| return m_blockSize; |
| } |
| |
| /*! \internal |
| |
| */ |
| BlockSizeManagerV2::BlockSizeManagerV2(int iterationCount) |
| : maxBlockSize(iterationCount / (QThreadPool::globalInstance()->maxThreadCount() * 2)), |
| beforeUser(0), afterUser(0), |
| m_blockSize(1) |
| { } |
| |
| // Records the time before user code. |
| void BlockSizeManagerV2::timeBeforeUser() |
| { |
| if (blockSizeMaxed()) |
| return; |
| |
| beforeUser = getticks(); |
| controlPartElapsed.addValue(elapsed(beforeUser, afterUser)); |
| } |
| |
| // Records the time after user code and adjust the block size if we are spending |
| // to much time in the for control code compared with the user code. |
| void BlockSizeManagerV2::timeAfterUser() |
| { |
| if (blockSizeMaxed()) |
| return; |
| |
| afterUser = getticks(); |
| userPartElapsed.addValue(elapsed(afterUser, beforeUser)); |
| |
| if (controlPartElapsed.isMedianValid() == false) |
| return; |
| |
| if (controlPartElapsed.median() * TargetRatio < userPartElapsed.median()) |
| return; |
| |
| m_blockSize = qMin(m_blockSize * 2, maxBlockSize); |
| |
| #ifdef QTCONCURRENT_FOR_DEBUG |
| qDebug() << QThread::currentThread() << "adjusting block size" << controlPartElapsed.median() << userPartElapsed.median() << m_blockSize; |
| #endif |
| |
| // Reset the medians after adjusting the block size so we get |
| // new measurements with the new block size. |
| controlPartElapsed.reset(); |
| userPartElapsed.reset(); |
| } |
| |
| int BlockSizeManagerV2::blockSize() |
| { |
| return m_blockSize; |
| } |
| |
| } // namespace QtConcurrent |
| |
| QT_END_NAMESPACE |
| |
| #endif // QT_NO_CONCURRENT |