diff options
Diffstat (limited to 'src/corelib/thread/qreadwritelock_p.h')
-rw-r--r-- | src/corelib/thread/qreadwritelock_p.h | 114 |
1 files changed, 63 insertions, 51 deletions
diff --git a/src/corelib/thread/qreadwritelock_p.h b/src/corelib/thread/qreadwritelock_p.h index a4d002b7f2..68fa642a73 100644 --- a/src/corelib/thread/qreadwritelock_p.h +++ b/src/corelib/thread/qreadwritelock_p.h @@ -1,42 +1,6 @@ -/**************************************************************************** -** -** Copyright (C) 2016 The Qt Company Ltd. -** Copyright (C) 2016 Olivier Goffart <ogoffart@woboq.com> -** Contact: https://www.qt.io/licensing/ -** -** This file is part of the QtCore 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 The Qt Company. For licensing terms -** and conditions see https://www.qt.io/terms-conditions. For further -** information use the contact form at https://www.qt.io/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 3 as published by the Free Software -** Foundation and appearing in the file LICENSE.LGPL3 included in the -** packaging of this file. Please review the following information to -** ensure the GNU Lesser General Public License version 3 requirements -** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. -** -** 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 -** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 -** included in the packaging of this file. Please review the following -** information to ensure the GNU General Public License requirements will -** be met: https://www.gnu.org/licenses/gpl-2.0.html and -** https://www.gnu.org/licenses/gpl-3.0.html. -** -** $QT_END_LICENSE$ -** -****************************************************************************/ +// Copyright (C) 2016 The Qt Company Ltd. +// Copyright (C) 2016 Olivier Goffart <ogoffart@woboq.com> +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only #ifndef QREADWRITELOCK_P_H #define QREADWRITELOCK_P_H @@ -52,23 +16,39 @@ // We mean it. // -#include <QtCore/private/qglobal_p.h> -#include <QtCore/qhash.h> -#include <QtCore/qwaitcondition.h> +#include <QtCore/private/qlocking_p.h> +#include <QtCore/private/qwaitcondition_p.h> +#include <QtCore/qreadwritelock.h> +#include <QtCore/qvarlengtharray.h> QT_REQUIRE_CONFIG(thread); QT_BEGIN_NAMESPACE +namespace QReadWriteLockStates { +enum { + StateMask = 0x3, + StateLockedForRead = 0x1, + StateLockedForWrite = 0x2, +}; +enum StateForWaitCondition { + LockedForRead, + LockedForWrite, + Unlocked, + RecursivelyLocked +}; +} + class QReadWriteLockPrivate { public: explicit QReadWriteLockPrivate(bool isRecursive = false) : recursive(isRecursive) {} - QMutex mutex; - QWaitCondition writerCond; - QWaitCondition readerCond; + alignas(QtPrivate::IdealMutexAlignment) std::condition_variable writerCond; + std::condition_variable readerCond; + + alignas(QtPrivate::IdealMutexAlignment) std::mutex mutex; int readerCount = 0; int writerCount = 0; int waitingReaders = 0; @@ -76,8 +56,8 @@ public: const bool recursive; //Called with the mutex locked - bool lockForWrite(int timeout); - bool lockForRead(int timeout); + bool lockForWrite(std::unique_lock<std::mutex> &lock, QDeadlineTimer timeout); + bool lockForRead(std::unique_lock<std::mutex> &lock, QDeadlineTimer timeout); void unlock(); //memory management @@ -85,15 +65,47 @@ public: void release(); static QReadWriteLockPrivate *allocate(); - // Recusive mutex handling + // Recursive mutex handling Qt::HANDLE currentWriter = {}; - QHash<Qt::HANDLE, int> currentReaders; + + struct Reader { + Qt::HANDLE handle; + int recursionLevel; + }; + + QVarLengthArray<Reader, 16> currentReaders; // called with the mutex unlocked - bool recursiveLockForWrite(int timeout); - bool recursiveLockForRead(int timeout); + bool recursiveLockForWrite(QDeadlineTimer timeout); + bool recursiveLockForRead(QDeadlineTimer timeout); void recursiveUnlock(); + + static QReadWriteLockStates::StateForWaitCondition + stateForWaitCondition(const QReadWriteLock *lock); }; +Q_DECLARE_TYPEINFO(QReadWriteLockPrivate::Reader, Q_PRIMITIVE_TYPE);\ + +/*! \internal Helper for QWaitCondition::wait */ +inline QReadWriteLockStates::StateForWaitCondition +QReadWriteLockPrivate::stateForWaitCondition(const QReadWriteLock *q) +{ + using namespace QReadWriteLockStates; + QReadWriteLockPrivate *d = q->d_ptr.loadAcquire(); + switch (quintptr(d) & StateMask) { + case StateLockedForRead: return LockedForRead; + case StateLockedForWrite: return LockedForWrite; + } + + if (!d) + return Unlocked; + const auto lock = qt_scoped_lock(d->mutex); + if (d->writerCount > 1) + return RecursivelyLocked; + else if (d->writerCount == 1) + return LockedForWrite; + return LockedForRead; + +} QT_END_NAMESPACE |