Revision control
++ // Copyright (C) 2016 The Qt Company Ltd.
++ // Copyright (C) 2016 Intel Corporation.
++ // Copyright (C) 2012 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
++ // Qt-Security score:significant reason:default
++
++ #ifndef QMUTEX_P_H
++ #define QMUTEX_P_H
++
++ //
++ // W A R N I N G
++ // -------------
++ //
++ // This file is not part of the Qt API. It exists for the convenience of
++ // qmutex.cpp and qmutex_unix.cpp. This header file may change from version to
++ // version without notice, or even be removed.
++ //
++ // We mean it.
++ //
++
++ #include <QtCore/private/qglobal_p.h>
++ #include <QtCore/qnamespace.h>
++ #include <QtCore/qmutex.h>
++ #include <QtCore/qatomic.h>
++ #include <QtCore/qdeadlinetimer.h>
++
++ #include "qplatformdefs.h" // _POSIX_VERSION
++
++ #if defined(Q_OS_UNIX)
++ # include <semaphore.h>
++ #endif
++
++ struct timespec;
++
++ QT_BEGIN_NAMESPACE
++
++ // ### Qt7 remove this comment block
++ // We manipulate the pointer to this class in inline, atomic code,
++ // so syncqt mustn't mark them as private, so ELFVERSION:ignore-next
++ class QMutexPrivate
++ {
++ public:
++ ~QMutexPrivate();
++ QMutexPrivate();
++
++ bool wait(QDeadlineTimer timeout = QDeadlineTimer::Forever);
++ void wakeUp() noexcept;
++
++ // Control the lifetime of the privates
++ QAtomicInt refCount;
++ int id;
++
++ bool ref()
++ {
++ Q_ASSERT(refCount.loadRelaxed() >= 0);
++ int c;
++ do {
++ c = refCount.loadRelaxed();
++ if (c == 0)
++ return false;
++ } while (!refCount.testAndSetRelaxed(c, c + 1));
++ Q_ASSERT(refCount.loadRelaxed() >= 0);
++ return true;
++ }
++ void deref()
++ {
++ Q_ASSERT(refCount.loadRelaxed() >= 0);
++ if (!refCount.deref())
++ release();
++ Q_ASSERT(refCount.loadRelaxed() >= 0);
++ }
++ void release();
++ static QMutexPrivate *allocate();
++
++ QAtomicInt waiters; // Number of threads waiting on this mutex. (may be offset by -BigNumber)
++ QAtomicInt possiblyUnlocked; /* Boolean indicating that a timed wait timed out.
++ When it is true, a reference is held.
++ It is there to avoid a race that happens if unlock happens right
++ when the mutex is unlocked.
++ */
++ enum { BigNumber = 0x100000 }; //Must be bigger than the possible number of waiters (number of threads)
++ void derefWaiters(int value) noexcept;
++
++ //platform specific stuff
++ #if defined(Q_OS_UNIX)
++ sem_t semaphore;
++ #endif
++ };
++
++ QT_END_NAMESPACE
++
++ #endif // QMUTEX_P_H