qautoresetevent_linux.cpp

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// Copyright (C) 2024 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#include "qautoresetevent_linux_p.h"
 
#include <QtMultimedia/private/qtmm_rtsan_support_p.h>
#include <QtCore/private/qcore_unix_p.h>
#include <QtCore/qdebug.h>
 
#include <sys/eventfd.h>
#include <cstdint>
 
QT_BEGIN_NAMESPACE
 
namespace QtPrivate {
 
QAutoResetEventEventFD::QAutoResetEventEventFD(QObject *parent)
    : QObject{
          parent,
      },
      m_fd{
          eventfd(/*initval=*/0, EFD_NONBLOCK),
      },
      m_notifier{
          QSocketNotifier::Type::Read,
          this,
      }
{
    if (!isValid()) {
        qCritical() << "eventfd failed:" << qt_error_string(errno);
        return;
    }
 
    connect(&m_notifier, &QSocketNotifier::activated, this, [this] {
        uint64_t payload;
 
        std::ignore = qt_safe_read(m_fd.get(), &payload, sizeof(payload));
 
        Q_EMIT activated();
    });
    m_notifier.setSocket(m_fd.get());
    m_notifier.setEnabled(true);
}
 
void QAutoResetEventEventFD::set()
{
    Q_ASSERT(isValid());
 
    constexpr uint64_t increment{ 1 };
 
    ScopedRTSanDisabler disabler; // opened via EFD_NONBLOCK
    qint64 bytesWritten = qt_safe_write(m_fd.get(), &increment, sizeof(increment));
    if (bytesWritten == -1)
        qCritical("QAutoResetEvent::set failed");
}
 
} // namespace QtPrivate
 
QT_END_NAMESPACE
 
#include "moc_qautoresetevent_linux_p.cpp"