/*
    SPDX-FileCopyrightText: 2020 Vlad Zahorodnii <vlad.zahorodnii@kde.org>

    SPDX-License-Identifier: GPL-2.0-or-later
*/

#include "eglnativefence.h"
#include "egldisplay.h"

#include <unistd.h>

namespace KWin
{

#ifndef EGL_ANDROID_native_fence_sync
#define EGL_SYNC_NATIVE_FENCE_ANDROID 0x3144
#define EGL_NO_NATIVE_FENCE_FD_ANDROID -1
#endif // EGL_ANDROID_native_fence_sync

EGLNativeFence::EGLNativeFence(EglDisplay *display)
    : m_display(display)
{
    if (!display->supportsNativeFence()) {
        m_sync = EGL_NO_SYNC_KHR;
        return;
    }

    m_sync = eglCreateSyncKHR(display->handle(), EGL_SYNC_NATIVE_FENCE_ANDROID, nullptr);

    if (m_sync != EGL_NO_SYNC_KHR) {
        // The native fence will get a valid sync file fd only after a flush.
        glFlush();
        m_fileDescriptor = FileDescriptor(eglDupNativeFenceFDANDROID(m_display->handle(), m_sync));
    }
}

EGLNativeFence::EGLNativeFence(EglDisplay *display, EGLSyncKHR sync)
    : m_sync(sync)
    , m_display(display)
{
}

EGLNativeFence::~EGLNativeFence()
{
    m_fileDescriptor.reset();
    if (m_sync != EGL_NO_SYNC_KHR) {
        eglDestroySyncKHR(m_display->handle(), m_sync);
    }
}

bool EGLNativeFence::isValid() const
{
    return m_sync != EGL_NO_SYNC_KHR && m_fileDescriptor.isValid();
}

const FileDescriptor &EGLNativeFence::fileDescriptor() const
{
    return m_fileDescriptor;
}

FileDescriptor &&EGLNativeFence::takeFileDescriptor()
{
    return std::move(m_fileDescriptor);
}

bool EGLNativeFence::waitSync() const
{
    return eglWaitSync(m_display->handle(), m_sync, 0) == EGL_TRUE;
}

EGLNativeFence EGLNativeFence::importFence(EglDisplay *display, FileDescriptor &&fd)
{
    EGLint attributes[] = {
        EGL_SYNC_NATIVE_FENCE_FD_ANDROID, fd.get(),
        EGL_NONE};
    auto ret = eglCreateSyncKHR(display->handle(), EGL_SYNC_NATIVE_FENCE_ANDROID, attributes);
    if (ret != EGL_NO_SYNC_KHR) {
        // eglCreateSyncKHR takes ownership only on success
        fd.take();
    }
    return EGLNativeFence(display, ret);
}

} // namespace KWin
