kwin/src/x11syncmanager.cpp
Vlad Zahorodnii e88a4e34a3 Remove some include_directories()
It seems we've settled on dir/dir/header.h includes, so let's use them
consistently.
2023-03-23 14:37:48 +02:00

232 lines
6.3 KiB
C++

/*
SPDX-FileCopyrightText: 2014 Fredrik Höglund <fredrik@kde.org>
Explicit command stream synchronization based on the sample implementation by James Jones <jajones@nvidia.com>,
SPDX-FileCopyrightText: 2011 NVIDIA Corporation
SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "x11syncmanager.h"
#include "composite.h"
#include "core/outputbackend.h"
#include "core/renderbackend.h"
#include "main.h"
#include "scene/workspacescene.h"
#include "utils/common.h"
#include "libkwineffects/kwinglplatform.h"
namespace KWin
{
X11SyncObject::X11SyncObject()
{
m_state = Ready;
xcb_connection_t *const connection = kwinApp()->x11Connection();
m_fence = xcb_generate_id(connection);
xcb_sync_create_fence(connection, kwinApp()->x11RootWindow(), m_fence, false);
xcb_flush(connection);
m_sync = glImportSyncEXT(GL_SYNC_X11_FENCE_EXT, m_fence, 0);
}
X11SyncObject::~X11SyncObject()
{
xcb_connection_t *const connection = kwinApp()->x11Connection();
// If glDeleteSync is called before the xcb fence is signalled
// the nvidia driver (the only one to implement GL_SYNC_X11_FENCE_EXT)
// deadlocks waiting for the fence to be signalled.
// To avoid this, make sure the fence is signalled before
// deleting the sync.
if (m_state == Resetting || m_state == Ready) {
trigger();
// The flush is necessary!
// The trigger command needs to be sent to the X server.
xcb_flush(connection);
}
xcb_sync_destroy_fence(connection, m_fence);
glDeleteSync(m_sync);
if (m_state == Resetting) {
xcb_discard_reply(connection, m_reset_cookie.sequence);
}
}
void X11SyncObject::trigger()
{
Q_ASSERT(m_state == Ready || m_state == Resetting);
// Finish resetting the fence if necessary
if (m_state == Resetting) {
finishResetting();
}
xcb_sync_trigger_fence(kwinApp()->x11Connection(), m_fence);
m_state = TriggerSent;
}
void X11SyncObject::wait()
{
if (m_state != TriggerSent) {
return;
}
glWaitSync(m_sync, 0, GL_TIMEOUT_IGNORED);
m_state = Waiting;
}
bool X11SyncObject::finish()
{
if (m_state == Done) {
return true;
}
// Note: It is possible that we never inserted a wait for the fence.
// This can happen if we ended up not rendering the damaged
// window because it is fully occluded.
Q_ASSERT(m_state == TriggerSent || m_state == Waiting);
// Check if the fence is signaled
GLint value;
glGetSynciv(m_sync, GL_SYNC_STATUS, 1, nullptr, &value);
if (value != GL_SIGNALED) {
qCDebug(KWIN_CORE) << "Waiting for X fence to finish";
// Wait for the fence to become signaled with a one second timeout
const GLenum result = glClientWaitSync(m_sync, 0, 1000000000);
switch (result) {
case GL_TIMEOUT_EXPIRED:
qCWarning(KWIN_CORE) << "Timeout while waiting for X fence";
return false;
case GL_WAIT_FAILED:
qCWarning(KWIN_CORE) << "glClientWaitSync() failed";
return false;
}
}
m_state = Done;
return true;
}
void X11SyncObject::reset()
{
Q_ASSERT(m_state == Done);
xcb_connection_t *const connection = kwinApp()->x11Connection();
// Send the reset request along with a sync request.
// We use the cookie to ensure that the server has processed the reset
// request before we trigger the fence and call glWaitSync().
// Otherwise there is a race condition between the reset finishing and
// the glWaitSync() call.
xcb_sync_reset_fence(connection, m_fence);
m_reset_cookie = xcb_get_input_focus(connection);
xcb_flush(connection);
m_state = Resetting;
}
void X11SyncObject::finishResetting()
{
Q_ASSERT(m_state == Resetting);
free(xcb_get_input_focus_reply(kwinApp()->x11Connection(), m_reset_cookie, nullptr));
m_state = Ready;
}
X11SyncManager *X11SyncManager::create()
{
if (kwinApp()->operationMode() != Application::OperationModeX11) {
return nullptr;
}
if (Compositor::self()->backend()->compositingType() != OpenGLCompositing) {
return nullptr;
}
GLPlatform *glPlatform = GLPlatform::instance();
const bool haveSyncObjects = glPlatform->isGLES()
? hasGLVersion(3, 0)
: hasGLVersion(3, 2) || hasGLExtension("GL_ARB_sync");
if (hasGLExtension("GL_EXT_x11_sync_object") && haveSyncObjects) {
const QString useExplicitSync = qEnvironmentVariable("KWIN_EXPLICIT_SYNC");
if (useExplicitSync != QLatin1String("0")) {
qCDebug(KWIN_CORE) << "Initializing fences for synchronization with the X command stream";
return new X11SyncManager;
} else {
qCDebug(KWIN_CORE) << "Explicit synchronization with the X command stream disabled by environment variable";
}
}
return nullptr;
}
X11SyncManager::X11SyncManager()
{
for (int i = 0; i < MaxFences; ++i) {
m_fences.append(new X11SyncObject);
}
}
X11SyncManager::~X11SyncManager()
{
Compositor::self()->scene()->makeOpenGLContextCurrent();
qDeleteAll(m_fences);
}
bool X11SyncManager::endFrame()
{
if (!m_currentFence) {
return true;
}
for (int i = 0; i < std::min<int>(2, m_fences.count() - 1); i++) {
const int index = (m_next + i) % m_fences.count();
X11SyncObject *fence = m_fences[index];
switch (fence->state()) {
case X11SyncObject::Ready:
break;
case X11SyncObject::TriggerSent:
case X11SyncObject::Waiting:
if (!fence->finish()) {
return false;
}
fence->reset();
break;
// Should not happen in practice since we always reset the fence after finishing it
case X11SyncObject::Done:
fence->reset();
break;
case X11SyncObject::Resetting:
fence->finishResetting();
break;
}
}
m_currentFence = nullptr;
return true;
}
void X11SyncManager::triggerFence()
{
m_currentFence = m_fences[m_next];
m_next = (m_next + 1) % m_fences.count();
m_currentFence->trigger();
}
void X11SyncManager::insertWait()
{
if (m_currentFence && m_currentFence->state() != X11SyncObject::Waiting) {
m_currentFence->wait();
}
}
} // namespace KWin