From 1012f1d4b5753ad63da3cca1226fb034e297ae6d Mon Sep 17 00:00:00 2001
From: Vlad Zahorodnii <vlad.zahorodnii@kde.org>
Date: Tue, 8 Nov 2022 16:10:18 +0200
Subject: [PATCH 41/55] Client: Ensure that wl_surface lives as long as qtquick
 render thread needs it

wl_surface can be destroyed while qtquick render thread still uses it.
That can end up in eglSwapBuffers() using defunct wl_surface, which will
eventually lead to a crash due to the compositor posting an error.

This is partially cherry-pick of dff579147b07cd15888a47c303e36684e9930f9f

Change-Id: I044f40dd64e6672027a833379b57ccd9973d8305
---
 src/client/qwaylandwindow.cpp                       | 13 ++++++++++++-
 src/client/qwaylandwindow_p.h                       |  3 +++
 .../client/wayland-egl/qwaylandglcontext.cpp        |  6 +++++-
 3 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/src/client/qwaylandwindow.cpp b/src/client/qwaylandwindow.cpp
index 4ddf9fbe..1f2d56b5 100644
--- a/src/client/qwaylandwindow.cpp
+++ b/src/client/qwaylandwindow.cpp
@@ -76,6 +76,7 @@ QWaylandWindow *QWaylandWindow::mMouseGrab = nullptr;
 QWaylandWindow::QWaylandWindow(QWindow *window, QWaylandDisplay *display)
     : QPlatformWindow(window)
     , mDisplay(display)
+    , mSurfaceLock(QReadWriteLock::Recursive)
     , mResizeAfterSwap(qEnvironmentVariableIsSet("QT_WAYLAND_RESIZE_AFTER_SWAP"))
 {
     {
@@ -237,6 +238,16 @@ bool QWaylandWindow::shouldCreateSubSurface() const
     return QPlatformWindow::parent() != nullptr;
 }
 
+void QWaylandWindow::beginFrame()
+{
+    mSurfaceLock.lockForRead();
+}
+
+void QWaylandWindow::endFrame()
+{
+    mSurfaceLock.unlock();
+}
+
 void QWaylandWindow::reset()
 {
     closeChildPopups();
@@ -245,10 +256,10 @@ void QWaylandWindow::reset()
     delete mSubSurfaceWindow;
     mSubSurfaceWindow = nullptr;
 
-    invalidateSurface();
     if (mSurface) {
         emit wlSurfaceDestroyed();
         QWriteLocker lock(&mSurfaceLock);
+        invalidateSurface();
         mSurface.reset();
     }
 
diff --git a/src/client/qwaylandwindow_p.h b/src/client/qwaylandwindow_p.h
index ea3d1995..e18609d9 100644
--- a/src/client/qwaylandwindow_p.h
+++ b/src/client/qwaylandwindow_p.h
@@ -207,6 +207,9 @@ public:
     void handleUpdate();
     void deliverUpdateRequest() override;
 
+    void beginFrame();
+    void endFrame();
+
     void addChildPopup(QWaylandWindow* child);
     void removeChildPopup(QWaylandWindow* child);
     void closeChildPopups();
diff --git a/src/hardwareintegration/client/wayland-egl/qwaylandglcontext.cpp b/src/hardwareintegration/client/wayland-egl/qwaylandglcontext.cpp
index c1f45fa6..5d6fb2bf 100644
--- a/src/hardwareintegration/client/wayland-egl/qwaylandglcontext.cpp
+++ b/src/hardwareintegration/client/wayland-egl/qwaylandglcontext.cpp
@@ -432,8 +432,10 @@ bool QWaylandGLContext::makeCurrent(QPlatformSurface *surface)
         return true;
     }
 
-    if (window->isExposed())
+    if (window->isExposed()) {
+        window->beginFrame();
         window->setCanResize(false);
+    }
     if (m_decorationsContext != EGL_NO_CONTEXT && !window->decoration())
         window->createDecoration();
 
@@ -449,6 +451,7 @@ bool QWaylandGLContext::makeCurrent(QPlatformSurface *surface)
     if (!eglMakeCurrent(m_eglDisplay, eglSurface, eglSurface, m_context)) {
         qWarning("QWaylandGLContext::makeCurrent: eglError: %x, this: %p \n", eglGetError(), this);
         window->setCanResize(true);
+        window->endFrame();
         return false;
     }
 
@@ -502,6 +505,7 @@ void QWaylandGLContext::swapBuffers(QPlatformSurface *surface)
     eglSwapBuffers(m_eglDisplay, eglSurface);
 
     window->setCanResize(true);
+    window->endFrame();
 }
 
 GLuint QWaylandGLContext::defaultFramebufferObject(QPlatformSurface *surface) const
-- 
2.40.0