protocols: prune stale subsurface refs in hot traversals

5 files changed, 61 insertions, 12 deletions

diff --git a/src/protocols/PresentationTime.cpp b/src/protocols/PresentationTime.cpp
index 456ad724..ab15d701 100644
--- a/src/protocols/PresentationTime.cpp
+++ b/src/protocols/PresentationTime.cpp
@@ -146,3 +146,7 @@ void CPresentationProtocol::onPresented(PHLMONITOR pMonitor, const timespec& whe
 void CPresentationProtocol::queueData(UP<CQueuedPresentationData>&& data) {
     m_queue.emplace_back(std::move(data));
 }
+
+bool CPresentationProtocol::hasPendingFeedbacks() const {
+    return !m_feedbacks.empty();
+}
diff --git a/src/protocols/PresentationTime.hpp b/src/protocols/PresentationTime.hpp
index caf63ace..6bac9919 100644
--- a/src/protocols/PresentationTime.hpp
+++ b/src/protocols/PresentationTime.hpp
@@ -56,6 +56,7 @@ class CPresentationProtocol : public IWaylandProtocol {
 
     void         onPresented(PHLMONITOR pMonitor, const timespec& when, uint32_t untilRefreshNs, uint64_t seq, uint32_t reportedFlags);
     void         queueData(UP<CQueuedPresentationData>&& data);
+    bool         hasPendingFeedbacks() const;
 
   private:
     void onManagerResourceDestroy(wl_resource* res);
diff --git a/src/protocols/core/Compositor.cpp b/src/protocols/core/Compositor.cpp
index e5008a3c..a51c60a2 100644
--- a/src/protocols/core/Compositor.cpp
+++ b/src/protocols/core/Compositor.cpp
@@ -358,13 +358,21 @@ void CWLSurfaceResource::bfHelper(std::vector<SP<CWLSurfaceResource>> const& nod
     // first, gather all nodes below
     for (auto const& n : nodes) {
         std::erase_if(n->m_subsurfaces, [](const auto& e) { return e.expired(); });
+
         // subsurfaces is sorted lowest -> highest
-        for (auto const& c : n->m_subsurfaces) {
-            if (c->m_zIndex >= 0)
+        for (auto const& subsurfaceRef : n->m_subsurfaces) {
+            const auto subsurface = subsurfaceRef.lock();
+            if (!subsurface)
+                continue;
+
+            if (subsurface->m_zIndex >= 0)
                 break;
-            if (c->m_surface.expired())
+
+            const auto surface = subsurface->m_surface.lock();
+            if (!surface)
                 continue;
-            nodes2.emplace_back(c->m_surface.lock());
+
+            nodes2.emplace_back(surface);
         }
     }
 
@@ -377,19 +385,29 @@ void CWLSurfaceResource::bfHelper(std::vector<SP<CWLSurfaceResource>> const& nod
         Vector2D offset = {};
         if (n->m_role->role() == SURFACE_ROLE_SUBSURFACE) {
             auto subsurface = sc<CSubsurfaceRole*>(n->m_role.get())->m_subsurface.lock();
-            offset          = subsurface->posRelativeToParent();
+            if (subsurface)
+                offset = subsurface->posRelativeToParent();
         }
 
         fn(n, offset, data);
     }
 
     for (auto const& n : nodes) {
-        for (auto const& c : n->m_subsurfaces) {
-            if (c->m_zIndex < 0)
+        std::erase_if(n->m_subsurfaces, [](const auto& e) { return e.expired(); });
+
+        for (auto const& subsurfaceRef : n->m_subsurfaces) {
+            const auto subsurface = subsurfaceRef.lock();
+            if (!subsurface)
                 continue;
-            if (c->m_surface.expired())
+
+            if (subsurface->m_zIndex < 0)
+                continue;
+
+            const auto surface = subsurface->m_surface.lock();
+            if (!surface)
                 continue;
-            nodes2.emplace_back(c->m_surface.lock());
+
+            nodes2.emplace_back(surface);
         }
     }
 
@@ -406,10 +424,19 @@ void CWLSurfaceResource::breadthfirst(std::function<void(SP<CWLSurfaceResource>,
 SP<CWLSurfaceResource> CWLSurfaceResource::findFirstPreorderHelper(SP<CWLSurfaceResource> root, std::function<bool(SP<CWLSurfaceResource>)> fn) {
     if (fn(root))
         return root;
-    for (auto const& sub : root->m_subsurfaces) {
-        if (sub.expired() || sub->m_surface.expired())
+
+    std::erase_if(root->m_subsurfaces, [](const auto& e) { return e.expired(); });
+
+    for (auto const& subsurfaceRef : root->m_subsurfaces) {
+        const auto subsurface = subsurfaceRef.lock();
+        if (!subsurface)
+            continue;
+
+        const auto surface = subsurface->m_surface.lock();
+        if (!surface)
             continue;
-        const auto found = findFirstPreorderHelper(sub->m_surface.lock(), fn);
+
+        const auto found = findFirstPreorderHelper(surface, fn);
         if (found)
             return found;
     }
@@ -598,6 +625,7 @@ PImageDescription CWLSurfaceResource::getPreferredImageDescription() {
 }
 
 void CWLSurfaceResource::sortSubsurfaces() {
+    std::erase_if(m_subsurfaces, [](const auto& subsurface) { return !subsurface; });
     std::ranges::sort(m_subsurfaces, [](const auto& a, const auto& b) { return a->m_zIndex < b->m_zIndex; });
 
     // find the first non-negative index. We will preserve negativity: e.g. -2, -1, 1, 2
@@ -698,6 +726,10 @@ void CWLSurfaceResource::updateCursorShm(CRegion damage) {
 
 void CWLSurfaceResource::presentFeedback(const Time::steady_tp& when, PHLMONITOR pMonitor, bool discarded) {
     frame(when);
+
+    if (!PROTO::presentation->hasPendingFeedbacks())
+        return;
+
     auto FEEDBACK = makeUnique<CQueuedPresentationData>(m_self.lock());
     FEEDBACK->attachMonitor(pMonitor);
     if (discarded)
diff --git a/src/protocols/core/Subcompositor.cpp b/src/protocols/core/Subcompositor.cpp
index 14dc4666..d8a3e860 100644
--- a/src/protocols/core/Subcompositor.cpp
+++ b/src/protocols/core/Subcompositor.cpp
@@ -91,12 +91,15 @@ CWLSubsurfaceResource::CWLSubsurfaceResource(SP<CWlSubsurface> resource_, SP<CWL
 }
 
 CWLSubsurfaceResource::~CWLSubsurfaceResource() {
+    unlinkFromParent();
     m_events.destroy.emit();
     if (m_surface)
         m_surface->resetRole();
 }
 
 void CWLSubsurfaceResource::destroy() {
+    unlinkFromParent();
+
     if (m_surface && m_surface->m_mapped) {
         m_surface->m_events.unmap.emit();
         m_surface->unmap();
@@ -105,6 +108,14 @@ void CWLSubsurfaceResource::destroy() {
     PROTO::subcompositor->destroyResource(this);
 }
 
+void CWLSubsurfaceResource::unlinkFromParent() {
+    const auto PARENT = m_parent.lock();
+    if (!PARENT)
+        return;
+
+    std::erase_if(PARENT->m_subsurfaces, [this](const auto& subsurface) { return !subsurface || subsurface.get() == this; });
+}
+
 Vector2D CWLSubsurfaceResource::posRelativeToParent() {
     Vector2D               pos  = m_position;
     SP<CWLSurfaceResource> surf = m_parent.lock();
diff --git a/src/protocols/core/Subcompositor.hpp b/src/protocols/core/Subcompositor.hpp
index 45b84eba..6c46c2e6 100644
--- a/src/protocols/core/Subcompositor.hpp
+++ b/src/protocols/core/Subcompositor.hpp
@@ -55,6 +55,7 @@ class CWLSubsurfaceResource {
     SP<CWlSubsurface> m_resource;
 
     void              destroy();
+    void              unlinkFromParent();
 
     struct {
         CHyprSignalListener commitSurface;