monitor: avoid dangling references to old monitors being undestroyed

ref #7414

src/Compositor.cpp

@@ -2935,7 +2935,7 @@ PHLWINDOW CCompositor::windowForCPointer(CWindow* pWindow) {
 
 void CCompositor::onNewMonitor(SP<Aquamarine::IOutput> output) {
     // add it to real
-    auto PNEWMONITOR = g_pCompositor->m_vRealMonitors.emplace_back(makeShared<CMonitor>());
+    auto PNEWMONITOR = g_pCompositor->m_vRealMonitors.emplace_back(makeShared<CMonitor>(output));
     if (std::string("HEADLESS-1") == output->name) {
         g_pCompositor->m_pUnsafeOutput = PNEWMONITOR.get();
         output->name                   = "FALLBACK"; // we are allowed to do this :)
@@ -2944,7 +2944,6 @@ void CCompositor::onNewMonitor(SP<Aquamarine::IOutput> output) {
     Debug::log(LOG, "New output with name {}", output->name);
 
     PNEWMONITOR->szName           = output->name;
-    PNEWMONITOR->output           = output;
     PNEWMONITOR->self             = PNEWMONITOR;
     const bool FALLBACK           = g_pCompositor->m_pUnsafeOutput ? output == g_pCompositor->m_pUnsafeOutput->output : false;
     PNEWMONITOR->ID               = FALLBACK ? MONITOR_INVALID : g_pCompositor->getNextAvailableMonitorID(output->name);

src/events/Events.hpp

@@ -27,7 +27,6 @@ namespace Events {
 
     // Monitor part 2 the sequel
     DYNLISTENFUNC(monitorFrame);
-    DYNLISTENFUNC(monitorDestroy);
     DYNLISTENFUNC(monitorStateRequest);
     DYNLISTENFUNC(monitorDamage);
     DYNLISTENFUNC(monitorNeedsFrame);

src/events/Monitors.cpp

@@ -85,31 +85,6 @@ void Events::listener_monitorFrame(void* owner, void* data) {
     }
 }
 
-void Events::listener_monitorDestroy(void* owner, void* data) {
-    CMonitor* pMonitor = (CMonitor*)owner;
-
-    for (auto& m : g_pCompositor->m_vRealMonitors) {
-        if (m->output == pMonitor->output) {
-            pMonitor = m.get();
-            break;
-        }
-    }
-
-    if (!pMonitor)
-        return;
-
-    Debug::log(LOG, "Destroy called for monitor {}", pMonitor->szName);
-
-    pMonitor->onDisconnect(true);
-
-    pMonitor->output                 = nullptr;
-    pMonitor->m_bRenderingInitPassed = false;
-
-    Debug::log(LOG, "Removing monitor {} from realMonitors", pMonitor->szName);
-
-    std::erase_if(g_pCompositor->m_vRealMonitors, [&](SP<CMonitor>& el) { return el.get() == pMonitor; });
-}
-
 void Events::listener_monitorNeedsFrame(void* owner, void* data) {
     const auto PMONITOR = (CMonitor*)owner;
 

src/helpers/Monitor.cpp

@@ -25,7 +25,7 @@ int ratHandler(void* data) {
     return 1;
 }
 
-CMonitor::CMonitor() : state(this) {
+CMonitor::CMonitor(SP<Aquamarine::IOutput> output_) : state(this), output(output_) {
     ;
 }
 
@@ -40,16 +40,29 @@ void CMonitor::onConnect(bool noRule) {
         outTimeline = CSyncTimeline::create(output->getBackend()->drmFD());
     }
 
-    listeners.frame   = output->events.frame.registerListener([this](std::any d) { Events::listener_monitorFrame(this, nullptr); });
+    listeners.frame  = output->events.frame.registerListener([this](std::any d) { Events::listener_monitorFrame(this, nullptr); });
-    listeners.destroy = output->events.destroy.registerListener([this](std::any d) { Events::listener_monitorDestroy(this, nullptr); });
+    listeners.commit = output->events.commit.registerListener([this](std::any d) { Events::listener_monitorCommit(this, nullptr); });
-    listeners.commit  = output->events.commit.registerListener([this](std::any d) { Events::listener_monitorCommit(this, nullptr); });
     listeners.needsFrame =
         output->events.needsFrame.registerListener([this](std::any d) { g_pCompositor->scheduleFrameForMonitor(this, Aquamarine::IOutput::AQ_SCHEDULE_NEEDS_FRAME); });
+
     listeners.presented = output->events.present.registerListener([this](std::any d) {
         auto E = std::any_cast<Aquamarine::IOutput::SPresentEvent>(d);
         PROTO::presentation->onPresented(this, E.when, E.refresh, E.seq, E.flags);
     });
 
+    listeners.destroy = output->events.destroy.registerListener([this](std::any d) {
+        Debug::log(LOG, "Destroy called for monitor {}", szName);
+
+        onDisconnect(true);
+
+        output                 = nullptr;
+        m_bRenderingInitPassed = false;
+
+        Debug::log(LOG, "Removing monitor {} from realMonitors", szName);
+
+        std::erase_if(g_pCompositor->m_vRealMonitors, [&](SP<CMonitor>& el) { return el.get() == this; });
+    });
+
     listeners.state = output->events.state.registerListener([this](std::any d) {
         auto E = std::any_cast<Aquamarine::IOutput::SStateEvent>(d);
 

src/helpers/Monitor.hpp

@@ -59,7 +59,7 @@ class CMonitorState {
 
 class CMonitor {
   public:
-    CMonitor();
+    CMonitor(SP<Aquamarine::IOutput> output);
     ~CMonitor();
 
     Vector2D                    vecPosition         = Vector2D(-1, -1); // means unset