From f1bd62806e538fa2bfa7899c2b2ad02d6a5ca2db Mon Sep 17 00:00:00 2001
From: maround95 <39220886+maround95@users.noreply.github.com>
Date: Thu, 23 Jan 2025 13:08:19 +0200
Subject: [PATCH] core/renderer: Add GPU hotplug support (#8980)

---
 src/managers/eventLoop/EventLoopManager.cpp | 32 +++++++++++++++++----
 src/managers/eventLoop/EventLoopManager.hpp | 29 +++++++++++++------
 2 files changed, 47 insertions(+), 14 deletions(-)

diff --git a/src/managers/eventLoop/EventLoopManager.cpp b/src/managers/eventLoop/EventLoopManager.cpp
index f98efc92..4021c171 100644
--- a/src/managers/eventLoop/EventLoopManager.cpp
+++ b/src/managers/eventLoop/EventLoopManager.cpp
@@ -5,6 +5,7 @@
 
 #include <algorithm>
 #include <limits>
+#include <ranges>
 
 #include <sys/timerfd.h>
 #include <ctime>
@@ -20,8 +21,8 @@ CEventLoopManager::CEventLoopManager(wl_display* display, wl_event_loop* wlEvent
 }
 
 CEventLoopManager::~CEventLoopManager() {
-    for (auto const& eventSource : m_sWayland.aqEventSources) {
-        wl_event_source_remove(eventSource);
+    for (auto const& [_, eventSourceData] : aqEventSources) {
+        wl_event_source_remove(eventSourceData.eventSource);
     }
 
     if (m_sWayland.eventSource)
@@ -56,10 +57,8 @@ void CEventLoopManager::enterLoop() {
     if (const auto FD = g_pConfigWatcher->getInotifyFD(); FD >= 0)
         m_configWatcherInotifySource = wl_event_loop_add_fd(m_sWayland.loop, FD, WL_EVENT_READABLE, configWatcherWrite, nullptr);
 
-    aqPollFDs = g_pCompositor->m_pAqBackend->getPollFDs();
-    for (auto const& fd : aqPollFDs) {
-        m_sWayland.aqEventSources.emplace_back(wl_event_loop_add_fd(m_sWayland.loop, fd->fd, WL_EVENT_READABLE, aquamarineFDWrite, fd.get()));
-    }
+    syncPollFDs();
+    m_sListeners.pollFDsChanged = g_pCompositor->m_pAqBackend->events.pollFDsChanged.registerListener([this](std::any d) { syncPollFDs(); });
 
     // if we have a session, dispatch it to get the pending input devices
     if (g_pCompositor->m_pAqBackend->hasSession())
@@ -144,3 +143,24 @@ void CEventLoopManager::doLater(const std::function<void()>& fn) {
         },
         &m_sIdle);
 }
+
+void CEventLoopManager::syncPollFDs() {
+    auto aqPollFDs = g_pCompositor->m_pAqBackend->getPollFDs();
+
+    std::erase_if(aqEventSources, [&](const auto& item) {
+        auto const& [fd, eventSourceData] = item;
+
+        // If no pollFD has the same fd, remove this event source
+        const bool shouldRemove = std::ranges::none_of(aqPollFDs, [&](const auto& pollFD) { return pollFD->fd == fd; });
+
+        if (shouldRemove)
+            wl_event_source_remove(eventSourceData.eventSource);
+
+        return shouldRemove;
+    });
+
+    for (auto& fd : aqPollFDs | std::views::filter([&](SP<Aquamarine::SPollFD> fd) { return !aqEventSources.contains(fd->fd); })) {
+        auto eventSource       = wl_event_loop_add_fd(m_sWayland.loop, fd->fd, WL_EVENT_READABLE, aquamarineFDWrite, fd.get());
+        aqEventSources[fd->fd] = {.pollFD = fd, .eventSource = eventSource};
+    }
+}
diff --git a/src/managers/eventLoop/EventLoopManager.hpp b/src/managers/eventLoop/EventLoopManager.hpp
index 90402de2..e1c243d3 100644
--- a/src/managers/eventLoop/EventLoopManager.hpp
+++ b/src/managers/eventLoop/EventLoopManager.hpp
@@ -1,9 +1,11 @@
 #pragma once
 
 #include <condition_variable>
+#include <map>
 #include <mutex>
 #include <thread>
 #include <wayland-server.h>
+#include "helpers/signal/Signal.hpp"
 
 #include "EventLoopTimer.hpp"
 
@@ -36,11 +38,18 @@ class CEventLoopManager {
     };
 
   private:
+    // Manages the event sources after AQ pollFDs change.
+    void syncPollFDs();
+
+    struct SEventSourceData {
+        SP<Aquamarine::SPollFD> pollFD;
+        wl_event_source*        eventSource = nullptr;
+    };
+
     struct {
-        wl_event_loop*                loop        = nullptr;
-        wl_display*                   display     = nullptr;
-        wl_event_source*              eventSource = nullptr;
-        std::vector<wl_event_source*> aqEventSources;
+        wl_event_loop*   loop        = nullptr;
+        wl_display*      display     = nullptr;
+        wl_event_source* eventSource = nullptr;
     } m_sWayland;
 
     struct {
@@ -48,12 +57,16 @@ class CEventLoopManager {
         int                              timerfd = -1;
     } m_sTimers;
 
-    SIdleData                            m_sIdle;
-    std::vector<SP<Aquamarine::SPollFD>> aqPollFDs;
+    SIdleData                       m_sIdle;
+    std::map<int, SEventSourceData> aqEventSources;
 
-    wl_event_source*                     m_configWatcherInotifySource = nullptr;
+    struct {
+        CHyprSignalListener pollFDsChanged;
+    } m_sListeners;
+
+    wl_event_source* m_configWatcherInotifySource = nullptr;
 
     friend class CSyncTimeline;
 };
 
-inline std::unique_ptr<CEventLoopManager> g_pEventLoopManager;
\ No newline at end of file
+inline std::unique_ptr<CEventLoopManager> g_pEventLoopManager;