add doOnReadable to event loop manager

Author: ikalco

src/managers/eventLoop/EventLoopManager.cpp

@@ -26,6 +26,11 @@ CEventLoopManager::~CEventLoopManager() {
         wl_event_source_remove(eventSourceData.eventSource);
     }
 
+    for (auto const& w : m_vReadableWaiters) {
+        if (w->source != nullptr)
+            wl_event_source_remove(w->source);
+    }
+
     if (m_sWayland.eventSource)
         wl_event_source_remove(m_sWayland.eventSource);
     if (m_sIdle.eventSource)
@@ -50,6 +55,33 @@ static int configWatcherWrite(int fd, uint32_t mask, void* data) {
     return 0;
 }
 
+static int handleWaiterFD(int fd, uint32_t mask, void* data) {
+    if (mask & (WL_EVENT_HANGUP | WL_EVENT_ERROR)) {
+        Debug::log(ERR, "handleWaiterFD: readable waiter error");
+        return 0;
+    }
+
+    if (mask & WL_EVENT_READABLE)
+        g_pEventLoopManager->onFdReadable((CEventLoopManager::SReadableWaiter*)data);
+
+    return 0;
+}
+
+void CEventLoopManager::onFdReadable(SReadableWaiter* waiter) {
+    auto it = std::ranges::find_if(m_vReadableWaiters, [waiter](const UP<SReadableWaiter>& w) { return waiter == w.get() && w->fd == waiter->fd && w->source == waiter->source; });
+
+    if (waiter->source) {
+        wl_event_source_remove(waiter->source);
+        waiter->source = nullptr;
+    }
+
+    if (waiter->fn)
+        waiter->fn();
+
+    if (it != m_vReadableWaiters.end())
+        m_vReadableWaiters.erase(it);
+}
+
 void CEventLoopManager::enterLoop() {
     m_sWayland.eventSource = wl_event_loop_add_fd(m_sWayland.loop, m_sTimers.timerfd.get(), WL_EVENT_READABLE, timerWrite, nullptr);
 
@@ -143,6 +175,16 @@ void CEventLoopManager::doLater(const std::function<void()>& fn) {
         &m_sIdle);
 }
 
+void CEventLoopManager::doOnReadable(CFileDescriptor fd, const std::function<void()>& fn) {
+    if (!fd.isValid() || fd.isReadable()) {
+        fn();
+        return;
+    }
+
+    auto& waiter   = m_vReadableWaiters.emplace_back(makeUnique<SReadableWaiter>(nullptr, std::move(fd), fn));
+    waiter->source = wl_event_loop_add_fd(g_pEventLoopManager->m_sWayland.loop, waiter->fd.get(), WL_EVENT_READABLE, ::handleWaiterFD, waiter.get());
+}
+
 void CEventLoopManager::syncPollFDs() {
     auto aqPollFDs = g_pCompositor->m_pAqBackend->getPollFDs();
 

src/managers/eventLoop/EventLoopManager.hpp

@@ -38,6 +38,17 @@ class CEventLoopManager {
         std::vector<std::function<void()>> fns;
     };
 
+    struct SReadableWaiter {
+        wl_event_source*               source;
+        Hyprutils::OS::CFileDescriptor fd;
+        std::function<void()>          fn;
+    };
+
+    // schedule function to when fd is readable (WL_EVENT_READABLE / POLLIN),
+    // takes ownership of fd
+    void doOnReadable(Hyprutils::OS::CFileDescriptor fd, const std::function<void()>& fn);
+    void onFdReadable(SReadableWaiter* waiter);
+
   private:
     // Manages the event sources after AQ pollFDs change.
     void syncPollFDs();
@@ -58,8 +69,9 @@ class CEventLoopManager {
         Hyprutils::OS::CFileDescriptor   timerfd;
     } m_sTimers;
 
-    SIdleData                       m_sIdle;
-    std::map<int, SEventSourceData> aqEventSources;
+    SIdleData                        m_sIdle;
+    std::map<int, SEventSourceData>  aqEventSources;
+    std::vector<UP<SReadableWaiter>> m_vReadableWaiters;
 
     struct {
         CHyprSignalListener pollFDsChanged;