gclient: Create two example windows

apps/gclient.cpp

@@ -1,5 +1,23 @@
 #include <os/ArgumentParser.h>
+#include <os/File.h>
 #include <os/LocalClient.h>
+#include <ui/ipc/Server.h>
+#include <unistd.h>
+
+Result<void> handle_ipc_client_event(os::LocalClient&, u8)
+{
+    todo();
+}
+
+Result<int> create_window(os::LocalClient& client, ui::Rect rect, StringView name, ui::Color color)
+{
+    ui::CreateWindowRequest request;
+    request.rect = rect;
+    SET_IPC_STRING(request.name, name.chars());
+    request.color = color;
+    auto response = TRY(os::IPC::send_sync<ui::CreateWindowResponse>(client, request));
+    return response.window;
+}
 
 Result<int> luna_main(int argc, char** argv)
 {
@@ -13,8 +31,16 @@ Result<int> luna_main(int argc, char** argv)
 
     auto client = TRY(os::LocalClient::connect(socket_path, false));
 
-    StringView message = "hello";
+    int id = TRY(create_window(*client, ui::Rect { 200, 200, 400, 300 }, "My Window", ui::CYAN));
-    TRY(client->send((const u8*)message.chars(), message.length()));
+    os::println("Created new window with id %d!", id);
+
+    sleep(3);
+
+    id =
+        TRY(create_window(*client, ui::Rect { 100, 100, 200, 150 }, "Super Long Name that is Way Too Long ", ui::BLUE));
+    os::println("Created new window with id %d!", id);
+
+    sleep(6);
 
     return 0;
 }

kernel/src/net/Socket.h

@@ -69,6 +69,8 @@ class Socket : public VFS::FileInode
 
     virtual bool can_read_data() const = 0;
 
+    virtual bool peer_disconnected() const = 0;
+
     virtual ~Socket() = default;
 
   protected:

kernel/src/net/UnixSocket.h

@@ -27,6 +27,11 @@ class UnixSocket : public Socket
         return !m_listen_queue.is_empty();
     }
 
+    bool peer_disconnected() const override
+    {
+        return m_state == Reset;
+    }
+
     Result<usize> send(const u8*, usize, int) override;
     Result<usize> recv(u8*, usize, int) const override;
 

kernel/src/sys/poll.cpp

@@ -56,6 +56,11 @@ Result<u64> sys_poll(Registers*, SyscallArgs args)
                         fds_with_events++;
                         kfds[i].revents |= POLLIN;
                     }
+                    if (socket->peer_disconnected())
+                    {
+                        fds_with_events++;
+                        kfds[i].revents |= POLLHUP;
+                    }
                 }
                 else
                 {

libc/include/bits/poll.h

@@ -8,6 +8,7 @@
 #define POLLIN (1 << 0)
 #define POLLERR (1 << 1)
 #define POLLNVAL (1 << 2)
+#define POLLHUP (1 << 3)
 
 typedef __u64_t nfds_t;
 

libos/CMakeLists.txt

@@ -16,6 +16,7 @@ set(SOURCES
     src/Security.cpp
     src/LocalServer.cpp
     src/LocalClient.cpp
+    src/IPC.cpp
 )
 
 add_library(os ${SOURCES})

libos/include/os/IPC.h

@@ -0,0 +1,157 @@
+/**
+ * @file IPC.h
+ * @author apio (cloudapio.eu)
+ * @brief Inter-process communication primitives.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
+#pragma once
+#include <os/LocalClient.h>
+#include <os/LocalServer.h>
+
+#define IPC_ENUM_SERVER(name) __##name##_SERVER_ERROR = 0
+#define IPC_ENUM_CLIENT(name) __##name##_CLIENT_ERROR = 0
+
+/**
+ * @brief Called to handle IPC events (client-side).
+ *
+ * @param conn The connection object being used.
+ * @param id The ID of the message.
+ * @return Result<void> Whether the operation succeded.
+ */
+extern Result<void> handle_ipc_client_event(os::LocalClient& conn, u8 id);
+
+/**
+ * @brief Called to handle IPC events (server-side).
+ *
+ * @param conn The connection object being used.
+ * @param id The ID of the message.
+ * @return Result<void> Whether the operation succeded.
+ */
+extern Result<void> handle_ipc_server_event(os::LocalServer::Client& conn, u8 id);
+
+namespace os
+{
+    namespace IPC
+    {
+        static constexpr usize IPC_STRING_LENGTH = 256;
+
+#define IPC_STRING(name) char name[os::IPC::IPC_STRING_LENGTH];
+#define COPY_IPC_STRING(name)                                                                                          \
+    TRY(String::from_string_view(StringView::from_fixed_size_cstring(name, os::IPC::IPC_STRING_LENGTH)))
+#define SET_IPC_STRING(name, value) strlcpy(name, value, os::IPC::IPC_STRING_LENGTH)
+
+        /**
+         * @brief Sends an IPC message without waiting for a reply.
+         *
+         * @tparam Client The type of the client interface being used to communicate.
+         * @tparam T The type of the message.
+         * @param client The connection object being used to communicate.
+         * @param message The IPC message.
+         * @return Result<void> Whether the operation succeded.
+         */
+        template <typename Client, typename T> Result<void> send_async(Client& client, const T& message)
+        {
+            u8 id = T::id;
+            TRY(client.send_typed(id));
+            TRY(client.send_typed(message));
+            return {};
+        }
+
+        /**
+         * @brief Sends an error result to the IPC connection, indicating that an operation could not be performed.
+         *
+         * @tparam Client The type of the client interface being used to communicate.
+         * @param client The connection object being used to communicate.
+         * @param error The error code.
+         * @return Result<void> Whether the operation succeded.
+         */
+        template <typename Client> Result<void> send_error(Client& client, int error)
+        {
+            u8 id = 0;
+            TRY(client.send_typed(id));
+            TRY(client.send_typed(error));
+            return {};
+        }
+
+        /**
+         * @brief Sends an IPC message and waits for a reply (client-only).
+         *
+         * @tparam ResponseType The type of the response.
+         * @tparam T The type of the message.
+         * @param client The connection object being used to communicate.
+         * @param message The IPC message.
+         * @param handler The function used to handle messages that do not match the reply.
+         * @return Result<ResponseType> An error, or the response.
+         */
+        template <typename ResponseType, typename T>
+        Result<ResponseType> send_sync(os::LocalClient& client, const T& message,
+                                       decltype(handle_ipc_client_event) handler = handle_ipc_client_event)
+        {
+            u8 id = T::id;
+            TRY(client.send_typed(id));
+            TRY(client.send_typed(message));
+
+            // We allow receiving 5 messages of different types, but if those have passed and we still don't have a
+            // reply, fail with ENOMSG.
+            int max_other_messages = 5;
+
+            while (max_other_messages)
+            {
+                u8 response_id;
+                auto rc = client.recv_typed(response_id);
+                if (rc.has_error() && rc.error() == EAGAIN) continue;
+
+                if (response_id == 0) // Error result
+                {
+                    while (1)
+                    {
+                        int code;
+                        rc = client.recv_typed(code);
+                        if (rc.has_error() && rc.error() == EAGAIN) continue;
+                        return err(code);
+                    }
+                }
+
+                if (response_id != ResponseType::id)
+                {
+                    TRY(handler(client, response_id));
+                    max_other_messages--;
+                    continue;
+                }
+
+                while (1)
+                {
+                    ResponseType response;
+                    rc = client.recv_typed(response);
+                    if (rc.has_error() && rc.error() == EAGAIN) continue;
+                    return response;
+                }
+            }
+
+            return err(ENOMSG);
+        }
+
+        /**
+         * @brief Check for new IPC messages on a connection and handle them appropriately.
+         *
+         * @param client The client connection.
+         * @param handler The function used to handle messages.
+         * @return Result<void> Whether the operation succeded.
+         */
+        Result<void> check_for_messages(os::LocalClient& client,
+                                        decltype(handle_ipc_client_event) handler = handle_ipc_client_event);
+
+        /**
+         * @brief Check for new IPC messages on a connection and handle them appropriately.
+         *
+         * @param server The server connection.
+         * @param handler The function used to handle messages.
+         * @return Result<void> Whether the operation succeded.
+         */
+        Result<void> check_for_messages(os::LocalServer::Client& server,
+                                        decltype(handle_ipc_server_event) handler = handle_ipc_server_event);
+    }
+}

libos/include/os/LocalClient.h

@@ -1,3 +1,12 @@
+/**
+ * @file LocalClient.h
+ * @author apio (cloudapio.eu)
+ * @brief UNIX local domain client class.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #pragma once
 #include <luna/OwnedPtr.h>
 #include <luna/StringView.h>

libos/include/os/LocalServer.h

@@ -1,3 +1,12 @@
+/**
+ * @file LocalServer.h
+ * @author apio (cloudapio.eu)
+ * @brief UNIX local domain server class.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #pragma once
 #include <luna/OwnedPtr.h>
 #include <luna/Result.h>

libos/src/IPC.cpp

@@ -0,0 +1,39 @@
+/**
+ * @file IPC.cpp
+ * @author apio (cloudapio.eu)
+ * @brief Inter-process communication primitives.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
+#include <os/IPC.h>
+
+namespace os::IPC
+{
+    Result<void> check_for_messages(os::LocalClient& client, decltype(handle_ipc_client_event) handler)
+    {
+        u8 id;
+        auto rc = client.recv_typed(id);
+        if (rc.has_error())
+        {
+            if (rc.error() == EAGAIN) return {}; // No messages, and the caller does not want us to block.
+            return rc.release_error();
+        }
+
+        return handler(client, id);
+    }
+
+    Result<void> check_for_messages(os::LocalServer::Client& client, decltype(handle_ipc_server_event) handler)
+    {
+        u8 id;
+        auto rc = client.recv_typed(id);
+        if (rc.has_error())
+        {
+            if (rc.error() == EAGAIN) return {}; // No messages, and the caller does not want us to block.
+            return rc.release_error();
+        }
+
+        return handler(client, id);
+    }
+}

libos/src/LocalClient.cpp

@@ -1,3 +1,12 @@
+/**
+ * @file LocalClient.cpp
+ * @author apio (cloudapio.eu)
+ * @brief UNIX local domain client class.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #include <errno.h>
 #include <fcntl.h>
 #include <os/LocalClient.h>

libos/src/LocalServer.cpp

@@ -1,3 +1,12 @@
+/**
+ * @file LocalServer.cpp
+ * @author apio (cloudapio.eu)
+ * @brief UNIX local domain server class.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #include <errno.h>
 #include <fcntl.h>
 #include <os/FileSystem.h>

libui/CMakeLists.txt

@@ -4,6 +4,8 @@ file(GLOB HEADERS include/ui/*.h)
 
 set(SOURCES
     ${HEADERS}
+    include/ui/ipc/Server.h
+    include/ui/ipc/Client.h
     src/Canvas.cpp
     src/Rect.cpp
     src/Font.cpp

libui/include/ui/Canvas.h

@@ -1,3 +1,12 @@
+/**
+ * @file Canvas.h
+ * @author apio (cloudapio.eu)
+ * @brief Drawable surfaces.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #pragma once
 #include <luna/Result.h>
 #include <luna/Types.h>

libui/include/ui/Color.h

@@ -1,3 +1,12 @@
+/**
+ * @file Color.h
+ * @author apio (cloudapio.eu)
+ * @brief RGBA colors.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #pragma once
 #include <luna/Types.h>
 

libui/include/ui/Font.h

@@ -1,3 +1,12 @@
+/**
+ * @file Font.h
+ * @author apio (cloudapio.eu)
+ * @brief PSF font loading and rendering.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #pragma once
 #include <luna/Buffer.h>
 #include <luna/SharedPtr.h>

libui/include/ui/Image.h

@@ -1,3 +1,12 @@
+/**
+ * @file Image.h
+ * @author apio (cloudapio.eu)
+ * @brief TGA image loading and rendering.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #pragma once
 #include <luna/Buffer.h>
 #include <luna/SharedPtr.h>

libui/include/ui/Point.h

@@ -1,3 +1,12 @@
+/**
+ * @file Point.h
+ * @author apio (cloudapio.eu)
+ * @brief 2D space points.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #pragma once
 
 namespace ui

libui/include/ui/Rect.h

@@ -1,3 +1,12 @@
+/**
+ * @file Rect.h
+ * @author apio (cloudapio.eu)
+ * @brief A simple 2D rectangle representation.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #pragma once
 #include <ui/Point.h>
 

libui/include/ui/ipc/Client.h

@@ -0,0 +1,27 @@
+/**
+ * @file ipc/Client.h
+ * @author apio (cloudapio.eu)
+ * @brief IPC message definitions for UI messages sent to the client.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
+#pragma once
+#include <os/IPC.h>
+
+namespace ui
+{
+    enum ClientMessages : u8
+    {
+        IPC_ENUM_CLIENT(ui),
+        CREATE_WINDOW_RESPONSE_ID,
+    };
+
+    struct CreateWindowResponse
+    {
+        static constexpr u8 id = CREATE_WINDOW_RESPONSE_ID;
+
+        int window;
+    };
+}

libui/include/ui/ipc/Server.h

@@ -0,0 +1,33 @@
+/**
+ * @file ipc/Server.h
+ * @author apio (cloudapio.eu)
+ * @brief IPC message definitions for UI messages sent to the server.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
+#pragma once
+#include <os/IPC.h>
+#include <ui/Color.h>
+#include <ui/Rect.h>
+#include <ui/ipc/Client.h>
+
+namespace ui
+{
+    enum ServerMessages : u8
+    {
+        IPC_ENUM_SERVER(ui),
+        CREATE_WINDOW_ID,
+    };
+
+    struct CreateWindowRequest
+    {
+        using ResponseType = CreateWindowResponse;
+        static constexpr u8 id = CREATE_WINDOW_ID;
+
+        ui::Rect rect;
+        IPC_STRING(name);
+        ui::Color color;
+    };
+}

libui/src/Canvas.cpp

@@ -1,3 +1,12 @@
+/**
+ * @file Canvas.cpp
+ * @author apio (cloudapio.eu)
+ * @brief Drawable surfaces.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #include <ui/Canvas.h>
 
 namespace ui

libui/src/Font.cpp

@@ -1,3 +1,12 @@
+/**
+ * @file Font.cpp
+ * @author apio (cloudapio.eu)
+ * @brief PSF font loading and rendering.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #include <luna/String.h>
 #include <os/File.h>
 #include <ui/Font.h>

libui/src/Image.cpp

@@ -1,3 +1,12 @@
+/**
+ * @file Image.cpp
+ * @author apio (cloudapio.eu)
+ * @brief TGA image loading and rendering.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #include <os/File.h>
 #include <ui/Image.h>
 

libui/src/Rect.cpp

@@ -1,3 +1,12 @@
+/**
+ * @file Rect.cpp
+ * @author apio (cloudapio.eu)
+ * @brief A simple 2D rectangle representation.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
 #include <ui/Rect.h>
 
 namespace ui

wind/CMakeLists.txt

@@ -6,6 +6,9 @@ set(SOURCES
     Mouse.cpp
     Window.h
     Window.cpp
+    IPC.cpp
+    IPC.h
+    Client.h
 )
 
 add_executable(wind ${SOURCES})

wind/Client.h

@@ -0,0 +1,11 @@
+#pragma once
+#include "Window.h"
+#include <os/LocalServer.h>
+
+struct Client
+{
+    os::LocalServer::Client conn;
+    Vector<Window*> windows;
+    bool rpc_in_progress { false };
+    u8 rpc_id { 0 };
+};

wind/IPC.cpp

@@ -0,0 +1,75 @@
+#include "IPC.h"
+#include <luna/String.h>
+#include <os/File.h>
+
+static Result<void> handle_create_window_message(Client& client)
+{
+    ui::CreateWindowRequest request;
+    auto rc = client.conn.recv_typed(request);
+    if (rc.has_error())
+    {
+        if (rc.error() == EAGAIN)
+        {
+            client.rpc_in_progress = true;
+            client.rpc_id = ui::CREATE_WINDOW_ID;
+            return {};
+        }
+        else
+            return rc.release_error();
+    }
+
+    request.rect = request.rect.normalized();
+    request.rect.height += Window::titlebar_height(); // Make sure we provide the full contents rect that was asked for.
+
+    auto name = COPY_IPC_STRING(request.name);
+
+    auto* window = new (std::nothrow) Window(request.rect, request.color, move(name));
+    if (!window)
+    {
+        os::IPC::send_error(client.conn, ENOMEM);
+        return {};
+    }
+
+    int id = static_cast<int>(client.windows.size());
+    rc = client.windows.try_append(window);
+    if (rc.has_error())
+    {
+        delete window;
+        os::IPC::send_error(client.conn, rc.error());
+        return {};
+    }
+
+    ui::CreateWindowResponse response;
+    response.window = id;
+    os::IPC::send_async(client.conn, response);
+    return {};
+}
+
+namespace wind
+{
+    Result<void> handle_ipc_message(Client& client, u8 id)
+    {
+        client.rpc_in_progress = false;
+        switch (id)
+        {
+        case ui::CREATE_WINDOW_ID: return handle_create_window_message(client);
+        default: os::eprintln("wind: Invalid IPC message from client!"); return err(EINVAL);
+        }
+    }
+
+    Result<void> handle_ipc(Client& client)
+    {
+        if (client.rpc_in_progress) return handle_ipc_message(client, client.rpc_id);
+
+        u8 id;
+        auto rc = client.conn.recv_typed(id);
+        if (rc.has_error())
+        {
+            if (rc.error() == EAGAIN) { return {}; }
+            else
+                return rc.release_error();
+        }
+
+        return handle_ipc_message(client, id);
+    }
+}

wind/IPC.h

@@ -0,0 +1,10 @@
+#pragma once
+#include "Client.h"
+#include <ui/ipc/Server.h>
+
+namespace wind
+{
+    Result<void> handle_ipc_message(Client& client, u8 id);
+
+    Result<void> handle_ipc(Client& client);
+}

wind/Window.cpp

@@ -38,7 +38,7 @@ void Window::focus()
     g_windows.append(this);
 }
 
-Window::Window(ui::Rect r, ui::Color c, StringView n) : surface(r), color(c), name(n)
+Window::Window(ui::Rect r, ui::Color c, String&& n) : surface(r), color(c), name(move(n))
 {
     auto font = ui::Font::default_font();
     if (surface.width < 36) surface.width = 36;
@@ -48,3 +48,9 @@ Window::Window(ui::Rect r, ui::Color c, StringView n) : surface(r), color(c), na
     contents = ui::Rect { 0, font->height() + 20, surface.width, surface.height - (font->height() + 20) };
     g_windows.append(this);
 }
+
+int Window::titlebar_height()
+{
+    auto font = ui::Font::default_font();
+    return font->height() + 20;
+}

wind/Window.h

@@ -1,6 +1,6 @@
 #pragma once
 #include <luna/LinkedList.h>
-#include <luna/StringView.h>
+#include <luna/String.h>
 #include <ui/Canvas.h>
 #include <ui/Color.h>
 #include <ui/Rect.h>
@@ -12,9 +12,11 @@ struct Window : public LinkedListNode<Window>
     ui::Rect close_button;
     ui::Rect contents;
     ui::Color color;
-    StringView name;
+    String name;
 
-    Window(ui::Rect, ui::Color, StringView);
+    static int titlebar_height();
+
+    Window(ui::Rect, ui::Color, String&&);
 
     void focus();
 

wind/main.cpp

@@ -1,3 +1,5 @@
+#include "Client.h"
+#include "IPC.h"
 #include "Mouse.h"
 #include "Screen.h"
 #include "Window.h"
@@ -20,7 +22,7 @@ Result<int> luna_main(int argc, char** argv)
 {
     srand((unsigned)time(NULL));
 
-    TRY(os::Security::pledge("stdio rpath wpath cpath unix proc exec tty id", NULL));
+    TRY(os::Security::pledge("stdio rpath wpath cpath unix proc exec tty signal id", NULL));
 
     StringView socket_path = "/tmp/wind.sock";
     StringView user;
@@ -82,13 +84,13 @@ Result<int> luna_main(int argc, char** argv)
 
     ui::Color background = ui::BLACK;
 
-    TRY(make<Window>(ui::Rect { 200, 200, 600, 400 }, ui::GREEN, "Calculator"_sv));
+    Vector<Client> clients;
-    TRY(make<Window>(ui::Rect { 100, 100, 300, 200 }, ui::RED, "Settings"_sv));
+    Vector<struct pollfd> fds;
-    TRY(make<Window>(ui::Rect { 600, 130, 350, 250 }, ui::CYAN, "File Manager"_sv));
+    TRY(fds.try_append({ .fd = mouse->fd(), .events = POLLIN, .revents = 0 }));
+    TRY(fds.try_append({ .fd = keyboard->fd(), .events = POLLIN, .revents = 0 }));
+    TRY(fds.try_append({ .fd = server->fd(), .events = POLLIN, .revents = 0 }));
 
-    Vector<os::LocalServer::Client> clients;
+    TRY(os::Security::pledge("stdio rpath unix signal proc", NULL));
-
-    TRY(os::Security::pledge("stdio rpath unix", NULL));
 
     while (1)
     {
@@ -97,13 +99,9 @@ Result<int> luna_main(int argc, char** argv)
         mouse_pointer.draw(screen.canvas());
         screen.sync();
 
-        struct pollfd fds[] = {
+        for (auto& pfd : fds) { pfd.revents = 0; }
-            { .fd = mouse->fd(), .events = POLLIN, .revents = 0 },
-            { .fd = keyboard->fd(), .events = POLLIN, .revents = 0 },
-            { .fd = server->fd(), .events = POLLIN, .revents = 0 },
-        };
 
-        int rc = poll(fds, 3, 1000);
+        int rc = poll(fds.data(), fds.size(), 1000);
         if (!rc) continue;
         if (rc < 0 && errno != EINTR) { os::println("poll: error: %s", strerror(errno)); }
 
@@ -117,20 +115,31 @@ Result<int> luna_main(int argc, char** argv)
         {
             moon::KeyboardPacket packet;
             TRY(keyboard->read_typed(packet));
-            if (!packet.released)
+            os::println("%s key %d", packet.released ? "Released" : "Pressed", packet.key);
+        }
+        for (usize i = 0; i < clients.size(); i++)
         {
-                TRY(make<Window>(ui::Rect { rand() % screen.canvas().width, rand() % screen.canvas().height,
+            if (fds[i + 3].revents & POLLIN) wind::handle_ipc(clients[i]);
-                                            rand() % screen.canvas().width, rand() % screen.canvas().height },
+            if (fds[i + 3].revents & POLLHUP)
-                                 ui::Color::from_rgb(static_cast<u8>(rand() % 256), static_cast<u8>(rand() % 256),
+            {
-                                                     static_cast<u8>(rand() % 256)),
+                os::println("wind: Client %d disconnected", i);
-                                 strerror(packet.key)));
+                fds.remove_at(i + 3);
+                auto client = clients.remove_at(i);
+                client.conn.disconnect();
+                for (auto& window : client.windows)
+                {
+                    g_windows.remove(window);
+                    delete window;
+                }
             }
         }
         if (fds[2].revents & POLLIN)
         {
             auto client = TRY(server->accept());
             os::println("wind: New client connected!");
-            TRY(clients.try_append(move(client)));
+            TRY(fds.try_append({ .fd = client.fd(), .events = POLLIN, .revents = 0 }));
+            Client c { move(client), {} };
+            TRY(clients.try_append(move(c)));
         }
     }
 }