WebDriver: Stop using the ancient Core::EventReceiver parent/child API

Before this change, clients were kept alive by making them children of
the TCPServer object. This ownership model is going away (and this was
the only remaining use of it!) so let's just put the clients in a hash
table instead.

Libraries/LibWeb/WebDriver/Client.cpp

@@ -176,9 +176,8 @@ static JsonValue make_success_response(JsonValue value)
     return result;
 }
 
-Client::Client(NonnullOwnPtr<Core::BufferedTCPSocket> socket, Core::EventReceiver* parent)
+Client::Client(NonnullOwnPtr<Core::BufferedTCPSocket> socket)
-    : Core::EventReceiver(parent)
+    : m_socket(move(socket))
-    , m_socket(move(socket))
 {
     m_socket->on_ready_to_read = [this] {
         if (auto result = on_ready_to_read(); result.is_error())
@@ -194,7 +193,10 @@ Client::~Client()
 void Client::die()
 {
     // We defer removing this connection to avoid closing its socket while we are inside the on_ready_to_read callback.
-    deferred_invoke([this] { remove_from_parent(); });
+    deferred_invoke([this] {
+        if (on_death)
+            on_death();
+    });
 }
 
 ErrorOr<void, Client::WrappedError> Client::on_ready_to_read()

Libraries/LibWeb/WebDriver/Client.h

@@ -116,8 +116,10 @@ public:
     // 18. Print, https://w3c.github.io/webdriver/#print
     virtual Response print_page(Parameters parameters, JsonValue payload) = 0;
 
+    Function<void()> on_death;
+
 protected:
-    Client(NonnullOwnPtr<Core::BufferedTCPSocket>, Core::EventReceiver* parent);
+    explicit Client(NonnullOwnPtr<Core::BufferedTCPSocket>);
 
 private:
     using WrappedError = Variant<AK::Error, HTTP::HttpRequest::ParseError, WebDriver::Error>;

Services/WebDriver/Client.cpp

@@ -21,17 +21,17 @@
 
 namespace WebDriver {
 
-ErrorOr<NonnullRefPtr<Client>> Client::try_create(NonnullOwnPtr<Core::BufferedTCPSocket> socket, LaunchBrowserCallback launch_browser_callback, Core::EventReceiver* parent)
+ErrorOr<NonnullRefPtr<Client>> Client::try_create(NonnullOwnPtr<Core::BufferedTCPSocket> socket, LaunchBrowserCallback launch_browser_callback)
 {
     if (!launch_browser_callback)
         return Error::from_string_literal("The callback to launch the browser must be provided");
 
     TRY(socket->set_blocking(true));
-    return adopt_nonnull_ref_or_enomem(new (nothrow) Client(move(socket), move(launch_browser_callback), parent));
+    return adopt_nonnull_ref_or_enomem(new (nothrow) Client(move(socket), move(launch_browser_callback)));
 }
 
-Client::Client(NonnullOwnPtr<Core::BufferedTCPSocket> socket, LaunchBrowserCallback launch_browser_callback, Core::EventReceiver* parent)
+Client::Client(NonnullOwnPtr<Core::BufferedTCPSocket> socket, LaunchBrowserCallback launch_browser_callback)
-    : Web::WebDriver::Client(move(socket), parent)
+    : Web::WebDriver::Client(move(socket))
     , m_launch_browser_callback(move(launch_browser_callback))
 {
 }

Services/WebDriver/Client.h

@@ -23,13 +23,13 @@ class Client final : public Web::WebDriver::Client {
     C_OBJECT_ABSTRACT(Client);
 
 public:
-    static ErrorOr<NonnullRefPtr<Client>> try_create(NonnullOwnPtr<Core::BufferedTCPSocket>, LaunchBrowserCallback, Core::EventReceiver* parent);
+    static ErrorOr<NonnullRefPtr<Client>> try_create(NonnullOwnPtr<Core::BufferedTCPSocket>, LaunchBrowserCallback);
     virtual ~Client() override;
 
     LaunchBrowserCallback const& launch_browser_callback() const { return m_launch_browser_callback; }
 
 private:
-    Client(NonnullOwnPtr<Core::BufferedTCPSocket>, LaunchBrowserCallback, Core::EventReceiver* parent);
+    Client(NonnullOwnPtr<Core::BufferedTCPSocket>, LaunchBrowserCallback);
 
     virtual Web::WebDriver::Response new_session(Web::WebDriver::Parameters parameters, JsonValue payload) override;
     virtual Web::WebDriver::Response delete_session(Web::WebDriver::Parameters parameters, JsonValue payload) override;

Services/WebDriver/main.cpp

@@ -106,6 +106,8 @@ ErrorOr<int> ladybird_main(Main::Arguments arguments)
     Core::EventLoop loop;
     auto server = TRY(Core::TCPServer::try_create());
 
+    HashTable<NonnullRefPtr<WebDriver::Client>> clients;
+
     // FIXME: Propagate errors
     server->on_ready_to_accept = [&] {
         auto maybe_client_socket = server->accept();
@@ -125,11 +127,17 @@ ErrorOr<int> ladybird_main(Main::Arguments arguments)
             return launch_process("Ladybird"sv, arguments.span());
         };
 
-        auto maybe_client = WebDriver::Client::try_create(maybe_buffered_socket.release_value(), move(launch_browser_callback), server);
+        auto maybe_client = WebDriver::Client::try_create(maybe_buffered_socket.release_value(), move(launch_browser_callback));
         if (maybe_client.is_error()) {
             warnln("Could not create a WebDriver client: {}", maybe_client.error());
             return;
         }
+
+        auto client = maybe_client.release_value();
+        client->on_death = [&] {
+            clients.remove(client);
+        };
+        clients.set(move(client));
     };
 
     TRY(server->listen(ipv4_address.value(), port, Core::TCPServer::AllowAddressReuse::Yes));