LibWebView+Services+UI: Move process helpers to LibWebView

Author: https://github.com/trflynn89
Commit: 0ff91a5273
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/2269

Libraries/LibWebView/MachPortServer.h

@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2024, Andrew Kaster <akaster@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Atomic.h>
+#include <AK/Platform.h>
+#include <AK/String.h>
+#include <LibCore/MachPort.h>
+#include <LibThreading/Thread.h>
+
+#if !defined(AK_OS_MACH)
+#    error "This file is only for Mach kernel-based OS's"
+#endif
+
+namespace WebView {
+
+class MachPortServer {
+
+public:
+    MachPortServer();
+    ~MachPortServer();
+
+    void start();
+    void stop();
+
+    bool is_initialized();
+
+    Function<void(pid_t, Core::MachPort)> on_receive_child_mach_port;
+    struct BackingStoresMessage {
+        pid_t pid { -1 };
+        u64 page_id { 0 };
+        i32 front_backing_store_id { 0 };
+        i32 back_backing_store_id { 0 };
+        Core::MachPort front_backing_store_port;
+        Core::MachPort back_backing_store_port;
+    };
+    Function<void(BackingStoresMessage)> on_receive_backing_stores;
+
+    ByteString const& server_port_name() const { return m_server_port_name; }
+
+private:
+    void thread_loop();
+    ErrorOr<void> allocate_server_port();
+
+    NonnullRefPtr<Threading::Thread> m_thread;
+    ByteString const m_server_port_name;
+    Core::MachPort m_server_port_recv_right;
+    Core::MachPort m_server_port_send_right;
+
+    Atomic<bool> m_should_stop { false };
+};
+
+}