LibWebView+Services+UI: Move process helpers to LibWebView

Author: https://github.com/trflynn89 Commit: 0ff91a5273 Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/2269
2025-08-09 17:49:40 +00:00 · 2024-11-10 10:26:07 -05:00 · 2024-11-10 10:26:07 -05:00 · 0ff91a5273 · 2024-11-11 12:36:39 +00:00
commit 0ff91a5273
parent a14937c45e
29 changed files with 110 additions and 119 deletions
--- a/Libraries/LibWebView/MachPortServer.cpp
+++ b/Libraries/LibWebView/MachPortServer.cpp
@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 2024, Andrew Kaster <akaster@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/Debug.h>
+#include <LibCore/Platform/MachMessageTypes.h>
+#include <LibCore/Platform/ProcessStatisticsMach.h>
+#include <LibWebView/MachPortServer.h>
+
+namespace WebView {
+
+MachPortServer::MachPortServer()
+    : m_thread(Threading::Thread::construct([this]() -> intptr_t { thread_loop(); return 0; }, "MachPortServer"sv))
+    , m_server_port_name(ByteString::formatted("org.ladybird.Ladybird.helper.{}", getpid()))
+{
+    if (auto err = allocate_server_port(); err.is_error())
+        dbgln("Failed to allocate server port: {}", err.error());
+    else
+        start();
+}
+
+MachPortServer::~MachPortServer()
+{
+    stop();
+}
+
+void MachPortServer::start()
+{
+    m_thread->start();
+}
+
+void MachPortServer::stop()
+{
+    // FIXME: We should join instead (after storing should_stop = false) when we have a way to interrupt the thread's mach_msg call
+    m_thread->detach();
+    m_should_stop.store(true, MemoryOrder::memory_order_release);
+}
+
+bool MachPortServer::is_initialized()
+{
+    return MACH_PORT_VALID(m_server_port_recv_right.port()) && MACH_PORT_VALID(m_server_port_send_right.port());
+}
+
+ErrorOr<void> MachPortServer::allocate_server_port()
+{
+    m_server_port_recv_right = TRY(Core::MachPort::create_with_right(Core::MachPort::PortRight::Receive));
+    m_server_port_send_right = TRY(m_server_port_recv_right.insert_right(Core::MachPort::MessageRight::MakeSend));
+    TRY(m_server_port_recv_right.register_with_bootstrap_server(m_server_port_name));
+
+    dbgln_if(MACH_PORT_DEBUG, "Success! we created and attached mach port {:x} to bootstrap server with name {}", m_server_port_recv_right.port(), m_server_port_name);
+    return {};
+}
+
+void MachPortServer::thread_loop()
+{
+    while (!m_should_stop.load(MemoryOrder::memory_order_acquire)) {
+        Core::Platform::ReceivedMachMessage message {};
+
+        // Get the pid of the child from the audit trailer so we can associate the port w/it
+        mach_msg_options_t const options = MACH_RCV_MSG | MACH_RCV_TRAILER_TYPE(MACH_RCV_TRAILER_AUDIT) | MACH_RCV_TRAILER_ELEMENTS(MACH_RCV_TRAILER_AUDIT);
+
+        // FIXME: How can we interrupt this call during application shutdown?
+        auto const ret = mach_msg(&message.header, options, 0, sizeof(message), m_server_port_recv_right.port(), MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
+        if (ret != KERN_SUCCESS) {
+            dbgln("mach_msg failed: {}", mach_error_string(ret));
+            break;
+        }
+
+        if (message.header.msgh_id == Core::Platform::BACKING_STORE_IOSURFACES_MESSAGE_ID) {
+            auto pid = static_cast<pid_t>(message.body.parent_iosurface.trailer.msgh_audit.val[5]);
+            auto const& backing_stores_message = message.body.parent_iosurface;
+            auto front_child_port = Core::MachPort::adopt_right(backing_stores_message.front_descriptor.name, Core::MachPort::PortRight::Send);
+            auto back_child_port = Core::MachPort::adopt_right(backing_stores_message.back_descriptor.name, Core::MachPort::PortRight::Send);
+            auto const& metadata = backing_stores_message.metadata;
+            if (on_receive_backing_stores)
+                on_receive_backing_stores({ .pid = pid,
+                    .page_id = metadata.page_id,
+                    .front_backing_store_id = metadata.front_backing_store_id,
+                    .back_backing_store_id = metadata.back_backing_store_id,
+                    .front_backing_store_port = move(front_child_port),
+                    .back_backing_store_port = move(back_child_port) });
+            continue;
+        }
+
+        if (message.header.msgh_id == Core::Platform::SELF_TASK_PORT_MESSAGE_ID) {
+            if (MACH_MSGH_BITS_LOCAL(message.header.msgh_bits) != MACH_MSG_TYPE_MOVE_SEND) {
+                dbgln("Received message with invalid local port rights {}, ignoring", MACH_MSGH_BITS_LOCAL(message.header.msgh_bits));
+                continue;
+            }
+
+            auto const& task_port_message = message.body.parent;
+            auto pid = static_cast<pid_t>(task_port_message.trailer.msgh_audit.val[5]);
+            auto child_port = Core::MachPort::adopt_right(task_port_message.port_descriptor.name, Core::MachPort::PortRight::Send);
+            dbgln_if(MACH_PORT_DEBUG, "Received child port {:x} from pid {}", child_port.port(), pid);
+            if (on_receive_child_mach_port)
+                on_receive_child_mach_port(pid, move(child_port));
+            continue;
+        }
+
+        dbgln("Received message with id {}, ignoring", message.header.msgh_id);
+    }
+}
+}