WebContent: Exit cleanly when browser IPC disconnects

Exit WebContent immediately when either browser-side IPC peer
disconnects. Plumb Unix process exit status through LibWebView so the
browser process can tell clean owner-driven shutdown apart from renderer
crashes.

This keeps nonzero exits and signal deaths reported as crashes, while
letting status 0 exits disappear without making test-web report the page
as crashed.

Libraries/LibWebView/Application.cpp

@@ -35,6 +35,10 @@
 #    include <LibIPC/TransportBootstrapMach.h>
 #endif
 
+#if !defined(AK_OS_WINDOWS)
+#    include <sys/wait.h>
+#endif
+
 namespace WebView {
 
 Application* Application::s_the = nullptr;
@@ -472,8 +476,8 @@ ErrorOr<void> Application::launch_services()
     m_bookmark_store_observer = make<ApplicationBookmarkStoreObserver>();
 
     m_process_manager = make<ProcessManager>();
-    m_process_manager->on_process_exited = [this](Process&& process) {
-        process_did_exit(move(process));
+    m_process_manager->on_process_exited = [this](Process&& process, Optional<int> exit_status) {
+        process_did_exit(move(process), exit_status);
     };
 
     if (m_browser_options.disable_sql_database == DisableSQLDatabase::No) {
@@ -727,7 +731,7 @@ Optional<Process&> Application::find_process(pid_t pid)
     return m_process_manager->find_process(pid);
 }
 
-void Application::process_did_exit(Process&& process)
+void Application::process_did_exit(Process&& process, Optional<int> exit_status)
 {
     if (m_event_loop->was_exit_requested())
         return;
@@ -751,6 +755,10 @@ void Application::process_did_exit(Process&& process)
         }
         break;
     case ProcessType::WebContent:
+#if !defined(AK_OS_WINDOWS)
+        if (exit_status.has_value() && WIFEXITED(*exit_status) && WEXITSTATUS(*exit_status) == 0)
+            break;
+#endif
         if (auto client = process.client<WebContentClient>(); client.has_value())
             client->notify_all_views_of_crash();
         break;

Libraries/LibWebView/Application.h

@@ -171,7 +171,7 @@ protected:
 
     ErrorOr<void> initialize(Main::Arguments const&);
 
-    virtual void process_did_exit(Process&&);
+    virtual void process_did_exit(Process&&, Optional<int> exit_status);
 
     virtual void create_platform_arguments(Core::ArgsParser&) { }
     virtual void create_platform_options(BrowserOptions&, RequestServerOptions&, WebContentOptions&) { }

Libraries/LibWebView/ProcessManager.cpp

@@ -49,10 +49,10 @@ StringView process_name_from_type(ProcessType type)
 
 ProcessManager::ProcessManager()
     : on_process_added([](Process&) {})
-    , on_process_exited([](Process&&) {})
-    , m_process_monitor(ProcessMonitor([this](pid_t pid) {
+    , on_process_exited([](Process&&, Optional<int>) {})
+    , m_process_monitor(ProcessMonitor([this](pid_t pid, Optional<int> exit_status) {
         if (auto process = remove_process(pid); process.has_value())
-            on_process_exited(process.release_value());
+            on_process_exited(process.release_value(), exit_status);
     }))
 {
     add_process(Process(WebView::ProcessType::Browser, nullptr, Core::Process::current()));

Libraries/LibWebView/ProcessManager.h

@@ -40,7 +40,7 @@ public:
     JsonValue serialize_json();
 
     Function<void(Process&)> on_process_added; // test-web
-    Function<void(Process&&)> on_process_exited;
+    Function<void(Process&&, Optional<int> exit_status)> on_process_exited;
 
 private:
     void verify_event_loop() const;

Libraries/LibWebView/ProcessMonitor.cpp

@@ -12,7 +12,7 @@
 
 namespace WebView {
 
-ProcessMonitor::ProcessMonitor(Function<void(pid_t)> exit_handler)
+ProcessMonitor::ProcessMonitor(Function<void(pid_t, Optional<int> exit_status)> exit_handler)
     : m_on_process_exit(move(exit_handler))
 {
 #if !defined(AK_OS_WINDOWS)
@@ -23,7 +23,7 @@ ProcessMonitor::ProcessMonitor(Function<void(pid_t)> exit_handler)
             if (m_monitored_processes.contains(pid)) {
                 if (WIFEXITED(status) || WIFSIGNALED(status)) {
                     m_monitored_processes.remove(pid);
-                    m_on_process_exit(pid);
+                    m_on_process_exit(pid, status);
                 }
             }
             result = Core::System::waitpid(-1, WNOHANG);
@@ -51,7 +51,7 @@ void ProcessMonitor::add_process(pid_t pid)
 #if defined(AK_OS_WINDOWS)
     Core::EventLoop::register_process(pid, [this](pid_t pid) {
         m_monitored_processes.remove(pid);
-        m_on_process_exit(pid);
+        m_on_process_exit(pid, {});
     });
 #endif
 }

Libraries/LibWebView/ProcessMonitor.h

@@ -13,13 +13,13 @@ namespace WebView {
 
 class ProcessMonitor {
 public:
-    ProcessMonitor(Function<void(pid_t)> exit_handler);
+    ProcessMonitor(Function<void(pid_t, Optional<int> exit_status)> exit_handler);
     ~ProcessMonitor();
 
     void add_process(pid_t pid);
 
 private:
-    Function<void(pid_t)> m_on_process_exit;
+    Function<void(pid_t, Optional<int> exit_status)> m_on_process_exit;
     HashTable<pid_t> m_monitored_processes;
     [[maybe_unused]] int m_signal_handle { -1 };
 };

Services/WebContent/ConnectionFromClient.cpp

@@ -78,7 +78,10 @@ class CompositorConnectionFromClient final
     C_OBJECT(CompositorConnectionFromClient)
 
 public:
-    virtual void die() override { }
+    virtual void die() override
+    {
+        _exit(0);
+    }
 
 private:
     explicit CompositorConnectionFromClient(NonnullOwnPtr<IPC::Transport> transport)
@@ -134,7 +137,7 @@ ConnectionFromClient::~ConnectionFromClient() = default;
 
 void ConnectionFromClient::die()
 {
-    Web::Platform::EventLoopPlugin::the().quit();
+    _exit(0);
 }
 
 Messages::WebContentServer::InitTransportResponse ConnectionFromClient::init_transport([[maybe_unused]] int peer_pid)

Tests/LibWeb/test-web/TestRunCapture.cpp

@@ -29,9 +29,9 @@ TestRunCapture::TestRunCapture()
         setup_output_capture_for_helper_process(process);
     };
     m_previous_on_process_exited = move(process_manager.on_process_exited);
-    process_manager.on_process_exited = [this](WebView::Process&& process) {
+    process_manager.on_process_exited = [this](WebView::Process&& process, Optional<int> exit_status) {
         consume_helper_capture(process.pid());
-        m_previous_on_process_exited(move(process));
+        m_previous_on_process_exited(move(process), exit_status);
     };
 
     process_manager.for_each_process([this](WebView::Process& process) {

Tests/LibWeb/test-web/TestRunCapture.h

@@ -72,7 +72,7 @@ private:
     void consume_helper_capture(pid_t pid);
     void destroy_view_capture_of(TestWebView const& view);
 
-    Function<void(WebView::Process&&)> m_previous_on_process_exited;
+    Function<void(WebView::Process&&, Optional<int> exit_status)> m_previous_on_process_exited;
     HashMap<TestWebView const*, NonnullOwnPtr<ViewOutputCapture>> m_test_output_captures;
     HashMap<pid_t, NonnullOwnPtr<HelperOutputCapture>> m_helper_output_captures;
     CaptureFile m_helper_output;