From d13a15a0c569348cfd5aa207ee219b73117e938c Mon Sep 17 00:00:00 2001 From: Benjamin Berg Date: Tue, 28 Jul 2020 12:11:13 +0200 Subject: [PATCH 3/4] gdesktopappinfo: Handle task completion from spawn function This allows delaying the return of the task until all dbus calls (in particular the ones to setup the scope) have finished. This fixes the behaviour of the previous commit which would not correctly move the process into the scope if the application exited right after the task returned. --- gio/gdesktopappinfo.c | 214 +++++++++++++++++++++++++++++------------- 1 file changed, 147 insertions(+), 67 deletions(-) diff --git a/gio/gdesktopappinfo.c b/gio/gdesktopappinfo.c index 2f1e6828b..743027422 100644 --- a/gio/gdesktopappinfo.c +++ b/gio/gdesktopappinfo.c @@ -2849,11 +2849,17 @@ create_systemd_scope (GDBusConnection *session_bus, g_free (unit_name); } +typedef struct { + GTask *task; + int fd; +} ScopeCreatedData; + static void systemd_scope_created_cb (GObject *object, GAsyncResult *result, gpointer user_data) { + ScopeCreatedData *data = user_data; GVariant *res = NULL; GError *error = NULL; @@ -2865,13 +2871,47 @@ systemd_scope_created_cb (GObject *object, } /* Unblock the waiting wrapper binary. */ - close (GPOINTER_TO_INT (user_data)); + + close (data->fd); + + if (data->task) + { + gint pending; + pending = GPOINTER_TO_INT (g_task_get_task_data (data->task)); + pending -= 1; + g_task_set_task_data (data->task, GINT_TO_POINTER (pending), NULL); + + if (pending == 0 && !g_task_get_completed (data->task)) + g_task_return_boolean (data->task, TRUE); + } if (res) g_variant_unref (res); + g_clear_object (&data->task); + g_free (data); } #endif +static void +launch_uris_with_spawn_flush_cb (GObject *object, + GAsyncResult *result, + gpointer user_data) +{ + GTask *task = G_TASK (user_data); + gint pending; + + g_dbus_connection_flush_finish (G_DBUS_CONNECTION (object), result, NULL); + + pending = GPOINTER_TO_INT (g_task_get_task_data (task)); + pending -= 1; + g_task_set_task_data (task, GINT_TO_POINTER (pending), NULL); + + if (pending == 0 && !g_task_get_completed (task)) + g_task_return_boolean (task, TRUE); + + g_object_unref (task); +} + static gboolean g_desktop_app_info_launch_uris_with_spawn (GDesktopAppInfo *info, GDBusConnection *session_bus, @@ -2886,9 +2926,10 @@ g_desktop_app_info_launch_uris_with_spawn (GDesktopAppInfo *info, gint stdin_fd, gint stdout_fd, gint stderr_fd, - GError **error) + GTask *task, + GError **error_out) { - gboolean completed = FALSE; + GError *error = NULL; GList *old_uris; GList *dup_uris; @@ -2898,8 +2939,15 @@ g_desktop_app_info_launch_uris_with_spawn (GDesktopAppInfo *info, char *sn_id = NULL; int argc; + /* We may get a task to report back on or an error. But never both. */ + g_assert (!(task && error_out)); g_return_val_if_fail (info != NULL, FALSE); + /* Surrounding code must not have set any data on the task + * (it is cleared before calling this function). */ + if (session_bus && task) + g_assert (g_task_get_task_data (task) == NULL); + if (launch_context) envp = g_app_launch_context_get_environment (launch_context); else @@ -2922,8 +2970,8 @@ g_desktop_app_info_launch_uris_with_spawn (GDesktopAppInfo *info, gpointer setup_data = user_setup_data; old_uris = dup_uris; - if (!expand_application_parameters (info, exec_line, &dup_uris, &argc, &argv, error)) - return FALSE; + if (!expand_application_parameters (info, exec_line, &dup_uris, &argc, &argv, &error)) + goto out; /* Get the subset of URIs we're launching with this process */ for (iter = old_uris; iter != NULL && iter != dup_uris; iter = iter->next) @@ -2932,9 +2980,9 @@ g_desktop_app_info_launch_uris_with_spawn (GDesktopAppInfo *info, if (info->terminal && !prepend_terminal_to_vector (&argc, &argv)) { - g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_FAILED, - _("Unable to find terminal required for application")); - return FALSE; + error = g_error_new_literal (G_IO_ERROR, G_IO_ERROR_FAILED, + _("Unable to find terminal required for application")); + goto out; } if (info->filename) @@ -2991,9 +3039,9 @@ g_desktop_app_info_launch_uris_with_spawn (GDesktopAppInfo *info, * otherwise our wrapper script will close both sides. */ if (!g_unix_open_pipe (wrapper_data.pipe, 0, NULL)) { - g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_FAILED, - _("Unable to create pipe for systemd synchronization")); - return FALSE; + error = g_error_new_literal (G_IO_ERROR, G_IO_ERROR_FAILED, + _("Unable to create pipe for systemd synchronization")); + goto out; } /* Set CLOEXEC on the write pipe, so we don't need to deal with it in the child. */ @@ -3030,7 +3078,7 @@ g_desktop_app_info_launch_uris_with_spawn (GDesktopAppInfo *info, stdin_fd, stdout_fd, stderr_fd, - error)) + &error)) { #if defined(__linux__) && !defined(__BIONIC__) close (wrapper_data.pipe[0]); @@ -3043,7 +3091,7 @@ g_desktop_app_info_launch_uris_with_spawn (GDesktopAppInfo *info, g_free (sn_id); g_list_free (launched_uris); - goto err; + goto out; } #if defined(__linux__) && !defined(__BIONIC__) @@ -3052,11 +3100,29 @@ g_desktop_app_info_launch_uris_with_spawn (GDesktopAppInfo *info, close (wrapper_data.pipe[0]); if (session_bus) - create_systemd_scope (session_bus, - info, - pid, - systemd_scope_created_cb, - GINT_TO_POINTER (wrapper_data.pipe[1])); + { + ScopeCreatedData *data; + + data = g_new0 (ScopeCreatedData, 1); + + if (task) + { + gint pending; + pending = GPOINTER_TO_INT (g_task_get_task_data (task)); + pending += 1; + g_task_set_task_data (task, GINT_TO_POINTER (pending), NULL); + + data->task = g_object_ref (task); + } + + data->fd = wrapper_data.pipe[1]; + + create_systemd_scope (session_bus, + info, + pid, + systemd_scope_created_cb, + data); + } else close (wrapper_data.pipe[1]); #endif @@ -3091,8 +3157,6 @@ g_desktop_app_info_launch_uris_with_spawn (GDesktopAppInfo *info, } while (dup_uris != NULL); - completed = TRUE; - out: g_strfreev (argv); g_strfreev (envp); @@ -3100,7 +3164,52 @@ out: g_list_free (launched_uris); g_free (sn_id); - return completed; + if (!error) + { + if (session_bus && task) + { + GCancellable *cancellable = g_task_get_cancellable (task); + gint pending; + pending = GPOINTER_TO_INT (g_task_get_task_data (task)); + pending += 1; + g_task_set_task_data (task, GINT_TO_POINTER (pending), NULL); + + /* FIXME: The D-Bus message from the notify_desktop_launch() function + * can be still lost even if flush is called later. See: + * https://gitlab.freedesktop.org/dbus/dbus/issues/72 + */ + g_dbus_connection_flush (session_bus, + cancellable, + launch_uris_with_spawn_flush_cb, + g_steal_pointer (&task)); + } + else if (session_bus) + { + /* No task available. */ + g_dbus_connection_flush (session_bus, + NULL, + NULL, + NULL); + } + else if (task) + { + /* Return the given task. */ + g_task_return_boolean (task, TRUE); + g_object_unref (task); + } + } + else + { + if (task) + { + g_task_return_error (task, error); + g_object_unref (task); + } + else + g_propagate_error (error_out, error); + } + + return !error; } static gchar * @@ -3249,17 +3358,9 @@ g_desktop_app_info_launch_uris_internal (GAppInfo *appinfo, success = g_desktop_app_info_launch_uris_with_spawn (info, session_bus, info->exec, uris, launch_context, spawn_flags, user_setup, user_setup_data, pid_callback, pid_callback_data, - stdin_fd, stdout_fd, stderr_fd, error); + stdin_fd, stdout_fd, stderr_fd, NULL, error); - if (session_bus != NULL) - { - /* This asynchronous flush holds a reference until it completes, - * which ensures that the following unref won't immediately kill - * the connection if we were the initial owner. - */ - g_dbus_connection_flush (session_bus, NULL, NULL, NULL); - g_object_unref (session_bus); - } + g_clear_object (&session_bus); return success; } @@ -3313,18 +3414,6 @@ launch_uris_with_dbus_cb (GObject *object, g_object_unref (task); } -static void -launch_uris_flush_cb (GObject *object, - GAsyncResult *result, - gpointer user_data) -{ - GTask *task = G_TASK (user_data); - - g_dbus_connection_flush_finish (G_DBUS_CONNECTION (object), result, NULL); - g_task_return_boolean (task, TRUE); - g_object_unref (task); -} - static void launch_uris_bus_get_cb (GObject *object, GAsyncResult *result, @@ -3333,12 +3422,20 @@ launch_uris_bus_get_cb (GObject *object, GTask *task = G_TASK (user_data); GDesktopAppInfo *info = G_DESKTOP_APP_INFO (g_task_get_source_object (task)); LaunchUrisData *data = g_task_get_task_data (task); + LaunchUrisData *data_copy = NULL; GCancellable *cancellable = g_task_get_cancellable (task); GDBusConnection *session_bus; - GError *error = NULL; session_bus = g_bus_get_finish (result, NULL); + data_copy = g_new0 (LaunchUrisData, 1); + data_copy->appinfo = g_steal_pointer (&data->appinfo); + data_copy->uris = g_steal_pointer (&data->uris); + data_copy->context = g_steal_pointer (&data->context); + + /* Allow other data to be attached to the task. */ + g_task_set_task_data (task, NULL, NULL); + if (session_bus && info->app_id) { /* FIXME: The g_document_portal_add_documents() function, which is called @@ -3346,34 +3443,21 @@ launch_uris_bus_get_cb (GObject *object, * uses blocking calls. */ g_desktop_app_info_launch_uris_with_dbus (info, session_bus, - data->uris, data->context, + data_copy->uris, data_copy->context, cancellable, launch_uris_with_dbus_cb, g_steal_pointer (&task)); } else { - /* FIXME: The D-Bus message from the notify_desktop_launch() function - * can be still lost even if flush is called later. See: - * https://gitlab.freedesktop.org/dbus/dbus/issues/72 - */ g_desktop_app_info_launch_uris_with_spawn (info, session_bus, info->exec, - data->uris, data->context, + data_copy->uris, data_copy->context, _SPAWN_FLAGS_DEFAULT, NULL, NULL, NULL, NULL, -1, -1, -1, - &error); - if (error != NULL) - { - g_task_return_error (task, g_steal_pointer (&error)); - g_object_unref (task); - } - else - g_dbus_connection_flush (session_bus, - cancellable, - launch_uris_flush_cb, - g_steal_pointer (&task)); + g_steal_pointer (&task), NULL); } + launch_uris_data_free (data_copy); g_clear_object (&session_bus); } @@ -5189,16 +5273,12 @@ g_desktop_app_info_launch_action (GDesktopAppInfo *info, if (exec_line) g_desktop_app_info_launch_uris_with_spawn (info, session_bus, exec_line, NULL, launch_context, _SPAWN_FLAGS_DEFAULT, NULL, NULL, NULL, NULL, - -1, -1, -1, NULL); + -1, -1, -1, NULL, NULL); g_free (exec_line); } - if (session_bus != NULL) - { - g_dbus_connection_flush (session_bus, NULL, NULL, NULL); - g_object_unref (session_bus); - } + g_clear_object (&session_bus); } /* Epilogue {{{1 */ -- 2.29.2