gnome-shell/js/dbusServices/dbusService.js
Florian Müllner 2c91b6164c dbusServices: Allow to inhibit auto-shutdown
While we only shut down after a method call completed or (if the
interface has signals) the sender disconnects from the bus, services
may need to inhibit auto-shutdown for more specific reasons themselves,
for example when a method call kicks off an operation that should
complete before shutting down.

Add hold() and release() methods like Gio.Application for those cases.

https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1115
2020-03-21 20:16:22 +00:00

178 lines
4.5 KiB
JavaScript

/* exported DBusService, ServiceImplementation */
const { Gio, GLib } = imports.gi;
const Signals = imports.signals;
const IDLE_SHUTDOWN_TIME = 2; // s
var ServiceImplementation = class {
constructor(info, objectPath) {
this._objectPath = objectPath;
this._dbusImpl = Gio.DBusExportedObject.wrapJSObject(info, this);
this._injectTracking('return_dbus_error');
this._injectTracking('return_error_literal');
this._injectTracking('return_gerror');
this._injectTracking('return_value');
this._injectTracking('return_value_with_unix_fd_list');
this._senders = new Map();
this._holdCount = 0;
this._hasSignals = this._dbusImpl.get_info().signals.length > 0;
this._shutdownTimeoutId = 0;
// subclasses may override this to disable automatic shutdown
this._autoShutdown = true;
}
// subclasses may override this to own additional names
register() {
}
export() {
this._dbusImpl.export(Gio.DBus.session, this._objectPath);
}
unexport() {
this._dbusImpl.unexport();
}
hold() {
this._holdCount++;
}
release() {
if (this._holdCount === 0) {
logError(new Error('Unmatched call to release()'));
return;
}
this._holdCount--;
if (this._holdCount === 0)
this._queueShutdownCheck();
}
/**
* _handleError:
* @param {Gio.DBusMethodInvocation}
* @param {Error}
*
* Complete @invocation with an appropriate error if @error is set;
* useful for implementing early returns from method implementations.
*
* @returns {bool} - true if @invocation was completed
*/
_handleError(invocation, error) {
if (error === null)
return false;
if (error instanceof GLib.Error) {
invocation.return_gerror(error);
} else {
let name = error.name;
if (!name.includes('.')) // likely a normal JS error
name = `org.gnome.gjs.JSError.${name}`;
invocation.return_dbus_error(name, error.message);
}
return true;
}
_maybeShutdown() {
if (!this._autoShutdown)
return;
if (this._holdCount > 0)
return;
this.emit('shutdown');
}
_queueShutdownCheck() {
if (this._shutdownTimeoutId)
GLib.source_remove(this._shutdownTimeoutId);
this._shutdownTimeoutId = GLib.timeout_add_seconds(
GLib.PRIORITY_DEFAULT, IDLE_SHUTDOWN_TIME,
() => {
this._shutdownTimeoutId = 0;
this._maybeShutdown();
return GLib.SOURCE_REMOVE;
});
}
_trackSender(sender) {
if (this._senders.has(sender))
return;
this.hold();
this._senders.set(sender,
this._dbusImpl.get_connection().watch_name(
sender,
Gio.BusNameWatcherFlags.NONE,
null,
() => this._untrackSender(sender)));
}
_untrackSender(sender) {
const id = this._senders.get(sender);
if (id)
this._dbusImpl.get_connection().unwatch_name(id);
if (this._senders.delete(sender))
this.release();
}
_injectTracking(methodName) {
const { prototype } = Gio.DBusMethodInvocation;
const origMethod = prototype[methodName];
const that = this;
prototype[methodName] = function (...args) {
origMethod.apply(this, args);
if (that._hasSignals)
that._trackSender(this.get_sender());
that._queueShutdownCheck();
};
}
};
Signals.addSignalMethods(ServiceImplementation.prototype);
var DBusService = class {
constructor(name, service) {
this._name = name;
this._service = service;
this._loop = new GLib.MainLoop(null, false);
this._service.connect('shutdown', () => this._loop.quit());
}
run() {
// Bail out when not running under gnome-shell
Gio.DBus.watch_name(Gio.BusType.SESSION,
'org.gnome.Shell',
Gio.BusNameWatcherFlags.NONE,
null,
() => this._loop.quit());
this._service.register();
Gio.DBus.own_name(Gio.BusType.SESSION,
this._name,
Gio.BusNameOwnerFlags.REPLACE,
() => this._service.export(),
null,
() => this._loop.quit());
this._loop.run();
}
};