[Spice-devel] [spice-gtk 5/5] usb-redir: move USB events handling to USB backend
Yuri Benditovich
yuri.benditovich at daynix.com
Mon Jul 22 15:31:24 UTC 2019
On Mon, Jul 22, 2019 at 6:00 PM Victor Toso <victortoso at redhat.com> wrote:
>
> Hi,
>
> On Mon, Jul 22, 2019 at 04:34:48PM +0300, Yuri Benditovich wrote:
> > Ping
>
> Sorry, missed it.
>
> Patch seems fine and again, code is getting nicer thanks to
> usb-backend.[ch]. Thanks. Only cosmetic changes for v2.
>
> > On Sun, Jul 14, 2019 at 5:07 PM Yuri Benditovich
> > <yuri.benditovich at daynix.com> wrote:
> > >
> > > Before this commit:
> > > usb-device-manager starts thread for handling libusb events.
> > > On Linux - from the beginning (as it is needed for hotplug
> > > callbacks)
> > > On Windows - starts it on first redirection and stops when
> > > there are no redirections (it can't keep the thread when
> > > there are no redirections as with libusb < 1.0.21 it will
> > > not be able to force the thread to exit as there are no events)
> > > Current commit moves the event thread and handling events
> > > completely to usb backend; usb-device-manager and other
> > > are not aware of libusb and should not assume what it
> > > needs to work. We start the event thread from the beginning
> > > on both Linux and Windows and on Linux it works only for
> > > hotplug callbacks, on Windows - just waits until device
> > > redirection starts. On dispose of usb-device-manager
> > > (when hotplug callbacks are deregistered), we interrupt
> > > the thread once to stop it.
> > > This removes many lines of code and also removes all the
> > > differences between Linux and Windows in usb-device-manager.
>
> Log is fine, I'd remove the indentation space and add empty line
> before 'Current commit', not important.
>
> > > Signed-off-by: Yuri Benditovich <yuri.benditovich at daynix.com>
> > > ---
> > > src/channel-usbredir.c | 28 -------------
> > > src/usb-backend.c | 48 ++++++++++++++-------
> > > src/usb-backend.h | 2 -
> > > src/usb-device-manager-priv.h | 6 ---
> > > src/usb-device-manager.c | 79 -----------------------------------
> > > 5 files changed, 33 insertions(+), 130 deletions(-)
> > >
> > > diff --git a/src/channel-usbredir.c b/src/channel-usbredir.c
> > > index 04acf0b..8d4cd66 100644
> > > --- a/src/channel-usbredir.c
> > > +++ b/src/channel-usbredir.c
> > > @@ -72,7 +72,6 @@ struct _SpiceUsbredirChannelPrivate {
> > > SpiceUsbAclHelper *acl_helper;
> > > #endif
> > > GMutex device_connect_mutex;
> > > - SpiceUsbDeviceManager *usb_device_manager;
> > > };
> > >
> > > static void channel_set_handlers(SpiceChannelClass *klass);
> > > @@ -169,11 +168,6 @@ static void spice_usbredir_channel_dispose(GObject *obj)
> > > SpiceUsbredirChannel *channel = SPICE_USBREDIR_CHANNEL(obj);
> > >
> > > spice_usbredir_channel_disconnect_device(channel);
> > > - /* This should have been set to NULL during device disconnection,
> > > - * but better not to leak it if this does not happen for some reason
> > > - */
> > > - g_warn_if_fail(channel->priv->usb_device_manager == NULL);
> > > - g_clear_object(&channel->priv->usb_device_manager);
> > >
> > > /* Chain up to the parent class */
> > > if (G_OBJECT_CLASS(spice_usbredir_channel_parent_class)->dispose)
> > > @@ -248,8 +242,6 @@ static gboolean spice_usbredir_channel_open_device(
> > > SpiceUsbredirChannel *channel, GError **err)
> > > {
> > > SpiceUsbredirChannelPrivate *priv = channel->priv;
> > > - SpiceSession *session;
> > > - SpiceUsbDeviceManager *manager;
> > >
> > > g_return_val_if_fail(priv->state == STATE_DISCONNECTED
> > > #ifdef USE_POLKIT
> > > @@ -265,16 +257,6 @@ static gboolean spice_usbredir_channel_open_device(
> > > return FALSE;
> > > }
> > >
> > > - session = spice_channel_get_session(SPICE_CHANNEL(channel));
> > > - manager = spice_usb_device_manager_get(session, NULL);
> > > - g_return_val_if_fail(manager != NULL, FALSE);
> > > -
> > > - priv->usb_device_manager = g_object_ref(manager);
> > > - if (!spice_usb_device_manager_start_event_listening(priv->usb_device_manager, err)) {
> > > - spice_usb_backend_channel_detach(priv->host);
> > > - return FALSE;
> > > - }
> > > -
> > > priv->state = STATE_CONNECTED;
> > >
> > > return TRUE;
> > > @@ -445,16 +427,6 @@ void spice_usbredir_channel_disconnect_device(SpiceUsbredirChannel *channel)
> > > break;
> > > #endif
> > > case STATE_CONNECTED:
> > > - /*
> > > - * This sets the usb event thread run condition to FALSE, therefor
> > > - * it must be done before usbredirhost_set_device NULL, as
> > > - * usbredirhost_set_device NULL will interrupt the
> > > - * libusb_handle_events call in the thread.
> > > - */
> > > - g_warn_if_fail(priv->usb_device_manager != NULL);
> > > - spice_usb_device_manager_stop_event_listening(priv->usb_device_manager);
> > > - g_clear_object(&priv->usb_device_manager);
> > > -
> > > /* This also closes the libusb handle we passed from open_device */
> > > spice_usb_backend_channel_detach(priv->host);
> > > g_clear_pointer(&priv->device, spice_usb_backend_device_unref);
> > > diff --git a/src/usb-backend.c b/src/usb-backend.c
> > > index 829d81d..37db951 100644
> > > --- a/src/usb-backend.c
> > > +++ b/src/usb-backend.c
> > > @@ -58,6 +58,9 @@ struct _SpiceUsbBackend
> > > usb_hot_plug_callback hotplug_callback;
> > > void *hotplug_user_data;
> > > libusb_hotplug_callback_handle hotplug_handle;
> > > + GThread *event_thread;
> > > + gint event_thread_run;
> > > +
> > > #ifdef G_OS_WIN32
> > > HANDLE hWnd;
> > > libusb_device **libusb_device_list;
> > > @@ -406,28 +409,25 @@ SpiceUsbBackend *spice_usb_backend_new(GError **error)
> > > return be;
> > > }
> > >
> > > -gboolean spice_usb_backend_handle_events(SpiceUsbBackend *be)
> > > +static gpointer handle_libusb_events(gpointer user_data)
> > > {
> > > + SpiceUsbBackend *be = (SpiceUsbBackend *)user_data;
>
> I don't think you need to cast from gpointer.
>
> > > SPICE_DEBUG("%s >>", __FUNCTION__);
> > > - gboolean ok = FALSE;
> > > - if (be->libusb_context) {
> > > - int res = libusb_handle_events(be->libusb_context);
> > > - ok = res == 0;
> > > + int res = 0;
> > > + const char *desc = "";
> > > + while (g_atomic_int_get(&be->event_thread_run)) {
> > > + res = libusb_handle_events(be->libusb_context);
> > > if (res && res != LIBUSB_ERROR_INTERRUPTED) {
> > > - const char *desc = libusb_strerror(res);
> > > + desc = libusb_strerror(res);
> > > g_warning("Error handling USB events: %s [%i]", desc, res);
> > > - ok = FALSE;
> > > + break;
> > > }
> > > }
> > > - SPICE_DEBUG("%s << %d", __FUNCTION__, ok);
> > > - return ok;
> > > -}
> > > -
> > > -void spice_usb_backend_interrupt_event_handler(SpiceUsbBackend *be)
> > > -{
> > > - if (be->libusb_context) {
> > > - libusb_interrupt_event_handler(be->libusb_context);
> > > + if (be->event_thread_run) {
> > > + SPICE_DEBUG("%s: the thread aborted, %s(%d)", __FUNCTION__, desc, res);
> > > }
> > > + SPICE_DEBUG("%s <<", __FUNCTION__);
> > > + return NULL;
> > > }
> > >
> > > void spice_usb_backend_deregister_hotplug(SpiceUsbBackend *be)
> > > @@ -438,6 +438,12 @@ void spice_usb_backend_deregister_hotplug(SpiceUsbBackend *be)
> > > be->hotplug_handle = 0;
> > > }
> > > be->hotplug_callback = NULL;
> > > + g_atomic_int_set(&be->event_thread_run, FALSE);
> > > + if (be->event_thread) {
> > > + libusb_interrupt_event_handler(be->libusb_context);
> > > + g_thread_join(be->event_thread);
> > > + be->event_thread = NULL;
> > > + }
> > > }
> > >
> > > gboolean spice_usb_backend_register_hotplug(SpiceUsbBackend *be,
> > > @@ -461,6 +467,16 @@ gboolean spice_usb_backend_register_hotplug(SpiceUsbBackend *be,
> > > "Error on USB hotplug detection: %s [%i]", desc, rc);
> > > return FALSE;
> > > }
> > > +
> > > + g_atomic_int_set(&be->event_thread_run, TRUE);
> > > + be->event_thread = g_thread_try_new("usb_ev_thread",
> > > + handle_libusb_events,
> > > + be, error);
>
> It was g_thread_new() before, this changed it, why do you think
> it is important? I'd do that in a separate patch with a proper
> rationale for it.
>From the beginning it should be g_thread_try_new but this was not
available in old glib.
g_thread_try_new does not abort the application on error when g_thread_new does.
>
> > > + if (!be->event_thread) {
> > > + g_warning("Error starting event thread");
> > > + spice_usb_backend_deregister_hotplug(be);
> > > + return FALSE;
> > > + }
> > > return TRUE;
> > > }
> > >
> > > @@ -468,6 +484,8 @@ void spice_usb_backend_delete(SpiceUsbBackend *be)
> > > {
> > > g_return_if_fail(be != NULL);
> > > SPICE_DEBUG("%s >>", __FUNCTION__);
> > > + /* just to be on the safe side if not deregistered */
> > > + spice_usb_backend_deregister_hotplug(be);
>
> Not sure if I follow the comment, should a warn be added in case
> spice_usb_backend_delete() is called in some unexpected situation?
>
> Cheers,
> Victor
>
> > > if (be->libusb_context) {
> > > libusb_exit(be->libusb_context);
> > > }
> > > diff --git a/src/usb-backend.h b/src/usb-backend.h
> > > index 814da46..69a490b 100644
> > > --- a/src/usb-backend.h
> > > +++ b/src/usb-backend.h
> > > @@ -56,8 +56,6 @@ enum {
> > > SpiceUsbBackend *spice_usb_backend_new(GError **error);
> > > void spice_usb_backend_delete(SpiceUsbBackend *context);
> > >
> > > -gboolean spice_usb_backend_handle_events(SpiceUsbBackend *be);
> > > -void spice_usb_backend_interrupt_event_handler(SpiceUsbBackend *be);
> > > gboolean spice_usb_backend_register_hotplug(SpiceUsbBackend *be,
> > > void *user_data,
> > > usb_hot_plug_callback proc,
> > > diff --git a/src/usb-device-manager-priv.h b/src/usb-device-manager-priv.h
> > > index 39aaf2f..66acf6d 100644
> > > --- a/src/usb-device-manager-priv.h
> > > +++ b/src/usb-device-manager-priv.h
> > > @@ -25,12 +25,6 @@
> > >
> > > G_BEGIN_DECLS
> > >
> > > -gboolean spice_usb_device_manager_start_event_listening(
> > > - SpiceUsbDeviceManager *manager, GError **err);
> > > -
> > > -void spice_usb_device_manager_stop_event_listening(
> > > - SpiceUsbDeviceManager *manager);
> > > -
> > > #ifdef USE_USBREDIR
> > > void spice_usb_device_manager_device_error(
> > > SpiceUsbDeviceManager *manager, SpiceUsbDevice *device, GError *err);
> > > diff --git a/src/usb-device-manager.c b/src/usb-device-manager.c
> > > index 7105ff1..25fac04 100644
> > > --- a/src/usb-device-manager.c
> > > +++ b/src/usb-device-manager.c
> > > @@ -93,9 +93,6 @@ struct _SpiceUsbDeviceManagerPrivate {
> > > gchar *redirect_on_connect;
> > > #ifdef USE_USBREDIR
> > > SpiceUsbBackend *context;
> > > - int event_listeners;
> > > - GThread *event_thread;
> > > - gint event_thread_run;
> > > struct usbredirfilter_rule *auto_conn_filter_rules;
> > > struct usbredirfilter_rule *redirect_on_connect_rules;
> > > int auto_conn_filter_rules_count;
> > > @@ -262,9 +259,6 @@ static gboolean spice_usb_device_manager_initable_init(GInitable *initable,
> > > spice_usb_backend_delete(priv->context);
> > > return FALSE;
> > > }
> > > -#ifndef G_OS_WIN32
> > > - spice_usb_device_manager_start_event_listening(self, NULL);
> > > -#endif
> > >
> > > /* Start listening for usb channels connect/disconnect */
> > > spice_g_signal_connect_object(priv->session, "channel-new", G_CALLBACK(channel_new), self, G_CONNECT_AFTER);
> > > @@ -286,27 +280,8 @@ static void spice_usb_device_manager_dispose(GObject *gobject)
> > > SpiceUsbDeviceManager *self = SPICE_USB_DEVICE_MANAGER(gobject);
> > > SpiceUsbDeviceManagerPrivate *priv = self->priv;
> > >
> > > -#ifndef G_OS_WIN32
> > > - spice_usb_device_manager_stop_event_listening(self);
> > > - if (g_atomic_int_get(&priv->event_thread_run)) {
> > > - /* Force termination of the event thread even if there were some
> > > - * mismatched spice_usb_device_manager_{start,stop}_event_listening
> > > - * calls. Otherwise, the usb event thread will be leaked, and will
> > > - * try to use the libusb context we destroy in finalize(), which would
> > > - * cause a crash */
> > > - g_warn_if_reached();
> > > - g_atomic_int_set(&priv->event_thread_run, FALSE);
> > > - }
> > > -#endif
> > > spice_usb_backend_deregister_hotplug(priv->context);
> > >
> > > - if (priv->event_thread) {
> > > - g_warn_if_fail(g_atomic_int_get(&priv->event_thread_run) == FALSE);
> > > - g_atomic_int_set(&priv->event_thread_run, FALSE);
> > > - spice_usb_backend_interrupt_event_handler(priv->context);
> > > - g_thread_join(priv->event_thread);
> > > - priv->event_thread = NULL;
> > > - }
> > > #endif
> > >
> > > /* Chain up to the parent class */
> > > @@ -324,7 +299,6 @@ static void spice_usb_device_manager_finalize(GObject *gobject)
> > > if (priv->devices) {
> > > g_ptr_array_unref(priv->devices);
> > > }
> > > - g_return_if_fail(priv->event_thread == NULL);
> > > if (priv->context) {
> > > spice_usb_backend_delete(priv->context);
> > > }
> > > @@ -916,59 +890,6 @@ static void spice_usb_device_manager_channel_connect_cb(
> > > /* ------------------------------------------------------------------ */
> > > /* private api */
> > >
> > > -static gpointer spice_usb_device_manager_usb_ev_thread(gpointer user_data)
> > > -{
> > > - SpiceUsbDeviceManager *self = SPICE_USB_DEVICE_MANAGER(user_data);
> > > - SpiceUsbDeviceManagerPrivate *priv = self->priv;
> > > -
> > > - while (g_atomic_int_get(&priv->event_thread_run)) {
> > > - if (!spice_usb_backend_handle_events(priv->context)) {
> > > - break;
> > > - }
> > > - }
> > > -
> > > - return NULL;
> > > -}
> > > -
> > > -gboolean spice_usb_device_manager_start_event_listening(
> > > - SpiceUsbDeviceManager *self, GError **err)
> > > -{
> > > - SpiceUsbDeviceManagerPrivate *priv = self->priv;
> > > -
> > > - g_return_val_if_fail(err == NULL || *err == NULL, FALSE);
> > > -
> > > - priv->event_listeners++;
> > > - if (priv->event_listeners > 1)
> > > - return TRUE;
> > > -
> > > - /* We don't join the thread when we stop event listening, as the
> > > - libusb_handle_events call in the thread won't exit until the
> > > - libusb_close call for the device is made from usbredirhost_close. */
> > > - if (priv->event_thread) {
> > > - g_atomic_int_set(&priv->event_thread_run, FALSE);
> > > - spice_usb_backend_interrupt_event_handler(priv->context);
> > > - g_thread_join(priv->event_thread);
> > > - priv->event_thread = NULL;
> > > - }
> > > - g_atomic_int_set(&priv->event_thread_run, TRUE);
> > > - priv->event_thread = g_thread_new("usb_ev_thread",
> > > - spice_usb_device_manager_usb_ev_thread,
> > > - self);
> > > - return priv->event_thread != NULL;
> > > -}
> > > -
> > > -void spice_usb_device_manager_stop_event_listening(
> > > - SpiceUsbDeviceManager *self)
> > > -{
> > > - SpiceUsbDeviceManagerPrivate *priv = self->priv;
> > > -
> > > - g_return_if_fail(priv->event_listeners > 0);
> > > -
> > > - priv->event_listeners--;
> > > - if (priv->event_listeners == 0)
> > > - g_atomic_int_set(&priv->event_thread_run, FALSE);
> > > -}
> > > -
> > > static void spice_usb_device_manager_check_redir_on_connect(
> > > SpiceUsbDeviceManager *self, SpiceChannel *channel)
> > > {
> > > --
> > > 2.17.1
> > >
> > _______________________________________________
> > Spice-devel mailing list
> > Spice-devel at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/spice-devel
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