[Spice-devel] [PATCH spice-gtk 7/7] usb-device-manager: Last chance to avoid deadlock handling libusb events

[Frediano Ziglio]

Attempt to better interrupt event handling loop.
If the thread handling events is stuck waiting events or handling an
event try to interrupt before joining the thread.

Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
---
 src/usb-backend.c        | 7 +++++++
 src/usb-backend.h        | 1 +
 src/usb-device-manager.c | 4 ++++
 3 files changed, 12 insertions(+)

diff --git a/src/usb-backend.c b/src/usb-backend.c
index 48a62cd1..a2c502da 100644
--- a/src/usb-backend.c
+++ b/src/usb-backend.c
@@ -230,6 +230,13 @@ gboolean spice_usb_backend_handle_events(SpiceUsbBackend *be)
     return ok;
 }
 
+void spice_usb_backend_interrupt_event_handler(SpiceUsbBackend *be)
+{
+    if (be->libusb_context) {
+        libusb_interrupt_event_handler(be->libusb_context);
+    }
+}
+
 static int LIBUSB_CALL hotplug_callback(libusb_context *ctx,
                                         libusb_device *device,
                                         libusb_hotplug_event event,
diff --git a/src/usb-backend.h b/src/usb-backend.h
index 9f2a97a6..cbb73c22 100644
--- a/src/usb-backend.h
+++ b/src/usb-backend.h
@@ -65,6 +65,7 @@ after it finishes list processing
 SpiceUsbBackendDevice **spice_usb_backend_get_device_list(SpiceUsbBackend *backend);
 void spice_usb_backend_free_device_list(SpiceUsbBackendDevice **devlist);
 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.c b/src/usb-device-manager.c
index 4960667e..0d12432f 100644
--- a/src/usb-device-manager.c
+++ b/src/usb-device-manager.c
@@ -328,6 +328,8 @@ static void spice_usb_device_manager_dispose(GObject *gobject)
 #endif
     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;
     }
@@ -988,6 +990,8 @@ gboolean spice_usb_device_manager_start_event_listening(
        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;
     }
-- 
2.20.1