[Spice-devel] [PATCH v6 05/14] usbredir: Protect data accessed by asynchronous redirection flows

[Dmitry Fleytman]

From: Kirill Moizik <kmoizik at redhat.com>

This commit adds locking to ensure thread safety required
after start/stop redirection flows moved to separate threads.
This is done in preparation to following commits that
will introduce actual multithreaded access to corresponding
routines.

Signed-off-by: Kirill Moizik <kmoizik at redhat.com>
Signed-off-by: Dmitry Fleytman <dfleytma at redhat.com>
---
 src/channel-usbredir.c   |  9 ++++++++-
 src/usb-device-manager.c | 12 ++++++++++--
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/src/channel-usbredir.c b/src/channel-usbredir.c
index c91b3f7..5489afb 100644
--- a/src/channel-usbredir.c
+++ b/src/channel-usbredir.c
@@ -660,13 +660,18 @@ static void usbredir_handle_msg(SpiceChannel *c, SpiceMsgIn *in)
     priv->read_buf = buf;
     priv->read_buf_size = size;
 
+    spice_usbredir_channel_lock(channel);
+
     r = usbredirhost_read_guest_data(priv->host);
     if (r != 0) {
         SpiceUsbDevice *spice_device = priv->spice_device;
         gchar *desc;
         GError *err;
 
-        g_return_if_fail(spice_device != NULL);
+        if (spice_device == NULL) {
+            spice_usbredir_channel_unlock(channel);
+            return;
+        }
 
         desc = spice_usb_device_get_description(spice_device, NULL);
         switch (r) {
@@ -703,6 +708,8 @@ static void usbredir_handle_msg(SpiceChannel *c, SpiceMsgIn *in)
 
         g_error_free(err);
     }
+
+    spice_usbredir_channel_unlock(channel);
 }
 
 #endif /* USE_USBREDIR */
diff --git a/src/usb-device-manager.c b/src/usb-device-manager.c
index f4e48eb..4d376b6 100644
--- a/src/usb-device-manager.c
+++ b/src/usb-device-manager.c
@@ -1326,9 +1326,13 @@ static SpiceUsbredirChannel *spice_usb_device_manager_get_channel_for_dev(
 
     for (i = 0; i < priv->channels->len; i++) {
         SpiceUsbredirChannel *channel = g_ptr_array_index(priv->channels, i);
+        spice_usbredir_channel_lock(channel);
         libusb_device *libdev = spice_usbredir_channel_get_device(channel);
-        if (spice_usb_manager_device_equal_libdev(manager, device, libdev))
+        if (spice_usb_manager_device_equal_libdev(manager, device, libdev)) {
+            spice_usbredir_channel_unlock(channel);
             return channel;
+        }
+        spice_usbredir_channel_unlock(channel);
     }
 #endif
     return NULL;
@@ -1730,9 +1734,13 @@ spice_usb_device_manager_can_redirect_device(SpiceUsbDeviceManager  *self,
     /* Check if there are free channels */
     for (i = 0; i < priv->channels->len; i++) {
         SpiceUsbredirChannel *channel = g_ptr_array_index(priv->channels, i);
+        spice_usbredir_channel_lock(channel);
 
-        if (!spice_usbredir_channel_get_device(channel))
+        if (!spice_usbredir_channel_get_device(channel)){
+            spice_usbredir_channel_unlock(channel);
             break;
+        }
+        spice_usbredir_channel_unlock(channel);
     }
     if (i == priv->channels->len) {
         g_set_error_literal(err, SPICE_CLIENT_ERROR, SPICE_CLIENT_ERROR_FAILED,
-- 
2.5.0