UI Resource Manager

cc/trees/layer_tree_host.cc

Index: cc/trees/layer_tree_host.cc
===================================================================
--- cc/trees/layer_tree_host.cc	(revision 213649)
+++ cc/trees/layer_tree_host.cc	(working copy)
@@ -78,7 +78,8 @@
 
 LayerTreeHost::LayerTreeHost(LayerTreeHostClient* client,
                              const LayerTreeSettings& settings)
-    : animating_(false),
+    : ui_resource_id_(1),
+      animating_(false),
       needs_full_tree_sync_(true),
       needs_filter_context_(false),
       client_(client),
@@ -354,6 +355,15 @@
     pending_page_scale_animation_.reset();
   }
 
+  if (!ui_resource_request_queue_.empty()) {
+    sync_tree->set_ui_resource_request_queue(ui_resource_request_queue_);
+    ui_resource_request_queue_.clear();
+    // Process any ui resource requests in the queue.  For impl-side-painting,
+    // the queue is processed in LayerTreeHostImpl::ActivatePendingTree.
+    if (!settings_.impl_side_painting)
+      sync_tree->ProcessUIResourceRequestQueue();
+  }
+
   DCHECK(!sync_tree->ViewportSizeInvalid());
 
   if (new_impl_tree_has_no_evicted_resources) {
@@ -419,6 +429,8 @@
   if (output_surface_lost_)
     return;
 
+  DidLoseUIResources();
+
   num_failed_recreate_attempts_ = 0;
   output_surface_lost_ = true;
   SetNeedsCommit();
@@ -1024,7 +1036,7 @@
 }
 
 void LayerTreeHost::SetDeviceScaleFactor(float device_scale_factor) {
-  if (device_scale_factor ==  device_scale_factor_)
+  if (device_scale_factor == device_scale_factor_)
     return;
   device_scale_factor_ = device_scale_factor;
 
@@ -1080,4 +1092,77 @@
   }
 }
 
+UIResourceId LayerTreeHost::CreateUIResource(
+    const UIResourceCallback& bitmap_cb) {
+  UIResourceRequest request;
+  bool resource_lost = false;
+  request.type = UIResourceCreate;
+  request.id = ui_resource_id_++;
+
+  DCHECK(ui_resource_client_map_.find(request.id) ==
+         ui_resource_client_map_.end());
+
+  request.bitmap = bitmap_cb.Run(resource_lost);
+  ui_resource_request_queue_.push_back(request);
+  ui_resource_client_map_[request.id] = bitmap_cb;
+  return request.id;
+}
+
+// Deletes a UI resource.  May safely be called more than once.
+void LayerTreeHost::DeleteUIResource(UIResourceId uid) {
+  UIResourceClientMap::iterator iter = ui_resource_client_map_.find(uid);
+  if (iter != ui_resource_client_map_.end()) {
+    UIResourceRequest request;
+    request.type = UIResourceDelete;
+    request.id = uid;
+    ui_resource_request_queue_.push_back(request);
+    ui_resource_client_map_.erase(uid);
+  }
+}
+
+void LayerTreeHost::UIResourceLost(UIResourceId uid) {
+  UIResourceClientMap::iterator iter = ui_resource_client_map_.find(uid);
+  if (iter != ui_resource_client_map_.end()) {
+    UIResourceRequest request;
+    bool resource_lost = true;
+    request.type = UIResourceCreate;
+    request.id = uid;
+    request.bitmap = iter->second.Run(resource_lost);
+    ui_resource_request_queue_.push_back(request);
+  }
+}
+
+void LayerTreeHost::DidLoseUIResources() {
+  typedef base::hash_set<UIResourceId> UIResourceIdSet;
+  UIResourceIdSet create_resource_set;
+  UIResourceRequestQueue request_recovery_queue;
+
+  for (UIResourceRequestQueue::iterator iter =
+           ui_resource_request_queue_.begin();
+       iter != ui_resource_request_queue_.end();
+       iter++) {
+    // Only add the create request if a delete has not been issued for the same
+    // resource.  If a delete has been issued, then this resource would not have
+    // an entry in the map.
+    if (iter->type == UIResourceCreate &&

[aelias_OOO_until_Jul13, 2013/07/25 23:59:45]

I suggest removing this if() and just creating a "request_set" from all
UIResourceRequests instead (to avoid n^2 finds and for no other reasons). 
Ultimately you just want to avoid calling UIResourceLost for anything with an
existing request, whether create or delete.

[powei, 2013/07/26 23:07:27]

Done.

+        ui_resource_client_map_.find(iter->id) !=
+            ui_resource_client_map_.end()) {
+      create_resource_set.insert(iter->id);
+      request_recovery_queue.push_back(*iter);
+    }
+  }
+
+  ui_resource_request_queue_ = request_recovery_queue;

[aelias_OOO_until_Jul13, 2013/07/25 23:59:45]

I don't see the need for this assignment.  It seems to be for the purpose of
removing the deletes, but I think the impl-side code should be robust to
spurious deletes instead.

[powei, 2013/07/26 23:07:27]

Done.

+
+  // When output surface is lost, we need to recreate the resource.
+  for (UIResourceClientMap::iterator iter = ui_resource_client_map_.begin();
+       iter != ui_resource_client_map_.end();
+       iter++) {
+    // If the resource was to be created, then the original request will be
+    // honored instead of treating it as resource lost.
+    if (create_resource_set.find(iter->first) == create_resource_set.end())
+      UIResourceLost(iter->first);
+  }
+}
+
 }  // namespace cc