Make event-targeting asynchronous in window server.

services/ui/ws/window_manager_state.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "services/ui/ws/window_manager_state.h"
 
 #include <utility>
 
 #include "base/logging.h"
 #include "base/memory/weak_ptr.h"
@@ skipping 54 matching lines @@
 const ServerWindow* GetEmbedRoot(const ServerWindow* window) {
   DCHECK(window);
   const ServerWindow* embed_root = window->parent();
   while (embed_root && embed_root->id().client_id == window->id().client_id)
     embed_root = embed_root->parent();
   return embed_root;
 }
 
 }  // namespace
 
-WindowManagerState::InFlightEventDetails::InFlightEventDetails(
+WindowManagerState::InFlightEventDispatchDetails::InFlightEventDispatchDetails(
     WindowManagerState* window_manager_state,
     WindowTree* tree,
     int64_t display_id,
     const Event& event,
     EventDispatchPhase phase)
     : tree(tree),
       display_id(display_id),
       event(Event::Clone(event)),
       phase(phase),
       weak_factory(window_manager_state) {}
 
-WindowManagerState::InFlightEventDetails::~InFlightEventDetails() {}
+WindowManagerState::InFlightEventDispatchDetails::
+    ~InFlightEventDispatchDetails() {}
 
 class WindowManagerState::ProcessedEventTarget {
  public:
   ProcessedEventTarget(ServerWindow* window,
                        ClientSpecificId client_id,
                        Accelerator* accelerator)
       : client_id_(client_id) {
     tracker_.Add(window);
     if (accelerator)
       accelerator_ = accelerator->GetWeakPtr();
@@ skipping 87 matching lines @@
   event_dispatcher_.ReleaseCaptureBlockedByAnyModalWindow();
 }
 
 void WindowManagerState::SetDragDropSourceWindow(
     DragSource* drag_source,
     ServerWindow* window,
     DragTargetConnection* source_connection,
     const std::unordered_map<std::string, std::vector<uint8_t>>& drag_data,
     uint32_t drag_operation) {
   int32_t drag_pointer = MouseEvent::kMousePointerId;
-  if (in_flight_event_details_ &&
-      in_flight_event_details_->event->IsPointerEvent()) {
-    drag_pointer =
-        in_flight_event_details_->event->AsPointerEvent()->pointer_details().id;
+  if (in_flight_event_dispatch_details_ &&
+      in_flight_event_dispatch_details_->event->IsPointerEvent()) {
+    drag_pointer = in_flight_event_dispatch_details_->event->AsPointerEvent()
+                       ->pointer_details()
+                       .id;
   } else {
     NOTIMPLEMENTED() << "Set drag drop set up during something other than a "
                      << "pointer event; rejecting drag.";
     drag_source->OnDragCompleted(false, ui::mojom::kDropEffectNone);
     return;
   }
 
   event_dispatcher_.SetDragDropSourceWindow(drag_source, window,
                                             source_connection, drag_pointer,
                                             drag_data, drag_operation);
@@ skipping 34 matching lines @@
   NOTREACHED();
 }
 
 const UserId& WindowManagerState::user_id() const {
   return window_tree_->user_id();
 }
 
 void WindowManagerState::OnWillDestroyTree(WindowTree* tree) {
   event_dispatcher_.OnWillDestroyDragTargetConnection(tree);
 
-  if (!in_flight_event_details_ || in_flight_event_details_->tree != tree)
+  if (!in_flight_event_dispatch_details_ ||
+      in_flight_event_dispatch_details_->tree != tree)
     return;
 
   // The WindowTree is dying. So it's not going to ack the event.
   // If the dying tree matches the root |tree_| mark as handled so we don't
   // notify it of accelerators.
-  OnEventAck(in_flight_event_details_->tree,
+  OnEventAck(in_flight_event_dispatch_details_->tree,
              tree == window_tree_ ? mojom::EventResult::HANDLED
                                   : mojom::EventResult::UNHANDLED);
 }
 
 ServerWindow* WindowManagerState::GetOrphanedRootWithId(const WindowId& id) {
   for (auto& display_root_ptr : orphaned_window_manager_display_roots_) {
     if (display_root_ptr->root()->id() == id)
       return display_root_ptr->root();
   }
   return nullptr;
@@ skipping 15 matching lines @@
   // The tree is no longer active, so no point in dispatching any further
   // events.
   std::queue<std::unique_ptr<QueuedEvent>> event_queue;
   event_queue.swap(event_queue_);
 }
 
 void WindowManagerState::ProcessEvent(const ui::Event& event,
                                       int64_t display_id) {
   // If this is still waiting for an ack from a previously sent event, then
   // queue up the event to be dispatched once the ack is received.
-  if (in_flight_event_details_) {
+  if (event_dispatcher_.IsHitTestInFlight() ||
+      in_flight_event_dispatch_details_) {
     if (!event_queue_.empty() && !event_queue_.back()->processed_target &&
         EventsCanBeCoalesced(*event_queue_.back()->event, event)) {
       event_queue_.back()->event = CoalesceEvents(
           std::move(event_queue_.back()->event), ui::Event::Clone(event));
       event_queue_.back()->display_id = display_id;
       return;
     }
     QueueEvent(event, nullptr, display_id);
     return;
   }
 
   ProcessEventImpl(event, display_id);
 }
 
 void WindowManagerState::OnAcceleratorAck(
     mojom::EventResult result,
     const std::unordered_map<std::string, std::vector<uint8_t>>& properties) {
-  DCHECK(in_flight_event_details_);
+  DCHECK(in_flight_event_dispatch_details_);
   DCHECK_EQ(EventDispatchPhase::PRE_TARGET_ACCELERATOR,
-            in_flight_event_details_->phase);
+            in_flight_event_dispatch_details_->phase);
 
-  std::unique_ptr<InFlightEventDetails> details =
-      std::move(in_flight_event_details_);
+  std::unique_ptr<InFlightEventDispatchDetails> details =
+      std::move(in_flight_event_dispatch_details_);
 
   if (result == mojom::EventResult::UNHANDLED) {
     DCHECK(details->event->IsKeyEvent());
     if (!properties.empty())
       details->event->AsKeyEvent()->SetProperties(properties);
     event_processing_display_id_ = details->display_id;
     event_dispatcher_.ProcessEvent(
         *details->event, EventDispatcher::AcceleratorMatchPhase::POST_ONLY);
   } else {
     // We're not going to process the event any further, notify event observers.
@@ skipping 53 matching lines @@
   for (auto& display_root_ptr : window_manager_display_roots_) {
     if (display_root_ptr->root()->parent() == window)
       return display_root_ptr->GetClientVisibleRoot();
   }
   NOTREACHED();
   return nullptr;
 }
 
 void WindowManagerState::OnEventAck(mojom::WindowTree* tree,
                                     mojom::EventResult result) {
-  DCHECK(in_flight_event_details_);
-  std::unique_ptr<InFlightEventDetails> details =
-      std::move(in_flight_event_details_);
+  DCHECK(in_flight_event_dispatch_details_);
+  std::unique_ptr<InFlightEventDispatchDetails> details =
+      std::move(in_flight_event_dispatch_details_);
 
   if (result == mojom::EventResult::UNHANDLED &&
       details->post_target_accelerator) {
     OnAccelerator(details->post_target_accelerator->id(), *details->event,
                   AcceleratorPhase::POST);
   }
 
   ProcessNextEventFromQueue();
 }
 
 void WindowManagerState::OnEventAckTimeout(ClientSpecificId client_id) {
   WindowTree* hung_tree = window_server()->GetTreeWithId(client_id);
   if (hung_tree && !hung_tree->janky())
     window_tree_->ClientJankinessChanged(hung_tree);
-  if (in_flight_event_details_->phase ==
+  if (in_flight_event_dispatch_details_->phase ==
       EventDispatchPhase::PRE_TARGET_ACCELERATOR) {
     OnAcceleratorAck(mojom::EventResult::UNHANDLED, KeyEvent::Properties());
   } else {
-    OnEventAck(in_flight_event_details_->tree, mojom::EventResult::UNHANDLED);
+    OnEventAck(in_flight_event_dispatch_details_->tree,
+               mojom::EventResult::UNHANDLED);
   }
 }
 
 void WindowManagerState::ProcessEventImpl(const ui::Event& event,
                                           int64_t display_id) {
+  DCHECK(!in_flight_event_dispatch_details_ &&
+         !event_dispatcher_.IsHitTestInFlight());
   // Debug accelerators are always checked and don't interfere with processing.
   ProcessDebugAccelerator(event);
   event_processing_display_id_ = display_id;
   event_dispatcher_.ProcessEvent(event,
                                  EventDispatcher::AcceleratorMatchPhase::ANY);
 }
 
 void WindowManagerState::QueueEvent(
     const ui::Event& event,
     std::unique_ptr<ProcessedEventTarget> processed_event_target,
     int64_t display_id) {
   std::unique_ptr<QueuedEvent> queued_event(new QueuedEvent);
   queued_event->event = ui::Event::Clone(event);
   queued_event->processed_target = std::move(processed_event_target);
   queued_event->display_id = display_id;
   event_queue_.push(std::move(queued_event));
 }
 
-void WindowManagerState::ProcessNextEventFromQueue() {
-  // Loop through |event_queue_| stopping after dispatching the first valid
-  // event.
-  while (!event_queue_.empty()) {
-    std::unique_ptr<QueuedEvent> queued_event = std::move(event_queue_.front());
-    event_queue_.pop();
-    if (!queued_event->processed_target) {
-      ProcessEventImpl(*queued_event->event, queued_event->display_id);
-      return;
-    }
-    if (queued_event->processed_target->IsValid()) {
-      DispatchInputEventToWindowImpl(
-          queued_event->processed_target->window(),
-          queued_event->processed_target->client_id(), *queued_event->event,
-          queued_event->processed_target->accelerator());
-      return;
-    }
-  }
-}
-
+// TODO(riajiang): We might want to do event targeting for the next event while
+// waiting for the current event to be dispatched. crbug.com/724521
 void WindowManagerState::DispatchInputEventToWindowImpl(
     ServerWindow* target,
     ClientSpecificId client_id,
     const ui::Event& event,
     base::WeakPtr<Accelerator> accelerator) {
+  DCHECK(!in_flight_event_dispatch_details_);
   DCHECK(target);
   if (target->parent() == nullptr)
     target = GetWindowManagerRootForDisplayRoot(target);
 
   if (event.IsMousePointerEvent()) {
     DCHECK(event_dispatcher_.mouse_cursor_source_window());
     UpdateNativeCursorFromDispatcher();
   }
 
   WindowTree* tree = window_server()->GetTreeWithId(client_id);
   DCHECK(tree);
   ScheduleInputEventTimeout(tree, target, event, EventDispatchPhase::TARGET);
-  in_flight_event_details_->post_target_accelerator = accelerator;
+  in_flight_event_dispatch_details_->post_target_accelerator = accelerator;
 
   // Ignore |tree| because it will receive the event via normal dispatch.
-  window_server()->SendToPointerWatchers(event, user_id(), target, tree,
-                                         in_flight_event_details_->display_id);
+  window_server()->SendToPointerWatchers(
+      event, user_id(), target, tree,
+      in_flight_event_dispatch_details_->display_id);
 
   tree->DispatchInputEvent(
       target, event,
-      base::BindOnce(&WindowManagerState::OnEventAck,
-                     in_flight_event_details_->weak_factory.GetWeakPtr(),
-                     tree));
+      base::BindOnce(
+          &WindowManagerState::OnEventAck,
+          in_flight_event_dispatch_details_->weak_factory.GetWeakPtr(), tree));
 }
 
 void WindowManagerState::AddDebugAccelerators() {
   const DebugAccelerator accelerator = {
       DebugAcceleratorType::PRINT_WINDOWS, ui::VKEY_S,
       ui::EF_CONTROL_DOWN | ui::EF_ALT_DOWN | ui::EF_SHIFT_DOWN};
   debug_accelerators_.push_back(accelerator);
 }
 
 void WindowManagerState::ProcessDebugAccelerator(const ui::Event& event) {
@@ skipping 23 matching lines @@
   ServerWindow* focused_window = GetFocusedWindowForEventDispatcher();
   LOG(ERROR) << "Focused window: "
              << (focused_window ? focused_window->id().ToString() : "(null)");
 #endif
 }
 
 void WindowManagerState::ScheduleInputEventTimeout(WindowTree* tree,
                                                    ServerWindow* target,
                                                    const Event& event,
                                                    EventDispatchPhase phase) {
-  std::unique_ptr<InFlightEventDetails> details =
-      base::MakeUnique<InFlightEventDetails>(
+  std::unique_ptr<InFlightEventDispatchDetails> details =
+      base::MakeUnique<InFlightEventDispatchDetails>(
           this, tree, event_processing_display_id_, event, phase);
 
   // TOOD(sad): Adjust this delay, possibly make this dynamic.
   const base::TimeDelta max_delay = base::debug::BeingDebugged()
                                         ? base::TimeDelta::FromDays(1)
                                         : GetDefaultAckTimerDelay();
   details->timer.Start(
       FROM_HERE, max_delay,
       base::Bind(&WindowManagerState::OnEventAckTimeout,
                  details->weak_factory.GetWeakPtr(), tree->id()));
-  in_flight_event_details_ = std::move(details);
+  in_flight_event_dispatch_details_ = std::move(details);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // EventDispatcherDelegate:
 
 void WindowManagerState::OnAccelerator(uint32_t accelerator_id,
                                        const ui::Event& event,
                                        AcceleratorPhase phase) {
   DCHECK(IsActive());
   const bool needs_ack = phase == AcceleratorPhase::PRE;
   WindowTree::AcceleratorCallback ack_callback;
   if (needs_ack) {
-    DCHECK(!in_flight_event_details_);
+    DCHECK(!in_flight_event_dispatch_details_);
     ScheduleInputEventTimeout(window_tree_, nullptr, event,
                               EventDispatchPhase::PRE_TARGET_ACCELERATOR);
-    ack_callback =
-        base::BindOnce(&WindowManagerState::OnAcceleratorAck,
-                       in_flight_event_details_->weak_factory.GetWeakPtr());
+    ack_callback = base::BindOnce(
+        &WindowManagerState::OnAcceleratorAck,
+        in_flight_event_dispatch_details_->weak_factory.GetWeakPtr());
   }
   window_tree_->OnAccelerator(accelerator_id, event, std::move(ack_callback));
 }
 
 void WindowManagerState::SetFocusedWindowFromEventDispatcher(
     ServerWindow* new_focused_window) {
   DCHECK(IsActive());
   window_server()->SetFocusedWindow(new_focused_window);
 }
 
@@ skipping 49 matching lines @@
       ->OnMouseCursorLocationChanged(point);
 }
 
 void WindowManagerState::DispatchInputEventToWindow(ServerWindow* target,
                                                     ClientSpecificId client_id,
                                                     const ui::Event& event,
                                                     Accelerator* accelerator) {
   DCHECK(IsActive());
   // TODO(sky): this needs to see if another wms has capture and if so forward
   // to it.
-  if (in_flight_event_details_) {
+  if (in_flight_event_dispatch_details_) {
     std::unique_ptr<ProcessedEventTarget> processed_event_target(
         new ProcessedEventTarget(target, client_id, accelerator));
     QueueEvent(event, std::move(processed_event_target),
                event_processing_display_id_);
     return;
   }
 
   base::WeakPtr<Accelerator> weak_accelerator;
   if (accelerator)
     weak_accelerator = accelerator->GetWeakPtr();
   DispatchInputEventToWindowImpl(target, client_id, event, weak_accelerator);
 }
 
+void WindowManagerState::ProcessNextEventFromQueue() {
+  // Loop through |event_queue_| stopping after dispatching the first valid
+  // event.
+  while (!event_queue_.empty()) {
+    if (in_flight_event_dispatch_details_)
+      return;
+
+    if (!event_queue_.front()->processed_target &&
+        event_dispatcher_.IsHitTestInFlight())
+      return;
+
+    std::unique_ptr<QueuedEvent> queued_event = std::move(event_queue_.front());
+    event_queue_.pop();
+    if (!queued_event->processed_target) {
+      ProcessEventImpl(*queued_event->event, queued_event->display_id);
+      return;
+    }
+    if (queued_event->processed_target->IsValid()) {
+      DispatchInputEventToWindowImpl(
+          queued_event->processed_target->window(),
+          queued_event->processed_target->client_id(), *queued_event->event,
+          queued_event->processed_target->accelerator());
+      return;
+    }
+  }
+}
+
 ClientSpecificId WindowManagerState::GetEventTargetClientId(
     const ServerWindow* window,
     bool in_nonclient_area) {
   if (in_nonclient_area) {
     // Events in the non-client area always go to the window manager.
     return window_tree_->id();
   }
 
   // If the window is an embed root, it goes to the tree embedded in the window.
   WindowTree* tree = window_server()->GetTreeWithRoot(window);
@@ skipping 61 matching lines @@
       window->RemoveObserver(this);
       orphaned_window_manager_display_roots_.erase(iter);
       return;
     }
   }
   NOTREACHED();
 }
 
 }  // namespace ws
 }  // namespace ui