1 files changed, 77 insertions, 0 deletions
diff --git a/xpcom/threads/InputTaskManager.cpp b/xpcom/threads/InputTaskManager.cpp
new file mode 100644
index 0000000000..8464978268
--- /dev/null
+++ b/xpcom/threads/InputTaskManager.cpp
@@ -0,0 +1,77 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "InputTaskManager.h"
+
+namespace mozilla {
+
+StaticRefPtr<InputTaskManager> InputTaskManager::gInputTaskManager;
+
+void InputTaskManager::EnableInputEventPrioritization() {
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(mInputQueueState == STATE_DISABLED);
+  mInputQueueState = STATE_ENABLED;
+  mInputHandlingStartTime = TimeStamp();
+}
+
+void InputTaskManager::FlushInputEventPrioritization() {
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(mInputQueueState == STATE_ENABLED ||
+             mInputQueueState == STATE_SUSPEND);
+  mInputQueueState =
+      mInputQueueState == STATE_ENABLED ? STATE_FLUSHING : STATE_SUSPEND;
+}
+
+void InputTaskManager::SuspendInputEventPrioritization() {
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(mInputQueueState == STATE_ENABLED ||
+             mInputQueueState == STATE_FLUSHING);
+  mInputQueueState = STATE_SUSPEND;
+}
+
+void InputTaskManager::ResumeInputEventPrioritization() {
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(mInputQueueState == STATE_SUSPEND);
+  mInputQueueState = STATE_ENABLED;
+}
+
+int32_t InputTaskManager::GetPriorityModifierForEventLoopTurn(
+    const MutexAutoLock& aProofOfLock) {
+  size_t inputCount = PendingTaskCount();
+  if (State() == STATE_ENABLED && InputHandlingStartTime().IsNull() &&
+      inputCount > 0) {
+    SetInputHandlingStartTime(
+        InputEventStatistics::Get().GetInputHandlingStartTime(inputCount));
+  }
+
+  if (inputCount > 0 && (State() == InputTaskManager::STATE_FLUSHING ||
+                         (State() == InputTaskManager::STATE_ENABLED &&
+                          !InputHandlingStartTime().IsNull() &&
+                          TimeStamp::Now() > InputHandlingStartTime()))) {
+    return 0;
+  }
+
+  int32_t modifier = static_cast<int32_t>(EventQueuePriority::InputLow) -
+                     static_cast<int32_t>(EventQueuePriority::MediumHigh);
+  return modifier;
+}
+
+void InputTaskManager::WillRunTask() {
+  TaskManager::WillRunTask();
+  mStartTimes.AppendElement(TimeStamp::Now());
+}
+
+void InputTaskManager::DidRunTask() {
+  TaskManager::DidRunTask();
+  MOZ_ASSERT(!mStartTimes.IsEmpty());
+  TimeStamp start = mStartTimes.PopLastElement();
+  InputEventStatistics::Get().UpdateInputDuration(TimeStamp::Now() - start);
+}
+
+// static
+void InputTaskManager::Init() { gInputTaskManager = new InputTaskManager(); }
+
+}  // namespace mozilla