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diff --git a/compositor/FlatteningController.cpp b/compositor/FlatteningController.cpp
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+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * Usually, display controllers do not use intermediate buffer for composition
+ * results. Instead, they scan-out directly from the input buffers, composing
+ * the planes on the fly every VSYNC.
+ *
+ * Flattening is a technique that reduces memory bandwidth and power consumption
+ * by converting non-updating multi-plane composition into a single-plane.
+ * Additionally, flattening also makes more shared planes available for use by
+ * other CRTCs.
+ *
+ * If the client is not updating layers for 1 second, FlatCon triggers a
+ * callback to refresh the screen. The compositor should mark all layers to be
+ * composed by the client into a single framebuffer using GPU.
+ */
+
+#define LOG_TAG "hwc-flatcon"
+
+#include "FlatteningController.h"
+
+#include "utils/log.h"
+
+namespace android {
+
+auto FlatteningController::CreateInstance(FlatConCallbacks &cbks)
+    -> std::shared_ptr<FlatteningController> {
+  auto fc = std::shared_ptr<FlatteningController>(new FlatteningController());
+
+  fc->cbks_ = cbks;
+
+  std::thread(&FlatteningController::ThreadFn, fc).detach();
+
+  return fc;
+}
+
+/* Compositor should call this every frame */
+bool FlatteningController::NewFrame() {
+  bool wake_it = false;
+  auto lock = std::lock_guard<std::mutex>(mutex_);
+
+  if (flatten_next_frame_) {
+    flatten_next_frame_ = false;
+    return true;
+  }
+
+  sleep_until_ = std::chrono::system_clock::now() + kTimeout;
+  if (disabled_) {
+    wake_it = true;
+    disabled_ = false;
+  }
+
+  if (wake_it)
+    cv_.notify_all();
+
+  return false;
+}
+
+void FlatteningController::ThreadFn(
+    const std::shared_ptr<FlatteningController> &fc) {
+  for (;;) {
+    std::unique_lock<std::mutex> lock(fc->mutex_);
+    if (fc.use_count() == 1 || !fc->cbks_.trigger)
+      break;
+
+    if (fc->sleep_until_ <= std::chrono::system_clock::now() &&
+        !fc->disabled_) {
+      fc->disabled_ = true;
+      fc->flatten_next_frame_ = true;
+      ALOGV("Timeout. Sending an event to compositor");
+      fc->cbks_.trigger();
+    }
+
+    if (fc->disabled_) {
+      ALOGV("Wait");
+      fc->cv_.wait(lock);
+    } else {
+      ALOGV("Wait_until");
+      fc->cv_.wait_until(lock, fc->sleep_until_);
+    }
+  }
+}
+
+}  // namespace android