SF: Extract PresentLatencyTracker
Present fences will eventually be tracked per display to compute per-
display CompositorTiming, but for now extract a class and add tests.
Bug: 185535769
Test: libscheduler_test
Change-Id: Ifa7f27059dc0ca5c8ee4747dd2640fb9638fd2bc
diff --git a/services/surfaceflinger/Scheduler/src/PresentLatencyTracker.cpp b/services/surfaceflinger/Scheduler/src/PresentLatencyTracker.cpp
new file mode 100644
index 0000000..8f3e081
--- /dev/null
+++ b/services/surfaceflinger/Scheduler/src/PresentLatencyTracker.cpp
@@ -0,0 +1,56 @@
+/*
+ * Copyright 2022 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.
+ */
+
+#include <scheduler/PresentLatencyTracker.h>
+
+#include <cutils/compiler.h>
+#include <log/log.h>
+#include <ui/FenceTime.h>
+
+namespace android::scheduler {
+
+Duration PresentLatencyTracker::trackPendingFrame(TimePoint compositeTime,
+ std::shared_ptr<FenceTime> presentFenceTime) {
+ Duration presentLatency = Duration::zero();
+ while (!mPendingFrames.empty()) {
+ const auto& pendingFrame = mPendingFrames.front();
+ const auto presentTime =
+ TimePoint::fromNs(pendingFrame.presentFenceTime->getCachedSignalTime());
+
+ if (presentTime == TimePoint::fromNs(Fence::SIGNAL_TIME_PENDING)) {
+ break;
+ }
+
+ if (presentTime == TimePoint::fromNs(Fence::SIGNAL_TIME_INVALID)) {
+ ALOGE("%s: Invalid present fence", __func__);
+ } else {
+ presentLatency = presentTime - pendingFrame.compositeTime;
+ }
+
+ mPendingFrames.pop();
+ }
+
+ mPendingFrames.emplace(compositeTime, std::move(presentFenceTime));
+
+ if (CC_UNLIKELY(mPendingFrames.size() > kMaxPendingFrames)) {
+ ALOGE("%s: Too many pending frames", __func__);
+ mPendingFrames.pop();
+ }
+
+ return presentLatency;
+}
+
+} // namespace android::scheduler