1 files changed, 163 insertions, 0 deletions
diff --git a/services/surfaceflinger/Scheduler/VsyncModulator.cpp b/services/surfaceflinger/Scheduler/VsyncModulator.cpp
new file mode 100644
index 0000000000..194d808836
--- /dev/null
+++ b/services/surfaceflinger/Scheduler/VsyncModulator.cpp
@@ -0,0 +1,163 @@
+/*
+ * Copyright 2019 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.
+ */
+
+#define ATRACE_TAG ATRACE_TAG_GRAPHICS
+
+#undef LOG_TAG
+#define LOG_TAG "VsyncModulator"
+
+#include "VsyncModulator.h"
+
+#include <android-base/properties.h>
+#include <log/log.h>
+#include <utils/Trace.h>
+
+#include <chrono>
+#include <cinttypes>
+#include <mutex>
+
+using namespace std::chrono_literals;
+
+namespace android::scheduler {
+
+const std::chrono::nanoseconds VsyncModulator::MIN_EARLY_TRANSACTION_TIME = 1ms;
+
+VsyncModulator::VsyncModulator(const VsyncConfigSet& config, Now now)
+      : mVsyncConfigSet(config),
+        mNow(now),
+        mTraceDetailedInfo(base::GetBoolProperty("debug.sf.vsync_trace_detailed_info", false)) {}
+
+VsyncModulator::VsyncConfig VsyncModulator::setVsyncConfigSet(const VsyncConfigSet& config) {
+    std::lock_guard<std::mutex> lock(mMutex);
+    mVsyncConfigSet = config;
+    return updateVsyncConfigLocked();
+}
+
+VsyncModulator::VsyncConfigOpt VsyncModulator::setTransactionSchedule(
+        TransactionSchedule schedule) {
+    switch (schedule) {
+        case Schedule::EarlyStart:
+            ALOGW_IF(mEarlyWakeup, "%s: Duplicate EarlyStart", __FUNCTION__);
+            mEarlyWakeup = true;
+            break;
+        case Schedule::EarlyEnd:
+            ALOGW_IF(!mEarlyWakeup, "%s: Unexpected EarlyEnd", __FUNCTION__);
+            mEarlyWakeup = false;
+            break;
+        case Schedule::Late:
+            // No change to mEarlyWakeup for non-explicit states.
+            break;
+    }
+
+    if (mTraceDetailedInfo) {
+        ATRACE_INT("mEarlyWakeup", mEarlyWakeup);
+    }
+
+    if (!mEarlyWakeup && schedule == Schedule::EarlyEnd) {
+        mEarlyTransactionFrames = MIN_EARLY_TRANSACTION_FRAMES;
+        mEarlyTransactionStartTime = mNow();
+    }
+
+    // An early transaction stays an early transaction.
+    if (schedule == mTransactionSchedule || mTransactionSchedule == Schedule::EarlyEnd) {
+        return std::nullopt;
+    }
+    mTransactionSchedule = schedule;
+    return updateVsyncConfig();
+}
+
+VsyncModulator::VsyncConfigOpt VsyncModulator::onTransactionCommit() {
+    mLastTransactionCommitTime = mNow();
+    if (mTransactionSchedule == Schedule::Late) return std::nullopt;
+    mTransactionSchedule = Schedule::Late;
+    return updateVsyncConfig();
+}
+
+VsyncModulator::VsyncConfigOpt VsyncModulator::onRefreshRateChangeInitiated() {
+    if (mRefreshRateChangePending) return std::nullopt;
+    mRefreshRateChangePending = true;
+    return updateVsyncConfig();
+}
+
+VsyncModulator::VsyncConfigOpt VsyncModulator::onRefreshRateChangeCompleted() {
+    if (!mRefreshRateChangePending) return std::nullopt;
+    mRefreshRateChangePending = false;
+    return updateVsyncConfig();
+}
+
+VsyncModulator::VsyncConfigOpt VsyncModulator::onDisplayRefresh(bool usedGpuComposition) {
+    bool updateOffsetsNeeded = false;
+
+    if (mEarlyTransactionStartTime.load() + MIN_EARLY_TRANSACTION_TIME <=
+        mLastTransactionCommitTime.load()) {
+        if (mEarlyTransactionFrames > 0) {
+            mEarlyTransactionFrames--;
+            updateOffsetsNeeded = true;
+        }
+    }
+    if (usedGpuComposition) {
+        mEarlyGpuFrames = MIN_EARLY_GPU_FRAMES;
+        updateOffsetsNeeded = true;
+    } else if (mEarlyGpuFrames > 0) {
+        mEarlyGpuFrames--;
+        updateOffsetsNeeded = true;
+    }
+
+    if (!updateOffsetsNeeded) return std::nullopt;
+    return updateVsyncConfig();
+}
+
+VsyncModulator::VsyncConfig VsyncModulator::getVsyncConfig() const {
+    std::lock_guard<std::mutex> lock(mMutex);
+    return mVsyncConfig;
+}
+
+const VsyncModulator::VsyncConfig& VsyncModulator::getNextVsyncConfig() const {
+    // Early offsets are used if we're in the middle of a refresh rate
+    // change, or if we recently begin a transaction.
+    if (mEarlyWakeup || mTransactionSchedule == Schedule::EarlyEnd || mEarlyTransactionFrames > 0 ||
+        mRefreshRateChangePending) {
+        return mVsyncConfigSet.early;
+    } else if (mEarlyGpuFrames > 0) {
+        return mVsyncConfigSet.earlyGpu;
+    } else {
+        return mVsyncConfigSet.late;
+    }
+}
+
+VsyncModulator::VsyncConfig VsyncModulator::updateVsyncConfig() {
+    std::lock_guard<std::mutex> lock(mMutex);
+    return updateVsyncConfigLocked();
+}
+
+VsyncModulator::VsyncConfig VsyncModulator::updateVsyncConfigLocked() {
+    const VsyncConfig& offsets = getNextVsyncConfig();
+    mVsyncConfig = offsets;
+
+    if (mTraceDetailedInfo) {
+        const bool isEarly = &offsets == &mVsyncConfigSet.early;
+        const bool isEarlyGpu = &offsets == &mVsyncConfigSet.earlyGpu;
+        const bool isLate = &offsets == &mVsyncConfigSet.late;
+
+        ATRACE_INT("Vsync-EarlyOffsetsOn", isEarly);
+        ATRACE_INT("Vsync-EarlyGpuOffsetsOn", isEarlyGpu);
+        ATRACE_INT("Vsync-LateOffsetsOn", isLate);
+    }
+
+    return offsets;
+}
+
+} // namespace android::scheduler