SF: Rename VsyncModulator

Adopt Vsync/vsync spelling over the awkward and less common VSync/vSync.

Bug: 160012986
Test: Build
Change-Id: Ibe230906e969d2ef8100ca7b1f5650dfe227c927
diff --git a/services/surfaceflinger/Scheduler/VsyncModulator.cpp b/services/surfaceflinger/Scheduler/VsyncModulator.cpp
new file mode 100644
index 0000000..96d47ad
--- /dev/null
+++ b/services/surfaceflinger/Scheduler/VsyncModulator.cpp
@@ -0,0 +1,183 @@
+/*
+ * 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.
+ */
+
+// TODO(b/129481165): remove the #pragma below and fix conversion issues
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wconversion"
+
+#define ATRACE_TAG ATRACE_TAG_GRAPHICS
+
+#include "VsyncModulator.h"
+
+#include <cutils/properties.h>
+#include <utils/Trace.h>
+
+#include <chrono>
+#include <cinttypes>
+#include <mutex>
+
+namespace android::scheduler {
+
+VSyncModulator::VSyncModulator(IPhaseOffsetControl& phaseOffsetControl,
+                               Scheduler::ConnectionHandle appConnectionHandle,
+                               Scheduler::ConnectionHandle sfConnectionHandle,
+                               const OffsetsConfig& config)
+      : mPhaseOffsetControl(phaseOffsetControl),
+        mAppConnectionHandle(appConnectionHandle),
+        mSfConnectionHandle(sfConnectionHandle),
+        mOffsetsConfig(config) {
+    char value[PROPERTY_VALUE_MAX];
+    property_get("debug.sf.vsync_trace_detailed_info", value, "0");
+    mTraceDetailedInfo = atoi(value);
+}
+
+void VSyncModulator::setPhaseOffsets(const OffsetsConfig& config) {
+    std::lock_guard<std::mutex> lock(mMutex);
+    mOffsetsConfig = config;
+    updateOffsetsLocked();
+}
+
+void VSyncModulator::setTransactionStart(Scheduler::TransactionStart transactionStart) {
+    switch (transactionStart) {
+        case Scheduler::TransactionStart::EarlyStart:
+            ALOGW_IF(mExplicitEarlyWakeup, "Already in TransactionStart::EarlyStart");
+            mExplicitEarlyWakeup = true;
+            break;
+        case Scheduler::TransactionStart::EarlyEnd:
+            ALOGW_IF(!mExplicitEarlyWakeup, "Not in TransactionStart::EarlyStart");
+            mExplicitEarlyWakeup = false;
+            break;
+        case Scheduler::TransactionStart::Normal:
+        case Scheduler::TransactionStart::Early:
+            // Non explicit don't change the explicit early wakeup state
+            break;
+    }
+
+    if (mTraceDetailedInfo) {
+        ATRACE_INT("mExplicitEarlyWakeup", mExplicitEarlyWakeup);
+    }
+
+    if (!mExplicitEarlyWakeup &&
+        (transactionStart == Scheduler::TransactionStart::Early ||
+         transactionStart == Scheduler::TransactionStart::EarlyEnd)) {
+        mRemainingEarlyFrameCount = MIN_EARLY_FRAME_COUNT_TRANSACTION;
+        mEarlyTxnStartTime = std::chrono::steady_clock::now();
+    }
+
+    // An early transaction stays an early transaction.
+    if (transactionStart == mTransactionStart ||
+        mTransactionStart == Scheduler::TransactionStart::EarlyEnd) {
+        return;
+    }
+    mTransactionStart = transactionStart;
+    updateOffsets();
+}
+
+void VSyncModulator::onTransactionHandled() {
+    mTxnAppliedTime = std::chrono::steady_clock::now();
+    if (mTransactionStart == Scheduler::TransactionStart::Normal) return;
+    mTransactionStart = Scheduler::TransactionStart::Normal;
+    updateOffsets();
+}
+
+void VSyncModulator::onRefreshRateChangeInitiated() {
+    if (mRefreshRateChangePending) {
+        return;
+    }
+    mRefreshRateChangePending = true;
+    updateOffsets();
+}
+
+void VSyncModulator::onRefreshRateChangeCompleted() {
+    if (!mRefreshRateChangePending) {
+        return;
+    }
+    mRefreshRateChangePending = false;
+    updateOffsets();
+}
+
+void VSyncModulator::onRefreshed(bool usedRenderEngine) {
+    bool updateOffsetsNeeded = false;
+
+    // Apply a margin to account for potential data races
+    // This might make us stay in early offsets for one
+    // additional frame but it's better to be conservative here.
+    if ((mEarlyTxnStartTime.load() + MARGIN_FOR_TX_APPLY) < mTxnAppliedTime.load()) {
+        if (mRemainingEarlyFrameCount > 0) {
+            mRemainingEarlyFrameCount--;
+            updateOffsetsNeeded = true;
+        }
+    }
+    if (usedRenderEngine) {
+        mRemainingRenderEngineUsageCount = MIN_EARLY_GL_FRAME_COUNT_TRANSACTION;
+        updateOffsetsNeeded = true;
+    } else if (mRemainingRenderEngineUsageCount > 0) {
+        mRemainingRenderEngineUsageCount--;
+        updateOffsetsNeeded = true;
+    }
+    if (updateOffsetsNeeded) {
+        updateOffsets();
+    }
+}
+
+VSyncModulator::Offsets VSyncModulator::getOffsets() const {
+    std::lock_guard<std::mutex> lock(mMutex);
+    return mOffsets;
+}
+
+const VSyncModulator::Offsets& VSyncModulator::getNextOffsets() const {
+    // Early offsets are used if we're in the middle of a refresh rate
+    // change, or if we recently begin a transaction.
+    if (mExplicitEarlyWakeup || mTransactionStart == Scheduler::TransactionStart::EarlyEnd ||
+        mRemainingEarlyFrameCount > 0 || mRefreshRateChangePending) {
+        return mOffsetsConfig.early;
+    } else if (mRemainingRenderEngineUsageCount > 0) {
+        return mOffsetsConfig.earlyGl;
+    } else {
+        return mOffsetsConfig.late;
+    }
+}
+
+void VSyncModulator::updateOffsets() {
+    std::lock_guard<std::mutex> lock(mMutex);
+    updateOffsetsLocked();
+}
+
+void VSyncModulator::updateOffsetsLocked() {
+    const Offsets& offsets = getNextOffsets();
+
+    mPhaseOffsetControl.setPhaseOffset(mSfConnectionHandle, offsets.sf);
+    mPhaseOffsetControl.setPhaseOffset(mAppConnectionHandle, offsets.app);
+
+    mOffsets = offsets;
+
+    if (!mTraceDetailedInfo) {
+        return;
+    }
+
+    const bool isEarly = &offsets == &mOffsetsConfig.early;
+    const bool isEarlyGl = &offsets == &mOffsetsConfig.earlyGl;
+    const bool isLate = &offsets == &mOffsetsConfig.late;
+
+    ATRACE_INT("Vsync-EarlyOffsetsOn", isEarly);
+    ATRACE_INT("Vsync-EarlyGLOffsetsOn", isEarlyGl);
+    ATRACE_INT("Vsync-LateOffsetsOn", isLate);
+}
+
+} // namespace android::scheduler
+
+// TODO(b/129481165): remove the #pragma below and fix conversion issues
+#pragma clang diagnostic pop // ignored "-Wconversion"