diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 4e0d375..d3cf44b 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -1036,10 +1036,9 @@
         mScheduler->resyncToHardwareVsync(true, refreshRate.getVsyncPeriod());
         // As we called to set period, we will call to onRefreshRateChangeCompleted once
         // DispSync model is locked.
-        mVSyncModulator->onRefreshRateChangeInitiated();
+        modulateVsync(&VsyncModulator::onRefreshRateChangeInitiated);
 
-        mPhaseConfiguration->setRefreshRateFps(refreshRate.getFps());
-        mVSyncModulator->setPhaseOffsets(mPhaseConfiguration->getCurrentOffsets());
+        updatePhaseConfiguration(refreshRate);
         mScheduler->setConfigChangePending(true);
     }
 
@@ -1098,8 +1097,7 @@
     if (refreshRate.getVsyncPeriod() != oldRefreshRate.getVsyncPeriod()) {
         mTimeStats->incrementRefreshRateSwitches();
     }
-    mPhaseConfiguration->setRefreshRateFps(refreshRate.getFps());
-    mVSyncModulator->setPhaseOffsets(mPhaseConfiguration->getCurrentOffsets());
+    updatePhaseConfiguration(refreshRate);
     ATRACE_INT("ActiveConfigFPS", refreshRate.getFps());
 
     if (mUpcomingActiveConfig.event != Scheduler::ConfigEvent::None) {
@@ -1119,9 +1117,9 @@
 
     const auto& refreshRate =
             mRefreshRateConfigs->getRefreshRateFromConfigId(mDesiredActiveConfig.configId);
+
     mScheduler->resyncToHardwareVsync(true, refreshRate.getVsyncPeriod());
-    mPhaseConfiguration->setRefreshRateFps(refreshRate.getFps());
-    mVSyncModulator->setPhaseOffsets(mPhaseConfiguration->getCurrentOffsets());
+    updatePhaseConfiguration(refreshRate);
     mScheduler->setConfigChangePending(false);
 }
 
@@ -1600,7 +1598,7 @@
     bool periodFlushed = false;
     mScheduler->addResyncSample(timestamp, vsyncPeriod, &periodFlushed);
     if (periodFlushed) {
-        mVSyncModulator->onRefreshRateChangeCompleted();
+        modulateVsync(&VsyncModulator::onRefreshRateChangeCompleted);
     }
 }
 
@@ -1790,7 +1788,7 @@
     // We are storing the last 2 present fences. If sf's phase offset is to be
     // woken up before the actual vsync but targeting the next vsync, we need to check
     // fence N-2
-    return mVSyncModulator->getOffsets().sf > 0 ? mPreviousPresentFences[0]
+    return mVsyncModulator->getOffsets().sf > 0 ? mPreviousPresentFences[0]
                                                 : mPreviousPresentFences[1];
 }
 
@@ -1823,7 +1821,7 @@
     mScheduler->getDisplayStatInfo(&stats);
     const nsecs_t presentTime = mScheduler->getDispSyncExpectedPresentTime(now);
     // Inflate the expected present time if we're targetting the next vsync.
-    return mVSyncModulator->getOffsets().sf > 0 ? presentTime : presentTime + stats.vsyncPeriod;
+    return mVsyncModulator->getOffsets().sf > 0 ? presentTime : presentTime + stats.vsyncPeriod;
 }
 
 void SurfaceFlinger::onMessageReceived(int32_t what, nsecs_t expectedVSyncTime) {
@@ -2120,7 +2118,8 @@
     }
 
     // TODO: b/160583065 Enable skip validation when SF caches all client composition layers
-    mVSyncModulator->onRefreshed(mHadClientComposition || mReusedClientComposition);
+    const bool usedGpuComposition = mHadClientComposition || mReusedClientComposition;
+    modulateVsync(&VsyncModulator::onDisplayRefresh, usedGpuComposition);
 
     mLayersWithQueuedFrames.clear();
     if (mVisibleRegionsDirty) {
@@ -2416,7 +2415,7 @@
     // with mStateLock held to guarantee that mCurrentState won't change
     // until the transaction is committed.
 
-    mVSyncModulator->onTransactionHandled();
+    modulateVsync(&VsyncModulator::onTransactionCommit);
     transactionFlags = getTransactionFlags(eTransactionMask);
     handleTransactionLocked(transactionFlags);
 
@@ -2977,6 +2976,7 @@
     mRefreshRateStats->setConfigMode(currentConfig);
 
     mPhaseConfiguration = getFactory().createPhaseConfiguration(*mRefreshRateConfigs);
+    mVsyncModulator.emplace(mPhaseConfiguration->getCurrentOffsets());
 
     // start the EventThread
     mScheduler = getFactory().createScheduler(*mRefreshRateConfigs, *this);
@@ -2990,8 +2990,6 @@
                                          });
 
     mEventQueue->setEventConnection(mScheduler->getEventConnection(mSfConnectionHandle));
-    mVSyncModulator.emplace(*mScheduler, mAppConnectionHandle, mSfConnectionHandle,
-                            mPhaseConfiguration->getCurrentOffsets());
 
     mRegionSamplingThread =
             new RegionSamplingThread(*this, *mScheduler,
@@ -3009,8 +3007,17 @@
                                               vsyncPeriod);
 }
 
-void SurfaceFlinger::commitTransaction()
-{
+void SurfaceFlinger::updatePhaseConfiguration(const RefreshRate& refreshRate) {
+    mPhaseConfiguration->setRefreshRateFps(refreshRate.getFps());
+    setPhaseOffsets(mVsyncModulator->setPhaseOffsets(mPhaseConfiguration->getCurrentOffsets()));
+}
+
+void SurfaceFlinger::setPhaseOffsets(const VsyncModulator::Offsets& offsets) {
+    mScheduler->setPhaseOffset(mAppConnectionHandle, offsets.app);
+    mScheduler->setPhaseOffset(mSfConnectionHandle, offsets.sf);
+}
+
+void SurfaceFlinger::commitTransaction() {
     commitTransactionLocked();
     mTransactionPending = false;
     mAnimTransactionPending = false;
@@ -3250,16 +3257,13 @@
 }
 
 uint32_t SurfaceFlinger::setTransactionFlags(uint32_t flags) {
-    return setTransactionFlags(flags, Scheduler::TransactionStart::Normal);
+    return setTransactionFlags(flags, TransactionSchedule::Late);
 }
 
-uint32_t SurfaceFlinger::setTransactionFlags(uint32_t flags,
-                                             Scheduler::TransactionStart transactionStart) {
+uint32_t SurfaceFlinger::setTransactionFlags(uint32_t flags, TransactionSchedule schedule) {
     uint32_t old = mTransactionFlags.fetch_or(flags);
-    mVSyncModulator->setTransactionStart(transactionStart);
-    if ((old & flags)==0) { // wake the server up
-        signalTransaction();
-    }
+    modulateVsync(&VsyncModulator::setTransactionSchedule, schedule);
+    if ((old & flags) == 0) signalTransaction();
     return old;
 }
 
@@ -3467,17 +3471,11 @@
         mForceTraversal = true;
     }
 
-    const auto transactionStart = [](uint32_t flags) {
-        if (flags & eEarlyWakeup) {
-            return Scheduler::TransactionStart::Early;
-        }
-        if (flags & eExplicitEarlyWakeupEnd) {
-            return Scheduler::TransactionStart::EarlyEnd;
-        }
-        if (flags & eExplicitEarlyWakeupStart) {
-            return Scheduler::TransactionStart::EarlyStart;
-        }
-        return Scheduler::TransactionStart::Normal;
+    const auto schedule = [](uint32_t flags) {
+        if (flags & eEarlyWakeup) return TransactionSchedule::Early;
+        if (flags & eExplicitEarlyWakeupEnd) return TransactionSchedule::EarlyEnd;
+        if (flags & eExplicitEarlyWakeupStart) return TransactionSchedule::EarlyStart;
+        return TransactionSchedule::Late;
     }(flags);
 
     if (transactionFlags) {
@@ -3496,7 +3494,7 @@
         }
 
         // this triggers the transaction
-        setTransactionFlags(transactionFlags, transactionStart);
+        setTransactionFlags(transactionFlags, schedule);
 
         if (flags & eAnimation) {
             mAnimTransactionPending = true;
@@ -3534,11 +3532,10 @@
             }
         }
     } else {
-        // even if a transaction is not needed, we need to update VsyncModulator
-        // about explicit early indications
-        if (transactionStart == Scheduler::TransactionStart::EarlyStart ||
-            transactionStart == Scheduler::TransactionStart::EarlyEnd) {
-            mVSyncModulator->setTransactionStart(transactionStart);
+        // Update VsyncModulator state machine even if transaction is not needed.
+        if (schedule == TransactionSchedule::EarlyStart ||
+            schedule == TransactionSchedule::EarlyEnd) {
+            modulateVsync(&VsyncModulator::setTransactionSchedule, schedule);
         }
     }
 }