SF: add IEventThreadCallback to EventThread

.. so it will be easier to add more callbacks to EventThread

Bug: 299378819
Test: presubmit
Change-Id: I3787be9ad8162b059b4d59255581cd14cbcf1cd8
diff --git a/services/surfaceflinger/Scheduler/EventThread.cpp b/services/surfaceflinger/Scheduler/EventThread.cpp
index 21714da..edab7ec 100644
--- a/services/surfaceflinger/Scheduler/EventThread.cpp
+++ b/services/surfaceflinger/Scheduler/EventThread.cpp
@@ -171,10 +171,8 @@
 } // namespace
 
 EventThreadConnection::EventThreadConnection(EventThread* eventThread, uid_t callingUid,
-                                             ResyncCallback resyncCallback,
                                              EventRegistrationFlags eventRegistration)
-      : resyncCallback(std::move(resyncCallback)),
-        mOwnerUid(callingUid),
+      : mOwnerUid(callingUid),
         mEventRegistration(eventRegistration),
         mEventThread(eventThread),
         mChannel(gui::BitTube::DefaultSize) {}
@@ -250,9 +248,7 @@
 
 EventThread::EventThread(const char* name, std::shared_ptr<scheduler::VsyncSchedule> vsyncSchedule,
                          android::frametimeline::TokenManager* tokenManager,
-                         ThrottleVsyncCallback throttleVsyncCallback,
-                         GetVsyncPeriodFunction getVsyncPeriodFunction,
-                         std::chrono::nanoseconds workDuration,
+                         IEventThreadCallback& callback, std::chrono::nanoseconds workDuration,
                          std::chrono::nanoseconds readyDuration)
       : mThreadName(name),
         mVsyncTracer(base::StringPrintf("VSYNC-%s", name), 0),
@@ -261,11 +257,7 @@
         mVsyncSchedule(std::move(vsyncSchedule)),
         mVsyncRegistration(mVsyncSchedule->getDispatch(), createDispatchCallback(), name),
         mTokenManager(tokenManager),
-        mThrottleVsyncCallback(std::move(throttleVsyncCallback)),
-        mGetVsyncPeriodFunction(std::move(getVsyncPeriodFunction)) {
-    LOG_ALWAYS_FATAL_IF(getVsyncPeriodFunction == nullptr,
-            "getVsyncPeriodFunction must not be null");
-
+        mCallback(callback) {
     mThread = std::thread([this]() NO_THREAD_SAFETY_ANALYSIS {
         std::unique_lock<std::mutex> lock(mMutex);
         threadMain(lock);
@@ -307,10 +299,10 @@
 }
 
 sp<EventThreadConnection> EventThread::createEventConnection(
-        ResyncCallback resyncCallback, EventRegistrationFlags eventRegistration) const {
+        EventRegistrationFlags eventRegistration) const {
     return sp<EventThreadConnection>::make(const_cast<EventThread*>(this),
                                            IPCThreadState::self()->getCallingUid(),
-                                           std::move(resyncCallback), eventRegistration);
+                                           eventRegistration);
 }
 
 status_t EventThread::registerDisplayEventConnection(const sp<EventThreadConnection>& connection) {
@@ -353,9 +345,7 @@
 }
 
 void EventThread::requestNextVsync(const sp<EventThreadConnection>& connection) {
-    if (connection->resyncCallback) {
-        connection->resyncCallback();
-    }
+    mCallback.resync();
 
     std::lock_guard<std::mutex> lock(mMutex);
 
@@ -371,20 +361,18 @@
         const sp<EventThreadConnection>& connection) const {
     // Resync so that the vsync is accurate with hardware. getLatestVsyncEventData is an alternate
     // way to get vsync data (instead of posting callbacks to Choreographer).
-    if (connection->resyncCallback) {
-        connection->resyncCallback();
-    }
+    mCallback.resync();
 
     VsyncEventData vsyncEventData;
-    nsecs_t frameInterval = mGetVsyncPeriodFunction(connection->mOwnerUid);
-    vsyncEventData.frameInterval = frameInterval;
+    const Period frameInterval = mCallback.getVsyncPeriod(connection->mOwnerUid);
+    vsyncEventData.frameInterval = frameInterval.ns();
     const auto [presentTime, deadline] = [&]() -> std::pair<nsecs_t, nsecs_t> {
         std::lock_guard<std::mutex> lock(mMutex);
         const auto vsyncTime = mVsyncSchedule->getTracker().nextAnticipatedVSyncTimeFrom(
                 systemTime() + mWorkDuration.get().count() + mReadyDuration.count());
         return {vsyncTime, vsyncTime - mReadyDuration.count()};
     }();
-    generateFrameTimeline(vsyncEventData, frameInterval, systemTime(SYSTEM_TIME_MONOTONIC),
+    generateFrameTimeline(vsyncEventData, frameInterval.ns(), systemTime(SYSTEM_TIME_MONOTONIC),
                           presentTime, deadline);
     return vsyncEventData;
 }
@@ -549,9 +537,9 @@
                                             connection->frameRate);
         }
 
-        return mThrottleVsyncCallback &&
-                mThrottleVsyncCallback(event.vsync.vsyncData.preferredExpectedPresentationTime(),
-                                       connection->mOwnerUid);
+        const auto expectedPresentTime =
+                TimePoint::fromNs(event.vsync.vsyncData.preferredExpectedPresentationTime());
+        return mCallback.throttleVsync(expectedPresentTime, connection->mOwnerUid);
     };
 
     switch (event.header.type) {
@@ -671,9 +659,9 @@
     for (const auto& consumer : consumers) {
         DisplayEventReceiver::Event copy = event;
         if (event.header.type == DisplayEventReceiver::DISPLAY_EVENT_VSYNC) {
-            const int64_t frameInterval = mGetVsyncPeriodFunction(consumer->mOwnerUid);
-            copy.vsync.vsyncData.frameInterval = frameInterval;
-            generateFrameTimeline(copy.vsync.vsyncData, frameInterval, copy.header.timestamp,
+            const Period frameInterval = mCallback.getVsyncPeriod(consumer->mOwnerUid);
+            copy.vsync.vsyncData.frameInterval = frameInterval.ns();
+            generateFrameTimeline(copy.vsync.vsyncData, frameInterval.ns(), copy.header.timestamp,
                                   event.vsync.vsyncData.preferredExpectedPresentationTime(),
                                   event.vsync.vsyncData.preferredDeadlineTimestamp());
         }
diff --git a/services/surfaceflinger/Scheduler/EventThread.h b/services/surfaceflinger/Scheduler/EventThread.h
index 576910e..a7c8b74 100644
--- a/services/surfaceflinger/Scheduler/EventThread.h
+++ b/services/surfaceflinger/Scheduler/EventThread.h
@@ -54,7 +54,6 @@
 
 // ---------------------------------------------------------------------------
 
-using ResyncCallback = std::function<void()>;
 using FrameRateOverride = DisplayEventReceiver::Event::FrameRateOverride;
 
 enum class VSyncRequest {
@@ -69,7 +68,7 @@
 
 class EventThreadConnection : public gui::BnDisplayEventConnection {
 public:
-    EventThreadConnection(EventThread*, uid_t callingUid, ResyncCallback,
+    EventThreadConnection(EventThread*, uid_t callingUid,
                           EventRegistrationFlags eventRegistration = {});
     virtual ~EventThreadConnection();
 
@@ -80,9 +79,6 @@
     binder::Status requestNextVsync() override; // asynchronous
     binder::Status getLatestVsyncEventData(ParcelableVsyncEventData* outVsyncEventData) override;
 
-    // Called in response to requestNextVsync.
-    const ResyncCallback resyncCallback;
-
     VSyncRequest vsyncRequest = VSyncRequest::None;
     const uid_t mOwnerUid;
     const EventRegistrationFlags mEventRegistration;
@@ -104,7 +100,7 @@
     virtual ~EventThread();
 
     virtual sp<EventThreadConnection> createEventConnection(
-            ResyncCallback, EventRegistrationFlags eventRegistration = {}) const = 0;
+            EventRegistrationFlags eventRegistration = {}) const = 0;
 
     // Feed clients with fake VSYNC, e.g. while the display is off.
     virtual void enableSyntheticVsync(bool) = 0;
@@ -136,20 +132,25 @@
     virtual void onNewVsyncSchedule(std::shared_ptr<scheduler::VsyncSchedule>) = 0;
 };
 
+struct IEventThreadCallback {
+    virtual ~IEventThreadCallback() = default;
+
+    virtual bool throttleVsync(TimePoint, uid_t) = 0;
+    virtual Period getVsyncPeriod(uid_t) = 0;
+    virtual void resync() = 0;
+};
+
 namespace impl {
 
 class EventThread : public android::EventThread {
 public:
-    using ThrottleVsyncCallback = std::function<bool(nsecs_t, uid_t)>;
-    using GetVsyncPeriodFunction = std::function<nsecs_t(uid_t)>;
-
     EventThread(const char* name, std::shared_ptr<scheduler::VsyncSchedule>,
-                frametimeline::TokenManager*, ThrottleVsyncCallback, GetVsyncPeriodFunction,
+                frametimeline::TokenManager*, IEventThreadCallback& callback,
                 std::chrono::nanoseconds workDuration, std::chrono::nanoseconds readyDuration);
     ~EventThread();
 
     sp<EventThreadConnection> createEventConnection(
-            ResyncCallback, EventRegistrationFlags eventRegistration = {}) const override;
+            EventRegistrationFlags eventRegistration = {}) const override;
 
     status_t registerDisplayEventConnection(const sp<EventThreadConnection>& connection) override;
     void setVsyncRate(uint32_t rate, const sp<EventThreadConnection>& connection) override;
@@ -214,8 +215,7 @@
     scheduler::VSyncCallbackRegistration mVsyncRegistration GUARDED_BY(mMutex);
     frametimeline::TokenManager* const mTokenManager;
 
-    const ThrottleVsyncCallback mThrottleVsyncCallback;
-    const GetVsyncPeriodFunction mGetVsyncPeriodFunction;
+    IEventThreadCallback& mCallback;
 
     std::thread mThread;
     mutable std::mutex mMutex;
diff --git a/services/surfaceflinger/Scheduler/Scheduler.cpp b/services/surfaceflinger/Scheduler/Scheduler.cpp
index aa24f56..d72ae1f 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.cpp
+++ b/services/surfaceflinger/Scheduler/Scheduler.cpp
@@ -242,36 +242,35 @@
     return getVsyncSchedule()->getTracker().isVSyncInPhase(expectedVsyncTime.ns(), frameRate);
 }
 
-impl::EventThread::ThrottleVsyncCallback Scheduler::makeThrottleVsyncCallback() const {
-    return [this](nsecs_t expectedVsyncTime, uid_t uid) {
-        return !isVsyncValid(TimePoint::fromNs(expectedVsyncTime), uid);
-    };
+bool Scheduler::throttleVsync(android::TimePoint expectedPresentTime, uid_t uid) {
+    return !isVsyncValid(expectedPresentTime, uid);
 }
 
-impl::EventThread::GetVsyncPeriodFunction Scheduler::makeGetVsyncPeriodFunction() const {
-    return [this](uid_t uid) {
-        const auto [refreshRate, period] = [this] {
-            std::scoped_lock lock(mDisplayLock);
-            const auto pacesetterOpt = pacesetterDisplayLocked();
-            LOG_ALWAYS_FATAL_IF(!pacesetterOpt);
-            const Display& pacesetter = *pacesetterOpt;
-            return std::make_pair(pacesetter.selectorPtr->getActiveMode().fps,
-                                  pacesetter.schedulePtr->period());
-        }();
+Period Scheduler::getVsyncPeriod(uid_t uid) {
+    const auto [refreshRate, period] = [this] {
+        std::scoped_lock lock(mDisplayLock);
+        const auto pacesetterOpt = pacesetterDisplayLocked();
+        LOG_ALWAYS_FATAL_IF(!pacesetterOpt);
+        const Display& pacesetter = *pacesetterOpt;
+        return std::make_pair(pacesetter.selectorPtr->getActiveMode().fps,
+                              pacesetter.schedulePtr->period());
+    }();
 
-        const Period currentPeriod = period != Period::zero() ? period : refreshRate.getPeriod();
+    const Period currentPeriod = period != Period::zero() ? period : refreshRate.getPeriod();
 
-        const auto frameRate = getFrameRateOverride(uid);
-        if (!frameRate.has_value()) {
-            return currentPeriod.ns();
-        }
+    const auto frameRate = getFrameRateOverride(uid);
+    if (!frameRate.has_value()) {
+        return currentPeriod;
+    }
 
-        const auto divisor = RefreshRateSelector::getFrameRateDivisor(refreshRate, *frameRate);
-        if (divisor <= 1) {
-            return currentPeriod.ns();
-        }
-        return currentPeriod.ns() * divisor;
-    };
+    const auto divisor = RefreshRateSelector::getFrameRateDivisor(refreshRate, *frameRate);
+    if (divisor <= 1) {
+        return currentPeriod;
+    }
+
+    // TODO(b/299378819): the casting is not needed, but we need a flag as it might change
+    // behaviour.
+    return Period::fromNs(currentPeriod.ns() * divisor);
 }
 
 ConnectionHandle Scheduler::createEventThread(Cycle cycle,
@@ -279,9 +278,7 @@
                                               std::chrono::nanoseconds workDuration,
                                               std::chrono::nanoseconds readyDuration) {
     auto eventThread = std::make_unique<impl::EventThread>(cycle == Cycle::Render ? "app" : "appSf",
-                                                           getVsyncSchedule(), tokenManager,
-                                                           makeThrottleVsyncCallback(),
-                                                           makeGetVsyncPeriodFunction(),
+                                                           getVsyncSchedule(), tokenManager, *this,
                                                            workDuration, readyDuration);
 
     auto& handle = cycle == Cycle::Render ? mAppConnectionHandle : mSfConnectionHandle;
@@ -293,7 +290,7 @@
     const ConnectionHandle handle = ConnectionHandle{mNextConnectionHandleId++};
     ALOGV("Creating a connection handle with ID %" PRIuPTR, handle.id);
 
-    auto connection = eventThread->createEventConnection([&] { resync(); });
+    auto connection = eventThread->createEventConnection();
 
     std::lock_guard<std::mutex> lock(mConnectionsLock);
     mConnections.emplace(handle, Connection{connection, std::move(eventThread)});
@@ -307,8 +304,7 @@
         std::scoped_lock lock(mConnectionsLock);
         RETURN_IF_INVALID_HANDLE(handle, nullptr);
 
-        return mConnections[handle].thread->createEventConnection([&] { resync(); },
-                                                                  eventRegistration);
+        return mConnections[handle].thread->createEventConnection(eventRegistration);
     }();
     const auto layerId = static_cast<int32_t>(LayerHandle::getLayerId(layerHandle));
 
diff --git a/services/surfaceflinger/Scheduler/Scheduler.h b/services/surfaceflinger/Scheduler/Scheduler.h
index 822f7cc..5796d59 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.h
+++ b/services/surfaceflinger/Scheduler/Scheduler.h
@@ -98,7 +98,7 @@
 
 class VsyncSchedule;
 
-class Scheduler : android::impl::MessageQueue {
+class Scheduler : public IEventThreadCallback, android::impl::MessageQueue {
     using Impl = android::impl::MessageQueue;
 
 public:
@@ -217,7 +217,6 @@
         ftl::FakeGuard guard(kMainThreadContext);
         resyncToHardwareVsyncLocked(id, allowToEnable, refreshRate);
     }
-    void resync() EXCLUDES(mDisplayLock);
     void forceNextResync() { mLastResyncTime = 0; }
 
     // Passes a vsync sample to VsyncController. Returns true if
@@ -420,8 +419,10 @@
 
     void dispatchCachedReportedMode() REQUIRES(mPolicyLock) EXCLUDES(mDisplayLock);
 
-    android::impl::EventThread::ThrottleVsyncCallback makeThrottleVsyncCallback() const;
-    android::impl::EventThread::GetVsyncPeriodFunction makeGetVsyncPeriodFunction() const;
+    // IEventThreadCallback overrides
+    bool throttleVsync(TimePoint, uid_t) override;
+    Period getVsyncPeriod(uid_t) override EXCLUDES(mDisplayLock);
+    void resync() override EXCLUDES(mDisplayLock);
 
     // Stores EventThread associated with a given VSyncSource, and an initial EventThreadConnection.
     struct Connection {