libs/gui/Choreographer.cpp - LeafOS-Project/android_frameworks_native - Gitiles

 /*
  * 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.
  */

 // #define LOG_NDEBUG 0
 #define ATRACE_TAG ATRACE_TAG_GRAPHICS

 #include <gui/Choreographer.h>
 #include <gui/TraceUtils.h>
 #include <jni.h>

 #undef LOG_TAG
 #define LOG_TAG "AChoreographer"

 namespace {
 struct {
     // Global JVM that is provided by zygote
     JavaVM* jvm = nullptr;
     struct {
         jclass clazz;
         jmethodID getInstance;
         jmethodID registerNativeChoreographerForRefreshRateCallbacks;
         jmethodID unregisterNativeChoreographerForRefreshRateCallbacks;
     } displayManagerGlobal;
 } gJni;

 // Gets the JNIEnv* for this thread, and performs one-off initialization if we
 // have never retrieved a JNIEnv* pointer before.
 JNIEnv* getJniEnv() {
     if (gJni.jvm == nullptr) {
         ALOGW("AChoreographer: No JVM provided!");
         return nullptr;
     }

     JNIEnv* env = nullptr;
     if (gJni.jvm->GetEnv((void**)&env, JNI_VERSION_1_4) != JNI_OK) {
         ALOGD("Attaching thread to JVM for AChoreographer");
         JavaVMAttachArgs args = {JNI_VERSION_1_4, "AChoreographer_env", NULL};
         jint attachResult = gJni.jvm->AttachCurrentThreadAsDaemon(&env, (void*)&args);
         if (attachResult != JNI_OK) {
             ALOGE("Unable to attach thread. Error: %d", attachResult);
             return nullptr;
         }
     }
     if (env == nullptr) {
         ALOGW("AChoreographer: No JNI env available!");
     }
     return env;
 }

 inline const char* toString(bool value) {
     return value ? "true" : "false";
 }
 } // namespace

 namespace android {

 Choreographer::Context Choreographer::gChoreographers;

 static thread_local Choreographer* gChoreographer;

 void Choreographer::initJVM(JNIEnv* env) {
     env->GetJavaVM(&gJni.jvm);
     // Now we need to find the java classes.
     jclass dmgClass = env->FindClass("android/hardware/display/DisplayManagerGlobal");
     gJni.displayManagerGlobal.clazz = static_cast<jclass>(env->NewGlobalRef(dmgClass));
     gJni.displayManagerGlobal.getInstance =
             env->GetStaticMethodID(dmgClass, "getInstance",
                                    "()Landroid/hardware/display/DisplayManagerGlobal;");
     gJni.displayManagerGlobal.registerNativeChoreographerForRefreshRateCallbacks =
             env->GetMethodID(dmgClass, "registerNativeChoreographerForRefreshRateCallbacks", "()V");
     gJni.displayManagerGlobal.unregisterNativeChoreographerForRefreshRateCallbacks =
             env->GetMethodID(dmgClass, "unregisterNativeChoreographerForRefreshRateCallbacks",
                              "()V");
 }

 Choreographer* Choreographer::getForThread() {
     if (gChoreographer == nullptr) {
         sp<Looper> looper = Looper::getForThread();
         if (!looper.get()) {
             ALOGW("No looper prepared for thread");
             return nullptr;
         }
         gChoreographer = new Choreographer(looper);
         status_t result = gChoreographer->initialize();
         if (result != OK) {
             ALOGW("Failed to initialize");
             return nullptr;
         }
     }
     return gChoreographer;
 }

 Choreographer::Choreographer(const sp<Looper>& looper, const sp<IBinder>& layerHandle)
       : DisplayEventDispatcher(looper, gui::ISurfaceComposer::VsyncSource::eVsyncSourceApp, {},
                                layerHandle),
         mLooper(looper),
         mThreadId(std::this_thread::get_id()) {
     std::lock_guard<std::mutex> _l(gChoreographers.lock);
     gChoreographers.ptrs.push_back(this);
 }

 Choreographer::~Choreographer() {
     std::lock_guard<std::mutex> _l(gChoreographers.lock);
     gChoreographers.ptrs.erase(std::remove_if(gChoreographers.ptrs.begin(),
                                               gChoreographers.ptrs.end(),
                                               [=](Choreographer* c) { return c == this; }),
                                gChoreographers.ptrs.end());
     // Only poke DisplayManagerGlobal to unregister if we previously registered
     // callbacks.
     if (gChoreographers.ptrs.empty() && gChoreographers.registeredToDisplayManager) {
         gChoreographers.registeredToDisplayManager = false;
         JNIEnv* env = getJniEnv();
         if (env == nullptr) {
             ALOGW("JNI environment is unavailable, skipping choreographer cleanup");
             return;
         }
         jobject dmg = env->CallStaticObjectMethod(gJni.displayManagerGlobal.clazz,
                                                   gJni.displayManagerGlobal.getInstance);
         if (dmg == nullptr) {
             ALOGW("DMS is not initialized yet, skipping choreographer cleanup");
         } else {
             env->CallVoidMethod(dmg,
                                 gJni.displayManagerGlobal
                                         .unregisterNativeChoreographerForRefreshRateCallbacks);
             env->DeleteLocalRef(dmg);
         }
     }
 }

 void Choreographer::postFrameCallbackDelayed(AChoreographer_frameCallback cb,
                                              AChoreographer_frameCallback64 cb64,
                                              AChoreographer_vsyncCallback vsyncCallback, void* data,
                                              nsecs_t delay) {
     nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
     FrameCallback callback{cb, cb64, vsyncCallback, data, now + delay};
     {
         std::lock_guard<std::mutex> _l{mLock};
         mFrameCallbacks.push(callback);
     }
     if (callback.dueTime <= now) {
         if (std::this_thread::get_id() != mThreadId) {
             if (mLooper != nullptr) {
                 Message m{MSG_SCHEDULE_VSYNC};
                 mLooper->sendMessage(this, m);
             } else {
                 scheduleVsync();
             }
         } else {
             scheduleVsync();
         }
     } else {
         if (mLooper != nullptr) {
             Message m{MSG_SCHEDULE_CALLBACKS};
             mLooper->sendMessageDelayed(delay, this, m);
         } else {
             scheduleCallbacks();
         }
     }
 }

 void Choreographer::registerRefreshRateCallback(AChoreographer_refreshRateCallback cb, void* data) {
     std::lock_guard<std::mutex> _l{mLock};
     for (const auto& callback : mRefreshRateCallbacks) {
         // Don't re-add callbacks.
         if (cb == callback.callback && data == callback.data) {
             return;
         }
     }
     mRefreshRateCallbacks.emplace_back(
             RefreshRateCallback{.callback = cb, .data = data, .firstCallbackFired = false});
     bool needsRegistration = false;
     {
         std::lock_guard<std::mutex> _l2(gChoreographers.lock);
         needsRegistration = !gChoreographers.registeredToDisplayManager;
     }
     if (needsRegistration) {
         JNIEnv* env = getJniEnv();
         if (env == nullptr) {
             ALOGW("JNI environment is unavailable, skipping registration");
             return;
         }
         jobject dmg = env->CallStaticObjectMethod(gJni.displayManagerGlobal.clazz,
                                                   gJni.displayManagerGlobal.getInstance);
         if (dmg == nullptr) {
             ALOGW("DMS is not initialized yet: skipping registration");
             return;
         } else {
             env->CallVoidMethod(dmg,
                                 gJni.displayManagerGlobal
                                         .registerNativeChoreographerForRefreshRateCallbacks,
                                 reinterpret_cast<int64_t>(this));
             env->DeleteLocalRef(dmg);
             {
                 std::lock_guard<std::mutex> _l2(gChoreographers.lock);
                 gChoreographers.registeredToDisplayManager = true;
             }
         }
     } else {
         scheduleLatestConfigRequest();
     }
 }

 void Choreographer::unregisterRefreshRateCallback(AChoreographer_refreshRateCallback cb,
                                                   void* data) {
     std::lock_guard<std::mutex> _l{mLock};
     mRefreshRateCallbacks.erase(std::remove_if(mRefreshRateCallbacks.begin(),
                                                mRefreshRateCallbacks.end(),
                                                [&](const RefreshRateCallback& callback) {
                                                    return cb == callback.callback &&
                                                            data == callback.data;
                                                }),
                                 mRefreshRateCallbacks.end());
 }

 void Choreographer::scheduleLatestConfigRequest() {
     if (mLooper != nullptr) {
         Message m{MSG_HANDLE_REFRESH_RATE_UPDATES};
         mLooper->sendMessage(this, m);
     } else {
         // If the looper thread is detached from Choreographer, then refresh rate
         // changes will be handled in AChoreographer_handlePendingEvents, so we
         // need to wake up the looper thread by writing to the write-end of the
         // socket the looper is listening on.
         // Fortunately, these events are small so sending packets across the
         // socket should be atomic across processes.
         DisplayEventReceiver::Event event;
         event.header =
                 DisplayEventReceiver::Event::Header{DisplayEventReceiver::DISPLAY_EVENT_NULL,
                                                     PhysicalDisplayId::fromPort(0), systemTime()};
         injectEvent(event);
     }
 }

 void Choreographer::scheduleCallbacks() {
     const nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
     nsecs_t dueTime;
     {
         std::lock_guard<std::mutex> _l{mLock};
         // If there are no pending callbacks then don't schedule a vsync
         if (mFrameCallbacks.empty()) {
             return;
         }
         dueTime = mFrameCallbacks.top().dueTime;
     }

     if (dueTime <= now) {
         ALOGV("choreographer %p ~ scheduling vsync", this);
         scheduleVsync();
         return;
     }
 }

 void Choreographer::handleRefreshRateUpdates() {
     std::vector<RefreshRateCallback> callbacks{};
     const nsecs_t pendingPeriod = gChoreographers.mLastKnownVsync.load();
     const nsecs_t lastPeriod = mLatestVsyncPeriod;
     if (pendingPeriod > 0) {
         mLatestVsyncPeriod = pendingPeriod;
     }
     {
         std::lock_guard<std::mutex> _l{mLock};
         for (auto& cb : mRefreshRateCallbacks) {
             callbacks.push_back(cb);
             cb.firstCallbackFired = true;
         }
     }

     for (auto& cb : callbacks) {
         if (!cb.firstCallbackFired || (pendingPeriod > 0 && pendingPeriod != lastPeriod)) {
             cb.callback(pendingPeriod, cb.data);
         }
     }
 }

 void Choreographer::dispatchVsync(nsecs_t timestamp, PhysicalDisplayId, uint32_t,
                                   VsyncEventData vsyncEventData) {
     std::vector<FrameCallback> callbacks{};
     {
         std::lock_guard<std::mutex> _l{mLock};
         nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
         while (!mFrameCallbacks.empty() && mFrameCallbacks.top().dueTime < now) {
             callbacks.push_back(mFrameCallbacks.top());
             mFrameCallbacks.pop();
         }
     }
     mLastVsyncEventData = vsyncEventData;
     for (const auto& cb : callbacks) {
         if (cb.vsyncCallback != nullptr) {
             ATRACE_FORMAT("AChoreographer_vsyncCallback %" PRId64,
                           vsyncEventData.preferredVsyncId());
             const ChoreographerFrameCallbackDataImpl frameCallbackData =
                     createFrameCallbackData(timestamp);
             registerStartTime();
             mInCallback = true;
             cb.vsyncCallback(reinterpret_cast<const AChoreographerFrameCallbackData*>(
                                      &frameCallbackData),
                              cb.data);
             mInCallback = false;
         } else if (cb.callback64 != nullptr) {
             ATRACE_FORMAT("AChoreographer_frameCallback64");
             cb.callback64(timestamp, cb.data);
         } else if (cb.callback != nullptr) {
             ATRACE_FORMAT("AChoreographer_frameCallback");
             cb.callback(timestamp, cb.data);
         }
     }
 }

 void Choreographer::dispatchHotplug(nsecs_t, PhysicalDisplayId displayId, bool connected) {
     ALOGV("choreographer %p ~ received hotplug event (displayId=%s, connected=%s), ignoring.", this,
           to_string(displayId).c_str(), toString(connected));
 }

 void Choreographer::dispatchHotplugConnectionError(nsecs_t, int32_t connectionError) {
     ALOGV("choreographer %p ~ received hotplug connection error event (connectionError=%d), "
           "ignoring.",
           this, connectionError);
 }

 void Choreographer::dispatchModeChanged(nsecs_t, PhysicalDisplayId, int32_t, nsecs_t) {
     LOG_ALWAYS_FATAL("dispatchModeChanged was called but was never registered");
 }

 void Choreographer::dispatchFrameRateOverrides(nsecs_t, PhysicalDisplayId,
                                                std::vector<FrameRateOverride>) {
     LOG_ALWAYS_FATAL("dispatchFrameRateOverrides was called but was never registered");
 }

 void Choreographer::dispatchNullEvent(nsecs_t, PhysicalDisplayId) {
     ALOGV("choreographer %p ~ received null event.", this);
     handleRefreshRateUpdates();
 }

 void Choreographer::handleMessage(const Message& message) {
     switch (message.what) {
         case MSG_SCHEDULE_CALLBACKS:
             scheduleCallbacks();
             break;
         case MSG_SCHEDULE_VSYNC:
             scheduleVsync();
             break;
         case MSG_HANDLE_REFRESH_RATE_UPDATES:
             handleRefreshRateUpdates();
             break;
     }
 }

 int64_t Choreographer::getFrameInterval() const {
     return mLastVsyncEventData.frameInterval;
 }

 bool Choreographer::inCallback() const {
     return mInCallback;
 }

 ChoreographerFrameCallbackDataImpl Choreographer::createFrameCallbackData(nsecs_t timestamp) const {
     return {.frameTimeNanos = timestamp,
             .vsyncEventData = mLastVsyncEventData,
             .choreographer = this};
 }

 void Choreographer::registerStartTime() const {
     std::scoped_lock _l(gChoreographers.lock);
     for (VsyncEventData::FrameTimeline frameTimeline : mLastVsyncEventData.frameTimelines) {
         while (gChoreographers.startTimes.size() >= kMaxStartTimes) {
             gChoreographers.startTimes.erase(gChoreographers.startTimes.begin());
         }
         gChoreographers.startTimes[frameTimeline.vsyncId] = systemTime(SYSTEM_TIME_MONOTONIC);
     }
 }

 void Choreographer::signalRefreshRateCallbacks(nsecs_t vsyncPeriod) {
     std::lock_guard<std::mutex> _l(gChoreographers.lock);
     gChoreographers.mLastKnownVsync.store(vsyncPeriod);
     for (auto c : gChoreographers.ptrs) {
         c->scheduleLatestConfigRequest();
     }
 }

 int64_t Choreographer::getStartTimeNanosForVsyncId(AVsyncId vsyncId) {
     std::scoped_lock _l(gChoreographers.lock);
     const auto iter = gChoreographers.startTimes.find(vsyncId);
     if (iter == gChoreographers.startTimes.end()) {
         ALOGW("Start time was not found for vsync id: %" PRId64, vsyncId);
         return 0;
     }
     return iter->second;
 }

 } // namespace android
	/*
	* 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.
	*/

	// #define LOG_NDEBUG 0
	#define ATRACE_TAG ATRACE_TAG_GRAPHICS

	#include <gui/Choreographer.h>
	#include <gui/TraceUtils.h>
	#include <jni.h>

	#undef LOG_TAG
	#define LOG_TAG "AChoreographer"

	namespace {
	struct {
	// Global JVM that is provided by zygote
	JavaVM* jvm = nullptr;
	struct {
	jclass clazz;
	jmethodID getInstance;
	jmethodID registerNativeChoreographerForRefreshRateCallbacks;
	jmethodID unregisterNativeChoreographerForRefreshRateCallbacks;
	} displayManagerGlobal;
	} gJni;

	// Gets the JNIEnv* for this thread, and performs one-off initialization if we
	// have never retrieved a JNIEnv* pointer before.
	JNIEnv* getJniEnv() {
	if (gJni.jvm == nullptr) {
	ALOGW("AChoreographer: No JVM provided!");
	return nullptr;
	}

	JNIEnv* env = nullptr;
	if (gJni.jvm->GetEnv((void**)&env, JNI_VERSION_1_4) != JNI_OK) {
	ALOGD("Attaching thread to JVM for AChoreographer");
	JavaVMAttachArgs args = {JNI_VERSION_1_4, "AChoreographer_env", NULL};
	jint attachResult = gJni.jvm->AttachCurrentThreadAsDaemon(&env, (void*)&args);
	if (attachResult != JNI_OK) {
	ALOGE("Unable to attach thread. Error: %d", attachResult);
	return nullptr;
	}
	}
	if (env == nullptr) {
	ALOGW("AChoreographer: No JNI env available!");
	}
	return env;
	}

	inline const char* toString(bool value) {
	return value ? "true" : "false";
	}
	} // namespace

	namespace android {

	Choreographer::Context Choreographer::gChoreographers;

	static thread_local Choreographer* gChoreographer;

	void Choreographer::initJVM(JNIEnv* env) {
	env->GetJavaVM(&gJni.jvm);
	// Now we need to find the java classes.
	jclass dmgClass = env->FindClass("android/hardware/display/DisplayManagerGlobal");
	gJni.displayManagerGlobal.clazz = static_cast<jclass>(env->NewGlobalRef(dmgClass));
	gJni.displayManagerGlobal.getInstance =
	env->GetStaticMethodID(dmgClass, "getInstance",
	"()Landroid/hardware/display/DisplayManagerGlobal;");
	gJni.displayManagerGlobal.registerNativeChoreographerForRefreshRateCallbacks =
	env->GetMethodID(dmgClass, "registerNativeChoreographerForRefreshRateCallbacks", "()V");
	gJni.displayManagerGlobal.unregisterNativeChoreographerForRefreshRateCallbacks =
	env->GetMethodID(dmgClass, "unregisterNativeChoreographerForRefreshRateCallbacks",
	"()V");
	}

	Choreographer* Choreographer::getForThread() {
	if (gChoreographer == nullptr) {
	sp<Looper> looper = Looper::getForThread();
	if (!looper.get()) {
	ALOGW("No looper prepared for thread");
	return nullptr;
	}
	gChoreographer = new Choreographer(looper);
	status_t result = gChoreographer->initialize();
	if (result != OK) {
	ALOGW("Failed to initialize");
	return nullptr;
	}
	}
	return gChoreographer;
	}

	Choreographer::Choreographer(const sp<Looper>& looper, const sp<IBinder>& layerHandle)
	: DisplayEventDispatcher(looper, gui::ISurfaceComposer::VsyncSource::eVsyncSourceApp, {},
	layerHandle),
	mLooper(looper),
	mThreadId(std::this_thread::get_id()) {
	std::lock_guard<std::mutex> _l(gChoreographers.lock);
	gChoreographers.ptrs.push_back(this);
	}

	Choreographer::~Choreographer() {
	std::lock_guard<std::mutex> _l(gChoreographers.lock);
	gChoreographers.ptrs.erase(std::remove_if(gChoreographers.ptrs.begin(),
	gChoreographers.ptrs.end(),
	[=](Choreographer* c) { return c == this; }),
	gChoreographers.ptrs.end());
	// Only poke DisplayManagerGlobal to unregister if we previously registered
	// callbacks.
	if (gChoreographers.ptrs.empty() && gChoreographers.registeredToDisplayManager) {
	gChoreographers.registeredToDisplayManager = false;
	JNIEnv* env = getJniEnv();
	if (env == nullptr) {
	ALOGW("JNI environment is unavailable, skipping choreographer cleanup");
	return;
	}
	jobject dmg = env->CallStaticObjectMethod(gJni.displayManagerGlobal.clazz,
	gJni.displayManagerGlobal.getInstance);
	if (dmg == nullptr) {
	ALOGW("DMS is not initialized yet, skipping choreographer cleanup");
	} else {
	env->CallVoidMethod(dmg,
	gJni.displayManagerGlobal
	.unregisterNativeChoreographerForRefreshRateCallbacks);
	env->DeleteLocalRef(dmg);
	}
	}
	}

	void Choreographer::postFrameCallbackDelayed(AChoreographer_frameCallback cb,
	AChoreographer_frameCallback64 cb64,
	AChoreographer_vsyncCallback vsyncCallback, void* data,
	nsecs_t delay) {
	nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
	FrameCallback callback{cb, cb64, vsyncCallback, data, now + delay};
	{
	std::lock_guard<std::mutex> _l{mLock};
	mFrameCallbacks.push(callback);
	}
	if (callback.dueTime <= now) {
	if (std::this_thread::get_id() != mThreadId) {
	if (mLooper != nullptr) {
	Message m{MSG_SCHEDULE_VSYNC};
	mLooper->sendMessage(this, m);
	} else {
	scheduleVsync();
	}
	} else {
	scheduleVsync();
	}
	} else {
	if (mLooper != nullptr) {
	Message m{MSG_SCHEDULE_CALLBACKS};
	mLooper->sendMessageDelayed(delay, this, m);
	} else {
	scheduleCallbacks();
	}
	}
	}

	void Choreographer::registerRefreshRateCallback(AChoreographer_refreshRateCallback cb, void* data) {
	std::lock_guard<std::mutex> _l{mLock};
	for (const auto& callback : mRefreshRateCallbacks) {
	// Don't re-add callbacks.
	if (cb == callback.callback && data == callback.data) {
	return;
	}
	}
	mRefreshRateCallbacks.emplace_back(
	RefreshRateCallback{.callback = cb, .data = data, .firstCallbackFired = false});
	bool needsRegistration = false;
	{
	std::lock_guard<std::mutex> _l2(gChoreographers.lock);
	needsRegistration = !gChoreographers.registeredToDisplayManager;
	}
	if (needsRegistration) {
	JNIEnv* env = getJniEnv();
	if (env == nullptr) {
	ALOGW("JNI environment is unavailable, skipping registration");
	return;
	}
	jobject dmg = env->CallStaticObjectMethod(gJni.displayManagerGlobal.clazz,
	gJni.displayManagerGlobal.getInstance);
	if (dmg == nullptr) {
	ALOGW("DMS is not initialized yet: skipping registration");
	return;
	} else {
	env->CallVoidMethod(dmg,
	gJni.displayManagerGlobal
	.registerNativeChoreographerForRefreshRateCallbacks,
	reinterpret_cast<int64_t>(this));
	env->DeleteLocalRef(dmg);
	{
	std::lock_guard<std::mutex> _l2(gChoreographers.lock);
	gChoreographers.registeredToDisplayManager = true;
	}
	}
	} else {
	scheduleLatestConfigRequest();
	}
	}

	void Choreographer::unregisterRefreshRateCallback(AChoreographer_refreshRateCallback cb,
	void* data) {
	std::lock_guard<std::mutex> _l{mLock};
	mRefreshRateCallbacks.erase(std::remove_if(mRefreshRateCallbacks.begin(),
	mRefreshRateCallbacks.end(),
	[&](const RefreshRateCallback& callback) {
	return cb == callback.callback &&
	data == callback.data;
	}),
	mRefreshRateCallbacks.end());
	}

	void Choreographer::scheduleLatestConfigRequest() {
	if (mLooper != nullptr) {
	Message m{MSG_HANDLE_REFRESH_RATE_UPDATES};
	mLooper->sendMessage(this, m);
	} else {
	// If the looper thread is detached from Choreographer, then refresh rate
	// changes will be handled in AChoreographer_handlePendingEvents, so we
	// need to wake up the looper thread by writing to the write-end of the
	// socket the looper is listening on.
	// Fortunately, these events are small so sending packets across the
	// socket should be atomic across processes.
	DisplayEventReceiver::Event event;
	event.header =
	DisplayEventReceiver::Event::Header{DisplayEventReceiver::DISPLAY_EVENT_NULL,
	PhysicalDisplayId::fromPort(0), systemTime()};
	injectEvent(event);
	}
	}

	void Choreographer::scheduleCallbacks() {
	const nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
	nsecs_t dueTime;
	{
	std::lock_guard<std::mutex> _l{mLock};
	// If there are no pending callbacks then don't schedule a vsync
	if (mFrameCallbacks.empty()) {
	return;
	}
	dueTime = mFrameCallbacks.top().dueTime;
	}

	if (dueTime <= now) {
	ALOGV("choreographer %p ~ scheduling vsync", this);
	scheduleVsync();
	return;
	}
	}

	void Choreographer::handleRefreshRateUpdates() {
	std::vector<RefreshRateCallback> callbacks{};
	const nsecs_t pendingPeriod = gChoreographers.mLastKnownVsync.load();
	const nsecs_t lastPeriod = mLatestVsyncPeriod;
	if (pendingPeriod > 0) {
	mLatestVsyncPeriod = pendingPeriod;
	}
	{
	std::lock_guard<std::mutex> _l{mLock};
	for (auto& cb : mRefreshRateCallbacks) {
	callbacks.push_back(cb);
	cb.firstCallbackFired = true;
	}
	}

	for (auto& cb : callbacks) {
	if (!cb.firstCallbackFired \|\| (pendingPeriod > 0 && pendingPeriod != lastPeriod)) {
	cb.callback(pendingPeriod, cb.data);
	}
	}
	}

	void Choreographer::dispatchVsync(nsecs_t timestamp, PhysicalDisplayId, uint32_t,
	VsyncEventData vsyncEventData) {
	std::vector<FrameCallback> callbacks{};
	{
	std::lock_guard<std::mutex> _l{mLock};
	nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
	while (!mFrameCallbacks.empty() && mFrameCallbacks.top().dueTime < now) {
	callbacks.push_back(mFrameCallbacks.top());
	mFrameCallbacks.pop();
	}
	}
	mLastVsyncEventData = vsyncEventData;
	for (const auto& cb : callbacks) {
	if (cb.vsyncCallback != nullptr) {
	ATRACE_FORMAT("AChoreographer_vsyncCallback %" PRId64,
	vsyncEventData.preferredVsyncId());
	const ChoreographerFrameCallbackDataImpl frameCallbackData =
	createFrameCallbackData(timestamp);
	registerStartTime();
	mInCallback = true;
	cb.vsyncCallback(reinterpret_cast<const AChoreographerFrameCallbackData*>(
	&frameCallbackData),
	cb.data);
	mInCallback = false;
	} else if (cb.callback64 != nullptr) {
	ATRACE_FORMAT("AChoreographer_frameCallback64");
	cb.callback64(timestamp, cb.data);
	} else if (cb.callback != nullptr) {
	ATRACE_FORMAT("AChoreographer_frameCallback");
	cb.callback(timestamp, cb.data);
	}
	}
	}

	void Choreographer::dispatchHotplug(nsecs_t, PhysicalDisplayId displayId, bool connected) {
	ALOGV("choreographer %p ~ received hotplug event (displayId=%s, connected=%s), ignoring.", this,
	to_string(displayId).c_str(), toString(connected));
	}

	void Choreographer::dispatchHotplugConnectionError(nsecs_t, int32_t connectionError) {
	ALOGV("choreographer %p ~ received hotplug connection error event (connectionError=%d), "
	"ignoring.",
	this, connectionError);
	}

	void Choreographer::dispatchModeChanged(nsecs_t, PhysicalDisplayId, int32_t, nsecs_t) {
	LOG_ALWAYS_FATAL("dispatchModeChanged was called but was never registered");
	}

	void Choreographer::dispatchFrameRateOverrides(nsecs_t, PhysicalDisplayId,
	std::vector<FrameRateOverride>) {
	LOG_ALWAYS_FATAL("dispatchFrameRateOverrides was called but was never registered");
	}

	void Choreographer::dispatchNullEvent(nsecs_t, PhysicalDisplayId) {
	ALOGV("choreographer %p ~ received null event.", this);
	handleRefreshRateUpdates();
	}

	void Choreographer::handleMessage(const Message& message) {
	switch (message.what) {
	case MSG_SCHEDULE_CALLBACKS:
	scheduleCallbacks();
	break;
	case MSG_SCHEDULE_VSYNC:
	scheduleVsync();
	break;
	case MSG_HANDLE_REFRESH_RATE_UPDATES:
	handleRefreshRateUpdates();
	break;
	}
	}

	int64_t Choreographer::getFrameInterval() const {
	return mLastVsyncEventData.frameInterval;
	}

	bool Choreographer::inCallback() const {
	return mInCallback;
	}

	ChoreographerFrameCallbackDataImpl Choreographer::createFrameCallbackData(nsecs_t timestamp) const {
	return {.frameTimeNanos = timestamp,
	.vsyncEventData = mLastVsyncEventData,
	.choreographer = this};
	}

	void Choreographer::registerStartTime() const {
	std::scoped_lock _l(gChoreographers.lock);
	for (VsyncEventData::FrameTimeline frameTimeline : mLastVsyncEventData.frameTimelines) {
	while (gChoreographers.startTimes.size() >= kMaxStartTimes) {
	gChoreographers.startTimes.erase(gChoreographers.startTimes.begin());
	}
	gChoreographers.startTimes[frameTimeline.vsyncId] = systemTime(SYSTEM_TIME_MONOTONIC);
	}
	}

	void Choreographer::signalRefreshRateCallbacks(nsecs_t vsyncPeriod) {
	std::lock_guard<std::mutex> _l(gChoreographers.lock);
	gChoreographers.mLastKnownVsync.store(vsyncPeriod);
	for (auto c : gChoreographers.ptrs) {
	c->scheduleLatestConfigRequest();
	}
	}

	int64_t Choreographer::getStartTimeNanosForVsyncId(AVsyncId vsyncId) {
	std::scoped_lock _l(gChoreographers.lock);
	const auto iter = gChoreographers.startTimes.find(vsyncId);
	if (iter == gChoreographers.startTimes.end()) {
	ALOGW("Start time was not found for vsync id: %" PRId64, vsyncId);
	return 0;
	}
	return iter->second;
	}

	} // namespace android