services/surfaceflinger/Tracing/TransactionTracing.h - platform/frameworks/native - Git at Google

 /*
  * Copyright 2021 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.
  */

 #pragma once

 #include <android-base/thread_annotations.h>
 #include <layerproto/TransactionProto.h>
 #include <utils/Errors.h>
 #include <utils/Singleton.h>
 #include <utils/Timers.h>

 #include <mutex>
 #include <optional>
 #include <set>
 #include <thread>

 #include "FrontEnd/DisplayInfo.h"
 #include "FrontEnd/LayerCreationArgs.h"
 #include "FrontEnd/Update.h"
 #include "LocklessStack.h"
 #include "TransactionProtoParser.h"
 #include "TransactionRingBuffer.h"

 using namespace android::surfaceflinger;

 namespace android {

 class SurfaceFlinger;
 class TransactionTracingTest;

 /*
  * Records all committed transactions into a ring buffer.
  *
  * Transactions come in via the binder thread. They are serialized to proto
  * and stored in a map using the transaction id as key. Main thread will
  * pass the list of transaction ids that are committed every vsync and notify
  * the tracing thread. The tracing thread will then wake up and add the
  * committed transactions to the ring buffer.
  *
  * The traced data can then be collected via:
  * - Perfetto (preferred).
  * - File system, after triggering the disk write through SF backdoor. This is legacy and is going
  *   to be phased out.
  *
  * The Perfetto custom data source TransactionDataSource is registered with perfetto and is used
  * to listen to perfetto events (setup, start, stop, flush) and to write trace packets to perfetto.
  *
  * The user can configure/start/stop tracing via /system/bin/perfetto.
  *
  * Tracing can operate in the following modes.
  *
  * ACTIVE mode:
  * The transactions ring buffer (starting state + following committed transactions) is written
  * (only once) to perfetto when the 'start' event is received.
  * Transactions are then written to perfetto each time they are committed.
  * On the receiver side, the data source is to be configured to periodically
  * flush data to disk providing virtually infinite storage.
  *
  * CONTINUOUS mode:
  * Listens to the perfetto 'flush' event (e.g. when a bugreport is taken).
  * When a 'flush' event is received, the ring buffer of transactions (starting state + following
  * committed transactions) is written to perfetto. On the receiver side, the data source is to be
  * configured with a dedicated buffer large enough to store all the flushed data.
  *
  *
  * E.g. start active mode tracing:
  *
    adb shell perfetto \
      -c - --txt \
      -o /data/misc/perfetto-traces/trace \
    <<EOF
    unique_session_name: "surfaceflinger_transactions_active"
    buffers: {
        size_kb: 1024
        fill_policy: RING_BUFFER
    }
    data_sources: {
        config {
            name: "android.surfaceflinger.transactions"
            surfaceflinger_transactions_config: {
                mode: MODE_ACTIVE
            }
        }
    }
    write_into_file: true
    file_write_period_ms: 100
    EOF
  *
  *
  * E.g. start continuous mode tracing:
  *
    adb shell perfetto \
      -c - --txt \
      -o /data/misc/perfetto-traces/trace \
    <<EOF
    unique_session_name: "surfaceflinger_transactions_continuous"
    buffers: {
        size_kb: 1024
        fill_policy: RING_BUFFER
    }
    data_sources: {
        config {
            name: "android.surfaceflinger.transactions"
            surfaceflinger_transactions_config: {
                mode: MODE_CONTINUOUS
            }
        }
    }
    EOF
  *
  */
 class TransactionTracing {
 public:
     using Mode = perfetto::protos::pbzero::SurfaceFlingerTransactionsConfig::Mode;

     TransactionTracing();
     ~TransactionTracing();

     // Start event from perfetto data source
     void onStart(Mode mode);
     // Flush event from perfetto data source
     void onFlush(Mode mode);

     void addQueuedTransaction(const TransactionState&);
     void addCommittedTransactions(int64_t vsyncId, nsecs_t commitTime, frontend::Update& update,
                                   const frontend::DisplayInfos&, bool displayInfoChanged);
     status_t writeToFile(const std::string& filename = FILE_PATH);
     // Return buffer contents as trace file proto
     perfetto::protos::TransactionTraceFile writeToProto() EXCLUDES(mMainThreadLock);
     void setBufferSize(size_t bufferSizeInBytes);
     void onLayerRemoved(int layerId);
     void dump(std::string&) const;
     // Wait until all the committed transactions for the specified vsync id are added to the buffer.
     void flush() EXCLUDES(mMainThreadLock);

     static constexpr auto CONTINUOUS_TRACING_BUFFER_SIZE = 512 * 1024;
     static constexpr auto LEGACY_ACTIVE_TRACING_BUFFER_SIZE = 100 * 1024 * 1024;
     // version 1 - switching to support new frontend
     static constexpr auto TRACING_VERSION = 1;

 private:
     friend class TransactionTraceWriter;
     friend class TransactionTracingTest;
     friend class SurfaceFlinger;

     static constexpr auto DIR_NAME = "/data/misc/wmtrace/";
     static constexpr auto FILE_NAME = "transactions_trace.winscope";
     static constexpr auto FILE_PATH = "/data/misc/wmtrace/transactions_trace.winscope";
     static std::string getFilePath(const std::string& prefix) {
         return DIR_NAME + prefix + FILE_NAME;
     }

     mutable std::mutex mTraceLock;
     TransactionRingBuffer<perfetto::protos::TransactionTraceFile,
                           perfetto::protos::TransactionTraceEntry>
             mBuffer GUARDED_BY(mTraceLock);
     std::unordered_map<uint64_t, perfetto::protos::TransactionState> mQueuedTransactions
             GUARDED_BY(mTraceLock);
     LocklessStack<perfetto::protos::TransactionState> mTransactionQueue;
     nsecs_t mStartingTimestamp GUARDED_BY(mTraceLock);
     std::unordered_map<int, perfetto::protos::LayerCreationArgs> mCreatedLayers
             GUARDED_BY(mTraceLock);
     std::map<uint32_t /* layerId */, TracingLayerState> mStartingStates GUARDED_BY(mTraceLock);
     frontend::DisplayInfos mStartingDisplayInfos GUARDED_BY(mTraceLock);

     std::set<uint32_t /* layerId */> mRemovedLayerHandlesAtStart GUARDED_BY(mTraceLock);
     TransactionProtoParser mProtoParser;

     // We do not want main thread to block so main thread will try to acquire mMainThreadLock,
     // otherwise will push data to temporary container.
     std::mutex mMainThreadLock;
     std::thread mThread GUARDED_BY(mMainThreadLock);
     bool mDone GUARDED_BY(mMainThreadLock) = false;
     std::condition_variable mTransactionsAvailableCv;
     std::condition_variable mTransactionsAddedToBufferCv;
     struct CommittedUpdates {
         std::vector<uint64_t> transactionIds;
         std::vector<LayerCreationArgs> createdLayers;
         std::vector<uint32_t> destroyedLayerHandles;
         bool displayInfoChanged;
         frontend::DisplayInfos displayInfos;
         int64_t vsyncId;
         int64_t timestamp;
     };
     std::vector<CommittedUpdates> mUpdates GUARDED_BY(mMainThreadLock);
     std::vector<CommittedUpdates> mPendingUpdates; // only accessed by main thread

     std::vector<uint32_t /* layerId */> mDestroyedLayers GUARDED_BY(mMainThreadLock);
     std::vector<uint32_t /* layerId */> mPendingDestroyedLayers; // only accessed by main thread
     int64_t mLastUpdatedVsyncId = -1;

     void writeRingBufferToPerfetto(TransactionTracing::Mode mode);
     perfetto::protos::TransactionTraceFile createTraceFileProto() const;
     void loop();
     void addEntry(const std::vector<CommittedUpdates>& committedTransactions,
                   const std::vector<uint32_t>& removedLayers) EXCLUDES(mTraceLock);
     int32_t getLayerIdLocked(const sp<IBinder>& layerHandle) REQUIRES(mTraceLock);
     void tryPushToTracingThread() EXCLUDES(mMainThreadLock);
     std::optional<perfetto::protos::TransactionTraceEntry> createStartingStateProtoLocked()
             REQUIRES(mTraceLock);
     void updateStartingStateLocked(const perfetto::protos::TransactionTraceEntry& entry)
             REQUIRES(mTraceLock);
 };

 class TransactionTraceWriter : public Singleton<TransactionTraceWriter> {
     friend class Singleton<TransactionTracing>;
     std::function<void(const std::string& prefix, bool overwrite)> mWriterFunction =
             [](const std::string&, bool) {};
     std::atomic<bool> mEnabled{true};

     void doInvoke(const std::string& filename, bool overwrite) {
         if (mEnabled) {
             mWriterFunction(filename, overwrite);
         }
     };

 public:
     void setWriterFunction(
             std::function<void(const std::string& filename, bool overwrite)> function) {
         mWriterFunction = std::move(function);
     }
     void invoke(const std::string& prefix, bool overwrite) {
         doInvoke(TransactionTracing::getFilePath(prefix), overwrite);
     }
     /* pass in a complete file path for testing */
     void invokeForTest(const std::string& filename, bool overwrite) {
         doInvoke(filename, overwrite);
     }
     /* hacky way to avoid generating traces when converting transaction trace to layers trace. */
     void disable() { mEnabled.store(false); }
     void enable() { mEnabled.store(true); }
 };

 } // namespace android
	/*
	* Copyright 2021 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.
	*/

	#pragma once

	#include <android-base/thread_annotations.h>
	#include <layerproto/TransactionProto.h>
	#include <utils/Errors.h>
	#include <utils/Singleton.h>
	#include <utils/Timers.h>

	#include <mutex>
	#include <optional>
	#include <set>
	#include <thread>

	#include "FrontEnd/DisplayInfo.h"
	#include "FrontEnd/LayerCreationArgs.h"
	#include "FrontEnd/Update.h"
	#include "LocklessStack.h"
	#include "TransactionProtoParser.h"
	#include "TransactionRingBuffer.h"

	using namespace android::surfaceflinger;

	namespace android {

	class SurfaceFlinger;
	class TransactionTracingTest;

	/*
	* Records all committed transactions into a ring buffer.
	*
	* Transactions come in via the binder thread. They are serialized to proto
	* and stored in a map using the transaction id as key. Main thread will
	* pass the list of transaction ids that are committed every vsync and notify
	* the tracing thread. The tracing thread will then wake up and add the
	* committed transactions to the ring buffer.
	*
	* The traced data can then be collected via:
	* - Perfetto (preferred).
	* - File system, after triggering the disk write through SF backdoor. This is legacy and is going
	* to be phased out.
	*
	* The Perfetto custom data source TransactionDataSource is registered with perfetto and is used
	* to listen to perfetto events (setup, start, stop, flush) and to write trace packets to perfetto.
	*
	* The user can configure/start/stop tracing via /system/bin/perfetto.
	*
	* Tracing can operate in the following modes.
	*
	* ACTIVE mode:
	* The transactions ring buffer (starting state + following committed transactions) is written
	* (only once) to perfetto when the 'start' event is received.
	* Transactions are then written to perfetto each time they are committed.
	* On the receiver side, the data source is to be configured to periodically
	* flush data to disk providing virtually infinite storage.
	*
	* CONTINUOUS mode:
	* Listens to the perfetto 'flush' event (e.g. when a bugreport is taken).
	* When a 'flush' event is received, the ring buffer of transactions (starting state + following
	* committed transactions) is written to perfetto. On the receiver side, the data source is to be
	* configured with a dedicated buffer large enough to store all the flushed data.
	*
	*
	* E.g. start active mode tracing:
	*
	adb shell perfetto \
	-c - --txt \
	-o /data/misc/perfetto-traces/trace \
	<<EOF
	unique_session_name: "surfaceflinger_transactions_active"
	buffers: {
	size_kb: 1024
	fill_policy: RING_BUFFER
	}
	data_sources: {
	config {
	name: "android.surfaceflinger.transactions"
	surfaceflinger_transactions_config: {
	mode: MODE_ACTIVE
	}
	}
	}
	write_into_file: true
	file_write_period_ms: 100
	EOF
	*
	*
	* E.g. start continuous mode tracing:
	*
	adb shell perfetto \
	-c - --txt \
	-o /data/misc/perfetto-traces/trace \
	<<EOF
	unique_session_name: "surfaceflinger_transactions_continuous"
	buffers: {
	size_kb: 1024
	fill_policy: RING_BUFFER
	}
	data_sources: {
	config {
	name: "android.surfaceflinger.transactions"
	surfaceflinger_transactions_config: {
	mode: MODE_CONTINUOUS
	}
	}
	}
	EOF
	*
	*/
	class TransactionTracing {
	public:
	using Mode = perfetto::protos::pbzero::SurfaceFlingerTransactionsConfig::Mode;

	TransactionTracing();
	~TransactionTracing();

	// Start event from perfetto data source
	void onStart(Mode mode);
	// Flush event from perfetto data source
	void onFlush(Mode mode);

	void addQueuedTransaction(const TransactionState&);
	void addCommittedTransactions(int64_t vsyncId, nsecs_t commitTime, frontend::Update& update,
	const frontend::DisplayInfos&, bool displayInfoChanged);
	status_t writeToFile(const std::string& filename = FILE_PATH);
	// Return buffer contents as trace file proto
	perfetto::protos::TransactionTraceFile writeToProto() EXCLUDES(mMainThreadLock);
	void setBufferSize(size_t bufferSizeInBytes);
	void onLayerRemoved(int layerId);
	void dump(std::string&) const;
	// Wait until all the committed transactions for the specified vsync id are added to the buffer.
	void flush() EXCLUDES(mMainThreadLock);

	static constexpr auto CONTINUOUS_TRACING_BUFFER_SIZE = 512 * 1024;
	static constexpr auto LEGACY_ACTIVE_TRACING_BUFFER_SIZE = 100 * 1024 * 1024;
	// version 1 - switching to support new frontend
	static constexpr auto TRACING_VERSION = 1;

	private:
	friend class TransactionTraceWriter;
	friend class TransactionTracingTest;
	friend class SurfaceFlinger;

	static constexpr auto DIR_NAME = "/data/misc/wmtrace/";
	static constexpr auto FILE_NAME = "transactions_trace.winscope";
	static constexpr auto FILE_PATH = "/data/misc/wmtrace/transactions_trace.winscope";
	static std::string getFilePath(const std::string& prefix) {
	return DIR_NAME + prefix + FILE_NAME;
	}

	mutable std::mutex mTraceLock;
	TransactionRingBuffer<perfetto::protos::TransactionTraceFile,
	perfetto::protos::TransactionTraceEntry>
	mBuffer GUARDED_BY(mTraceLock);
	std::unordered_map<uint64_t, perfetto::protos::TransactionState> mQueuedTransactions
	GUARDED_BY(mTraceLock);
	LocklessStack<perfetto::protos::TransactionState> mTransactionQueue;
	nsecs_t mStartingTimestamp GUARDED_BY(mTraceLock);
	std::unordered_map<int, perfetto::protos::LayerCreationArgs> mCreatedLayers
	GUARDED_BY(mTraceLock);
	std::map<uint32_t /* layerId */, TracingLayerState> mStartingStates GUARDED_BY(mTraceLock);
	frontend::DisplayInfos mStartingDisplayInfos GUARDED_BY(mTraceLock);

	std::set<uint32_t /* layerId */> mRemovedLayerHandlesAtStart GUARDED_BY(mTraceLock);
	TransactionProtoParser mProtoParser;

	// We do not want main thread to block so main thread will try to acquire mMainThreadLock,
	// otherwise will push data to temporary container.
	std::mutex mMainThreadLock;
	std::thread mThread GUARDED_BY(mMainThreadLock);
	bool mDone GUARDED_BY(mMainThreadLock) = false;
	std::condition_variable mTransactionsAvailableCv;
	std::condition_variable mTransactionsAddedToBufferCv;
	struct CommittedUpdates {
	std::vector<uint64_t> transactionIds;
	std::vector<LayerCreationArgs> createdLayers;
	std::vector<uint32_t> destroyedLayerHandles;
	bool displayInfoChanged;
	frontend::DisplayInfos displayInfos;
	int64_t vsyncId;
	int64_t timestamp;
	};
	std::vector<CommittedUpdates> mUpdates GUARDED_BY(mMainThreadLock);
	std::vector<CommittedUpdates> mPendingUpdates; // only accessed by main thread

	std::vector<uint32_t /* layerId */> mDestroyedLayers GUARDED_BY(mMainThreadLock);
	std::vector<uint32_t /* layerId */> mPendingDestroyedLayers; // only accessed by main thread
	int64_t mLastUpdatedVsyncId = -1;

	void writeRingBufferToPerfetto(TransactionTracing::Mode mode);
	perfetto::protos::TransactionTraceFile createTraceFileProto() const;
	void loop();
	void addEntry(const std::vector<CommittedUpdates>& committedTransactions,
	const std::vector<uint32_t>& removedLayers) EXCLUDES(mTraceLock);
	int32_t getLayerIdLocked(const sp<IBinder>& layerHandle) REQUIRES(mTraceLock);
	void tryPushToTracingThread() EXCLUDES(mMainThreadLock);
	std::optional<perfetto::protos::TransactionTraceEntry> createStartingStateProtoLocked()
	REQUIRES(mTraceLock);
	void updateStartingStateLocked(const perfetto::protos::TransactionTraceEntry& entry)
	REQUIRES(mTraceLock);
	};

	class TransactionTraceWriter : public Singleton<TransactionTraceWriter> {
	friend class Singleton<TransactionTracing>;
	std::function<void(const std::string& prefix, bool overwrite)> mWriterFunction =
	[](const std::string&, bool) {};
	std::atomic<bool> mEnabled{true};

	void doInvoke(const std::string& filename, bool overwrite) {
	if (mEnabled) {
	mWriterFunction(filename, overwrite);
	}
	};

	public:
	void setWriterFunction(
	std::function<void(const std::string& filename, bool overwrite)> function) {
	mWriterFunction = std::move(function);
	}
	void invoke(const std::string& prefix, bool overwrite) {
	doInvoke(TransactionTracing::getFilePath(prefix), overwrite);
	}
	/* pass in a complete file path for testing */
	void invokeForTest(const std::string& filename, bool overwrite) {
	doInvoke(filename, overwrite);
	}
	/* hacky way to avoid generating traces when converting transaction trace to layers trace. */
	void disable() { mEnabled.store(false); }
	void enable() { mEnabled.store(true); }
	};

	} // namespace android