Revert^2 Integrate transaction tracing with perfetto
Define the perfetto custom data source TransactionDataSource.
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 a 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 (starting state + following
committed transactions) hold by TransactionTracing 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.
Bug: b/284424784
Test: atest libsurfaceflinger_unittest && atest transactiontrace_testsuite
Change-Id: I703ed53e71f442e2f6af7c4a638d2f847107167a
diff --git a/services/surfaceflinger/Tracing/TransactionDataSource.h b/services/surfaceflinger/Tracing/TransactionDataSource.h
new file mode 100644
index 0000000..be8373b
--- /dev/null
+++ b/services/surfaceflinger/Tracing/TransactionDataSource.h
@@ -0,0 +1,74 @@
+/*
+ * Copyright 2023 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 "TransactionTracing.h"
+
+#include <perfetto/tracing.h>
+
+namespace android {
+
+/*
+ * Thread local storage used for fast (lock free) read of data source's properties.
+ *
+ */
+struct TransactionDataSourceTlsState {
+ template <typename TraceContext>
+ explicit TransactionDataSourceTlsState(const TraceContext& trace_context) {
+ auto dataSource = trace_context.GetDataSourceLocked();
+ mMode = dataSource.valid() ? dataSource->GetMode()
+ : TransactionTracing::Mode::MODE_CONTINUOUS;
+ }
+
+ TransactionTracing::Mode mMode;
+};
+
+struct TransactionDataSourceTraits : public perfetto::DefaultDataSourceTraits {
+ using TlsStateType = TransactionDataSourceTlsState;
+};
+
+/*
+ * Defines the Perfetto custom data source 'android.surfaceflinger.transactions'.
+ *
+ * Registers the data source with Perfetto, listens to Perfetto events (setup/start/flush/stop)
+ * and writes trace packets to Perfetto.
+ *
+ */
+class TransactionDataSource
+ : public perfetto::DataSource<TransactionDataSource, TransactionDataSourceTraits> {
+public:
+ static void Initialize(TransactionTracing&);
+ static void UnregisterTransactionTracing();
+ void OnSetup(const SetupArgs&) override;
+ void OnStart(const StartArgs&) override;
+ void OnFlush(const FlushArgs&) override;
+ void OnStop(const StopArgs&) override;
+ TransactionTracing::Mode GetMode() const;
+
+ static constexpr auto* kName = "android.surfaceflinger.transactions";
+ static constexpr perfetto::BufferExhaustedPolicy kBufferExhaustedPolicy =
+ perfetto::BufferExhaustedPolicy::kStall;
+ static constexpr bool kRequiresCallbacksUnderLock = false;
+
+private:
+ static std::atomic<TransactionTracing*> mTransactionTracing;
+ TransactionTracing::Mode mMode;
+};
+
+} // namespace android
+
+PERFETTO_DECLARE_DATA_SOURCE_STATIC_MEMBERS(android::TransactionDataSource);