InputTracer: Trace motion and key events
Bug: 210460522
Test: manual with perfetto
Change-Id: I4bcac0b8bba5132d0e68815923ab8f89b2bede84
diff --git a/services/inputflinger/dispatcher/trace/InputTracingPerfettoBackend.cpp b/services/inputflinger/dispatcher/trace/InputTracingPerfettoBackend.cpp
new file mode 100644
index 0000000..db88726
--- /dev/null
+++ b/services/inputflinger/dispatcher/trace/InputTracingPerfettoBackend.cpp
@@ -0,0 +1,88 @@
+/*
+ * Copyright 2024 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_TAG "InputTracer"
+
+#include "InputTracingPerfettoBackend.h"
+
+#include "AndroidInputEventProtoConverter.h"
+
+#include <android-base/logging.h>
+#include <perfetto/trace/android/android_input_event.pbzero.h>
+
+namespace android::inputdispatcher::trace::impl {
+
+namespace {
+
+constexpr auto INPUT_EVENT_TRACE_DATA_SOURCE_NAME = "android.input.inputevent";
+
+} // namespace
+
+// --- PerfettoBackend::InputEventDataSource ---
+
+void PerfettoBackend::InputEventDataSource::OnStart(const perfetto::DataSourceBase::StartArgs&) {
+ LOG(INFO) << "Starting perfetto trace for: " << INPUT_EVENT_TRACE_DATA_SOURCE_NAME;
+}
+
+void PerfettoBackend::InputEventDataSource::OnStop(const perfetto::DataSourceBase::StopArgs&) {
+ LOG(INFO) << "Stopping perfetto trace for: " << INPUT_EVENT_TRACE_DATA_SOURCE_NAME;
+ InputEventDataSource::Trace([&](InputEventDataSource::TraceContext ctx) { ctx.Flush(); });
+}
+
+// --- PerfettoBackend ---
+
+std::once_flag PerfettoBackend::sDataSourceRegistrationFlag{};
+
+PerfettoBackend::PerfettoBackend() {
+ // Use a once-flag to ensure that the data source is only registered once per boot, since
+ // we never unregister the InputEventDataSource.
+ std::call_once(sDataSourceRegistrationFlag, []() {
+ perfetto::TracingInitArgs args;
+ args.backends = perfetto::kSystemBackend;
+ perfetto::Tracing::Initialize(args);
+
+ // Register our custom data source for input event tracing.
+ perfetto::DataSourceDescriptor dsd;
+ dsd.set_name(INPUT_EVENT_TRACE_DATA_SOURCE_NAME);
+ InputEventDataSource::Register(dsd);
+ LOG(INFO) << "InputTracer initialized for data source: "
+ << INPUT_EVENT_TRACE_DATA_SOURCE_NAME;
+ });
+}
+
+void PerfettoBackend::traceMotionEvent(const TracedMotionEvent& event) const {
+ InputEventDataSource::Trace([&](InputEventDataSource::TraceContext ctx) {
+ auto tracePacket = ctx.NewTracePacket();
+ auto* inputEvent = tracePacket->set_android_input_event();
+ auto* dispatchMotion = inputEvent->set_dispatcher_motion_event();
+ AndroidInputEventProtoConverter::toProtoMotionEvent(event, *dispatchMotion);
+ });
+}
+
+void PerfettoBackend::traceKeyEvent(const TracedKeyEvent& event) const {
+ InputEventDataSource::Trace([&](InputEventDataSource::TraceContext ctx) {
+ auto tracePacket = ctx.NewTracePacket();
+ auto* inputEvent = tracePacket->set_android_input_event();
+ auto* dispatchKey = inputEvent->set_dispatcher_key_event();
+ AndroidInputEventProtoConverter::toProtoKeyEvent(event, *dispatchKey);
+ });
+}
+
+void PerfettoBackend::traceWindowDispatch(const WindowDispatchArgs&) const {
+ // TODO(b/210460522): Implement.
+}
+
+} // namespace android::inputdispatcher::trace::impl