InputTracer: Add tests for perfetto backend
Add a new InputTraceSession class that encapsulates the logic to take
and decode a perfetto input trace for testing.
Then, use it to add new tests to verify the behavior of entire tracing
framework, using InputDispatcher as the interface.
Bug: 210460522
Test: atest inputflinger_tests
Change-Id: I5a9b47e831c5c30e5d7f2b60c9b8075b7d330e9e
diff --git a/services/inputflinger/dispatcher/trace/InputTracingPerfettoBackend.cpp b/services/inputflinger/dispatcher/trace/InputTracingPerfettoBackend.cpp
index 9c39743..91ebe9b 100644
--- a/services/inputflinger/dispatcher/trace/InputTracingPerfettoBackend.cpp
+++ b/services/inputflinger/dispatcher/trace/InputTracingPerfettoBackend.cpp
@@ -149,6 +149,8 @@
// --- PerfettoBackend ---
+bool PerfettoBackend::sUseInProcessBackendForTest{false};
+
std::once_flag PerfettoBackend::sDataSourceRegistrationFlag{};
std::atomic<int32_t> PerfettoBackend::sNextInstanceId{1};
@@ -159,7 +161,8 @@
// we never unregister the InputEventDataSource.
std::call_once(sDataSourceRegistrationFlag, []() {
perfetto::TracingInitArgs args;
- args.backends = perfetto::kSystemBackend;
+ args.backends = sUseInProcessBackendForTest ? perfetto::kInProcessBackend
+ : perfetto::kSystemBackend;
perfetto::Tracing::Initialize(args);
// Register our custom data source for input event tracing.
@@ -175,6 +178,9 @@
const TracedEventMetadata& metadata) {
InputEventDataSource::Trace([&](InputEventDataSource::TraceContext ctx) {
auto dataSource = ctx.GetDataSourceLocked();
+ if (!dataSource.valid()) {
+ return;
+ }
dataSource->initializeUidMap(mGetPackageUid);
if (dataSource->shouldIgnoreTracedInputEvent(event.eventType)) {
return;
@@ -196,6 +202,9 @@
const TracedEventMetadata& metadata) {
InputEventDataSource::Trace([&](InputEventDataSource::TraceContext ctx) {
auto dataSource = ctx.GetDataSourceLocked();
+ if (!dataSource.valid()) {
+ return;
+ }
dataSource->initializeUidMap(mGetPackageUid);
if (dataSource->shouldIgnoreTracedInputEvent(event.eventType)) {
return;
@@ -217,6 +226,9 @@
const TracedEventMetadata& metadata) {
InputEventDataSource::Trace([&](InputEventDataSource::TraceContext ctx) {
auto dataSource = ctx.GetDataSourceLocked();
+ if (!dataSource.valid()) {
+ return;
+ }
dataSource->initializeUidMap(mGetPackageUid);
if (!dataSource->getFlags().test(TraceFlag::TRACE_DISPATCHER_WINDOW_DISPATCH)) {
return;
diff --git a/services/inputflinger/dispatcher/trace/InputTracingPerfettoBackend.h b/services/inputflinger/dispatcher/trace/InputTracingPerfettoBackend.h
index e945066..fdfe495 100644
--- a/services/inputflinger/dispatcher/trace/InputTracingPerfettoBackend.h
+++ b/services/inputflinger/dispatcher/trace/InputTracingPerfettoBackend.h
@@ -51,6 +51,8 @@
public:
using GetPackageUid = std::function<gui::Uid(std::string)>;
+ static bool sUseInProcessBackendForTest;
+
explicit PerfettoBackend(GetPackageUid);
~PerfettoBackend() override = default;
@@ -61,6 +63,7 @@
private:
// Implementation of the perfetto data source.
// Each instance of the InputEventDataSource represents a different tracing session.
+ // Its lifecycle is controlled by perfetto.
class InputEventDataSource : public perfetto::DataSource<InputEventDataSource> {
public:
explicit InputEventDataSource();
diff --git a/services/inputflinger/dispatcher/trace/ThreadedBackend.cpp b/services/inputflinger/dispatcher/trace/ThreadedBackend.cpp
index 77d09cb..c0a98f5 100644
--- a/services/inputflinger/dispatcher/trace/ThreadedBackend.cpp
+++ b/services/inputflinger/dispatcher/trace/ThreadedBackend.cpp
@@ -84,13 +84,18 @@
std::unique_lock lock(mLock);
base::ScopedLockAssertion assumeLocked(mLock);
+ setIdleStatus(true);
+
// Wait until we need to process more events or exit.
mThreadWakeCondition.wait(lock,
[&]() REQUIRES(mLock) { return mThreadExit || !mQueue.empty(); });
if (mThreadExit) {
+ setIdleStatus(true);
return;
}
+ setIdleStatus(false);
+
mQueue.swap(entries);
} // release lock
@@ -109,6 +114,36 @@
entries.clear();
}
+template <typename Backend>
+std::function<void()> ThreadedBackend<Backend>::getIdleWaiterForTesting() {
+ std::scoped_lock lock(mLock);
+ if (!mIdleWaiter) {
+ mIdleWaiter = std::make_shared<IdleWaiter>();
+ }
+
+ // Return a lambda that holds a strong reference to the idle waiter, whose lifetime can extend
+ // beyond this threaded backend object.
+ return [idleWaiter = mIdleWaiter]() {
+ std::unique_lock idleLock(idleWaiter->idleLock);
+ base::ScopedLockAssertion assumeLocked(idleWaiter->idleLock);
+ idleWaiter->threadIdleCondition.wait(idleLock, [&]() REQUIRES(idleWaiter->idleLock) {
+ return idleWaiter->isIdle;
+ });
+ };
+}
+
+template <typename Backend>
+void ThreadedBackend<Backend>::setIdleStatus(bool isIdle) {
+ if (!mIdleWaiter) {
+ return;
+ }
+ std::scoped_lock idleLock(mIdleWaiter->idleLock);
+ mIdleWaiter->isIdle = isIdle;
+ if (isIdle) {
+ mIdleWaiter->threadIdleCondition.notify_all();
+ }
+}
+
// Explicit template instantiation for the PerfettoBackend.
template class ThreadedBackend<PerfettoBackend>;
diff --git a/services/inputflinger/dispatcher/trace/ThreadedBackend.h b/services/inputflinger/dispatcher/trace/ThreadedBackend.h
index 650a87e..52a84c4 100644
--- a/services/inputflinger/dispatcher/trace/ThreadedBackend.h
+++ b/services/inputflinger/dispatcher/trace/ThreadedBackend.h
@@ -42,6 +42,9 @@
void traceMotionEvent(const TracedMotionEvent&, const TracedEventMetadata&) override;
void traceWindowDispatch(const WindowDispatchArgs&, const TracedEventMetadata&) override;
+ /** Returns a function that, when called, will block until the tracing thread is idle. */
+ std::function<void()> getIdleWaiterForTesting();
+
private:
std::mutex mLock;
bool mThreadExit GUARDED_BY(mLock){false};
@@ -52,12 +55,21 @@
TracedEventMetadata>;
std::vector<TraceEntry> mQueue GUARDED_BY(mLock);
+ struct IdleWaiter {
+ std::mutex idleLock;
+ std::condition_variable threadIdleCondition;
+ bool isIdle GUARDED_BY(idleLock){false};
+ };
+ // The lazy-initialized object used to wait for the tracing thread to idle.
+ std::shared_ptr<IdleWaiter> mIdleWaiter GUARDED_BY(mLock);
+
// InputThread stops when its destructor is called. Initialize it last so that it is the
// first thing to be destructed. This will guarantee the thread will not access other
// members that have already been destructed.
InputThread mTracerThread;
void threadLoop();
+ void setIdleStatus(bool isIdle) REQUIRES(mLock);
};
} // namespace android::inputdispatcher::trace::impl