Initialize MotionClassifier from a separate thread
We are currently calling getService directly from the thread that calls
InputManager constructor. That means, the function call directly affects
the start-up time of the system.
But InputClassifier HAL is not mission-critical, and the system can
function perfectly fine without it. Moreover, we are already allowing
for mMotionClassifier to be null in our code.
In this change, mMotionClassifier will become non-null right away, but
may not be initialized when it is first created. The initialization will
happen in a separate thread. Once initialized, MotionClassifier may
become null inside InputClassifier if the latter receives a HAL death
callback.
To account for the possibility of the MotionClassifier not being valid
right away, we are allowing mService variable in the MotionClassifier to
be nullable.
The contract for mService is as follows: mService is null by default. If
MotionClassifier initializes successfully (may take ~ 100 ms), then
mService will become non-null. Once non-null, it stays non-null.
This allows MotionClassifier's separate thread to not have to check the
nullness of mService.
Other threads, however, must assume that mService can be null. They are
checking the value with a lock held.
If MotionClassifier init fails, it will also call the deathRecipient's
serviceDied call, to signal that it is no longer useful. This should
prompt the owner of MotionClassifier to dispose it.
Bug: 130184032
Test: atest google/perf/boottime/boottime-test
Test: atest libinput_tests inputflinger_tests
Change-Id: Id4f9c316ef6725d96abebc55a96079946647eb39
diff --git a/services/inputflinger/InputClassifier.cpp b/services/inputflinger/InputClassifier.cpp
index b4db338..4a6efa6 100644
--- a/services/inputflinger/InputClassifier.cpp
+++ b/services/inputflinger/InputClassifier.cpp
@@ -507,19 +507,53 @@
// --- MotionClassifier ---
-MotionClassifier::MotionClassifier(
- sp<android::hardware::input::classifier::V1_0::IInputClassifier> service) :
- mEvents(MAX_EVENTS), mService(service) {
+MotionClassifier::MotionClassifier(sp<android::hardware::hidl_death_recipient> deathRecipient) :
+ mDeathRecipient(deathRecipient), mEvents(MAX_EVENTS) {
mHalThread = std::thread(&MotionClassifier::callInputClassifierHal, this);
#if defined(__linux__)
// Set the thread name for debugging
pthread_setname_np(mHalThread.native_handle(), "InputClassifier");
#endif
+}
+
+/**
+ * This function may block for some time to initialize the HAL, so it should only be called
+ * from the "InputClassifier HAL" thread.
+ */
+bool MotionClassifier::init() {
+ ensureHalThread(__func__);
+ sp<android::hardware::input::classifier::V1_0::IInputClassifier> service =
+ classifier::V1_0::IInputClassifier::getService();
+ if (!service) {
+ // Not really an error, maybe the device does not have this HAL,
+ // but somehow the feature flag is flipped
+ ALOGI("Could not obtain InputClassifier HAL");
+ return false;
+ }
+
+ sp<android::hardware::hidl_death_recipient> recipient = mDeathRecipient.promote();
+ if (recipient != nullptr) {
+ const bool linked = service->linkToDeath(recipient, 0 /* cookie */).withDefault(false);
+ if (!linked) {
+ ALOGE("Could not link MotionClassifier to the HAL death");
+ return false;
+ }
+ }
+
// Under normal operation, we do not need to reset the HAL here. But in the case where system
// crashed, but HAL didn't, we may be connecting to an existing HAL process that might already
// have received events in the past. That means, that HAL could be in an inconsistent state
// once it receives events from the newly created MotionClassifier.
mEvents.push(ClassifierEvent::createHalResetEvent());
+
+ {
+ std::scoped_lock lock(mLock);
+ if (mService) {
+ ALOGE("MotionClassifier::%s should only be called once", __func__);
+ }
+ mService = service;
+ }
+ return true;
}
MotionClassifier::~MotionClassifier() {
@@ -530,7 +564,7 @@
void MotionClassifier::ensureHalThread(const char* function) {
if (DEBUG) {
if (std::this_thread::get_id() != mHalThread.get_id()) {
- ALOGE("Function %s should only be called from InputClassifier thread", function);
+ LOG_FATAL("Function %s should only be called from InputClassifier thread", function);
}
}
}
@@ -547,6 +581,21 @@
*/
void MotionClassifier::callInputClassifierHal() {
ensureHalThread(__func__);
+ const bool initialized = init();
+ if (!initialized) {
+ // MotionClassifier no longer useful.
+ // Deliver death notification from a separate thread
+ // because ~MotionClassifier may be invoked, which calls mHalThread.join()
+ std::thread([deathRecipient = mDeathRecipient](){
+ sp<android::hardware::hidl_death_recipient> recipient = deathRecipient.promote();
+ if (recipient != nullptr) {
+ recipient->serviceDied(0 /*cookie*/, nullptr);
+ }
+ }).detach();
+ return;
+ }
+ // From this point on, mService is guaranteed to be non-null.
+
while (true) {
ClassifierEvent event = mEvents.pop();
bool halResponseOk = true;
@@ -666,10 +715,19 @@
enqueueEvent(std::make_unique<NotifyDeviceResetArgs>(args));
}
+const char* MotionClassifier::getServiceStatus() REQUIRES(mLock) {
+ if (!mService) {
+ return "null";
+ }
+ if (mService->ping().isOk()) {
+ return "running";
+ }
+ return "not responding";
+}
+
void MotionClassifier::dump(std::string& dump) {
std::scoped_lock lock(mLock);
- std::string serviceStatus = mService->ping().isOk() ? "running" : " not responding";
- dump += StringPrintf(INDENT2 "mService status: %s\n", serviceStatus.c_str());
+ dump += StringPrintf(INDENT2 "mService status: %s\n", getServiceStatus());
dump += StringPrintf(INDENT2 "mEvents: %zu element(s) (max=%zu)\n",
mEvents.size(), MAX_EVENTS);
dump += INDENT2 "mClassifications, mLastDownTimes:\n";
@@ -700,28 +758,14 @@
}
void InputClassifier::onFirstRef() {
- std::scoped_lock lock(mLock);
if (!deepPressEnabled()) {
- // If feature is not enabled, the InputClassifier will just be in passthrough
- // mode, and will forward all events to the next InputListener, unmodified
+ // If feature is not enabled, MotionClassifier should stay null to avoid unnecessary work.
+ // When MotionClassifier is null, InputClassifier will forward all events
+ // to the next InputListener, unmodified.
return;
}
-
- sp<android::hardware::input::classifier::V1_0::IInputClassifier> service =
- classifier::V1_0::IInputClassifier::getService();
- if (!service) {
- // Not really an error, maybe the device does not have this HAL,
- // but somehow the feature flag is flipped
- ALOGI("Could not obtain InputClassifier HAL");
- return;
- }
- const bool linked = service->linkToDeath(this, 0 /* cookie */).withDefault(false);
- if (!linked) {
- ALOGE("Could not link android::InputClassifier to the HAL death");
- return;
- }
-
- mMotionClassifier = std::make_unique<MotionClassifier>(service);
+ std::scoped_lock lock(mLock);
+ mMotionClassifier = std::make_unique<MotionClassifier>(this);
}
void InputClassifier::notifyConfigurationChanged(const NotifyConfigurationChangedArgs* args) {
@@ -786,4 +830,4 @@
dump += "\n";
}
-} // namespace android
\ No newline at end of file
+} // namespace android