Allow dispatcher to be idle after metrics push

Earlier, the dispatcher was not being allowed to enter idle state
since processLatencyStatisticsLocked() would always wake it up in 6 hours,
causing many of the dispatcher tests to fail.
Now, the dispatcher will be idle after the latency statistics are
pushed. After the statistics push is complete, the next push will occur
after 6 hours upon the next input event being received by the
dispatcher.

Bug: 270049345
Test: atest inputflinger_tests
Flag: com.android.input.flags.enable_per_device_input_latency_metrics
Change-Id: I1cdb6df6110bff9e4fcb6cbfdc91c16c8e386f0b

Author: Asmita Poddar

services/inputflinger/dispatcher/InputDispatcher.cpp

@@ -1031,8 +1031,7 @@ void InputDispatcher::dispatchOnce() {
         nextWakeupTime = std::min(nextWakeupTime, nextAnrCheck);
 
         if (mPerDeviceInputLatencyMetricsFlag) {
-            const nsecs_t nextStatisticsPush = processLatencyStatisticsLocked();
-            nextWakeupTime = std::min(nextWakeupTime, nextStatisticsPush);
+            processLatencyStatisticsLocked();
         }
 
         // We are about to enter an infinitely long sleep, because we have no commands or
@@ -1117,17 +1116,15 @@ nsecs_t InputDispatcher::processAnrsLocked() {
 
 /**
  * Check if enough time has passed since the last latency statistics push.
- * Return the time at which we should wake up next.
  */
-nsecs_t InputDispatcher::processLatencyStatisticsLocked() {
+void InputDispatcher::processLatencyStatisticsLocked() {
     const nsecs_t currentTime = now();
     // Log the atom recording latency statistics if more than 6 hours passed from the last
     // push
     if (currentTime - mLastStatisticPushTime >= LATENCY_STATISTICS_PUSH_INTERVAL) {
         mInputEventTimelineProcessor->pushLatencyStatistics();
         mLastStatisticPushTime = currentTime;
     }
-    return mLastStatisticPushTime + LATENCY_STATISTICS_PUSH_INTERVAL;
 }
 
 std::chrono::nanoseconds InputDispatcher::getDispatchingTimeoutLocked(

services/inputflinger/dispatcher/InputDispatcher.h

@@ -329,7 +329,7 @@ class InputDispatcher : public android::InputDispatcherInterface {
     std::chrono::nanoseconds mMonitorDispatchingTimeout GUARDED_BY(mLock);
 
     nsecs_t processAnrsLocked() REQUIRES(mLock);
-    nsecs_t processLatencyStatisticsLocked() REQUIRES(mLock);
+    void processLatencyStatisticsLocked() REQUIRES(mLock);
     std::chrono::nanoseconds getDispatchingTimeoutLocked(
             const std::shared_ptr<Connection>& connection) REQUIRES(mLock);