power: throttle interaction hints

Don't send power HAL interaction hints more than every 100ms. Also can send userActivity
calls every 100ms too (down from 500ms).

Test: power HAL doesn't run every 8ms
Bug: 63632697

Change-Id: Ic986f6fc51e58f8060f7bf2d2ac61a9906be5c1f
(cherry picked from commit c203016b590230092d1385fdeac5a3a7d3206e33)
diff --git a/services/core/jni/com_android_server_power_PowerManagerService.cpp b/services/core/jni/com_android_server_power_PowerManagerService.cpp
index c722629..c71614d 100644
--- a/services/core/jni/com_android_server_power_PowerManagerService.cpp
+++ b/services/core/jni/com_android_server_power_PowerManagerService.cpp
@@ -62,7 +62,7 @@
 static nsecs_t gLastEventTime[USER_ACTIVITY_EVENT_LAST + 1];
 
 // Throttling interval for user activity calls.
-static const nsecs_t MIN_TIME_BETWEEN_USERACTIVITIES = 500 * 1000000L; // 500ms
+static const nsecs_t MIN_TIME_BETWEEN_USERACTIVITIES = 100 * 1000000L; // 100ms
 
 // ----------------------------------------------------------------------------
 
@@ -101,14 +101,6 @@
 }
 
 void android_server_PowerManagerService_userActivity(nsecs_t eventTime, int32_t eventType) {
-    // Tell the power HAL when user activity occurs.
-    gPowerHalMutex.lock();
-    if (getPowerHal()) {
-        Return<void> ret = gPowerHal->powerHint(PowerHint::INTERACTION, 0);
-        processReturn(ret, "powerHint");
-    }
-    gPowerHalMutex.unlock();
-
     if (gPowerManagerServiceObj) {
         // Throttle calls into user activity by event type.
         // We're a little conservative about argument checking here in case the caller
@@ -123,6 +115,17 @@
                 return;
             }
             gLastEventTime[eventType] = eventTime;
+
+
+            // Tell the power HAL when user activity occurs.
+            gPowerHalMutex.lock();
+            if (getPowerHal()) {
+              Return<void> ret;
+              ret = gPowerHal->powerHint(PowerHint::INTERACTION, 0);
+              processReturn(ret, "powerHint");
+            }
+            gPowerHalMutex.unlock();
+
         }
 
         JNIEnv* env = AndroidRuntime::getJNIEnv();