Change stopwatch accuracy from milliseconds to microseconds

The microsecond time information needs to be recorded in
the NetworkStack Metrics (NetworkIpProvisioningReported).
So the unit of stopwatch is converted from millisecond to microsecond.

Bug: 151926185
Test: atest com.android.server.connectivity.NetworkMonitorTest
Original-Change: https://android-review.googlesource.com/1299376
Merged-In: I5a27a3b1316c67bf076b2e490860385267358ef8
Change-Id: I5a27a3b1316c67bf076b2e490860385267358ef8

1 files changed, 12 insertions, 12 deletions

diff --git a/src/android/net/util/Stopwatch.java b/src/android/net/util/Stopwatch.java
index c316699..07618e9 100644
--- a/src/android/net/util/Stopwatch.java
+++ b/src/android/net/util/Stopwatch.java
@@ -23,15 +23,15 @@ import android.os.SystemClock;
  * @hide
  */
 public class Stopwatch {
-    private long mStartTimeMs;
-    private long mStopTimeMs;
+    private long mStartTimeNs;
+    private long mStopTimeNs;
 
     public boolean isStarted() {
-        return (mStartTimeMs > 0);
+        return (mStartTimeNs > 0);
     }
 
     public boolean isStopped() {
-        return (mStopTimeMs > 0);
+        return (mStopTimeNs > 0);
     }
 
     public boolean isRunning() {
@@ -43,31 +43,31 @@ public class Stopwatch {
      */
     public Stopwatch start() {
         if (!isStarted()) {
-            mStartTimeMs = SystemClock.elapsedRealtime();
+            mStartTimeNs = SystemClock.elapsedRealtimeNanos();
         }
         return this;
     }
 
     /**
      * Stop the Stopwatch.
-     * @return the total time recorded, in milliseconds, or 0 if not started.
+     * @return the total time recorded, in microseconds, or 0 if not started.
      */
     public long stop() {
         if (isRunning()) {
-            mStopTimeMs = SystemClock.elapsedRealtime();
+            mStopTimeNs = SystemClock.elapsedRealtimeNanos();
         }
         // Return either the delta after having stopped, or 0.
-        return (mStopTimeMs - mStartTimeMs);
+        return (mStopTimeNs - mStartTimeNs) / 1000;
     }
 
     /**
-     * Return the total time recorded to date, in milliseconds.
+     * Return the total time recorded to date, in microseconds.
      * If the Stopwatch is not running, returns the same value as stop(),
      * i.e. either the total time recorded before stopping or 0.
      */
     public long lap() {
         if (isRunning()) {
-            return (SystemClock.elapsedRealtime() - mStartTimeMs);
+            return (SystemClock.elapsedRealtimeNanos() - mStartTimeNs) / 1000;
         } else {
             return stop();
         }
@@ -77,7 +77,7 @@ public class Stopwatch {
      * Reset the Stopwatch. It will be stopped when this method returns.
      */
     public void reset() {
-        mStartTimeMs = 0;
-        mStopTimeMs = 0;
+        mStartTimeNs = 0;
+        mStopTimeNs = 0;
     }
 }