Fix pause/resume timing

Test: run SystemPerfTest#testPauseResumeOverhead

Change-Id: Icc34355e29f3a6ba8f7d73a904bf549d2685eee4

2 files changed, 29 insertions, 10 deletions

diff --git a/apct-tests/perftests/core/src/java/lang/perftests/SystemPerfTest.java b/apct-tests/perftests/core/src/java/lang/perftests/SystemPerfTest.java
index 80ce22eed925..1e9c49cf702a 100644
--- a/apct-tests/perftests/core/src/java/lang/perftests/SystemPerfTest.java
+++ b/apct-tests/perftests/core/src/java/lang/perftests/SystemPerfTest.java
@@ -24,6 +24,8 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
+import java.util.concurrent.TimeUnit;
+
 @RunWith(AndroidJUnit4.class)
 @LargeTest
 public class SystemPerfTest {
@@ -43,4 +45,19 @@ public class SystemPerfTest {
         BenchmarkState state = mPerfStatusReporter.getBenchmarkState();
         while (state.keepRunning()) {}
     }
+
+    void spinBlock(long durationNs) {
+        long start = System.nanoTime();
+        while (System.nanoTime() - start < durationNs) {}
+    }
+
+    @Test
+    public void testBenchmarkPauseResumeOverhead() {
+        BenchmarkState state = mPerfStatusReporter.getBenchmarkState();
+        while (state.keepRunning()) {
+            state.pauseTiming();
+            spinBlock(TimeUnit.MICROSECONDS.toNanos(5));
+            state.resumeTiming();
+        }
+    }
 }
diff --git a/apct-tests/perftests/utils/src/android/perftests/utils/BenchmarkState.java b/apct-tests/perftests/utils/src/android/perftests/utils/BenchmarkState.java
index bf04f6d2013b..519d5248a347 100644
--- a/apct-tests/perftests/utils/src/android/perftests/utils/BenchmarkState.java
+++ b/apct-tests/perftests/utils/src/android/perftests/utils/BenchmarkState.java
@@ -43,13 +43,13 @@ import java.util.concurrent.TimeUnit;
  * }
  */
 public final class BenchmarkState {
+
     private static final String TAG = "BenchmarkState";
 
     private static final int NOT_STARTED = 0;  // The benchmark has not started yet.
     private static final int WARMUP = 1; // The benchmark is warming up.
     private static final int RUNNING = 2;  // The benchmark is running.
-    private static final int RUNNING_PAUSED = 3;  // The benchmark is temporary paused.
-    private static final int FINISHED = 4;  // The benchmark has stopped.
+    private static final int FINISHED = 3;  // The benchmark has stopped.
 
     private int mState = NOT_STARTED;  // Current benchmark state.
 
@@ -63,6 +63,7 @@ public final class BenchmarkState {
     private static final int REPEAT_COUNT = 5;
 
     private long mStartTimeNs = 0;  // Previously captured System.nanoTime().
+    private boolean mPaused;
     private long mPausedTimeNs = 0; // The System.nanoTime() when the pauseTiming() is called.
     private long mPausedDurationNs = 0;  // The duration of paused state in nano sec.
 
@@ -118,24 +119,24 @@ public final class BenchmarkState {
     // Stops the benchmark timer.
     // This method can be called only when the timer is running.
     public void pauseTiming() {
-        if (mState == RUNNING_PAUSED) {
+        if (mPaused) {
             throw new IllegalStateException(
                     "Unable to pause the benchmark. The benchmark has already paused.");
         }
         mPausedTimeNs = System.nanoTime();
-        mState = RUNNING_PAUSED;
+        mPaused = true;
     }
 
     // Starts the benchmark timer.
     // This method can be called only when the timer is stopped.
     public void resumeTiming() {
-        if (mState == RUNNING) {
+        if (!mPaused) {
             throw new IllegalStateException(
                     "Unable to resume the benchmark. The benchmark is already running.");
         }
         mPausedDurationNs += System.nanoTime() - mPausedTimeNs;
         mPausedTimeNs = 0;
-        mState = RUNNING;
+        mPaused = false;
     }
 
     private void beginWarmup() {
@@ -194,11 +195,12 @@ public final class BenchmarkState {
                 if (mIteration >= mMaxIterations) {
                     return startNextTestRun();
                 }
+                if (mPaused) {
+                    throw new IllegalStateException(
+                            "Benchmark step finished with paused state. " +
+                            "Resume the benchmark before finishing each step.");
+                }
                 return true;
-            case RUNNING_PAUSED:
-                throw new IllegalStateException(
-                        "Benchmark step finished with paused state. " +
-                        "Resume the benchmark before finishing each step.");
             case FINISHED:
                 throw new IllegalStateException("The benchmark has finished.");
             default: