Add gauge counter to collector tests

Author: tejasd

firebase-perf/src/main/java/com/google/firebase/perf/session/gauges/CpuGaugeCollector.java

@@ -166,7 +166,7 @@ private synchronized void scheduleCpuMetricCollectionWithRate(
                 CpuMetricReading currCpuReading = syncCollectCpuMetric(referenceTime);
                 if (currCpuReading != null) {
                   cpuMetricReadings.add(currCpuReading);
-                  GaugeCounter.INSTANCE.incrementCounter();
+                  GaugeCounter.incrementCounter();
                 }
               },
               /* initialDelay */ 0,
@@ -186,7 +186,7 @@ private synchronized void scheduleCpuMetricCollectionOnce(Timer referenceTime) {
                 CpuMetricReading currCpuReading = syncCollectCpuMetric(referenceTime);
                 if (currCpuReading != null) {
                   cpuMetricReadings.add(currCpuReading);
-                  GaugeCounter.INSTANCE.incrementCounter();
+                  GaugeCounter.incrementCounter();
                 }
               },
               /* initialDelay */ 0,

firebase-perf/src/main/java/com/google/firebase/perf/session/gauges/GaugeCounter.kt

@@ -31,6 +31,7 @@ object GaugeCounter {
   @set:JvmStatic
   var gaugeManager: GaugeManager = GaugeManager.getInstance()
 
+  @JvmStatic
   fun incrementCounter() {
     val metricsCount = counter.incrementAndGet()
 
@@ -41,15 +42,17 @@ object GaugeCounter {
     logger.debug("Incremented logger to $metricsCount")
   }
 
+  @JvmStatic
   fun decrementCounter() {
     val curr = counter.decrementAndGet()
     logger.debug("Decremented logger to $curr")
   }
 
   @VisibleForTesting(otherwise = VisibleForTesting.NONE)
+  @JvmStatic
   fun resetCounter() {
     counter.set(0)
   }
 
-  @VisibleForTesting(otherwise = VisibleForTesting.NONE) fun count(): Int = counter.get()
+  @VisibleForTesting(otherwise = VisibleForTesting.NONE) @JvmStatic fun count(): Int = counter.get()
 }

firebase-perf/src/main/java/com/google/firebase/perf/session/gauges/GaugeManager.java

@@ -250,19 +250,18 @@ private void logExistingGaugeMetrics(
    */
   private void syncFlush(String sessionId, ApplicationProcessState appState) {
     GaugeMetric.Builder gaugeMetricBuilder = GaugeMetric.newBuilder();
-    GaugeCounter gaugeCounter = GaugeCounter.INSTANCE;
 
     // Adding CPU metric readings.
     while (!cpuGaugeCollector.get().cpuMetricReadings.isEmpty()) {
       gaugeMetricBuilder.addCpuMetricReadings(cpuGaugeCollector.get().cpuMetricReadings.poll());
-      gaugeCounter.decrementCounter();
+      GaugeCounter.decrementCounter();
     }
 
     // Adding Memory metric readings.
     while (!memoryGaugeCollector.get().memoryMetricReadings.isEmpty()) {
       gaugeMetricBuilder.addAndroidMemoryReadings(
           memoryGaugeCollector.get().memoryMetricReadings.poll());
-      gaugeCounter.decrementCounter();
+      GaugeCounter.decrementCounter();
     }
 
     // Adding Session ID info.

firebase-perf/src/main/java/com/google/firebase/perf/session/gauges/MemoryGaugeCollector.java

@@ -129,7 +129,7 @@ private synchronized void scheduleMemoryMetricCollectionWithRate(
                 AndroidMemoryReading memoryReading = syncCollectMemoryMetric(referenceTime);
                 if (memoryReading != null) {
                   memoryMetricReadings.add(memoryReading);
-                  GaugeCounter.INSTANCE.incrementCounter();
+                  GaugeCounter.incrementCounter();
                 }
               },
               /* initialDelay */ 0,
@@ -149,7 +149,7 @@ private synchronized void scheduleMemoryMetricCollectionOnce(Timer referenceTime
                 AndroidMemoryReading memoryReading = syncCollectMemoryMetric(referenceTime);
                 if (memoryReading != null) {
                   memoryMetricReadings.add(memoryReading);
-                  GaugeCounter.INSTANCE.incrementCounter();
+                  GaugeCounter.incrementCounter();
                 }
               },
               /* initialDelay */ 0,

firebase-perf/src/test/java/com/google/firebase/perf/FirebasePerformanceTestBase.java

@@ -59,7 +59,7 @@ public class FirebasePerformanceTestBase {
   @BeforeClass
   public static void setUpBeforeClass() {
     // TODO(b/394127311): Explore removing this.
-    GaugeCounter.INSTANCE.resetCounter();
+    GaugeCounter.resetCounter();
   }
 
   @Before

firebase-perf/src/test/java/com/google/firebase/perf/session/gauges/CpuGaugeCollectorTest.java

@@ -60,9 +60,11 @@ public void tearDown() {
   @Test
   public void testStartCollectingAddsCpuMetricReadingsToTheConcurrentLinkedQueue()
       throws Exception {
+    int priorGaugeCount = GaugeCounter.count();
     testGaugeCollector.startCollecting(100, new Timer());
     fakeScheduledExecutorService.simulateSleepExecutingAtMostOneTask();
     assertThat(testGaugeCollector.cpuMetricReadings).hasSize(1);
+    assertThat(GaugeCounter.count()).isEqualTo(priorGaugeCount + 1);
   }
 
   @Test
@@ -246,11 +248,17 @@ public void testCollectCpuMetricDoesntStartCollectingWithInvalidCpuMetricCollect
 
   @Test
   public void testCollectOnce_addOnlyOneCpuMetricReadingToQueue() {
+    int priorGaugeCount = GaugeCounter.count();
     assertThat(testGaugeCollector.cpuMetricReadings).isEmpty();
     testGaugeCollector.collectOnce(new Timer());
 
     fakeScheduledExecutorService.simulateSleepExecutingAtMostOneTask();
+
+    // Simulate running an additional task.
+    fakeScheduledExecutorService.simulateSleepExecutingAtMostOneTask();
+
     assertThat(testGaugeCollector.cpuMetricReadings).hasSize(1);
+    assertThat(GaugeCounter.count()).isEqualTo(priorGaugeCount + 1);
   }
 
   @Test

firebase-perf/src/test/java/com/google/firebase/perf/session/gauges/GaugeManagerTest.java

@@ -429,7 +429,7 @@ public void testGaugeManagerHandlesMultipleSessionIds() {
     fakeSession.setGaugeAndEventCollectionEnabled(true);
     testGaugeManager.setApplicationProcessState(ApplicationProcessState.BACKGROUND);
     testGaugeManager.startCollectingGauges(fakeSession);
-    GaugeCounter.INSTANCE.setGaugeManager(testGaugeManager);
+    GaugeCounter.setGaugeManager(testGaugeManager);
 
     // Generate metrics that don't exceed the GaugeCounter.MAX_COUNT.
     generateMetricsAndIncrementCounter(10);
@@ -615,10 +615,10 @@ private void generateMetricsAndIncrementCounter(int count) {
     for (int i = 0; i < count; ++i) {
       if (random.nextInt(2) == 0) {
         fakeCpuGaugeCollector.cpuMetricReadings.add(createFakeCpuMetricReading(100, 200));
-        GaugeCounter.INSTANCE.incrementCounter();
+        GaugeCounter.incrementCounter();
       } else {
         fakeMemoryGaugeCollector.memoryMetricReadings.add(createFakeAndroidMetricReading(100));
-        GaugeCounter.INSTANCE.incrementCounter();
+        GaugeCounter.incrementCounter();
       }
     }
   }

firebase-perf/src/test/java/com/google/firebase/perf/session/gauges/MemoryGaugeCollectorTest.java

@@ -59,9 +59,11 @@ private void mockMemory() {
 
   @Test
   public void testStartCollecting_addsMemoryMetricReadingsToQueue() {
+    int priorGaugeCount = GaugeCounter.count();
     testGaugeCollector.startCollecting(/* memoryMetricCollectionRateMs= */ 100, new Timer());
     fakeScheduledExecutorService.simulateSleepExecutingAtMostOneTask();
     assertThat(testGaugeCollector.memoryMetricReadings).hasSize(1);
+    assertThat(GaugeCounter.count()).isEqualTo(priorGaugeCount + 1);
   }
 
   @Test
@@ -148,11 +150,17 @@ public void testCollectedMemoryMetric_containsApproximatelyCorrectTimestamp() {
 
   @Test
   public void testCollectOnce_addOnlyOneMemoryMetricReadingToQueue() {
+    int priorGaugeCount = GaugeCounter.count();
     assertThat(testGaugeCollector.memoryMetricReadings).isEmpty();
     testGaugeCollector.collectOnce(new Timer());
 
     fakeScheduledExecutorService.simulateSleepExecutingAtMostOneTask();
+
+    // Simulate running an additional task.
+    fakeScheduledExecutorService.simulateSleepExecutingAtMostOneTask();
+
     assertThat(testGaugeCollector.memoryMetricReadings).hasSize(1);
+    assertThat(GaugeCounter.count()).isEqualTo(priorGaugeCount + 1);
   }
 
   @Test