Add custom traces + TraceSectionMetric

Author: mlykotom

MacrobenchmarkSample/app/src/main/java/com/example/macrobenchmark/target/activity/clicklatency/ComposeActivity.kt

@@ -48,6 +48,7 @@ import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.semantics.testTagsAsResourceId
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
+import androidx.tracing.trace
 import com.example.macrobenchmark.target.recyclerview.Entry
 import com.example.macrobenchmark.target.util.ClickTrace
 
@@ -90,23 +91,25 @@ class ComposeActivity : ComponentActivity() {
                         value = value,
                         onValueChange = { value = it },
                         placeholder = { Text("Enter text here") }
-                        )
+                    )
 
                     LazyColumn(
                         modifier = Modifier
                             .testTag("myLazyColumn")
                     ) {
                         items(data, key = { it.contents }) { item ->
-                            EntryRow(entry = item,
-                                Modifier
+                            EntryRow(
+                                entry = item,
+                                modifier = Modifier
                                     .padding(8.dp)
                                     .clickable {
                                         ClickTrace.onClickPerformed()
                                         AlertDialog
                                             .Builder(this@ComposeActivity)
                                             .setMessage("Item clicked")
                                             .show()
-                                    })
+                                    }
+                            )
                         }
                     }
                 }
@@ -124,7 +127,7 @@ class ComposeActivity : ComponentActivity() {
 }
 
 @Composable
-private fun EntryRow(entry: Entry, modifier: Modifier = Modifier) {
+private fun EntryRow(entry: Entry, modifier: Modifier = Modifier) = trace("EntryRow") {
     Card(modifier = modifier) {
         Row(verticalAlignment = Alignment.CenterVertically) {
             Text(

MacrobenchmarkSample/macrobenchmark/src/main/java/com/example/macrobenchmark/benchmark/frames/FrameTimingBenchmark.kt

@@ -19,8 +19,10 @@ package com.example.macrobenchmark.benchmark.frames
 import android.content.Intent
 import android.graphics.Point
 import androidx.benchmark.macro.CompilationMode
+import androidx.benchmark.macro.ExperimentalMetricApi
 import androidx.benchmark.macro.FrameTimingMetric
 import androidx.benchmark.macro.StartupMode
+import androidx.benchmark.macro.TraceSectionMetric
 import androidx.benchmark.macro.junit4.MacrobenchmarkRule
 import androidx.test.ext.junit.runners.AndroidJUnit4
 import androidx.test.filters.LargeTest
@@ -68,12 +70,25 @@ class FrameTimingBenchmark {
     }
     // [END macrobenchmark_control_your_app]
 
+    @OptIn(ExperimentalMetricApi::class)
     @Test
     fun scrollComposeList() {
         benchmarkRule.measureRepeated(
             // [START_EXCLUDE]
             packageName = TARGET_PACKAGE,
-            metrics = listOf(FrameTimingMetric()),
+            metrics = listOf(
+                FrameTimingMetric(),
+                // Measure custom trace sections by name EntryRow (which is added to the EntryRow composable).
+                // Mode.Sum measure combined duration and also how many times it occurred in the trace.
+                // This way, you can estimate whether a composable recomposes more than it should.
+                TraceSectionMetric("EntryRow", TraceSectionMetric.Mode.Sum),
+                // This trace section takes into account the SQL wildcard character %,
+                // which can find trace sections without knowing the full name.
+                // This way, you can measure composables produced by the composition tracing
+                // and measure how long they took and how many times they recomposed.
+                // WARNING: This metric only shows results when running with composition tracing, otherwise it won't be visible in the outputs.
+                TraceSectionMetric("%.EntryRow%", TraceSectionMetric.Mode.Sum),
+            ),
             // Try switching to different compilation modes to see the effect
             // it has on frame timing metrics.
             compilationMode = CompilationMode.None(),