Flow extensions for coroutine tracing (f405ea09) · Commits · e / os / android_frameworks_libs_systemui

tracinglib/Android.bp

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		//
		// Copyright (C) 2024 The Android Open Source Project
		//
		// Licensed under the Apache License, Version 2.0 (the "License");
		// you may not use this file except in compliance with the License.
		// You may obtain a copy of the License at
		//
		// http://www.apache.org/licenses/LICENSE-2.0
		//
		// Unless required by applicable law or agreed to in writing, software
		// distributed under the License is distributed on an "AS IS" BASIS,
		// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		// See the License for the specific language governing permissions and
		// limitations under the License.
		//

		package {
		default_team: "trendy_team_performance",
		}

tracinglib/core/Android.bp

+16 −14

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		@@ -27,20 +27,22 @@ java_library {
		srcs: ["android/src-platform-api/*/.kt"],
		}

		java_library {
		name: "tracinglib-androidx",
		defaults: ["tracinglib-defaults"],
		static_libs: [
		"kotlinx_coroutines_android",
		"com_android_systemui_flags_lib",
		"//frameworks/libs/systemui:compilelib",
		"androidx.tracing_tracing",
		],
		srcs: ["android/src-public-api/*/.kt"],
		sdk_version: "31",
		min_sdk_version: "19",
		java_version: "17",
		}
		// TODO(b/358541864): Remove source files of "tracinglib-androidx" and delete this target
		// Disable due to compilation error using java.lang.StackWalker:
		// java_library {
		// name: "tracinglib-androidx",
		// defaults: ["tracinglib-defaults"],
		// static_libs: [
		// "kotlinx_coroutines_android",
		// "com_android_systemui_flags_lib",
		// "//frameworks/libs/systemui:compilelib",
		// "androidx.tracing_tracing",
		// ],
		// srcs: ["android/src-public-api/*/.kt"],
		// sdk_version: "31",
		// min_sdk_version: "19",
		// java_version: "17",
		// }

		java_test_host {
		name: "tracinglib-host-test",

tracinglib/core/common/src/coroutines/flow/FlowExt.kt

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		/*
		* Copyright (C) 2024 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		package com.android.app.tracing.coroutines.flow

		import com.android.app.tracing.coroutines.traceCoroutine
		import com.android.app.tracing.traceBegin
		import com.android.app.tracing.traceEnd
		import kotlin.experimental.ExperimentalTypeInference
		import kotlinx.coroutines.CoroutineDispatcher
		import kotlinx.coroutines.CoroutineName
		import kotlinx.coroutines.flow.Flow
		import kotlinx.coroutines.flow.FlowCollector
		import kotlinx.coroutines.flow.collectLatest as kx_collectLatest
		import kotlinx.coroutines.flow.filter as kx_filter
		import kotlinx.coroutines.flow.filterIsInstance as kx_filterIsInstance
		import kotlinx.coroutines.flow.flowOn as kx_flowOn
		import kotlinx.coroutines.flow.map as kx_map

		fun <T> Flow<T>.withTraceName(name: String?): Flow<T> {
		return object : Flow<T> {
		override suspend fun collect(collector: FlowCollector<T>) {
		this@withTraceName.collect("${name ?: walkStackForClassName()}", collector)
		}
		}
		}

		/**
		* NOTE: We cannot use a default value for the String name because [Flow.collect] is a member
		* function. When an extension function has the same receiver type, name, and applicable arguments
		* as a class member function, the member takes precedence.
		*/
		@OptIn(ExperimentalTypeInference::class)
		suspend inline fun <T> Flow<T>.collect(
		name: String, /* cannot have a default parameter or else Flow#collect() override this call */
		@BuilderInference block: FlowCollector<T>,
		) {
		val (collectSlice, emitSlice) = getFlowSliceNames(name)
		traceCoroutine(collectSlice) {
		collect { value -> traceCoroutine(emitSlice) { block.emit(value) } }
		}
		}

		@OptIn(ExperimentalTypeInference::class)
		suspend inline fun <T> Flow<T>.collectTraced(
		@BuilderInference block: FlowCollector<T>,
		) {
		collect(walkStackForClassName(), block)
		}

		suspend fun <T> Flow<T>.collectLatest(name: String? = null, action: suspend (T) -> Unit) {
		val (collectSlice, emitSlice) = getFlowSliceNames(name)
		traceCoroutine(collectSlice) {
		kx_collectLatest { value -> traceCoroutine(emitSlice) { action(value) } }
		}
		}

		fun <T> Flow<T>.flowOn(context: kotlin.coroutines.CoroutineContext): Flow<T> {
		val contextName =
		context[CoroutineName]?.name
		?: context[CoroutineDispatcher]?.javaClass?.simpleName
		?: context.javaClass.simpleName
		return kx_flowOn(context).withTraceName("flowOn($contextName)")
		}

		inline fun <T> Flow<T>.filter(
		name: String? = null,
		crossinline predicate: suspend (T) -> Boolean,
		): Flow<T> {
		val flowName = "${name ?: walkStackForClassName()}"
		return withTraceName(flowName).kx_filter {
		return@kx_filter traceCoroutine("$flowName:predicate") { predicate(it) }
		}
		}

		inline fun <reified R> Flow<*>.filterIsInstance(): Flow<R> {
		return kx_filterIsInstance<R>().withTraceName("${walkStackForClassName()}#filterIsInstance")
		}

		inline fun <T, R> Flow<T>.map(
		name: String? = null,
		crossinline transform: suspend (T) -> R,
		): Flow<R> {
		val flowName = "${name ?: walkStackForClassName()}"
		return withTraceName(flowName).kx_map {
		return@kx_map traceCoroutine("$flowName:transform") { transform(it) }
		}
		}

		fun getFlowSliceNames(name: String?): Pair<String, String> {
		val flowName = "${name ?: walkStackForClassName()}"
		return Pair("$flowName:collect", "$flowName:emit")
		}

		object FlowExt {
		val currentFileName: String =
		StackWalker.getInstance().walk { stream -> stream.limit(1).findFirst() }.get().fileName
		}

		private fun isFrameInteresting(frame: StackWalker.StackFrame): Boolean {
		return frame.fileName != FlowExt.currentFileName
		}

		/** Get a name for the trace section include the name of the call site. */
		fun walkStackForClassName(): String {
		traceBegin("FlowExt#walkStackForClassName")
		try {
		val interestingFrame =
		StackWalker.getInstance().walk { stream ->
		stream.filter(::isFrameInteresting).limit(5).findFirst()
		}
		return if (interestingFrame.isPresent) {
		val frame = interestingFrame.get()
		return frame.className
		} else {
		"<unknown>"
		}
		} finally {
		traceEnd()
		}
		}

tracinglib/core/host/test/ExampleClass.kt

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		/*
		* Copyright (C) 2024 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		package com.android.app.tracing.coroutines

		class ExampleClass(
		private val testBase: TestBase,
		private val incrementCounter: suspend () -> Unit,
		) {
		suspend fun classMethod(value: Int) {
		testBase.expect(
		"launch-for-collect",
		"com.android.app.tracing.coroutines.FlowTracingTest\$stateFlowCollection$1\$collectJob$1$3:collect",
		"com.android.app.tracing.coroutines.FlowTracingTest\$stateFlowCollection$1\$collectJob$1$3:emit"
		)
		incrementCounter()
		}
		}

tracinglib/core/host/test/FlowTracingTest.kt

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		/*
		* Copyright (C) 2024 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		package com.android.app.tracing.coroutines

		import com.android.app.tracing.coroutines.flow.collect
		import com.android.app.tracing.coroutines.flow.collectTraced
		import com.android.app.tracing.coroutines.flow.filter
		import com.android.app.tracing.coroutines.flow.flowOn
		import com.android.app.tracing.coroutines.flow.map
		import com.android.app.tracing.coroutines.flow.withTraceName
		import kotlin.coroutines.EmptyCoroutineContext
		import kotlinx.coroutines.CoroutineName
		import kotlinx.coroutines.delay
		import kotlinx.coroutines.flow.MutableStateFlow
		import kotlinx.coroutines.flow.flowOf
		import kotlinx.coroutines.launch
		import kotlinx.coroutines.newFixedThreadPoolContext
		import kotlinx.coroutines.newSingleThreadContext
		import kotlinx.coroutines.withContext
		import org.junit.Assert.assertEquals
		import org.junit.Test
		import org.junit.runner.RunWith
		import org.junit.runners.BlockJUnit4ClassRunner

		@RunWith(BlockJUnit4ClassRunner::class)
		class FlowTracingTest : TestBase() {
		@Test
		fun stateFlowCollection() = runTestWithTraceContext {
		val state = MutableStateFlow(1)
		val bgThreadPool = newFixedThreadPoolContext(2, "bg-pool")

		// Inefficient fine-grained thread confinement
		val counterThread = newSingleThreadContext("counter-thread")
		var counter = 0
		val incrementCounter: suspend () -> Unit = {
		withContext("increment", counterThread) {
		expectEndsWith("increment")
		counter++
		}
		}

		val helper = ExampleClass(this@FlowTracingTest, incrementCounter)
		val collectJob =
		launch("launch-for-collect", bgThreadPool) {
		expect("launch-for-collect")
		launch {
		state.collect("state-flow") {
		expect("launch-for-collect", "state-flow:collect", "state-flow:emit")
		incrementCounter()
		}
		}
		launch {
		state.collectTraced {
		expect(
		"launch-for-collect",
		"com.android.app.tracing.coroutines.FlowTracingTest\$stateFlowCollection$1\$collectJob$1$2:collect",
		"com.android.app.tracing.coroutines.FlowTracingTest\$stateFlowCollection$1\$collectJob$1$2:emit"
		)
		incrementCounter()
		}
		}
		launch { state.collectTraced(helper::classMethod) }
		}
		val emitJob =
		launch(newSingleThreadContext("emitter thread")) {
		for (n in 2..5) {
		delay(100)
		state.value = n
		}
		}
		emitJob.join()
		delay(10)
		collectJob.cancel()
		withContext(counterThread) { assertEquals(15, counter) }
		}

		@Test
		fun flowOnWithTraceName() = runTestWithTraceContext {
		val state =
		flowOf(1, 2, 3, 4)
		.withTraceName("my-flow")
		.flowOn(
		newSingleThreadContext("flow-thread") +
		EmptyCoroutineContext +
		CoroutineName("the-name")
		)
		val bgThreadPool = newFixedThreadPoolContext(2, "bg-pool")
		val collectJob =
		launch("launch-for-collect", bgThreadPool) {
		expect("launch-for-collect")
		launch {
		state.collect("state-flow") {
		expect(
		"launch-for-collect",
		"state-flow:collect",
		"flowOn(the-name):collect",
		"flowOn(the-name):emit",
		"state-flow:emit"
		)
		}
		}
		}
		collectJob.join()
		}

		@Test
		fun mapAndFilter() = runTestWithTraceContext {
		val state =
		flowOf(1, 2, 3, 4)
		.withTraceName("my-flow")
		.map("multiply-by-3") { it * 2 }
		.filter("mod-2") { it % 2 == 0 }
		launch("launch-for-collect") {
		state.collect("my-collect-call") {
		expect(
		"launch-for-collect",
		"my-collect-call:collect",
		"mod-2:collect",
		"multiply-by-3:collect",
		"my-flow:collect",
		"my-flow:emit",
		"multiply-by-3:emit",
		"mod-2:emit",
		"my-collect-call:emit"
		)
		}
		}
		.join()
		}
		}