tracinglib: fix thread-local slice counter (81c78d6f) · Commits · e / os / android_frameworks_libs_systemui

tracinglib/benchmark/src/ThreadLocalMicroBenchmark.kt

0 → 100644

+102 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2025 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.benchmark

		import android.os.Trace
		import android.perftests.utils.PerfStatusReporter
		import android.platform.test.annotations.EnableFlags
		import android.platform.test.flag.junit.SetFlagsRule
		import android.platform.test.rule.EnsureDeviceSettingsRule
		import androidx.test.ext.junit.runners.AndroidJUnit4
		import androidx.test.filters.SmallTest
		import com.android.systemui.Flags
		import java.util.concurrent.atomic.AtomicInteger
		import org.junit.After
		import org.junit.Assert
		import org.junit.Before
		import org.junit.ClassRule
		import org.junit.Rule
		import org.junit.Test
		import org.junit.runner.RunWith

		@RunWith(AndroidJUnit4::class)
		@EnableFlags(Flags.FLAG_COROUTINE_TRACING)
		class ThreadLocalMicroBenchmark {

		@get:Rule val perfStatusReporter = PerfStatusReporter()

		@get:Rule val setFlagsRule = SetFlagsRule()

		companion object {
		@JvmField @ClassRule(order = 1) var ensureDeviceSettingsRule = EnsureDeviceSettingsRule()
		}

		@Before
		fun before() {
		Assert.assertTrue(Trace.isEnabled())
		}

		@After
		fun after() {
		Assert.assertTrue(Trace.isEnabled())
		}

		@SmallTest
		@Test
		fun testIntegerIncrement() {
		val state = perfStatusReporter.benchmarkState
		val count: ThreadLocal<Int> = ThreadLocal()
		count.set(0)
		while (state.keepRunning()) {
		count.set(count.get()!! + 1)
		}
		}

		@SmallTest
		@Test
		fun testAtomicIntegerIncrement() {
		val state = perfStatusReporter.benchmarkState
		val count: ThreadLocal<AtomicInteger> = ThreadLocal()
		count.set(AtomicInteger(0))
		while (state.keepRunning()) {
		count.get()!!.getAndIncrement()
		}
		}

		@SmallTest
		@Test
		fun testIntArrayIncrement() {
		val state = perfStatusReporter.benchmarkState
		val count: ThreadLocal<Array<Int>> = ThreadLocal()
		count.set(arrayOf(0))
		while (state.keepRunning()) {
		val arr = count.get()!!
		arr[0]++
		}
		}

		@SmallTest
		@Test
		fun testMutableIntIncrement() {
		val state = perfStatusReporter.benchmarkState
		class MutableInt(var value: Int)
		val count: ThreadLocal<MutableInt> = ThreadLocal()
		count.set(MutableInt(0))
		while (state.keepRunning()) {
		count.get()!!.value++
		}
		}
		}

tracinglib/core/src/coroutines/CoroutineTracing.kt

+4 −6

Original line number	Diff line number	Diff line
		@@ -222,12 +222,11 @@ public inline fun <T, R> R.traceCoroutine(crossinline spanName: () -> String, bl
		// For coroutine tracing to work, trace spans must be added and removed even when
		// tracing is not active (i.e. when TRACE_TAG_APP is disabled). Otherwise, when the
		// coroutine resumes when tracing is active, we won't know its name.
		val traceData = if (Flags.coroutineTracing()) traceThreadLocal.get() else null
		traceData?.beginSpan(spanName())
		try {
		if (Flags.coroutineTracing()) traceThreadLocal.get()?.beginSpan(spanName())
		return block()
		} finally {
		traceData?.endSpan()
		if (Flags.coroutineTracing()) traceThreadLocal.get()?.endSpan()
		}
		}

		@@ -239,12 +238,11 @@ public inline fun <T> traceCoroutine(crossinline spanName: () -> String, block:
		// For coroutine tracing to work, trace spans must be added and removed even when
		// tracing is not active (i.e. when TRACE_TAG_APP is disabled). Otherwise, when the
		// coroutine resumes when tracing is active, we won't know its name.
		val traceData = if (Flags.coroutineTracing()) traceThreadLocal.get() else null
		traceData?.beginSpan(spanName())
		try {
		if (Flags.coroutineTracing()) traceThreadLocal.get()?.beginSpan(spanName())
		return block()
		} finally {
		traceData?.endSpan()
		if (Flags.coroutineTracing()) traceThreadLocal.get()?.endSpan()
		}
		}

tracinglib/core/src/coroutines/TraceContextElement.kt

+8 −4

Original line number	Diff line number	Diff line
		@@ -338,9 +338,11 @@ internal class TraceContextElement(
		* OR
		*
		* ```
		* Thread #1 \| [restoreThreadContext]
		* Thread #1 \| [update].x..^ [ ... restore ... ] [update].x..^[restore]
		* --------------------------------------------------------------------------------------------
		* Thread #2 \| [updateThreadContext]...x....x..^[restoreThreadContext]
		* Thread #2 \| [update]...x....x..^[restore]
		* --------------------------------------------------------------------------------------------
		* Thread #3 \| [ ... update ... ] ....^ [restore]
		* ```
		*
		* (`...` indicate coroutine body is running; whitespace indicates the thread is not scheduled;
		@@ -355,10 +357,12 @@ internal class TraceContextElement(
		// so we can end the correct number of trace sections, restoring the thread to its state
		// prior to the last call to [updateThreadContext].
		if (oldState !== traceThreadLocal.get()) {
		if (Trace.isTagEnabled(Trace.TRACE_TAG_APP)) {
		contextTraceData?.endAllOnThread()
		traceThreadLocal.set(oldState)
		Trace.traceEnd(Trace.TRACE_TAG_APP) // end: coroutineTraceName
		}
		traceThreadLocal.set(oldState)
		}
		}

		override fun copyForChild(): CopyableThreadContextElement<TraceData?> {

tracinglib/core/src/coroutines/TraceData.kt

+37 −27

Original line number	Diff line number	Diff line
		@@ -29,12 +29,24 @@ import java.util.ArrayDeque
		*/
		private typealias TraceSection = String

		private class TraceCountThreadLocal : ThreadLocal<Int>() {
		override fun initialValue(): Int {
		return 0
		private class MutableInt(var value: Int)

		private class ThreadLocalInt : ThreadLocal<MutableInt>() {
		override fun initialValue(): MutableInt {
		return MutableInt(0)
		}
		}

		/**
		* ThreadLocal counter for how many open trace sections there are. This is needed because it is
		* possible that on a multi-threaded dispatcher, one of the threads could be slow, and
		* [TraceContextElement.restoreThreadContext] might be invoked _after_ the coroutine has already
		* resumed and modified [TraceData] - either adding or removing trace sections and changing the
		* count. If we did not store this thread-locally, then we would incorrectly end too many or too few
		* trace sections.
		*/
		private val openSliceCount = ThreadLocalInt()

		/**
		* Used for storing trace sections so that they can be added and removed from the currently running
		* thread when the coroutine is suspended and resumed.
		@@ -48,24 +60,16 @@ private class TraceCountThreadLocal : ThreadLocal<Int>() {
		@PublishedApi
		internal class TraceData(internal val currentId: Int, private val strictMode: Boolean) {

		internal var slices: ArrayDeque<TraceSection>? = null

		/**
		* ThreadLocal counter for how many open trace sections there are. This is needed because it is
		* possible that on a multi-threaded dispatcher, one of the threads could be slow, and
		* `restoreThreadContext` might be invoked _after_ the coroutine has already resumed and
		* modified TraceData - either adding or removing trace sections and changing the count. If we
		* did not store this thread-locally, then we would incorrectly end too many or too few trace
		* sections.
		*/
		private val openSliceCount = TraceCountThreadLocal()
		internal lateinit var slices: ArrayDeque<TraceSection>

		/** Adds current trace slices back to the current thread. Called when coroutine is resumed. */
		internal fun beginAllOnThread() {
		if (Trace.isTagEnabled(Trace.TRACE_TAG_APP)) {
		strictModeCheck()
		slices?.descendingIterator()?.forEach { beginSlice(it) }
		openSliceCount.set(slices?.size ?: 0)
		if (::slices.isInitialized) {
		slices.descendingIterator().forEach { sectionName -> beginSlice(sectionName) }
		openSliceCount.get()!!.value = slices.size
		}
		}
		}

		@@ -75,8 +79,9 @@ internal class TraceData(internal val currentId: Int, private val strictMode: Bo
		internal fun endAllOnThread() {
		if (Trace.isTagEnabled(Trace.TRACE_TAG_APP)) {
		strictModeCheck()
		repeat(openSliceCount.get() ?: 0) { endSlice() }
		openSliceCount.set(0)
		val sliceCount = openSliceCount.get()!!
		repeat(sliceCount.value) { endSlice() }
		sliceCount.value = 0
		}
		}

		@@ -89,11 +94,11 @@ internal class TraceData(internal val currentId: Int, private val strictMode: Bo
		@PublishedApi
		internal fun beginSpan(name: String) {
		strictModeCheck()
		if (slices == null) {
		slices = ArrayDeque()
		if (!::slices.isInitialized) {
		slices = ArrayDeque<TraceSection>(4)
		}
		slices!!.push(name)
		openSliceCount.set(slices!!.size)
		slices.push(name)
		openSliceCount.get()!!.value = slices.size
		beginSlice(name)
		}

		@@ -106,9 +111,9 @@ internal class TraceData(internal val currentId: Int, private val strictMode: Bo
		internal fun endSpan() {
		strictModeCheck()
		// Should never happen, but we should be defensive rather than crash the whole application
		if (slices != null && slices!!.size > 0) {
		slices!!.pop()
		openSliceCount.set(slices!!.size)
		if (::slices.isInitialized && slices.size > 0) {
		slices.pop()
		openSliceCount.get()!!.value = slices.size
		endSlice()
		} else if (strictMode) {
		throw IllegalStateException(INVALID_SPAN_END_CALL_ERROR_MESSAGE)
		@@ -116,8 +121,13 @@ internal class TraceData(internal val currentId: Int, private val strictMode: Bo
		}

		public override fun toString(): String =
		if (DEBUG) "{${slices?.joinToString(separator = "\", \"", prefix = "\"", postfix = "\"")}}"
		else super.toString()
		if (DEBUG) {
		if (::slices.isInitialized) {
		"{${slices.joinToString(separator = "\", \"", prefix = "\"", postfix = "\"")}}"
		} else {
		"{<uninitialized>}"
		}
		} else super.toString()

		private fun strictModeCheck() {
		if (strictMode && traceThreadLocal.get() !== this) {

tracinglib/robolectric/src/BackgroundThreadTracingTest.kt

0 → 100644

+72 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2025 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.
		*/

		@file:OptIn(DelicateCoroutinesApi::class, ExperimentalCoroutinesApi::class)

		package com.android.test.tracing.coroutines

		import android.platform.test.annotations.EnableFlags
		import com.android.app.tracing.coroutines.createCoroutineTracingContext
		import com.android.app.tracing.coroutines.launchTraced
		import com.android.app.tracing.coroutines.withContextTraced
		import com.android.systemui.Flags.FLAG_COROUTINE_TRACING
		import kotlinx.coroutines.CoroutineScope
		import kotlinx.coroutines.DelicateCoroutinesApi
		import kotlinx.coroutines.Dispatchers
		import kotlinx.coroutines.ExperimentalCoroutinesApi
		import kotlinx.coroutines.asCoroutineDispatcher
		import kotlinx.coroutines.asExecutor
		import kotlinx.coroutines.delay
		import kotlinx.coroutines.newSingleThreadContext
		import kotlinx.coroutines.plus
		import org.junit.Test

		@EnableFlags(FLAG_COROUTINE_TRACING)
		class BackgroundThreadTracingTest : TestBase() {

		override val scope = CoroutineScope(createCoroutineTracingContext("main", testMode = true))

		@Test
		fun withContext_reentrant() =
		runTest(totalEvents = 11) {
		expect("1^main")
		val thread1 = newSingleThreadContext("thread-#1").asExecutor().asCoroutineDispatcher()
		val bgScope = scope.plus(thread1)
		val otherJob =
		bgScope.launchTraced("AAA") {
		expect("2^AAA")
		delay(1)
		expect("2^AAA")
		withContextTraced("BBB", Dispatchers.Main.immediate) {
		expect("2^AAA", "BBB")
		delay(1)
		expect("2^AAA", "BBB")
		withContextTraced("CCC", thread1) {
		expect("2^AAA", "BBB", "CCC")
		delay(1)
		expect("2^AAA", "BBB", "CCC")
		}
		expect("2^AAA", "BBB")
		}
		expect("2^AAA")
		delay(1)
		expect("2^AAA")
		}
		delay(195)
		otherJob.cancel()
		expect("1^main")
		}
		}