StartupTracingInitializer.kt
/*
* Copyright 2023 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 androidx.tracing.perfetto
import android.content.Context
import android.os.Build
import android.os.StrictMode
import android.util.Log
import androidx.startup.Initializer
import androidx.tracing.perfetto.internal.handshake.protocol.Response
import java.io.File
/** Enables tracing at app startup if configured prior to app starting */
class StartupTracingInitializer : Initializer<Unit> {
private companion object {
private val TAG = StartupTracingInitializer::class.java.name
}
override fun create(context: Context) {
// TODO(234351579): Support API < 30
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.R) return
suppressStrictModeDiskWrites {
// read startup tracing config if present
val config = StartupTracingConfigStore.load(context)
?: return // early exit if no config is found
// delete config if not meant to be preserved between runs
if (!config.isPersistent) StartupTracingConfigStore.clear(context)
// enable tracing
val libFilePath = config.libFilePath
val enableTracingResponse =
if (libFilePath == null) PerfettoSdkTrace.enable()
else PerfettoSdkTrace.enable(File(libFilePath), context)
// log the result for debuggability
Log.d(TAG, "${Response::class.java.name}: { " +
"resultCode: ${enableTracingResponse.resultCode}, " +
"message: ${enableTracingResponse.message}, " +
"requiredVersion: ${enableTracingResponse.requiredVersion} " +
"}")
}
}
override fun dependencies(): List<Class<out Initializer<*>>> = emptyList()
// TODO(245426369): test in TrivialStartupTracingBenchmark
private inline fun <R> suppressStrictModeDiskWrites(block: () -> R): R {
val oldPolicy = StrictMode.allowThreadDiskWrites()
try {
return block()
} finally {
StrictMode.setThreadPolicy(oldPolicy)
}
}
}