// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
package org.chromium.android_webview.metrics;
import android.os.Build;
import android.os.Process;
import androidx.annotation.RequiresApi;
import androidx.annotation.VisibleForTesting;
import org.jni_zero.JNINamespace;
import org.json.JSONException;
import org.json.JSONObject;
import org.chromium.android_webview.AppState;
import org.chromium.base.Callback;
import org.chromium.base.FileUtils;
import org.chromium.base.Log;
import org.chromium.base.PathUtils;
import org.chromium.base.metrics.RecordHistogram;
import org.chromium.base.task.PostTask;
import org.chromium.base.task.TaskRunner;
import org.chromium.base.task.TaskTraits;
import org.chromium.components.crash.browser.ProcessExitReasonFromSystem;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.function.Supplier;
/**
* Tracks the most recent exit reason of interest in embedding WebView apps
* associated with WebView's last pid.
*
* @return The most recent exit reason of interest matching the last PID.
*/
@RequiresApi(Build.VERSION_CODES.R)
@JNINamespace("android_webview")
public class TrackExitReasonsOfInterest {
public static final String TAG = "TrackExitReasons";
public static final String LAST_EXIT_INFO_FILENAME = "last-exit-info";
public static final String LAST_EXIT_INFO_PID = "exitInfoPid";
public static final String TIMESTAMP_AT_LAST_RECORDING_IN_MILLIS =
"timestampAtLastRecordingInMillis";
public static final String LAST_STATE_KEY = "appState";
public static final String UMA_DELTA = "Android.WebView.HistoricalApplicationExitInfo.Delta";
public static final String UMA_COUNTS = "Android.WebView.HistoricalApplicationExitInfo.Counts";
private static long sTestTime;
private static int sPid;
private static int sMockedSystemExitReason;
private static int sTestCount;
private static boolean sUseMockedSystemExitReason;
@VisibleForTesting public static final Map<Integer, String> sUmaSuffixMap = createMap();
private static Map<Integer, String> createMap() {
Map<Integer, String> umaSuffixMap = new HashMap<Integer, String>();
umaSuffixMap.put(AppState.UNKNOWN, "UNKNOWN");
umaSuffixMap.put(AppState.FOREGROUND, "FOREGROUND");
umaSuffixMap.put(AppState.BACKGROUND, "BACKGROUND");
umaSuffixMap.put(AppState.DESTROYED, "DESTROYED");
return umaSuffixMap;
}
private static long sTimestampAtLastRecording;
// To avoid any potential synchronization issues we post all exit reason actions to
// the same sequence to be run serially. This should also guarantee that the #run method
// always runs prior to any #writeLastWebViewState invocations, since the run method is
// called at startup.
private static final TaskRunner sSequencedTaskRunner =
PostTask.createSequencedTaskRunner(TaskTraits.BEST_EFFORT_MAY_BLOCK);
private static Supplier<Integer> sAppStateSupplier;
private static @AppState int sLastStateWritten;
/**
*
* Posts the exit reason tracker work in task runner queue.
*/
public static void init(Supplier<Integer> stateSupplier) {
sAppStateSupplier = stateSupplier;
sSequencedTaskRunner.postTask(
() -> {
run();
});
}
/**
*
* @return The latest exit reason matching the last process's PID
*/
@VisibleForTesting
public static int run() {
ExitReasonData previousInfoData = readLastExitInfo();
int pid = sPid != 0 ? sPid : Process.myPid();
// No previous pid, so no need to attempt to log anything
// Return -1 for testing purposes
int systemExitReason = -1;
sTimestampAtLastRecording = currentTimeMillis();
if (previousInfoData != null) {
systemExitReason =
ProcessExitReasonFromSystem.getExitReason(previousInfoData.mExitInfoPid);
Integer mappedExitReasonData =
ProcessExitReasonFromSystem.convertApplicationExitInfoToExitReason(
systemExitReason);
// Log the new record
if (mappedExitReasonData != null) {
if (previousInfoData.mTimestampAtLastRecordingInMillis > 0L) {
long delta =
sTimestampAtLastRecording
- previousInfoData.mTimestampAtLastRecordingInMillis;
RecordHistogram.recordLongTimesHistogram100(UMA_DELTA, delta);
}
ProcessExitReasonFromSystem.recordAsEnumHistogram(UMA_COUNTS, systemExitReason);
ProcessExitReasonFromSystem.recordAsEnumHistogram(
UMA_COUNTS + "." + sUmaSuffixMap.get(previousInfoData.mState),
systemExitReason);
}
}
writeLastExitInfo(
new ExitReasonData(pid, sTimestampAtLastRecording, sAppStateSupplier.get()));
return systemExitReason;
}
/** Data class for tracking exit reasons */
public static class ExitReasonData {
public final int mExitInfoPid;
public final long mTimestampAtLastRecordingInMillis;
public final @AppState int mState;
public ExitReasonData(int pid, long timestampAtLastRecordingInMillis, @AppState int state) {
mExitInfoPid = pid;
mTimestampAtLastRecordingInMillis = timestampAtLastRecordingInMillis;
mState = state;
}
}
@VisibleForTesting
public static ExitReasonData readLastExitInfo() {
try (FileInputStream fis = new FileInputStream(getLastExitInfoFile())) {
String buffer = new String(FileUtils.readStream(fis));
JSONObject jsonObj = new JSONObject(buffer);
// Want to early return since we cannot do anything useful without previous PID
if (!jsonObj.has(LAST_EXIT_INFO_PID)) return null;
int exitInfoPid = jsonObj.getInt(LAST_EXIT_INFO_PID);
long timestampAtLastRecordingInMillis =
jsonObj.optLong(TIMESTAMP_AT_LAST_RECORDING_IN_MILLIS);
@AppState int state = jsonObj.optInt(LAST_STATE_KEY);
return new ExitReasonData(exitInfoPid, timestampAtLastRecordingInMillis, state);
} catch (IOException e) {
// File does not exist or the file read fails here
return null;
} catch (JSONException e) {
Log.i(TAG, "Failed to parse JSON from file.");
}
return null;
}
/**
* This stores the exit info data for future runs. The {@link
* org.chromium.android_webview.AwContentsLifecycleNotifier} will also call this when users
* change apps between the foreground & background.
*
* @param newData Provides the pid and timestamp at last recording
* @return whether the newData is valid
*/
@VisibleForTesting
public static boolean writeLastExitInfo(final ExitReasonData newData) {
return writeLastExitInfo(newData, /* callbackResult= */ null);
}
@VisibleForTesting
public static boolean writeLastExitInfo(
final ExitReasonData newData, final Callback<Boolean> callbackResult) {
try (FileOutputStream writer =
new FileOutputStream(getLastExitInfoFile(), /* append= */ false)) {
JSONObject jsonObj = new JSONObject();
jsonObj.put(LAST_EXIT_INFO_PID, newData.mExitInfoPid);
jsonObj.put(
TIMESTAMP_AT_LAST_RECORDING_IN_MILLIS,
newData.mTimestampAtLastRecordingInMillis);
jsonObj.put(LAST_STATE_KEY, newData.mState);
String jsonString = jsonObj.toString();
writer.write(jsonString.getBytes());
writer.flush();
} catch (JSONException | IOException e) {
Log.e(TAG, "Failed to write last exit info.");
if (callbackResult != null) {
callbackResult.onResult(false);
}
return false;
}
sLastStateWritten = newData.mState;
if (callbackResult != null) {
callbackResult.onResult(true);
}
return true;
}
@VisibleForTesting
public static File getLastExitInfoFile() {
return new File(PathUtils.getDataDirectory(), LAST_EXIT_INFO_FILENAME);
}
/** Commits the latest app state for exit reason tracking to disk. */
public static void writeLastWebViewState() {
writeLastWebViewState(/* callbackResult= */ null);
}
/**
* Commits the latest app state for exit reason tracking to disk.
*
* @param callbackResult Used for testing purposes only for waiting on disk writes to complete.
*/
@VisibleForTesting
public static void writeLastWebViewState(final Callback<Boolean> callbackResult) {
int pid = sPid != 0 ? sPid : Process.myPid();
sSequencedTaskRunner.postTask(
() -> {
@AppState int currentState = sAppStateSupplier.get();
if (sLastStateWritten != currentState) {
writeLastExitInfo(
new ExitReasonData(pid, sTimestampAtLastRecording, currentState),
callbackResult);
}
});
}
private static long currentTimeMillis() {
if (sTestTime > 0L) return sTestTime;
return System.currentTimeMillis();
}
@VisibleForTesting
public static void setSystemTimeForTest(long testTime) {
sTestTime = testTime;
}
@VisibleForTesting
public static void setPidForTest(int pid) {
sPid = pid;
}
@VisibleForTesting
public static void setCurrtimeForTest(long currTime) {
sTimestampAtLastRecording = currTime;
}
@VisibleForTesting
public static void setStateSupplier(Supplier<Integer> supplier) {
sAppStateSupplier = supplier;
}
}
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