Log subject in ANR dump file for ANRs + watchdogs

This is needed to be able to have access to the Subject header in bug
reports and the ApplicationExitInfo API.

Adds the subject to the top of the ANR dump file. Where the dump
file is copied into the dropbox entry, the subject is no longer passed
in explicitly to the call to addErrorToDropBox to avoid including the
subject twice in the dropbox entry.

Verified e2e by triggering an ANR and confirming that the subject
appears at the top of the ANR file.

Test: atest FrameworksServicesTests
Bug: b/188122403
Change-Id: If2ee927a56e3f93c521307ca6355df7f560ea494

services/core/java/com/android/server/SystemServerInitThreadPool.java

@@ -192,7 +192,7 @@ public final class SystemServerInitThreadPool implements Dumpable {
         final ArrayList<Integer> pids = new ArrayList<>();
         pids.add(Process.myPid());
         ActivityManagerService.dumpStackTraces(pids, null, null,
-                Watchdog.getInterestingNativePids(), null);
+                Watchdog.getInterestingNativePids(), null, null);
     }
 
     @Override

services/core/java/com/android/server/Watchdog.java

@@ -658,7 +658,7 @@ public class Watchdog {
                 // We've waited half the deadlock-detection interval.  Pull a stack
                 // trace and wait another half.
                 ActivityManagerService.dumpStackTraces(pids, null, null,
-                        getInterestingNativePids(), null);
+                        getInterestingNativePids(), null, subject);
                 continue;
             }
 
@@ -674,7 +674,7 @@ public class Watchdog {
             StringWriter tracesFileException = new StringWriter();
             final File stack = ActivityManagerService.dumpStackTraces(
                     pids, processCpuTracker, new SparseArray<>(), getInterestingNativePids(),
-                    tracesFileException);
+                    tracesFileException, subject);
 
             // Give some extra time to make sure the stack traces get written.
             // The system's been hanging for a minute, another second or two won't hurt much.
@@ -699,7 +699,8 @@ public class Watchdog {
                         if (mActivity != null) {
                             mActivity.addErrorToDropBox(
                                     "watchdog", null, "system_server", null, null, null,
-                                    localSubject, report.toString(), stack, null, null, null, null);
+                                    null, report.toString(), stack, null, null, null, null);
+
                         }
                         FrameworkStatsLog.write(FrameworkStatsLog.SYSTEM_SERVER_WATCHDOG_OCCURRED,
                                 localSubject);

services/core/java/com/android/server/am/ActivityManagerService.java

@@ -407,6 +407,7 @@ import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.PrintWriter;
 import java.io.StringWriter;
+import java.nio.charset.StandardCharsets;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -3153,7 +3154,23 @@ public class ActivityManagerService extends IActivityManager.Stub
             ProcessCpuTracker processCpuTracker, SparseArray<Boolean> lastPids,
             ArrayList<Integer> nativePids, StringWriter logExceptionCreatingFile) {
         return dumpStackTraces(firstPids, processCpuTracker, lastPids, nativePids,
-                logExceptionCreatingFile, null);
+                logExceptionCreatingFile, null, null);
+    }
+
+    /**
+     * If a stack trace dump file is configured, dump process stack traces.
+     * @param firstPids of dalvik VM processes to dump stack traces for first
+     * @param lastPids of dalvik VM processes to dump stack traces for last
+     * @param nativePids optional list of native pids to dump stack crawls
+     * @param logExceptionCreatingFile optional writer to which we log errors creating the file
+     * @param subject optional line related to the error
+     */
+    public static File dumpStackTraces(ArrayList<Integer> firstPids,
+            ProcessCpuTracker processCpuTracker, SparseArray<Boolean> lastPids,
+            ArrayList<Integer> nativePids, StringWriter logExceptionCreatingFile,
+            String subject) {
+        return dumpStackTraces(firstPids, processCpuTracker, lastPids, nativePids,
+                logExceptionCreatingFile, null, subject);
     }
 
     /**
@@ -3163,7 +3180,7 @@ public class ActivityManagerService extends IActivityManager.Stub
     /* package */ static File dumpStackTraces(ArrayList<Integer> firstPids,
             ProcessCpuTracker processCpuTracker, SparseArray<Boolean> lastPids,
             ArrayList<Integer> nativePids, StringWriter logExceptionCreatingFile,
-            long[] firstPidOffsets) {
+            long[] firstPidOffsets, String subject) {
         ArrayList<Integer> extraPids = null;
 
         Slog.i(TAG, "dumpStackTraces pids=" + lastPids + " nativepids=" + nativePids);
@@ -3215,6 +3232,15 @@ public class ActivityManagerService extends IActivityManager.Stub
             return null;
         }
 
+        if (subject != null) {
+            try (FileOutputStream fos = new FileOutputStream(tracesFile, true)) {
+                String header = "Subject: " + subject + "\n";
+                fos.write(header.getBytes(StandardCharsets.UTF_8));
+            } catch (IOException e) {
+                Slog.w(TAG, "Exception writing subject to ANR dump file:", e);
+            }
+        }
+
         Pair<Long, Long> offsets = dumpStackTraces(
                 tracesFile.getAbsolutePath(), firstPids, nativePids, extraPids);
         if (firstPidOffsets != null) {

services/core/java/com/android/server/am/ProcessErrorStateRecord.java

@@ -377,7 +377,7 @@ class ProcessErrorStateRecord {
         final long[] offsets = new long[2];
         File tracesFile = ActivityManagerService.dumpStackTraces(firstPids,
                 isSilentAnr ? null : processCpuTracker, isSilentAnr ? null : lastPids,
-                nativePids, tracesFileException, offsets);
+                nativePids, tracesFileException, offsets, annotation);
 
         if (isMonitorCpuUsage()) {
             mService.updateCpuStatsNow();
@@ -467,7 +467,7 @@ class ProcessErrorStateRecord {
         final ProcessRecord parentPr = parentProcess != null
                 ? (ProcessRecord) parentProcess.mOwner : null;
         mService.addErrorToDropBox("anr", mApp, mApp.processName, activityShortComponentName,
-                parentShortComponentName, parentPr, annotation, report.toString(), tracesFile,
+                parentShortComponentName, parentPr, null, report.toString(), tracesFile,
                 null, new Float(loadingProgress), incrementalMetrics, errorId);
 
         if (mApp.getWindowProcessController().appNotResponding(info.toString(),