Init PersistentDatablockService on the worker thread

Other services do not depend on PersistentDatabalockService in the early
stages of system server initialization.
Initialization is now done on the FgThread. The service also ensures that
init is complete before PHASE_ACTIVITY_MANAGER_READY.

Change-Id: I3b9a1994e37c1e995ed04257f271c425d48c2e7c
Test: Manual, device boots, service is initialized and published
Bug: 33199244

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

@@ -47,6 +47,8 @@ import java.nio.channels.FileChannel;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.util.Arrays;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
 
 /**
  * Service for reading and writing blocks to a persistent partition.
@@ -81,6 +83,7 @@ public class PersistentDataBlockService extends SystemService {
     private final Context mContext;
     private final String mDataBlockFile;
     private final Object mLock = new Object();
+    private final CountDownLatch mInitDoneSignal = new CountDownLatch(1);
 
     private int mAllowedUid = -1;
     private long mBlockDeviceSize;
@@ -110,9 +113,29 @@ public class PersistentDataBlockService extends SystemService {
 
     @Override
     public void onStart() {
-        enforceChecksumValidity();
-        formatIfOemUnlockEnabled();
-        publishBinderService(Context.PERSISTENT_DATA_BLOCK_SERVICE, mService);
+        // Do init on a separate thread, will join in PHASE_ACTIVITY_MANAGER_READY
+        FgThread.getHandler().post(() -> {
+            enforceChecksumValidity();
+            formatIfOemUnlockEnabled();
+            publishBinderService(Context.PERSISTENT_DATA_BLOCK_SERVICE, mService);
+            mInitDoneSignal.countDown();
+        });
+    }
+
+    @Override
+    public void onBootPhase(int phase) {
+        // Wait for initialization in onStart to finish
+        if (phase == PHASE_SYSTEM_SERVICES_READY) {
+            try {
+                if (!mInitDoneSignal.await(10, TimeUnit.SECONDS)) {
+                    throw new IllegalStateException("Service " + TAG + " init timeout");
+                }
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+                throw new IllegalStateException("Service " + TAG + " init interrupted", e);
+            }
+        }
+        super.onBootPhase(phase);
     }
 
     private void formatIfOemUnlockEnabled() {

services/java/com/android/server/SystemServer.java

@@ -1484,8 +1484,10 @@ public final class SystemServer {
             @Override
             public void run() {
                 Slog.i(TAG, "Making services ready");
+                traceBeginAndSlog("StartActivityManagerReadyPhase");
                 mSystemServiceManager.startBootPhase(
                         SystemService.PHASE_ACTIVITY_MANAGER_READY);
+                traceEnd();
                 traceBeginAndSlog("PhaseActivityManagerReady");
 
                 traceBeginAndSlog("StartObservingNativeCrashes");