Merge "Wait for RELRO before starting WebViewZygote at boot." into qt-dev

am: 49e9f80efd

Change-Id: I01a7479ad437dddd1723606a083442238cef6671

core/java/android/webkit/WebViewZygote.java

@@ -17,7 +17,6 @@
 package android.webkit;
 
 import android.content.pm.PackageInfo;
-import android.os.AsyncTask;
 import android.os.Build;
 import android.os.ChildZygoteProcess;
 import android.os.Process;
@@ -81,17 +80,9 @@ public class WebViewZygote {
         synchronized (sLock) {
             sMultiprocessEnabled = enabled;
 
-            // When toggling between multi-process being on/off, start or stop the
+            // When multi-process is disabled, kill the zygote. When it is enabled,
-            // zygote. If it is enabled and the zygote is not yet started, launch it.
+            // the zygote will be started when it is first needed in getProcess().
-            // Otherwise, kill it. The name may be null if the package information has
+            if (!enabled) {
-            // not yet been resolved.
-            if (enabled) {
-                // Run on a background thread as this waits for the zygote to start and we don't
-                // want to block the caller on this. It's okay if this is delayed as anyone trying
-                // to use the zygote will call it first anyway.
-                AsyncTask.THREAD_POOL_EXECUTOR.execute(WebViewZygote::getProcess);
-            } else {
-                // No need to run this in the background, it's very brief.
                 stopZygoteLocked();
             }
         }

services/core/java/com/android/server/webkit/SystemImpl.java

@@ -265,6 +265,11 @@ public class SystemImpl implements SystemInterface {
         WebViewZygote.setMultiprocessEnabled(enableMultiProcess);
     }
 
+    @Override
+    public void ensureZygoteStarted() {
+        WebViewZygote.getProcess();
+    }
+
     @Override
     public boolean isMultiProcessDefaultEnabled() {
         // Multiprocess is enabled for all 64-bit devices, since the ability to run the renderer

services/core/java/com/android/server/webkit/SystemInterface.java

@@ -61,5 +61,7 @@ public interface SystemInterface {
     public int getMultiProcessSetting(Context context);
     public void setMultiProcessSetting(Context context, int value);
     public void notifyZygote(boolean enableMultiProcess);
+    /** Start the zygote if it's not already running. */
+    public void ensureZygoteStarted();
     public boolean isMultiProcessDefaultEnabled();
 }

services/core/java/com/android/server/webkit/WebViewUpdateServiceImpl.java

@@ -17,6 +17,7 @@ package com.android.server.webkit;
 
 import android.content.Context;
 import android.content.pm.PackageInfo;
+import android.os.AsyncTask;
 import android.os.UserHandle;
 import android.webkit.WebViewProviderInfo;
 import android.webkit.WebViewProviderResponse;
@@ -81,6 +82,14 @@ public class WebViewUpdateServiceImpl {
         migrateFallbackStateOnBoot();
         mWebViewUpdater.prepareWebViewInSystemServer();
         mSystemInterface.notifyZygote(isMultiProcessEnabled());
+        AsyncTask.THREAD_POOL_EXECUTOR.execute(this::startZygoteWhenReady);
+    }
+
+    void startZygoteWhenReady() {
+        // Wait on a background thread for RELRO creation to be done. We ignore the return value
+        // because even if RELRO creation failed we still want to start the zygote.
+        waitForAndGetProvider();
+        mSystemInterface.ensureZygoteStarted();
     }
 
     void handleNewUser(int userId) {

services/tests/servicestests/src/com/android/server/webkit/TestSystemImpl.java

@@ -184,6 +184,9 @@ public class TestSystemImpl implements SystemInterface {
     @Override
     public void notifyZygote(boolean enableMultiProcess) {}
 
+    @Override
+    public void ensureZygoteStarted() {}
+
     @Override
     public boolean isMultiProcessDefaultEnabled() {
         return mMultiProcessDefault;