Create the WebViewZygote and implement WebViewZygoteInit.

This adds a new init-spawned daemon, webview_zygote, that starts a JVM and
acts as a zygote process for WebView isolated_app services.

Test: m
Test: angler boots
Test: Turn on Settings>Developer>Multiprocess Webview. webview_zygote32 or
      webview_zygote64 start (requires dependent CLs).

Bug: 21643067
Change-Id: Ida98bd04b4d77736b672b03af651c4eb97ce88c1

1 files changed, 135 insertions, 0 deletions

diff --git a/core/java/android/webkit/WebViewZygote.java b/core/java/android/webkit/WebViewZygote.java
new file mode 100644
index 000000000000..bc6e7b4a9dd3
--- /dev/null
+++ b/core/java/android/webkit/WebViewZygote.java
@@ -0,0 +1,135 @@
+/*
+ * Copyright (C) 2016 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 android.webkit;
+
+import android.content.pm.PackageInfo;
+import android.os.Build;
+import android.os.SystemService;
+import android.os.ZygoteProcess;
+import android.util.Log;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.concurrent.TimeoutException;
+
+/** @hide */
+public class WebViewZygote {
+    private static final String LOGTAG = "WebViewZygote";
+
+    private static final String WEBVIEW_ZYGOTE_SERVICE_32 = "webview_zygote32";
+    private static final String WEBVIEW_ZYGOTE_SERVICE_64 = "webview_zygote64";
+
+    private static ZygoteProcess sZygote;
+
+    private static PackageInfo sPackage;
+
+    private static boolean sMultiprocessEnabled = false;
+
+    public static ZygoteProcess getProcess() {
+        connectToZygoteIfNeeded();
+        return sZygote;
+    }
+
+    public static String getPackageName() {
+        return sPackage.packageName;
+    }
+
+    public static void setMultiprocessEnabled(boolean enabled) {
+        sMultiprocessEnabled = enabled;
+
+        // When toggling between multi-process being on/off, start or stop the
+        // service. If it is enabled and the zygote is not yet started, bring up the service.
+        // Otherwise, bring down the service. The name may be null if the package
+        // information has not yet been resolved.
+        final String serviceName = getServiceName();
+        if (serviceName == null) return;
+
+        if (enabled && sZygote == null) {
+            SystemService.start(serviceName);
+        } else {
+            SystemService.stop(serviceName);
+            sZygote = null;
+        }
+    }
+
+    public static void onWebViewProviderChanged(PackageInfo packageInfo) {
+        sPackage = packageInfo;
+
+        // If multi-process is not enabled, then do not start the zygote service.
+        if (!sMultiprocessEnabled) {
+            return;
+        }
+
+        final String serviceName = getServiceName();
+
+        if (SystemService.isStopped(serviceName)) {
+            SystemService.start(serviceName);
+        } else if (sZygote != null) {
+            SystemService.restart(serviceName);
+        }
+
+        try {
+            SystemService.waitForState(serviceName, SystemService.State.RUNNING, 5000);
+        } catch (TimeoutException e) {
+            Log.e(LOGTAG, "Timed out waiting for " + serviceName);
+            return;
+        }
+
+        connectToZygoteIfNeeded();
+    }
+
+    private static String getServiceName() {
+        if (sPackage == null)
+            return null;
+
+        if (Arrays.asList(Build.SUPPORTED_64_BIT_ABIS).contains(
+                    sPackage.applicationInfo.primaryCpuAbi)) {
+            return WEBVIEW_ZYGOTE_SERVICE_64;
+        }
+
+        return WEBVIEW_ZYGOTE_SERVICE_32;
+    }
+
+    private static void connectToZygoteIfNeeded() {
+        if (sZygote != null)
+            return;
+
+        if (sPackage == null) {
+            Log.e(LOGTAG, "Cannot connect to zygote, no package specified");
+            return;
+        }
+
+        final String serviceName = getServiceName();
+        if (!SystemService.isRunning(serviceName)) {
+            Log.e(LOGTAG, serviceName + " is not running");
+            return;
+        }
+
+        try {
+            sZygote = new ZygoteProcess("webview_zygote", null);
+
+            String packagePath = sPackage.applicationInfo.sourceDir;
+            String libsPath = sPackage.applicationInfo.nativeLibraryDir;
+
+            Log.d(LOGTAG, "Preloading package " + packagePath + " " + libsPath);
+            sZygote.preloadPackageForAbi(packagePath, libsPath, Build.SUPPORTED_ABIS[0]);
+        } catch (Exception e) {
+            Log.e(LOGTAG, "Error connecting to " + serviceName, e);
+            sZygote = null;
+        }
+    }
+}