Fix up the WebCoreThreadWatchdog (74d37b96) · Commits · e / os / android_frameworks_base

core/java/android/webkit/WebCoreThreadWatchdog.java

+111 −42

Original line number	Diff line number	Diff line
		@@ -26,6 +26,10 @@ import android.os.Message;
		import android.os.Process;
		import android.webkit.WebViewCore.EventHub;

		import java.util.HashSet;
		import java.util.Iterator;
		import java.util.Set;

		// A Runnable that will monitor if the WebCore thread is still
		// processing messages by pinging it every so often. It is safe
		// to call the public methods of this class from any thread.
		@@ -51,25 +55,31 @@ class WebCoreThreadWatchdog implements Runnable {
		// After the first timeout, use a shorter period before re-prompting the user.
		private static final int SUBSEQUENT_TIMEOUT_PERIOD = 15 * 1000;

		private Context mContext;
		private Handler mWebCoreThreadHandler;
		private Handler mHandler;
		private boolean mPaused;

		private Set<WebViewClassic> mWebViews;

		private static WebCoreThreadWatchdog sInstance;

		public synchronized static WebCoreThreadWatchdog start(Context context,
		Handler webCoreThreadHandler) {
		public synchronized static WebCoreThreadWatchdog start(Handler webCoreThreadHandler) {
		if (sInstance == null) {
		sInstance = new WebCoreThreadWatchdog(context, webCoreThreadHandler);
		sInstance = new WebCoreThreadWatchdog(webCoreThreadHandler);
		new Thread(sInstance, "WebCoreThreadWatchdog").start();
		}
		return sInstance;
		}

		public synchronized static void updateContext(Context context) {
		public synchronized static void registerWebView(WebViewClassic w) {
		if (sInstance != null) {
		sInstance.addWebView(w);
		}
		}

		public synchronized static void unregisterWebView(WebViewClassic w) {
		if (sInstance != null) {
		sInstance.setContext(context);
		sInstance.removeWebView(w);
		}
		}

		@@ -85,12 +95,18 @@ class WebCoreThreadWatchdog implements Runnable {
		}
		}

		private void setContext(Context context) {
		mContext = context;
		private void addWebView(WebViewClassic w) {
		if (mWebViews == null) {
		mWebViews = new HashSet<WebViewClassic>();
		}
		mWebViews.add(w);
		}

		private WebCoreThreadWatchdog(Context context, Handler webCoreThreadHandler) {
		mContext = context;
		private void removeWebView(WebViewClassic w) {
		mWebViews.remove(w);
		}

		private WebCoreThreadWatchdog(Handler webCoreThreadHandler) {
		mWebCoreThreadHandler = webCoreThreadHandler;
		}

		@@ -147,7 +163,80 @@ class WebCoreThreadWatchdog implements Runnable {
		break;

		case TIMED_OUT:
		if ((mContext == null) \|\| !(mContext instanceof Activity)) return;
		boolean postedDialog = false;
		synchronized (WebCoreThreadWatchdog.class) {
		Iterator<WebViewClassic> it = mWebViews.iterator();
		// Check each WebView we are aware of and find one that is capable of
		// showing the user a prompt dialog.
		while (it.hasNext()) {
		WebView activeView = it.next().getWebView();

		if (activeView.getWindowToken() != null &&
		activeView.getViewRootImpl() != null) {
		postedDialog = activeView.post(new PageNotRespondingRunnable(
		activeView.getContext(), this));

		if (postedDialog) {
		// We placed the message into the UI thread for an attached
		// WebView so we've made our best attempt to display the
		// "page not responding" dialog to the user. Although the
		// message is in the queue, there is no guarantee when/if
		// the runnable will execute. In the case that the runnable
		// never executes, the user will need to terminate the
		// process manually.
		break;
		}
		}
		}

		if (!postedDialog) {
		// There's no active webview we can use to show the dialog, so
		// wait again. If we never get a usable view, the user will
		// never get the chance to terminate the process, and will
		// need to do it manually.
		sendMessageDelayed(obtainMessage(TIMED_OUT),
		SUBSEQUENT_TIMEOUT_PERIOD);
		}
		}
		break;
		}
		}
		};
		}
		}

		@Override
		public void run() {
		Looper.prepare();

		createHandler();

		// Send the initial control to WebViewCore and start the timeout timer as long as we aren't
		// paused.
		synchronized (WebCoreThreadWatchdog.class) {
		if (!mPaused) {
		mWebCoreThreadHandler.obtainMessage(EventHub.HEARTBEAT,
		mHandler.obtainMessage(IS_ALIVE)).sendToTarget();
		mHandler.sendMessageDelayed(mHandler.obtainMessage(TIMED_OUT), TIMEOUT_PERIOD);
		}
		}

		Looper.loop();
		}

		private class PageNotRespondingRunnable implements Runnable {
		Context mContext;
		private Handler mWatchdogHandler;

		public PageNotRespondingRunnable(Context context, Handler watchdogHandler) {
		mContext = context;
		mWatchdogHandler = watchdogHandler;
		}

		@Override
		public void run() {
		// This must run on the UI thread as it is displaying an AlertDialog.
		assert Looper.getMainLooper().getThread() == Thread.currentThread();
		new AlertDialog.Builder(mContext)
		.setMessage(com.android.internal.R.string.webpage_unresponsive)
		.setPositiveButton(com.android.internal.R.string.force_close,
		@@ -167,42 +256,22 @@ class WebCoreThreadWatchdog implements Runnable {
		// we need to do is post another TIMED_OUT so that the
		// user will get prompted again if the WebCore thread
		// doesn't sort itself out.
		sendMessageDelayed(obtainMessage(TIMED_OUT),
		mWatchdogHandler.sendMessageDelayed(
		mWatchdogHandler.obtainMessage(TIMED_OUT),
		SUBSEQUENT_TIMEOUT_PERIOD);
		}
		})
		.setOnCancelListener(new DialogInterface.OnCancelListener() {
		.setOnCancelListener(
		new DialogInterface.OnCancelListener() {
		@Override
		public void onCancel(DialogInterface dialog) {
		sendMessageDelayed(obtainMessage(TIMED_OUT),
		mWatchdogHandler.sendMessageDelayed(
		mWatchdogHandler.obtainMessage(TIMED_OUT),
		SUBSEQUENT_TIMEOUT_PERIOD);
		}
		})
		.setIcon(android.R.drawable.ic_dialog_alert)
		.show();
		break;
		}
		}
		};
		}
		}

		@Override
		public void run() {
		Looper.prepare();

		createHandler();

		// Send the initial control to WebViewCore and start the timeout timer as long as we aren't
		// paused.
		synchronized (WebCoreThreadWatchdog.class) {
		if (!mPaused) {
		mWebCoreThreadHandler.obtainMessage(EventHub.HEARTBEAT,
		mHandler.obtainMessage(IS_ALIVE)).sendToTarget();
		mHandler.sendMessageDelayed(mHandler.obtainMessage(TIMED_OUT), TIMEOUT_PERIOD);
		}
		}

		Looper.loop();
		}
		}

core/java/android/webkit/WebViewClassic.java

+0 −5

Original line number	Diff line number	Diff line
		@@ -3365,11 +3365,6 @@ public final class WebViewClassic implements WebViewProvider, WebViewProvider.Sc
		nativeSetPauseDrawing(mNativeClass, false);
		}
		}
		// Ensure that the watchdog has a currently valid Context to be able to display
		// a prompt dialog. For example, if the Activity was finished whilst the WebCore
		// thread was blocked and the Activity is started again, we may reuse the blocked
		// thread, but we'll have a new Activity.
		WebCoreThreadWatchdog.updateContext(mContext);
		// We get a call to onResume for new WebViews (i.e. mIsPaused will be false). We need
		// to ensure that the Watchdog thread is running for the new WebView, so call
		// it outside the if block above.

core/java/android/webkit/WebViewCore.java

+4 −1

Original line number	Diff line number	Diff line
		@@ -178,8 +178,10 @@ public final class WebViewCore {

		// Start the singleton watchdog which will monitor the WebCore thread
		// to verify it's still processing messages.
		WebCoreThreadWatchdog.start(context, sWebCoreHandler);
		WebCoreThreadWatchdog.start(sWebCoreHandler);
		}
		// Make sure the Watchdog is aware of this new WebView.
		WebCoreThreadWatchdog.registerWebView(w);
		}
		// Create an EventHub to handle messages before and after the thread is
		// ready.
		@@ -1979,6 +1981,7 @@ public final class WebViewCore {
		mEventHub.sendMessageAtFrontOfQueue(
		Message.obtain(null, EventHub.DESTROY));
		mEventHub.blockMessages();
		WebCoreThreadWatchdog.unregisterWebView(mWebViewClassic);
		}
		}