[icedtea-web] RFC: Patch to stabilize applet initialization
Dr Andrew John Hughes
ahughes at redhat.com
Thu Oct 21 14:52:40 PDT 2010
On 17:38 Thu 21 Oct , Deepak Bhole wrote:
> Hi,
>
> The attached patch envelopes fixes for two of Andrew's pending patches
> (fixing 100% CPU load and the frame pop-up issue). In addition to those,
> it fixes a lot of other initialization issues, particularly when
> initializing multiple applets and/or closing other tabs with applets
> which are being initialized.
>
> With this patch, I tested over 200 parallel applet inits, randomly
> closing tabs, and everything works correctly.
>
> One known issue is that if timed correctly, a frame can appear outside
> for a fraction of a second. It always goes away instantly though, and I
> will be posting a patch to fix that problem in the near future.
>
> Cheers,
> Deepak
Do you have a ChangeLog for this? It would be good to know why each change
is being made.
In particular, why:
> +
> + // Add first, remove later
> + newFrame.add("Center", panel);
> oldFrame.remove(panel);
> oldFrame.dispose();
> + } else {
> + newFrame.add("Center", panel);
> }
>
> - newFrame.add("Center", panel);
is this necessary?
Also there seems to be some odd whitespace changes and excessive (8 space) indenting.
> diff -r 85db7b3a1c93 plugin/icedteanp/java/sun/applet/PluginAppletViewer.java
> --- a/plugin/icedteanp/java/sun/applet/PluginAppletViewer.java Thu Oct 21 21:12:21 2010 +0100
> +++ b/plugin/icedteanp/java/sun/applet/PluginAppletViewer.java Thu Oct 21 17:22:56 2010 -0700
> @@ -136,12 +136,10 @@
> }
> }
> });
> +
> + // create the frame.
> + PluginAppletViewer.reFrame(null, identifier, System.out, 0, panel);
>
> -
> -
> - // create the frame.
> - PluginAppletViewer.reFrame(null, identifier, System.out, handle, panel);
> -
> panel.init();
>
> // Start the applet
> @@ -179,15 +177,7 @@
>
> // Wait for the panel to initialize
> // (happens in a separate thread)
> - while (panel.getApplet() == null &&
> - ((NetxPanel) panel).isAlive()) {
> - try {
> - Thread.sleep(50);
> - PluginDebug.debug("Waiting for applet to initialize...");
> - } catch (InterruptedException ie) {
> - // just wait
> - }
> - }
> + PluginAppletViewer.waitForAppletInit((NetxPanel) panel);
>
> a = panel.getApplet();
>
> @@ -317,7 +307,17 @@
> */
> private static String defaultSaveFile = "Applet.ser";
>
> - private static enum PAV_INIT_STATUS {PRE_INIT, IN_INIT, INIT_COMPLETE, INACTIVE};
> +
> + /**
> + * Enumerates the current status of an applet
> + *
> + * PRE_INIT -> Parsing and initialization phase
> + * INIT_COMPLETE -> Initialization complete, reframe pending
> + * REFRAME_COMPLETE -> Reframe complete, applet is initialized and usable by the user
> + * INACTIVE -> Browser has directed that the applet be destroyed (this state is non-overridable except by DESTROYED)
> + * DESTROYED -> Applet has been destroyed
> + */
> + private static enum PAV_INIT_STATUS {PRE_INIT, INIT_COMPLETE, REFRAME_COMPLETE, INACTIVE, DESTROYED};
>
> /**
> * The panel in which the applet is being displayed.
> @@ -350,7 +350,6 @@
>
> private static HashMap<Integer, PAV_INIT_STATUS> status =
> new HashMap<Integer,PAV_INIT_STATUS>();
> -
>
> private long handle = 0;
> private WindowListener windowEventListener = null;
> @@ -380,16 +379,20 @@
> return;
>
> PluginAppletViewer newFrame = new PluginAppletViewer(handle, identifier, statusMsgStream, panel);
> -
> +
> if (oldFrame != null) {
> applets.remove(oldFrame.identifier);
> oldFrame.removeWindowListener(oldFrame.windowEventListener);
> panel.removeAppletListener(oldFrame.appletEventListener);
> +
> + // Add first, remove later
> + newFrame.add("Center", panel);
> oldFrame.remove(panel);
> oldFrame.dispose();
> + } else {
> + newFrame.add("Center", panel);
> }
>
> - newFrame.add("Center", panel);
> newFrame.pack();
>
> newFrame.appletEventListener = new AppletEventListener(newFrame, newFrame);
> @@ -397,11 +400,6 @@
>
> applets.put(identifier, newFrame);
>
> - // dispose oldframe if necessary
> - if (oldFrame != null) {
> - oldFrame.dispose();
> - }
> -
> PluginDebug.debug(panel + " reframed");
> }
>
> @@ -449,7 +447,7 @@
> this.frame = frame;
> this.appletViewer = appletViewer;
> }
> -
> +
> public void appletStateChanged(AppletEvent evt)
> {
> AppletPanel src = (AppletPanel)evt.getSource();
> @@ -483,9 +481,9 @@
> AppletPanel.changeFrameAppContext(frame, SunToolkit.targetToAppContext(a));
> else
> AppletPanel.changeFrameAppContext(frame, AppContext.getAppContext());
> -
> - status.put(appletViewer.identifier, PAV_INIT_STATUS.INIT_COMPLETE);
> -
> +
> + updateStatus(appletViewer.identifier, PAV_INIT_STATUS.INIT_COMPLETE);
> +
> break;
> }
> }
> @@ -510,7 +508,13 @@
>
> try {
> if (message.startsWith("handle")) {
> -
> +
> + // If there is a key for this status, it means it
> + // was either initialized before, or destroy has been
> + // processed. Stop moving further.
> + if (updateStatus(identifier, PAV_INIT_STATUS.PRE_INIT) != null)
> + return;
> +
> // Extract the information from the message
> String[] msgParts = new String[4];
> for (int i=0; i < 3; i++) {
> @@ -519,32 +523,38 @@
> msgParts[i] = message.substring(spaceLocation + 1, nextSpaceLocation);
> message = message.substring(nextSpaceLocation + 1);
> }
> -
> +
> long handle = Long.parseLong(msgParts[0]);
> String width = msgParts[1];
> String height = msgParts[2];
> -
> +
> int spaceLocation = message.indexOf(' ', "tag".length()+1);
> String documentBase =
> UrlUtil.decode(message.substring("tag".length() + 1, spaceLocation));
> - String tag = message.substring(spaceLocation+1);
> + String tag = message.substring(spaceLocation+1);
> +
> + // Decode the tag
> + tag = tag.replace(">", ">");
> + tag = tag.replace("<", "<");
> + tag = tag.replace("&", "&");
> + tag = tag.replace(" ", "\n");
> + tag = tag.replace(" ", "\r");
> + tag = tag.replace(""", "\"");
>
> PluginDebug.debug ("Handle = " + handle + "\n" +
> "Width = " + width + "\n" +
> "Height = " + height + "\n" +
> "DocumentBase = " + documentBase + "\n" +
> "Tag = " + tag);
> -
> - status.put(identifier, PAV_INIT_STATUS.PRE_INIT);
> +
> PluginAppletViewer.parse
> (identifier, handle, width, height,
> new StringReader(tag),
> new URL(documentBase));
> -
>
> int maxWait = APPLET_TIMEOUT; // wait for applet to fully load
> int wait = 0;
> - while (!status.get(identifier).equals(PAV_INIT_STATUS.INIT_COMPLETE) &&
> + while ( !applets.containsKey(identifier) && // Map is populated only by reFrame
> (wait < maxWait)) {
>
> try {
> @@ -555,9 +565,44 @@
> }
> }
>
> - if (!status.get(identifier).equals(PAV_INIT_STATUS.INIT_COMPLETE))
> + // If wait exceeded maxWait, we timed out. Throw an exception
> + if (wait >= maxWait)
> throw new Exception("Applet initialization timeout");
>
> + PluginAppletViewer oldFrame = applets.get(identifier);
> +
> + // We should not try to destroy an applet during
> + // initialization. It may cause an inconsistent state,
> + // which would bad if it's a trusted applet that
> + // read/writes to files
> + waitForAppletInit((NetxPanel) applets.get(identifier).panel);
> +
> + // Should we proceed with reframing?
> + if (status.get(identifier).equals(PAV_INIT_STATUS.INACTIVE)) {
> + destroyApplet(identifier);
> + return;
> + }
> +
> + // Proceed with re-framing
> + reFrame(oldFrame, identifier, System.out, handle, oldFrame.panel);
> +
> + // There is a slight chance that destroy can happen
> + // between the above and below line
> + if (updateStatus(identifier, PAV_INIT_STATUS.REFRAME_COMPLETE).equals(PAV_INIT_STATUS.INACTIVE)) {
> + destroyApplet(identifier);
> + }
> +
> + } else if (message.startsWith("destroy")) {
> +
> + // Set it inactive, and try to do cleanup is applicable
> + PAV_INIT_STATUS previousStatus = updateStatus(identifier, PAV_INIT_STATUS.INACTIVE);
> + PluginDebug.debug("Destroy status set for " + identifier);
> +
> + if (previousStatus != null &&
> + previousStatus.equals(PAV_INIT_STATUS.REFRAME_COMPLETE)) {
> + destroyApplet(identifier);
> + }
> +
> } else {
> PluginDebug.debug ("Handling message: " + message + " instance " + identifier + " " + Thread.currentThread());
>
> @@ -568,7 +613,7 @@
> status.get(identifier).equals(PAV_INIT_STATUS.PRE_INIT)
> )
> );
> -
> +
> // don't bother processing further for inactive applets
> if (status.get(identifier).equals(PAV_INIT_STATUS.INACTIVE))
> return;
> @@ -580,31 +625,131 @@
> e.printStackTrace();
>
> // If an exception happened during pre-init, we need to update status
> - if (status.get(identifier).equals(PAV_INIT_STATUS.PRE_INIT))
> - status.put(identifier, PAV_INIT_STATUS.INACTIVE);
> + updateStatus(identifier, PAV_INIT_STATUS.INACTIVE);
>
> throw new RuntimeException("Failed to handle message: " +
> message + " for instance " + identifier, e);
> }
> }
> -
> +
> + /**
> + * Sets the status unless an overriding status is set (e.g. if
> + * status is DESTROYED, it may not be overridden).
> + *
> + * @param identifier The identifier for which the status is to be set
> + * @param status The status to switch to
> + * @return The previous status
> + */
> + private static synchronized PAV_INIT_STATUS updateStatus(int identifier, PAV_INIT_STATUS newStatus) {
> +
> + PAV_INIT_STATUS prev = status.get(identifier);
> +
> + // If the status is set
> + if (status.containsKey(identifier)) {
> +
> + // Nothing may override destroyed status
> + if (status.get(identifier).equals(PAV_INIT_STATUS.DESTROYED)) {
> + return prev;
> + }
> +
> + // If status is inactive, only DESTROYED may override it
> + if (status.get(identifier).equals(PAV_INIT_STATUS.INACTIVE)) {
> + if (!newStatus.equals(PAV_INIT_STATUS.DESTROYED)) {
> + return prev;
> + }
> + }
> + }
> +
> + // Else set to given status
> + status.put(identifier, newStatus);
> +
> + return prev;
> + }
> +
> + /**
> + * Destroys the given applet instance.
> + *
> + * This function may be called multiple times without problems.
> + * It does a synchronized check on the status and will only
> + * attempt to destroy the applet if not previously destroyed.
> + *
> + * @param identifier The instance which is to be destroyed
> + */
> +
> + private static synchronized void destroyApplet(int identifier) {
> +
> + PluginDebug.debug("DestroyApplet called for " + identifier);
> +
> + PAV_INIT_STATUS prev = updateStatus(identifier, PAV_INIT_STATUS.DESTROYED);
> +
> + // If already destroyed, return
> + if (prev.equals(PAV_INIT_STATUS.DESTROYED)) {
> + PluginDebug.debug(identifier + " already destroyed. Returning.");
> + return;
> + }
> +
> + // If already disposed, return
> + if (applets.get(identifier).panel.applet == null) {
> + // Try to still dispose the panel itself -- no harm done with double dispose
> + applets.get(identifier).dispose();
> +
> + PluginDebug.debug(identifier + " inactive. Returning.");
> + return;
> + }
> +
> + PluginDebug.debug("Attempting to destroy " + identifier);
> +
> + final int fIdentifier = identifier;
> + SwingUtilities.invokeLater(new Runnable() {
> + public void run() {
> + applets.get(fIdentifier).appletClose();
> + }
> + });
> +
> + PluginDebug.debug(identifier + " destroyed");
> + }
> +
> + /**
> + * Function to block until applet initialization is complete
> + *
> + * @param identifier The instance to wait for
> + */
> + public static void waitForAppletInit(NetxPanel panel) {
> +
> + int waitTime = 0;
> +
> + // Wait till initialization finishes
> + while (panel.getApplet() == null &&
> + panel.isAlive() &&
> + waitTime < APPLET_TIMEOUT) {
> + try {
> + if (waitTime%500 == 0)
> + PluginDebug.debug("Waiting for applet panel " + panel + " to initialize...");
> +
> + Thread.sleep(waitTime += 50);
> + } catch (InterruptedException ie) {
> + // just wait
> + }
> + }
> +
> + PluginDebug.debug("Applet panel " + panel + " initialized");
> + }
> +
> public void handleMessage(int reference, String message)
> {
> if (message.startsWith("width")) {
>
> // Wait for panel to come alive
> int maxWait = APPLET_TIMEOUT; // wait for panel to come alive
> - int wait = 0;
> + int wait = 0;
> while (!status.get(identifier).equals(PAV_INIT_STATUS.INIT_COMPLETE) && wait < maxWait) {
> -
> - try {
> - Thread.sleep(50);
> - wait += 50;
> - } catch (InterruptedException ie) {
> - // just wait
> - }
> - }
> -
> + try {
> + Thread.sleep(50);
> + wait += 50;
> + } catch (InterruptedException ie) {
> + // just wait
> + }
> + }
>
> // 0 => width, 1=> width_value, 2 => height, 3=> height_value
> String[] dimMsg = message.split(" ");
> @@ -636,7 +781,7 @@
>
> panel.setSize(width, height);
> panel.validate();
> -
> +
> panel.applet.resize(width, height);
> panel.applet.validate();
> }
> @@ -649,9 +794,6 @@
> e.printStackTrace();
> }
>
> - } else if (message.startsWith("destroy")) {
> - dispose();
> - status.put(identifier, PAV_INIT_STATUS.INACTIVE);
> } else if (message.startsWith("GetJavaObject")) {
>
> // FIXME: how do we determine what security context this
> @@ -672,15 +814,7 @@
>
> // Wait for the panel to initialize
> // (happens in a separate thread)
> - while (panel.getApplet() == null &&
> - ((NetxPanel) panel).isAlive()) {
> - try {
> - Thread.sleep(50);
> - PluginDebug.debug("Waiting for applet to initialize...");
> - } catch (InterruptedException ie) {
> - // just wait
> - }
> - }
> + waitForAppletInit((NetxPanel) panel);
>
> PluginDebug.debug(panel + " -- " + panel.getApplet() + " -- " + ((NetxPanel) panel).isAlive());
>
> @@ -1548,10 +1682,11 @@
> if (countApplets() == 0) {
> appletSystemExit();
> }
> +
> + updateStatus(identifier, PAV_INIT_STATUS.DESTROYED);
> }
> }).start();
>
> - status.put(identifier, PAV_INIT_STATUS.INACTIVE);
> }
>
> /**
> @@ -1677,18 +1812,6 @@
> val = buf.toString();
> }
>
> - att = att.replace(">", ">");
> - att = att.replace("<", "<");
> - att = att.replace("&", "&");
> - att = att.replace(" ", "\n");
> - att = att.replace(" ", "\r");
> -
> - val = val.replace(">", ">");
> - val = val.replace("<", "<");
> - val = val.replace("&", "&");
> - val = val.replace(" ", "\n");
> - val = val.replace(" ", "\r");
> -
> PluginDebug.debug("PUT " + att + " = '" + val + "'");
> atts.put(att.toLowerCase(java.util.Locale.ENGLISH), val);
>
> @@ -1708,7 +1831,6 @@
> // private static final == inline
> private static final boolean isInt(Object o) {
> boolean isInt = false;
> -
> try {
> Integer.parseInt((String) o);
> isInt = true;
> @@ -1763,7 +1885,6 @@
> } catch (IOException ioe) {
> return ioe;
> }
> -
> return null;
> }
> };
> @@ -1785,6 +1906,7 @@
> boolean isObjectTag = false;
> boolean isEmbedTag = false;
> boolean objectTagAlreadyParsed = false;
> +
> // The current character
> // FIXME: This is an evil hack to force pass-by-reference.. the
> // parsing code needs to be rewritten from scratch to prevent such
> @@ -1879,19 +2001,6 @@
> if (val == null) {
> statusMsgStream.println(requiresNameWarning);
> } else if (atts != null) {
> - att = att.replace(">", ">");
> - att = att.replace("<", "<");
> - att = att.replace("&", "&");
> - att = att.replace(" ", "\n");
> - att = att.replace(" ", "\r");
> - att = att.replace(""", "\"");
> -
> - val = val.replace(">", ">");
> - val = val.replace("<", "<");
> - val = val.replace("&", "&");
> - val = val.replace(" ", "\n");
> - val = val.replace(" ", "\r");
> - val = val.replace(""", "\"");
> PluginDebug.debug("PUT " + att + " = " + val);
> atts.put(att.toLowerCase(), val);
> } else {
> @@ -1920,8 +2029,8 @@
>
> if (atts.get("width") == null || !isInt(atts.get("width"))) {
> atts.put("width", width);
> - }
> -
> + }
> +
> if (atts.get("height") == null || !isInt(atts.get("height"))) {
> atts.put("height", height);
> }
> @@ -1974,7 +2083,7 @@
> if (atts.get("width") == null || !isInt(atts.get("width"))) {
> atts.put("width", width);
> }
> -
> +
> if (atts.get("height") == null || !isInt(atts.get("height"))) {
> atts.put("height", height);
> }
> @@ -2023,10 +2132,11 @@
> if (atts.get("width") == null || !isInt(atts.get("width"))) {
> atts.put("width", width);
> }
> -
> +
> if (atts.get("height") == null || !isInt(atts.get("height"))) {
> atts.put("height", height);
> }
> +
> }
> }
> }
> diff -r 85db7b3a1c93 plugin/icedteanp/java/sun/applet/PluginMessageConsumer.java
> --- a/plugin/icedteanp/java/sun/applet/PluginMessageConsumer.java Thu Oct 21 21:12:21 2010 +0100
> +++ b/plugin/icedteanp/java/sun/applet/PluginMessageConsumer.java Thu Oct 21 17:22:56 2010 -0700
> @@ -126,6 +126,10 @@
> }
>
> private String getPriorityStrIfPriority(String message) {
> +
> + // Destroy messages are permanently high priority
> + if (message.endsWith("destroy"))
> + return "destroy";
>
> synchronized (priorityWaitQueue) {
> Iterator<String> it = priorityWaitQueue.iterator();
> @@ -150,7 +154,6 @@
> }
> }
>
> -
> public void notifyWorkerIsFree(PluginMessageHandlerWorker worker) {
> synchronized (initWorkers) {
> Iterator<Integer> i = initWorkers.keySet().iterator();
> @@ -176,6 +179,32 @@
> }
>
> protected class ConsumerThread extends Thread {
> +
> + /**
> + * Scans the readQueue for priority messages and brings them to the front
> + */
> + private void bringPriorityMessagesToFront() {
> + synchronized (readQueue) {
> +
> + // iterate through the list
> + for (int i=0; i < readQueue.size(); i++) {
> +
> + // remove element at i to inspect it
> + String message = readQueue.remove(i);
> +
> + // if element at i is a priority msg, bring it forward
> + if (getPriorityStrIfPriority(message) != null) {
> + readQueue.addFirst(message);
> + } else { // else keep it where it was
> + readQueue.add(i, message);
> + }
> +
> + // by the end the queue size is the same, so the
> + // position indicator (i) is still valid
> + }
> + }
> + }
> +
> public void run() {
>
> while (true) {
> @@ -190,7 +219,6 @@
>
> String[] msgParts = message.split(" ");
>
> -
> String priorityStr = getPriorityStrIfPriority(message);
> boolean isPriorityResponse = (priorityStr != null);
>
> @@ -199,9 +227,12 @@
>
> if (worker == null) {
> synchronized(readQueue) {
> - readQueue.addLast(message);
> + readQueue.addFirst(message);
> }
>
> + // re-scan to see if any priority message came in
> + bringPriorityMessagesToFront();
> +
> continue; // re-loop to try next msg
> }
>
--
Andrew :)
Free Java Software Engineer
Red Hat, Inc. (http://www.redhat.com)
Support Free Java!
Contribute to GNU Classpath and the OpenJDK
http://www.gnu.org/software/classpath
http://openjdk.java.net
PGP Key: 94EFD9D8 (http://subkeys.pgp.net)
Fingerprint = F8EF F1EA 401E 2E60 15FA 7927 142C 2591 94EF D9D8
More information about the distro-pkg-dev
mailing list