paul.luminos.nl

After the previous Nokia PC Suite update, my Nokia 6300 could no longer synchronize via Bluetooth. Upon reading that the 7.1.26 update fixed several connectivity problems, I was excited to install the new version.

When the download completed, however, the installer didn't show up and nothing appeared to have happened. Checking for updates downloaded the same version, but again, no cigar.

After some messing around, it turned out that my anti-virus was causing the updater to fail to launch. The same happened for the updated version of Nokia Software Updater.

Simply disabling my anti-virus allowed both installers to proceed.

I've been having some strange Vista behavior recently. Double-clicking or pressing enter on a folder in the Explorer would open the folder in a new window, but clicking on in the navigation pane wouldn't. Even stranger, right-clicking on the folder and selecting "Explore" worked normally.

I tried the following solutions, finally fixing it with only the last suggestion.

Folder options

Open the Explorer. Go to the menu Tools, then click Folder Options. Under the General tab, ensure that the option for "Browse folders" is set to "Open each folder in the same window" is selected.

Registry

Open the Registry Editor and navigate to:

HKEY_CLASSES_ROOT\Folder\shell

Make sure that the data for the value (Default) displays as (value not set). If it doesn't, right-click on (Default) and select Delete.

(Re)register DLL

Open a command prompt with administrator privileges. Type the following command to (re)register actxprxy.dll into the system:

regsvr32.exe actxprxy.dll

You should receive a notification that the DLL has successfully been registered.

I'm unsure how this may have become unregistered, but I suspect it may have happened unjustly during some uninstall.

During our development for QuickGene here at CrimsonBase, we ran into a curious issue under Vista.

When our automatic update program is run from the Program Files directory, Vista displays the following UAC notification:

The problem, we discovered, is that files compiled with update in the filename trigger UAC. You can't simply rename the file to avoid the UAC pop-up; you have to recompile the executable using a different filename.

After moving from temporary room to temporary room, I finally have a permanent place. Previously, I had lived in various student houses in Lunetten: on the Hondsrug, Boven Zevenwouden, Oeral and Pyreneeën. Now I've once again returned to the Hondsrug to settle in to my very own little corner of Utrecht.

I have my own back door, a small patio, and my room opens out into the kitchen. Perfect!

Connection problems in Internet Explorer are fairly difficult to diagnose, despite the convenient "Diagnose Connection Problems" wizard that displays when a page fails to load. There are some reasons IE can't connect that won't show up after the wizard completes, so here are some pointers.

First, make sure your internet connection is working by using a proper web browser such as Firefox, Opera, Safari or SeaMonkey.

If you can open pages in other browsers without problems, but Internet Explorer is giving problems, follow the steps below. These solutions may concern you if you are receiving the following message:

Internet Explorer cannot display the webpage

Check Windows Updates

This may sound silly, but check if you have rebooted your machine after finishing any updates. In some cases, IE is blocked or stops working until a reboot is performed.

You might also want to check for new updates that affect Internet Explorer, and reboot if you install any.

Turn off your anti-virus / firewall / network software

Make sure your anti-virus or firewall programs aren't blocking access to the Internet. If they are, consult the developer's website for a solution.

A network guardian such as PeerGuardian, PeerBlock or NetLimiter may be restricting HTTP access. Check whether you have anything of this sort running.

Check third-party add-ons

You can easily disable all add-ons by starting Internet Explorer with the following command:

iexplore -extoff

Run this command by hitting + R on your keyboard to open the "Run..." dialog, then entering the command and pressing OK.

Make sure any instances of Internet Explorer are closed and that the iexplore.exe and ieuser.exe processes are actually terminated in the Task Manager before starting it in this mode. You should get a message that add-ons are disabled.

If the connection is working fine, then one of your add-ons is messing something up. In my case, Orbit Grab++ was messing up my connection. You can disable the third-party add-on by going to Tools then Internet Options. Open the tab Programs, then click Manage add-ons. From that list, you can look around for a problematic add-on and disable it. Restart Internet Explorer in normal mode to see if it fixed the problem.

Clear the cache

Just to make sure that the cache isn't causing the problem, clear it out. Go to Internet Options again, and hit the Delete... button on the General tab, under "Browsing history". Then click "Delete files..." to remove all the Temporary Internet Files. (This won't delete your session data, passwords, etc.)

Proxy connection

If all else fails, make sure that your proxy connection (if you need one) is set up identically to the functioning browser. Unless your internet connection passes through another machine in your household, you typically don't need this set up and it will only cause problems. In that case, make sure it's switched off in the LAN settings of Internet Options, under the Connections tab.

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Once you're done using Internet Explorer, reward yourself by quickly resorting back to Firefox.

I was puzzled why Apache 2.2 returned the following error upon installation:

Installing the Apache2.2 service
The Apache2.2 service is successfully installed.
Testing httpd.conf....
Errors reported here must be corrected before the service can be started.
(OS 10048)Only one usage of each socket address (protocol/network address/port)
is normally permitted.  : make_sock: could not bind to address 0.0.0.0:80
no listening sockets available, shutting down
Unable to open logs

You can check if the port is indeed in use by opening a command prompt and typing:

netstat -na

If you can find a row containing port 80, then it is in use. For instance:

Proto  Local Address          Foreign Address        State
TCP    0.0.0.0:80             0.0.0.0:0              LISTENING

If you're having difficulties discovering which application is using the port, run the command prompt as administrator and enter the following command, which will report the executable file that is responsible:

netstat -nab

In my case, it turned out to be Skype. Check that your Skype settings aren't blocking the port and close Skype. Restart the Apache service and everything should be working.

Tuesday night it soon became clear that, much to my delight, Obama was going to win the election. I enjoyed watching the ensuing victory speech, where the president-elect reiterated the hopes and promises of positive change for the next four years, but also emphasized the severity of the problems the United States is facing.

Below is a short montage I made of my favorite part of his speech.

Just like last year, and for the past several years, Eigendomweg 53 in Soest is a sight to see on Halloween! My family has been promoting the holiday ever since we moved to the Netherlands by expanding our spooky horror show a little bit each year.

This year we had more than one hundred little witches, monsters, grim reapers, skeletons, zombies, devils, vampires and ghosts. We were happy to also see more original and home-made costumes, like princesses, divas, an Indian, Luke Skywalker, a bumble-bee and even a Chinese dragon!

It's a challenge to maintain our neighborhood reputation of the spookiest house on the block. Good friend and business partner Mathijs Lagerberg joined in with the fun again this year!

Our neighbor was kind enough to take many photographs, which you can find on his website, eigendomweg.nl.

Here is a selection of photos from this year's October sensation:

One of the key technical highlights of QuickGene is its threaded-based architecture. Concurrency has been exploited to ensure that the user is provided a responsive interface despite performing computationally difficult operations.

In CrimsonBase applications, the interface always runs in a single thread. Other operations—may it be loading, saving, searching, drawing or updating—are run in separate threads. This construction is nothing new to seasoned software engineers, and much has been written in the literature about avoiding dead-locks and race conditions.

Even with a well-defined, synchronized construction, interesting problems arise from separating the interface from the operations that are produced by it. Suppose, for instance, that the user wishes to save the current project. Once the save button is pressed, a thread is instantiated that performs the task. As the interface remains responsive, it may be possible for the user to make a quick change to the project and hit save again before the operation completes.

The question now arises how to handle this issue. There are two conventional approaches to this problem:

• Have the first thread lock the operation. Upon completion, unlock the operation and notify the next thread; the second thread then saves the project again. This construction is slow: all save operations need to complete one after the other.
• Alternatively, one could consider ignoring any parallel threads and only letting the first finish. The second (or any other simultaneous save thread) is then aborted. This is faster than the above method, but the last changes are, to the confusion of the user, left unsaved!

We were quick to realize that neither of these approaches provided the desired functionality. Ideally, the operation would proceed as follows:

• The first thread is outdated; the project has been modified and a newer save operation is in the queue. Therefore, all but the most recent thread is interrupted and the last thread is permitted to execute. This is essentially as fast as running only one thread, but ensures that the most recent changes are saved as the user expected.

This construction is implemented in CrimsonBase applications under the class TerminatingThread, which controls the synchronisation of threads. Each operation class, such as saving, loading, redrawing or searching, is uniquely identified so that TerminatingThread can keep track of which thread belongs to which "class" of threads.

In essence, to maintain synchronization, prior to actually performing a thread, a synchronize() function is performed to ensure that no other threads of the same class are running. If it is safe to proceed, the thread's mainLoop() is run that contains the functionality of what the thread is intended to do. Finally, upon completion, the end() is called to notify the thread manager that the current thread has completed.

To illustrate this, consider the following schematic to be a thread using the above construction:

With this construction, multiple threads of the same class can be started without causing concurrency problems. The synchronize() function will sort out which threads are outdated, and interrupt them and wait for them to acknowledge their termination. It will also detect if it is not the most recent thread, in which case it will quickly terminate. Furthermore, when a thread is interrupted, end() will notify any threads waiting and allow them to proceed.

Various areas of QuickGene have benefited from a improved performance and feedback by using this framework. Most interestingly, complicated redraw operations are passed through a specialized subclass, PaintThread, that further enhances fast visual feedback through buffering and multi-step drawing.

Being so busy with school and work, I haven't updated my blog for over a month. In August I went to see Iron Maiden together with my brother and two cousins, which I had very much been looking forward to.

Here are the best photographs: