How to identify a memory leak

Useful article on publish/subscribe UI Design Patterns using the EventBus and Apache Pivot. Code refactorings show how to turn a MVC tightly coupled application into decouple UI components using pub/sub. Example uses Apache Pivot but can be applied to any UI technology.

Garbage collector (GC) is a blessing in .NET, if you happen to program in C++ in the past, where it was one of the prime responsibility of a developer was to manage the heap. That means when ever an object is created on the heap, it has to be deleted in the corresponding method or in the destructor, if the life is object long. And if he/she forgot to do so, then the nightmare begins in the form of memory leaks and troubleshooting may take hours and some times even days.

Everyone wants to be good in what he’s doing – that’s human nature, that’s how we’re raised. The key is constant improvement without being disappointed by small failures and bumps on the way. In the last 10 years I’ve been working as a developer and I feel I’ve learnt a lot of valuable lessons – many of which can be applied to other areas of life and work. Let me share my lessons with you, dear reader.

Silicon Valley investors often have a picture in their heads of the type of person who is worthy of funding: young, brash, stubborn, and arrogant. They believe that successful entrepreneurs come from entrepreneurial families and that they start their entrepreneurial journey by selling lemonade while in grade school. Angel investor and entrepreneur, Jason Calacanis said as much in his recent talk to Penn State students. And after meeting Wharton students, VC Fred Wilson expressed shock when a professor told him that you could teach people to be entrepreneurs. Wilson wrote, “I’ve been working with entrepreneurs for almost 25 years now and it is ingrained in my mind that someone is either born an entrepreneur or is not.”

Jason, Fred, and Silicon Valley VCs, I’ve got news for you: you’ve got it all wrong. Entrepreneurs aren’t born, they’re made. And they aren’t anything like you think they are. My team surveyed 549 successful entrepreneurs. We found that the majority didn’t have entrepreneurial parents. They didn’t even have entrepreneurial aspirations while going to school. They simply got tired of working for others, had a great idea they wanted to commercialize, or woke up one day with an urgent desire to build wealth before they retired. So they took the big leap.

We found that 52% of the successful entrepreneurs were the first in their immediate families to start a business — just like Bill Gates, Jeff Bezos, Larry Page, Sergei Brin, and Russell Simons (Def Jam founder). Their parents were academics, lawyers, factory workers, priests, bureaucrats, etc. About 39% had an entrepreneurial father, and 7% had an entrepreneurial mother. (Some had both.)

Only a quarter caught the entrepreneurial bug when in college. Half didn’t even think about entrepreneurship, and they had little interest in it when in school.

There was no significant difference between the success factors or hurdles faced by entrepreneurs who were extremely interested in entrepreneurship in school (and who likely set up the lemonade stands) and the ones who lacked interest. But entrepreneurs with extreme interest started more companies and did it sooner. Of the 24.5% who indicated that they were “extremely interested” in becoming entrepreneurs during college, 47.1% went on to start more than two companies (as compared with 32.9% of the overall sample). Sixty-nine percent started their companies within 10 years of working for someone else (as compared to 46.8% of the rest of the sample population).

What did affect their successes?  Education — but not the college they graduate from. In a different study of the 652 CEOs and CTOs of 502 tech companies, we researched the correlation between education and the sales and headcount of companies founded. We learned that the there was a significant difference between companies started by founders with just high-school diplomas and the rest. Education provided a huge advantage. But there wasn’t a big difference between firms founded by Ivy-league graduates and the graduates of other universities.

The education and training of entrepreneurs is something that the Kauffman Foundation has been researching extensively. Over the last six years, it has invested around $50 million on academic research to understand what makes entrepreneurs tick and what policies are most conducive to entrepreneurship and to construct data bases to permit analyses of these subjects. (Kauffman has also funded some of my research at Duke, UC-Berkeley, and Harvard.) Its VP of Research, Bob Litan, says that Kauffman has learnt conclusively that entrepreneurship can be taught. The key is to provide education at “teachable moments” — when the entrepreneur is thinking about starting a venture or ready to scale it. What entrepreneurs need isn’t the type of abstract course they teach in business schools, but practical, relevant knowledge.  That’s why Kauffman created a program called Fast Trac, which has trained 300,000 entrepreneurs so far.

One of the findings of Kauffman research is that of the appx. 600,000 businesses that are started every year, less than a fraction of 1% become high-growth “scale” businesses. These new firms, especially the “scale” firms, have added all of the net incremental jobs to U.S. economy since 1980 (about 40 million), and probably account for about 1/3 of GDP growth since then. So the key to boosting economic growth is to increase the number of successful high-growth startups.  After all, the growth rate of our economy is nothing more than the aggregation of the growth of our firms.

That is why Kauffman (which has a $2 billion endowment) is investing heavily in an ambitious new program called Kauffman Labs.  This aims to dramatically increase the ability of small businesses to become big businesses. The Labs program is built around a novel idea: that highly motivated individuals with “scalable ideas” can be recruited to be entrepreneurs and to be made successful, by surrounding them with a network of other experienced entrepreneurs; sources of money; and mentors. The goal is to educate entrepreneurs and surround them with a powerful network. This is like a Y Combinator on steroids.

Anecdotal evidence also shows that there are many more factors at play than that of genes. Note this BusinessWeek article about waves of spinoffs from Google. I doubt that all of these Google employees who are starting successful businesses were born with entrepreneurial genes. VC and former entrepreneur Brad Feld also blogged about how many of his frat buddies at MIT had become successful entrepreneurs. Were all of these people born to be entrepreneurs as well? I don’t think so. It is probably education, exposure to entrepreneurship, and networks that led these people to pursue the entrepreneurial path — which means that Kauffman Foundation may have hit on the right idea with Kauffman Labs.

The reason this topic is really important is that, as Wilson writes, “Venture Capital is a lot about pattern recognition”. The reality is that VCs like him make quick judgments about people based on the stereotypes in their minds. So, like the women that I wrote about in my previous posts, we may be disadvantaging another important segment of our population – a segment that is older, more humble, more sensible, and more realistic than the population that is getting all the attention (and the money).

Editor’s note: Guest writer Vivek Wadhwa is an entrepreneur turned academic. He is a Visiting Scholar at UC-Berkeley, Senior Research Associate at Harvard Law School and Director of Research at the Center for Entrepreneurship and Research Commercialization at Duke University. Follow him on Twitter at @vwadhwa.

At the PDC last year, you may have seen that NASA and Microsoft made a number of announcements! New data apis in Microsoft Codename "Dallas", a Silverlight+ASP.NET MVC 2 site on Azure.... but did you realize they also launched a programming competition??

About three weeks ago, eBay’s electronic payments daughter PayPal suddenly started blocking personal payments going in or coming out of accounts from Indian customers, resulting in a flood of online complaints from the latter that ranged from accusations of racism to sheer amateurism.

Last week, rumors that PayPal was actually forced into halting personal payments by Reserve Bank Of India (RBI) because they did not comply with all relevant regulatory requirements, were confirmed. Last night, PayPal posted a status update on its corporate blog, saying that they anticipate to resume part of its service, namely bank withdrawal abilities, as of Wednesday, March 3rd.

From the blog post:

We have been diligently working with the RBI and our business partners to resume Indian bank withdrawals for the thousands of Indian businesses who use PayPal to sell their goods or services in the global marketplace.

I’m pleased to tell you that the RBI has now allowed us to resume bank withdrawals for settlements for exports of goods and services. We are currently making changes to comply with Indian regulations for settlements for exports of goods and services, and we anticipate that as of Wednesday, March 3rd, we will be able to resume the bank withdrawal service.

As part of the changes, Indian customers will be required to fill out a new field dubbed ‘Export Code’ when they request a withdrawal (here’s how to get one). This information is apparently required under current Indian laws in order to identify the nature of cross-border merchant transactions. PayPal will share specific instructions on how users can move money into bank accounts on Monday, March 1st.

But Reserve Bank Of India has informed the eBay company that it requires specific approvals to allow personal inward remittances to India, which it currently does not have. In other words: PayPal is still forced by law to effectively suspend personal payments going into the accounts of its Indian customers for the foreseeable future, unless they are exporters.

We’ll provide an update when that changes.

Example showing how to use Flex as front-end with Spring as back-end to upload files

Programmers love to work long hours! There I said it, c'mon admit it, your job/boss doesn't make you do it, we do it to ourselves. Alright, I'll concede, maybe not all programmers love long hours, but surely with the amount of overtime that is prevalent in this industry at least half of us must love it. Right? I can hear the excuses already. "No, no that's not it, we just love working with cool tech and don't want to leave a problem unsolved. It is actually a good thing it's what makes us awesome!"

Today I have compiled 7 jquery and css demos created by me so that nobody miss one. Take a look and save for future reference , somehow , they may be useful for you.

Efficiency is a business school idea that suggests a company is running smoothly. It’s absolutely terrific when you’re talking about a coal mining operation or a Supercuts. But when it comes to a company like Yahoo it’s not a positive. The Internet is still in its wild west days, and the “ready, fire, aim” game plan of Facebook and the other young guns is eating their lunch. Even the massive Google is still trying to shake things up with new and controversial products.

Yahoo’s strategy seems more like “ready, aim, aim, aim, aim…”

Yesterday Jordan Rohan at Thomas Weisel Partners described Yahoo in his first analyst report on the company. He thinks this is the right management team to bring more efficiency to Yahoo. But he spends most of his time talking about the negatives, and there’s no excitement around new products or ideas:

For the record, we happen to believe the current management team is the right one at this stage in Yahoo!’s corporate evolution. The team is bringing efficiency to a massively inefficient company. Yahoo! is weighed down today by dozens of code bases, thousands of revenue-producing properties, at least three sales force factions (display, search, ad network), and a few thousand “extra” employees needed to run the media company today due to its complicated legacy assets and far-flung acquisitions.

On the upside, he notes that a cyclical upswing in advertising is likely to help Yahoo.

Here are a few of the negatives:

• “Morale may have rebounded a bit from the trough, but our conversations reveal that morale has a long way to go.”
• “Our recent discussion with Yahoo! management focused more on costs and efficiency than growth.”
• “User behavior is shifting strongly to social and mobile media and away from traditional portals.”
• “Efforts to become more meaningful in social media have been unsuccessful”
• “U.S. assets make up only about onethird of Yahoo!’s $21 billion value today”
• “Yahoo!’s stock compensation expense is approximately equal to 25% of its annual EBITDA, compared with 11% for GOOG and 13% for EBAY”

More worrying are the metrics comparisons to Facebook. Rohan notes that total minutes spent by U.S. visitors to Facebook are set to surpass Yahoo. And the worldwide numbers are even worse. Facebook now has 160 million daily visitors and 227 billion monthly page views worldwide (Comscore), compared to 160 million and just 94 billion for Yahoo. Yahoo still has tons of daily visitors, but they are spending 12% less time on the site in aggregate compared to a year ago. In the same period Facebook has grown total page views by 217%.

Yahoo will continue to shrink as sites are sold off and shuttered, and CEO Carol Bartz works on those efficiency gains. But this is no longer even close to an exciting company that thrives on chaotic creativity. Yahoo’s foundation is rotten. They have no plan to get back into the game. Or if they do have a plan, no one knows about it.

Sadly, the first site many of us ever visited on the Internet is turning into little more than a business school study in financial engineering. It deserved a better fate.

When looking for a web hosting service, you should be careful as there are a lot of things they may try to hide from you.

Adobe AIR, which stands for Adobe Integrated Runtime, is a cross-functioning system runtime engine that allows web designers and web developers to create rich internet applications, and Adobe AIR is compatible with Windows, Macs and Linux. Adobe AIR is a very functional and useful system for web designers and web developers because it permits Flash, Flex, JavaScript, HTML and AJAX code to look like traditional desktop applications by running without the Web browser.

Good news, Palm fans! If you’ve taken a break from jamming on the “Update” button, it’s time to go tap it one last time: the rollout of webOS 1.4 has just begun. The catch: it seems that it’s only for Sprint handsets right now, with the Verizon Pre Plus and Pixi Plus still reporting that 1.3 is the latest release.

We knew it was coming in February thanks to Palm’s announcement at CES — and thanks to the rumor mill, we were all lead to believe it was coming a few weeks ago. All false starts and false hopes aside, it’s available now. We’re seeing reports (thanks Twitter!) that it just has gone live on Sprint handsets.

Read the rest at MobileCrunch >>

One of the very hard things with Wicket is mounting pages where the first words of the URL are a parameter; listening to a URL like http://twitter.com/erik_van_oosten is just completely impossible. This article shows you how to mount pages on the root URL with Wicket 1.4.

Daring Fireball’s John Gruber wrote what I thought was a good response to my post about Apple’s App Store sexy app policy. While I noted that one of the reasons Apple’s policy was silly was because each iPhone contains two apps, iTunes and Safari (both made by Apple), that grant users access to content much worse than the kind of stuff now being banned from the App Store, he comes back to say that maybe the idea isn’t to remove this content from the iPhone itself, but rather just from the actual App Store.

My first reaction to this was the humorous thought that both iTunes and Safari would be banned from the App Store had they not been included by default on every iPhone. But that actually lead to a more interesting thought that a few other posts around the web back up today: Safari is the iPhone’s peephole.

What I mean is that Apple very tightly controls nearly every aspect of the iPhone (and really, all products). While they undoubtedly have both selfish (app revenues) and unselfish (protection) reasons for doing this, this type of suffocating control should be enough to make users walk away. But it’s not. And a big reason may be Safari.

Think about it: you can’t have porn on your iPhone — but actually, you can. You just have to go through Safari. You can’t have Google Voice on your iPhone — but actually, you can. You just have to go through Safari. Other Google Apps? Same thing.

Sure, it’s not as easy or as nice as if there were a native app experience, but it’s doable. And as HTML5 continues to mature, it will be more and more doable. In fact, over the past few months I’ve encountered a number of web apps on the iPhone that are increasingly impressive. One is the Google Buzz app, which is better than Google Buzz on the desktop because it uses HTML5 to access your location through your phone.

Remember, when the iPhone first launched in 2007, no native third-party apps were allowed. All Apple said at the time was that if you wanted to make an app, it had to be a web app. The problem was that the HTML5 was basically non-existant at the time, and the older HTML/JavaScript/CSS combination simply wasn’t ideal for developers or users. So Apple shuffled (though native apps may have been the plan all along, who knows), and made third-party native apps the norm with the launch of the iPhone SDK.

Unfortunately, as we’ve all become well aware, there’s a price for this native development: you have to play by Apple’s rules. But, at the same time, Apple never said you still couldn’t work outside the App Store ecosystem and make any sort of web app you desired. Again, essentially, they made Safari a loophole — or, as I’ve been calling it, a peephole.

Today, Gruber elaborated on this a bit buried in his post about Adobe Flash. Here’s the key part:

The best counter-argument is perhaps that, given Apple’s desire for control, they’re always going to prefer their wholly owned proprietary platforms — native iPhone and Mac apps — over the web, and will eventually come to see the web as a threat. I don’t think Apple sees it that way, though. There is always going to be a lowest common denominator platform. That used to be Windows. Now it’s the web. Apple doesn’t build lowest common denominator platforms. Before, when Windows was the LCD, Apple was in a hard place because they were locked out of that platform: their platform was at odds with it. Now, with the web as the LCD, Apple has it both ways: their platforms gracefully coexist with it. Apple isn’t a web company, but the web might be the best thing that ever happened to them.

So with the web, Apple is giving both developers and users a way to still operate outside the system. And again, that method will keep improving as HTML5 does.

In fact, I’m surprised that Apple doesn’t play this up more in response to the criticisms of the App Store. If I were them, I’d simply say something like, “We made the App Store to provide our customers with the best guaranteed experience on their device. If you’d like an app that we don’t allow, that’s fine, you’ll just have to access it through the web on the device.”

The first part essentially is their line, but the second part they probably won’t say because then they’ll worry customers will start associating the web apps with Apple itself. But again, that was the initial idea behind the first iPhone, so if they thought it was going to work at one time, they should be comfortable with it now.

Another post today on Silicon Alley Insider notes that Apple is stacking the deck against its rivals like Amazon for digital goods because you can’t buy them within native iPhone (and soon iPad) apps. For example, with the Amazon Kindle app, you have to go to the web to purchase a new e-book.

But again, it’s not that you flat out cannot buy the book, you just have to go to the web to do it. And you can do that on the iPhone, through Safari. It’s a little more complicated, but it’s manageable.

Ideally, would Apple like to all the most popular web apps ported over to native apps available in the App Store? Provided they adhere to their guidelines, of course. At the same time, are they ever going to remove Safari from the iPhone and make all developers do native apps? No way. It would be suicide to do so. And Apple must know that.

You cannot remove the safety net just because you think not falling is better than falling.

Instead, Apple will focus on making a platform for developers that allows them to create a better tailored experience for users, provided they follow their rules. We see this with apps like Facebook, Pandora, and a number of Twitter apps. Each is better than their respective web app (well, except that you can’t run Pandora in the background, but that may change — soon). And each are among the most popular apps on the device.

Meanwhile, I’m using Google Voice, Buzz, and Gmail on my phone — I’m just using them through Safari. I thought it would bug me, but it really doesn’t because HTML5 is getting so good.

Is Apple still hypocritical in not allowing some sexy apps but allowing others? Yes. And it’s particularly bad because they initially didn’t allow them, then they did, now they’ve taken them away again. And it’s sad that this is destroying some businesses (no matter what you think of the content). But you still could get this content through the web using Safari. It sucks for the developers that they can’t as easily charge for it, but end users obviously won’t care about that. And those are the people buying iPhones.

The iPhone may be a closed door, but there is a peephole, Safari. And if you can’t find what you’re looking for on the device, you might want to look through it.

[photo: flickr/wfyurasko]

I needed to process some command-line options today in a Clojure app and I dug into the mostly undocumented with-command-line in clojure.contrib.

Hamburg, Germany based Qype, a Yelp-like site that’s focused on European markets, has recently had long acquisition looks from both Google and Nokia, we’ve heard from multiple sources. A deal with Nokia in particular was looking extremely likely until recently.

The site was first launched in 2005 and today attracts 9 million monthly worldwide visitors, according to Comscore, just a little less than Yelp’s 11 million. Both likely have far more actual visitors, but Comscore is good for comparision – in December, for example, Qype told us they had 17.7 million unique visitors. A year ago the company brought in a new CEO and have been expanding rapidly across Europe.

Google supposedly took a look at the company and passed, opting instead to just import Qype’s content. Nokia made a run for the company after Google, with one source saying that a term sheet had been signed in the $50 million range.

But another source says that a term sheet was never signed and the deal negotiations broke down over both price and other contract terms.

Qype isn’t helping much with the story, sticking to their no comments. But founder Stephan Uhrenbacher did email to tell us that the site has 500,000 registered users who’ve left over 1 million reviews. They are available in seven languages and have sites in UK, France, Germany, Spain, Italy, Poland, Brazil, Ireland.

So for now at least Qype may remain independent. But like Yelp, which had its own acquisition drama late last year, Qype is in the local advertising sweet spot, where billions of advertising dollars (and euros) will be flowing over the next few years.

Qype has raised around £8 million in venture capital.

Yesterday, Luke Wroblewski – Chief design architect at Yahoo! – wrote a blog post singing the praises of audiosharing site Huffduffer. But it wasn’t Huffduffer’s service that got Luke W animated, so much as their sign-up page.

While most sites use a standard form with text-boxes and radio buttons for new sign-ups, Huffduffer presents its questions as a ‘Mad Lib’ style statement…

“I would like to use Huffduffer. I want my username to be _____________ and I want my password to be _____________. My email address is _________. By the way, my name is ______________ and my website is ___________.”

…which is kinda neat.

But Luke, being a ‘chief design architect’ (one of the world’s more tautological job titles), wanted to find out more. Specifically, he wanted to know if this style of form actually encourages more people to sign up than the usual Name: ___________ / Email address: __________ format. So he persuaded Ron Kurti at Vast.com to do some A/B testing and, whaddya know?, it turns out the conversational fill-in-the-blanks form increased conversion by 25-40%.

Given those impressive numbers it’s a cast iron certainty that in the next few months dozens of sites, starting probably with Yahoo!, will consider upgrading their sign-up pages to this new, friendlier format. The trick, of course, will be to get the wording just right – to customize each sign-up page for the site’s particular audience.

…which has given me an idea for a ‘fun’ weekend contest! Hurrah!

Your challenge is this: suggest some Mad Lib-style wording for the sign up page of your favourite web 2.0 site. The funnier the better. Post your entry in the comments and his time next week I’ll pick the funniest (say) three and award some excellent prizes.

Prizes that will include (but are not limited to): fame, recognition of your brilliance and whatever crap I can find in my hotel room – a signed copy of my eBay-auction-winning book, a TechCrunch tshirt and maybe one of those little bottles of shampoo you get.

Here are some examples off the top of my head to inspire you. Yours should be better…

Twitter:

“I do everything Oprah tells me to do so I’d like to use Twitter for three days. I’d like my username to be __________ and my password to be ‘password123′, or the name of my dog which is ______________. Please autofollow me to Oprah, Ellen Degeneres and Taylor Swift.”

Google:

“My name is ___________ and I would like to sign up to use Gmail/Google Buzz. The name of the person I am secretly having an affair with is ___________ and my social security number is _______________. Please display this information on my public profile.”

YouTube:

“LOL!!!! My n@me is ____________ & I wanna join yutube becos this video sukkkssss!! I think _____________ is GAAY!!! LOLLZ”

Livejournal:

“My name is ______________ and joining Livejournal is my only hope of getting anyone to read my poetry. My birthstone is ____________ and my current mood is _____________ and lonely. No one understands me. I hate my life.”

MySpace:

“My name is ____________ and due to some kind of administrative error I would like to join MySpace.”

Go, submit!