Garbage Collection is the concept of collecting useless “dereferenced” memory, and freeing it for re-use by the system. De-referenced resources are those objects that are no longer in use by the program but are still allocated for use by it.
Languages like C/C++ could allow programmers to directly interact and play with memory, a responsibility that is often so abused that it does more harm than good… Problems arise when people recklessly allocate large system resources and the due to some mis-management the allocated memory is never freed. This leaves large chunks of unreacheable memory locations that ultimately cause “Memory Leaks”. In comes the invention by John McCarthy, which shoulders the responsibility of memory management by de-allocating memory that is not in use by the program anymore. While the concept was initially developed for LISP only, now it has spread to a variety of High Level Languages, including updated versions of C\C++ themselves.
C++/CLI (Common Language Infrastructure), which is Microsoft’s language specification has provision for both manual and automated memory management.
Garbage collector is the term used to represent automatic memory management by the system. Garbage collector scans the runtime environment for objects that are accessible directly or indirectly via references. Then it proceeds to discard all remaining objects. Typically, an object’s memory is reclaimed when the number of references to it reaches zero. These scans are done in cycles, which are started automatically by the Garbage collector or when explicit calls are made to it.
Garbage collection does not guarantee immunity from memory leaks, and obviously requires a considerable percentage of system resources to run, but definitely helps programmers who have to deal with a lot of memory in their projects. Garbage collection is not commonly used in embedded projects due to their already small resource size but are available on certain platforms like .NET Micro Framework and Java-ME.
The iPad has landed. But should campuses be throwing it a welcome party? A online search for “free iPad at college” shows that many are doing this now! Hundreds of educational institutions announced in the last weeks that they would be giving Apple’s new computing tablet to each new full-time student when they arrive on campus in the fall for free. For Example George Fox University, a Christian institution in Oregon, will expand its annual laptop giveaway to first-year students to offer students a choice between a Macbook and an iPad. The year after that, there will be no more choice: Everybody will get iPads. Interesting is also that even small ones (for example Eugene Bible College) are giving their students iPads ”to make learning [...] more interactive”.
The e-learning giant Blackboard, meanwhile, announced that it launched an app for the iPad that allows students to access their courses from the new device.
:: (Summary of the last month in mailinglist listserv.educause.edu)
But the arrival of the long-awaited device has also prompted questions. On Educause’s CIO listserv last week, higher-ed technologists wondered aloud about the costs and benefits of the efforts of some campuses the try to seed their student bodies with the gadget du jour.
Theresa Rowe, the CIO at Oakland University, noted the “pattern” of colleges announcing high-visibility technology giveaways of laptops, iPods, iPhones, and now the iPad — each time prompting peer institutions to wonder whether following suit would be strategically wise. “Our presidents or leaders ask ‘Why not us?’ ” Rowe wrote. “And then we scramble to put together a budget and support picture.” (Rowe was one of several CIOs to authorize Inside Higher Ed to quote from her contributions to the usually private forum.)
This time, Rowe decided to crowdsource the question to her counterparts on the listserv. What she got back was a mix of curiosity, enthusiasm, light number crunching, and some pointed skepticism. (See here)
Greg Smith, the CIO at George Fox, responded, saying that universities should not worry about justifying iPad giveaways with precise cost-versus-value analyses. The shifts that are happening in higher-ed technology — particularly from bound textbooks and research materials to electronic versions — are “bigger than the iPad,” said Smith. Universities know this change is coming, he said, so they should do what they can to enable it. “The iPad appears to be the perfect device for information at your fingertips which places it in the role to ignite the change,” Smith said.
But Robert Paterson, CIO at Molloy College, was not ready to anoint the tablet as a harbinger of institutional transformation. “Apple has done it again … created a proprietary hardware with no particular purpose, except it may be cool and then sell, sell, sell,” Paterson wrote. “… And these initiatives for students … without any experience in how it might be used, without faculty being able to experiment or to plan how to use them in the teaching/learning process… I apologize but it seems sort of gimmicky.”
Without a firm agenda in place for how the new technology is meant to be used, 5% of students at most might figure out a novel use of the iPad for learning, he said — “too few to justify a campus-wide giveaway”. By the time a substantial proportion of students start following the examples of the early innovators, Paterson said, “multiple iterations, improvement, enhancements to the tool have occurred… So you throw away the one first adopted in favor of better and cheaper versions.”
Stephen Landry, CIO at Seton Hall University (not to be confused with Seton Hill, which is the one doing an iPad giveaway), said that while he is more confident about students’ ability to adapt new devices into their learning processes, “it is wise to have concrete learning objectives that we hope to achieve by deploying that technology” nonetheless. “We should be able to discuss this with the students and parents who may want to know why tuition is going up and with our faculty who may want to know why we aren’t hiring more instructors,” Landry wrote. For example, he said, when Seton Hall first started giving out laptops in 1998, it did so as part of an effort to redesign its first-year English and math curriculums in order to improve learning outcomes through better use of technology.
So how much would an iPad giveaway actually cost for a typical campus? As it turned out, it was Rowe, the Oakland CIO who originally queried the listserv, who did some number crunching and estimated that to purchase and distribute the devices to a 3,000-student campus would cost about $2.2 million.
In an interview with Inside Higher Ed, Smith, the George Fox CIO, said that, more than getting students to use the iPad toward educational ends, campuses that choose to make it standard hardware could face pushback from professors, many of whom are used to using Microsoft Office’s suite of tools — Word, Power Point, Excel, etc. — to assign and receive student work (the iPad, unlike Apple’s Macbook laptop, does not run Microsoft Office and will not in the feature).
((By the way: Students can get office 2007 - for windows - for 59.95$ at http://www.microsoft.com/student/discounts/theultimatesteal-us/default.aspx and additionally to that they can upgrade to office 2010 for free as soon as it is released) )
He said that having to adjust to new technologies — regardless of whether students are likely to want them — gives professors everywhere jitters. “The biggest fear starting to grip [professors] is that … e-textbooks might actually become reality,” Smith said — acknowledging that there are exceptions, but they are the minority. “If you know higher ed, you know that the biggest fear of a professor is having to change how they deliver their course.”
And then there’s the observation made by a number of reviewers that the iPad is much better for consuming content than creating it — and content creation — of papers, presentations, video projects, etc. — is a big part of being a college student.
But Smith is not worried. One of the reason George Fox is phasing out its laptop program by way of the iPad giveaway is because most students there already have laptops — or at least have access to computers more oriented to creation. Besides, if you set up an iPad with its docking station and external keyboard — both of which George Fox will be providing to students — it is basically a desktop computer, he said.
In my opinion, trusting the iPad in Colleges as the only way for students to read and write their stuff is a really bad idea since this is just plain ignorance of any previous standardization and makes the school totally dependent on Apple. Previously students and also professors always had the freedom of choice in what hardware they buy (for example: a laptop or netbook or desktop from Dell or HP or Acer,..; and if they want to use Microsoft Windows, any Linux Distribution, *BSD or Apple Mac OS,…; and if they use Microsoft Office or OpenOffice,..). This freedom of choice created a market where people were able to get expensive products or even sometimes for free! If someone didn’t like a special product, then they were able to just change to another one; and so on…
But with just making the iPad a must use and relying on these devices, students don’t have a freedom of choice between what hardware, operating system, Office suite and other software they use.
But the fact that many institutions are still doing this, shows how good Apple’s marketing is. If you compare an iPad with a laptop; then the laptop clearly wins (for example because it has additional ports like USB, Bluetooth, sound in/out, CD/DVD drives,……. which the iPad doesn’t have!!). Also Apple’s decisions like banning flash from it’s devices aren’t what everyone wants – but this is the power of non-open systems with good marketing!
I hope that here in the USA they will soon release laws prohibiting public institutions to use/depend on products from just one company without allowing freedom of choice. Many countries worldwide already made that step!
PS: I am still waiting for all the open source and/or freedom supporters to jump up and do something against this (bad) change in today’s world!
Update: also see my next post Update: Should colleges start giving Apple’s iPad to students?“
I just found this really interesting ted talk from Dan Pink on the surprising science of motivation.
Here the description from http://ted.com/talks to the video:
Career analyst Dan Pink examines the puzzle of motivation, starting with a fact that social scientists know but most managers don’t: Traditional rewards aren’t always as effective as we think. Listen for illuminating stories — and maybe, a way forward.
Isn’t that amazing? What do you think? – Please comment.
Every developer wishes there was a way that an end-users could quickly and simply record a repro for the problem that they’re running into that is unique to their machine.
Here a little tool from Windows 7 comes to the rescue!
The in-built diagnostic tool ”Problem Steps Recorder” provides a simple screen capture tool that enables you to record a series of actions. Once you hit “record”, it tracks your mouse and keyboard and captures screenshots with any comments you choose to associate alongside them. Once you stop recording, it saves the whole thing to a ZIP file, containing an HTML-based “slide show” of the steps.
It’s a really neat little tool and I can’t wait for it to become ubiquitous on every desktop! The program is called psr.exe; you can also search for it from Control Panel or the Start-Menu search under “Record steps to reproduce a problem”.
If you are interested in modern technologies, climate change, nuclear power or how the feature power-solutions will look like, then you should watch this really good talk by Bill Gates:
TweetMyPC is a little software-application for Windows, written in VB.Net using the .Net-Framework v3.0, which allows you to control and access your computer from anywhere by simply sending a twitter-message with a special command as its content.
Most time when you want to connect two personal computers you need a Read the rest of this entry »
Environment variables are strings that contain information such as drive, path, or file name. They control the behavior of various programs. For example, the TEMP environment variable specifies the location in which programs place temporary files.
Sadly, Milw0rm.com was offline for a few days. Stroke said “permanently”. He posted the following message on the site before it went dark:
Well, this is my goodbye header for milw0rm. I wish I had the time I did in the past to post exploits, I just don’t . For the past 3 months I have actually done a pretty crappy job of getting peoples work out fast enough to be proud of, 0 to 72 hours (taking off weekends) isn’t fair to the authors on this site. I appreciate and thank everyone for their support in the past. Be safe, /str0ke
While it gets a bad rap for its large script kiddie user base…, I’ve learned a lot from the exploits on that site! Thanks Str0ke and all the authors! =)
BUT: While I was researching about this; I found some pages saying it looks like Stroke found some other people to take over for him. Anyway, the main website is back online, - Exploit submissions are still closed for now, and sometimes milw0rm.com seems to be offline from what the server responds, that may just be server overloading. – try it a few times…
The shell that users interact with in ReactOS is actually several components all tied together, which is why a rewrite is highly nontrivial. Besides the explorer shell itself there are the shell32, browseui, comctl32, and shlwapi libraries, to name just a few. In ReactOS, much of the functionality in the libraries are all crammed into the explorer shell because the libraries themselves did not really exist. This is due to the current explorer’s Wine heritage and the fact that Wine really does not need a shell32 implementation. One such example would be the start menu itself. This is not actually implemented in explorer, but merely exposed by it. Another is the menu system Read the rest of this entry »