Linked by Thom Holwerda on Wed 9th Nov 2011 21:26 UTC, submitted by edwin
Way back in 2002, MIT decided it needed to start teaching a course in operating system engineering. As part of this course, students would write an exokernel on x86, using Sixth Edition Unix (V6) and John Lions' commentary as course material. This, however, posed problems.
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RE[6]: binary for windows....
by Alfman on Sat 12th Nov 2011 04:59
in reply to "RE[5]: binary for windows.... "
Member since:2011-01-28
Vanders,
"That's not how shared libraries work. There is no more code required (at run time) to call a function in a shared library than there is in calling a function within the executable."
You're kind of missing my point, though. I know that shared library functions are mapped into the same address space as static functions, and can be called the same way. But the fact that a function belongs to a shared library implies that it must abide by a well defined calling convention, and subsequently translate it's internal variables to and from this interface. There are optimizations that can take place in a static binary that cannot take place with a shared library.
For example, we obviously cannot do inter-procedural analysis and optimization against a shared library function (since the shared library function is undefined at compile time). Theoretically, using static binaries, an optimizing compiler could analyze the call paths and eliminate all the glue code. Trivial functions could be inlined. Calling conventions could be ignored since there is no need to remain compatible with external dependencies.
In the ideal world, object files would be an intermediate representation like java class files, or .net assemblies. Not only would the run time compilation optimize for the current platform, but it could also perform inter-procedural optimization that might eliminate all costs currently associated with glue code.
RE[7]: binary for windows....
by Vanders on Sat 12th Nov 2011 14:09
in reply to "RE[6]: binary for windows.... "
Member since:2005-07-06
Theoretically, using static binaries, an optimizing compiler could analyze the call paths and eliminate all the glue code.
I can't help but feel that the time and effort needed to do that well would be significant, yet only save a tiny fraction of the load and link time for a binary that uses classic shared libraries.
News
Linked by Thom Holwerda on 05/18/13 7:37 UTC
"In NixOS, the entire operating system - the kernel, applications, system packages, configuration files, and so on - is built by the Nix package manager from a description in a purely functional build language. The fact that it's purely functional essentially means that building a new configuration cannot overwrite previous configurations. Most of the other features follow from this." Interesting approach. A Linux distribution, sure, but with some very refreshing ideas about system configuration.
Linked by fran on 05/18/13 1:38 UTC
Google added, among other features, C/C++ support to its new version of AIDE. From Android-IDE, "Now you can write parts of your app or your whole app in C/C++ on your device. AIDE supports the Standard Android NDK toolchain (GCC 4.6 + Bionic, STL, ...). No changes are necessary if you want to build an app developed on a PC with Eclipse. C/C++ development is fully integrated: Build errors appear in the error list and files can easily be navigated to with Go to file. The editor supports C/C++ syntax highlighting."
Linked by Thom Holwerda on 05/17/13 23:35 UTC, submitted by kragil
Ars nails it: "The answer is that Google did announce what amounts to a fairly substantial Android update yesterday. They simply did it without adding to the update fragmentation problems that continue to plague the platform. By focusing on these changes and not the apparently-waiting-in-the-wings update to the core software, Google is showing us one of the ways in which it's trying to fix the update problem."
Linked by MOS6510 on 05/17/13 22:22 UTC
"It is good for programmers to understand what goes on inside a processor. The CPU is at the heart of our career. What goes on inside the CPU? How long does it take for one instruction to run? What does it mean when a new CPU has a 12-stage pipeline, or 18-stage pipeline, or even a 'deep' 31-stage pipeline? Programs generally treat the CPU as a black box. Instructions go into the box in order, instructions come out of the box in order, and some processing magic happens inside. As a programmer, it is useful to learn what happens inside the box. This is especially true if you will be working on tasks like program optimization. If you don't know what is going on inside the CPU, how can you optimize for it? This article is about what goes on inside the x86 processor's deep pipeline."
Linked by Thom Holwerda on 05/17/13 22:15 UTC, submitted by Tom
"It was the only moment I heard regret slip into Otellini's voice during the several hours of conversations I had with him. 'The lesson I took away from that was, while we like to speak with data around here, so many times in my career I've ended up making decisions with my gut, and I should have followed my gut,' he said. 'My gut told me to say yes.'" The world would've been a much different place - Apple would have been less dependant on Samsung for its chips, which probably would've meant less money for Samsung to develop its Galaxy business.
Linked by Thom Holwerda on 05/16/13 21:41 UTC
Glass is getting some love at Google I/O as well. New applications have been released - Facebook, Twitter, Evernote, Elle, Tumblr, and CNN. Perhaps more interesting: the newly announced Google Glass Developer Kit will allow offline applications and direct hardware access - great for hacking and expanding Glass' potential. This kit will really allow hackers to put Glass through its paces.
Linked by Thom Holwerda on 05/16/13 17:04 UTC
"But Beck and Merrill decided that simply banning toxic players wasn't an acceptable solution for their game. Riot Games began experimenting with more constructive modes of player management through a formal player behavior initiative that actually conducts controlled experiments on its player base to see what helps reduce bad behavior. The results of that initiative have been shared at a lecture at the Massachusetts Institute of Technology and on panels at the Penny Arcade Expo East and the Game Developers Conference." Absolutely fascinating stuff. I'm a League of Legends player, and to be honest, the community isn't nearly as bad as some make it out to be. I'm happy Riot games has the guts to employ science to address the issue.
Linked by Thom Holwerda on 05/16/13 13:17 UTC
"Android and iOS, the number one and number two ranked smartphone operating systems worldwide, combined for 92.3% of all smartphone shipments during the first quarter of 2013 as Windows Phone crept past BlackBerry for 3rd place. According to the International Data Corporation Worldwide Quarterly Mobile Phone Tracker, Android smartphone vendors and Apple shipped a total of 199.5 million units worldwide during 1Q13, up 59.1% from the 125.4 million units shipped during 1Q12." Windows Phone doubles from a few to twice few, iOS loser market share as its growth is slower than that of the overall market. BlackBerry continues slide into irrelevance.
Linked by Thom Holwerda on 05/16/13 12:06 UTC
"According to the latest research from our Wireless Smartphone Strategies service, global Android smartphone profits reached US$5 billion in total during the first quarter of 2013. Samsung dominated and captured an impressive 95 percent share of all Android smartphone profits." Wow.
Linked by Thom Holwerda on 05/15/13 23:03 UTC
"During its Keynote today, Google announced new features coming to its flagship search function - you know, that thing we all started using Google for. VP Amit Singhal spent some time discussing what Google's search functionality will eventually morph into. Google's strategy is summarized by three words: answer, converse, and anticipate. Singhal explained that many of the pieces of these upcoming changes can already be seen in products that Google has recently introduced - namely, Google Knowledge Graph and Google Now, with perhaps a splash of Google Glass, too." I hold on to my hat every time Google changes Search. It's such a vital product in my daily life.More News »
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Member since:
2005-07-06
That's not how shared libraries work. There is no more code required (at run time) to call a function in a shared library than there is in calling a function within the executable.