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  • Craftsmanship is ALL that Matters

    - by Wayne Molina
    Today, I'm going to talk about a touchy subject: the notion of working in a company that doesn't use the prescribed "best practices" in its software development endeavours.  Over the years I have, using a variety of pseudonyms, asked this question on popular programming forums.  Although I always add in some minor variation of the story to avoid suspicion that it's the same person posting, the crux of the tale remains the same: A Programmer’s Tale A junior software developer has just started a new job at an average company, creating average line-of-business applications for internal use (the most typical scenario programmers find themselves in).  This hypothetical newbie has spent a lot of time reading up on the "theory" of software development, devouring books, blogs and screencasts from well-known and respected software developers in the community in order to broaden his knowledge and "do what the pros do".  He begins his new job, eager to apply what he's learned on a real-world project only to discover that his new teammates doesn't use any of those concepts and techniques.  They hack their way through development, or in a best-case scenario use some homebrew, thrown-together semblance of a framework for their applications that follows not one of the best practices suggested by the “elite” in the software community - things like TDD (TDD as a "best practice" is the only subjective part of this post, but it's included here due to a very large following of respected developers who consider it one), the SOLID principles, well-known and venerable tools, even version control in a worst case and truly nightmarish scenario.  Our protagonist is frustrated that he isn't doing things the "proper" way - a way he's spent personal time digesting and learning about and, more importantly, a way that some of the top developers in the industry advocate - and turns to a forum to ask the advice of his peers. Invariably the answer I, in the guise of the concerned newbie, will receive is that A) I don't know anything and should just shut my mouth and sling code the bad way like everybody else on the team, and B) These "best practices" are fade or a joke, and the only thing that matters is shipping software to your customers. I am here today to say that anyone who says this, or anything like it, is not only full of crap but indicative of exactly the type of “developer” that has helped to give our industry a bad name.  Here is why: One Who Knows Nothing, Understands Nothing On one hand, you have the cognoscenti of the .NET development world.  Guys like James Avery, Jeremy Miller, Ayende Rahien and Rob Conery; all well-respected and noted programmers that are pretty much our version of celebrities.  These guys write blogs, books, and post videos outlining the "correct" way of writing software to make sure it not only works but is maintainable and extensible and a joy to work with.  They tout the virtues of the SOLID principles, or of using TDD/BDD, or using a mature ORM like NHibernate, Subsonic or even Entity Framework. On the other hand, you have Joe Everyman, Lead Software Developer at Initrode Corporation - in our hypothetical story Joe is the junior developer's new boss.  Joe's been with Initrode for 10 years, starting as the company’s very first programmer and over the years building up a little fiefdom of his own until at the present he’s in charge of all Initrode’s software development.  Joe writes code the same way he always has, without bothering to learn much, if anything.  He looked at NHibernate once and found it was "too hard", so he uses a primitive implementation of the TableDataGateway pattern as a wrapper around SqlClient.SqlConnection and SqlClient.SqlCommand instead of an actual ORM (or, in a better case scenario, has created his own ORM); the thought of using LINQ or Entity Framework or really anything other than his own hastily homebrew solution has never occurred to him.  He doesn't understand TDD and considers “testing” to be using the .NET debugger to step through code, or simply loading up an app and entering some values to see if it works.  He doesn't really understand SOLID, and he doesn't care to.  He's worked as a programmer for years, and that's all that counts.  Right?  WRONG. Who would you rather trust?  Someone with years of experience and who writes books, creates well-known software and is akin to a celebrity, or someone with no credibility outside their own minute environment who throws around their clout and company seniority as the "proof" of their ability?  Joe Everyman may have years of experience at Initrode as a programmer, and says to do things "his way" but someone like Jeremy Miller or Ayende Rahien have years of experience at companies just like Initrode, THEY know ten times more than Joe Everyman knows or could ever hope to know, and THEY say to do things "this way". Here's another way of thinking about it: If you wanted to get into politics and needed advice on the best way to do it, would you rather listen to the mayor of Hicktown, USA or Barack Obama?  One is a small-time nobody while the other is very well-known and, as such, would probably have much more accurate and beneficial advice. NOTE: The selection of Barack Obama as an example in no way, shape, or form suggests a political affiliation or political bent to this post or blog, and no political innuendo should be mistakenly read from it; the intent was merely to compare a small-time persona with a well-known persona in a non-software field.  Feel free to replace the name "Barack Obama" with any well-known Congressman, Senator or US President of your choice. DIY Considered Harmful I will say right now that the homebrew development environment is the WORST one for an aspiring programmer, because it relies on nothing outside it's own little box - no useful skill outside of the small pond.  If you are forced to use some half-baked, homebrew ORM created by your Director of Software, you are not learning anything valuable you can take with you in the future; now, if you plan to stay at Initrode for 10 years like Joe Everyman, this is fine and dandy.  However if, like most of us, you want to advance your career outside a very narrow space you will do more harm than good by sticking it out in an environment where you, to be frank, know better than everybody else because you are aware of alternative and, in almost most cases, better tools for the job.  A junior developer who understands why the SOLID principles are good to follow, or why TDD is beneficial, or who knows that it's better to use NHibernate/Subsonic/EF/LINQ/well-known ORM versus some in-house one knows better than a senior developer with 20 years experience who doesn't understand any of that, plain and simple.  Anyone who disagrees is either a liar, or someone who, just like Joe Everyman, Lead Developer, relies on seniority and tenure rather than adapting their knowledge as things evolve. In many cases, the Joe Everymans of the world act this way out of fear - they cannot possibly fathom that a “junior” could know more than them; after all, they’ve spent 10 or more years in the same company, doing the same job, cranking out the same shoddy software.  And here comes a newbie who hasn’t spent 10+ years doing the same things, with a fresh and often radical take on the craft, and Joe Everyman is afraid he might have to put some real effort into his career again instead of just pointing to his 10 years of service at Initrode as “proof” that he’s good, or that he might have to learn something new to improve; in most cases the problem is Joe Everyman, and by extension Initrode itself, has a mentality of just being “good enough”, and mediocrity is the rule of the day. A Thorn Bush is No Place for a Phoenix My advice is that if you work on a team where they don't use the best practices that some of the most famous developers in our field say is the "right" way to do things (and have legions of people who agree), and YOU are aware of these practices and can see why they work, then LEAVE the company.  Find a company where they DO care about quality, and craftsmanship, otherwise you will never be happy.  There is no point in "dumbing" yourself down to the level of your co-workers and slinging code without care to craftsmanship.  In 95% of these situations there will be no point in bringing it to the attention of Joe Everyman because he won't listen; he might even get upset that someone is trying to "upstage" him and fire the newbie, and replace someone with loads of untapped potential with a drone that will just nod affirmatively and grind out the tasks assigned without question. Find a company that has people smart enough to listen to the "best and brightest", and be happy.  Do not, I repeat, DO NOT waste away in a job working for ignorant people.  At the end of the day software development IS a craft, and a level of craftsmanship is REQUIRED for any serious professional.  When you have knowledgeable people with the credibility to back it up saying one thing, and small-time people who are, to put it bluntly, nobodies in the field saying and doing something totally different because they can't comprehend it, leave the nobodies to their own devices to fade into obscurity.  Work for a company that uses REAL software engineering techniques and really cares about craftsmanship.  The biggest issue affecting our career, and the reason software development has never been the respected, white-collar career it was meant to be, is because hacks and charlatans can pass themselves off as professional programmers without following a lick of good advice from programmers much better at the craft than they are.  These modern day snake-oil salesmen entrench themselves in companies by hoodwinking non-technical businesspeople and customers with their shoddy wares, end up in senior/lead/executive positions, and push their lack of knowledge on everybody unfortunate enough to work with/for/under them, crushing any dissent or voices of reason and change under their tyrannical heel and leaving behind a trail of dismayed and, often, unemployed junior developers who were made examples of to keep up the facade and avoid the shadow of doubt being cast upon them. To sum this up another way: If you surround yourself with learned people, you will learn.  Surround yourself with ignorant people who can't, as the saying goes, see the forest through the trees, and you'll learn nothing of any real value.  There is more to software development than just writing code, and the end goal should not be just "shipping software", it should be shipping software that is extensible, maintainable, and above all else software whose creation has broadened your knowledge in some capacity, even if a minor one.  An eager newbie who knows theory and thirsts for knowledge can easily be moulded and taught the advanced topics, but the same can't be said of someone who only cares about the finish line.  This industry needs more people espousing the benefits of software craftsmanship and proper software engineering techniques, and less Joe Everymans who are unwilling to adapt or foster new ways of thinking. Conclusion - I Cast “Protection from Fire” I am fairly certain this post will spark some controversy and might even invite the flames.  Please keep in mind these are opinions and nothing more.  A little healthy rant and subsequent flamewar can be good for the soul once in a while.  To paraphrase The Godfather: It helps to get rid of the bad blood.

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  • Are there any font rendering libraries for games development that support hinting?

    - by Richard Fabian
    I've used angel code's bitmap font generator quite a bit and though it's very good, I wondered if there would be a way of using the hinting information to provide a better readable result by using hinting to provide differing thickness based on size/pixel coverage. I imagine any solution would have to use the distance field tech presented in the valve paper on smoothing fonts while maintaining or reducing asset size. (http://www.gamedev.net/community/forums/topic.asp?topic_id=494612) but I haven't found any demos of it being used with hinting information turned on or included in the field gradients in any way. Another way of looking at this is whether there are any font bitmap generators that will output mipmaps that still maintain their readability in the face of pixel size. I think the lower mip levels would try to guarantee fill and space where it is necessary to maintain readability/topology over maintaining style/form (the point of hinting). In response to "Is there a reason you can't just render the size you want", the problem lies in the fact that font rasterisers currently don't render in 3D, and hinting information would be important in different amounts due to the pixel density being different along different axes, even differing in importance along the length of a string due to the size reducing over distance. For example, I only want horizontal hinting in a texture that is viewed from the side, and only really want vertical hinting in a font that is viewed from below or above. This isn't meant to be a renderer that tries to render a perfect outline as accurately as possible, as hinting distorts the reality of the font, instead this is meant to be a rendering solution for quite static scenes, but scenes that have 3D transformed and warped text layout. In this case the legibility is important, more important than the accuracy of representation of the polygon shape.

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  • Remove CGI from IIS7

    - by jekcom
    I ran some security scan and the scan said that all kind of CGI stuff are potential thread. This is part of the result : (ash) is present in the cgi-bin directory (bash) is present in the cgi-bin directory By exploiting this vulnerability, a malicious user may be able to execute arbitrary commands on a remote system. In some cases, the hacker may be able to gain root level access to the system, in which case the hacker might be able to cause copious damage to the system, or use the system as a jumping off point to target other systems on the network for intrusion and/or denial of service attacks. and many more related to cgi-bin directory. First I searched all the server for cgi-bin folder and it did not find any. Second I'm running my website on pure .NET and I don't use any scripts like php. Question is how can I remove this CGI thing from the IIS?

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  • Load-balancer options

    - by toolkit
    I am looking at a number of possible options for load-balancing. So far, I am constrained to the following options: DNS server load-balancer, balancing to a cluster of tomcat servers, with terracotta for session replication. Pros - don't have to buy new kit. Cons - DNS lb can keep directing to a broken server. Hardware load-balancer, direct to cluster of tomcat servers. Pros - could have second box for failover lb. Cons - expense. Apache server load-balancer. Pros - apache's lb polls for broken servers. Cons - apache server is single point of failure, plus need to buy another server. Are there any other options I should consider? Thanks. Update: Thanks for all the answers so far +1's all round. Not accepting an answer yet, to keep more ideas coming.

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  • Transition domain to new web host without waiting for DNS propagation

    - by jcmoney
    I was considering switching to Amazon EC2 to host my website to handle more traffic. It seems like I would have to update DNS records to point to the new server but I was wondering if there was a way to avoid having to wait for the new DNS record to propagate. Putting the code on both hosts would not work for me since the app writes to a database pretty frequently. I thought about just using a meta redirect or php redirect on the old host to redirect to the new host ip but was wondering if there's a better more accepted way of doing this.

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  • Allow traffic from ssl-vpn to enter ipsec tunnel on fortigate

    - by Sascha
    we configured our FortiGate 50B to route traffic from our local net 192.168.10.* (which is our office) to a remote network 172.29.112.* using an ipsec tunnel. Everything works fine as long my computer has an ip from 192.168.10.*. We can also connect to the office network from at home using a ssl vpn connection. Once connected we receive an ip from 10.41.41.*. Now I want to allow the traffic flow from 10.41.41.* to 172.29.112.* just like it does from the office network. Could somebody point me in the right direction what I would need to do? Thanks, Sascha

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  • IIS will not install on Windows 7 Pro 64 bit

    - by Paul
    I have a new PC running Windows 7 Professional 64 bit. I have an issue installing IIS - it goes through the install process, but at the end tells me "not all components could be installed", with no additional information given. There is no sign of an error in the install log or in event viewer. However, at this point, IIS is installed and working! I can run IIS manager, browse to localhost and see the default page, but at the next reboot the system rolls back and th einstall vanishes. I have tried installing II using the Windows Components section in Add/Remove Programs, I have also tried the Web Platform Installer and using the command line, all with the same end result.

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  • Fix Firefox Not Scrolling with Up/Down Arrow Keys or Home/End Keys

    - by The Geek
    If you’ve encountered a problem where your Firefox installation no longer scrolls when you use the up or down arrow keys, and even the Home or End keys don’t work anymore, there’s an easy fix. When this problem happens, you’ll notice that moving the arrow keys around just moves the cursor around the page. Annoying! The problem is because you tripped the Caret Browsing feature at some point, and accidentally hit Yes. To fix this, you can just hit the F7 key again. Or, if you want to do it the about:config way, filter by accessibility.browsewithcaret and make sure it’s set to false. Remember, you can double-click on any boolean value to toggle between true and false. Similar Articles Productive Geek Tips Keyboard Ninja: Scrolling the Windows Command Prompt With Only the KeyboardShow Shortcut Keys in ScreenTips in Visual Studio 2003Show Shortcut Keys in ScreenTips in Visual Studio 2005Future Date a Post in Windows Live WriterDisable the Irritating Sticky / Filter Keys Popup Dialogs TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Need Help with Your Home Network? Awesome Lyrics Finder for Winamp & Windows Media Player Download Videos from Hulu Pixels invade Manhattan Convert PDF files to ePub to read on your iPad Hide Your Confidential Files Inside Images

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  • Apache AddType to all extention?

    - by acidzombie24
    I am follwing these awesome instructions http://blog.ruski.co.za/page/Install-Mono-on-Ubuntu.aspx and at this point i understand what is happening (except i dont reconize why .config would need to be an ext) I would like all urls to use x-asp-net so urls like site.com/data/user/more/title anything goes.lol woot.falseExt with space AddType application/x-asp-net .aspx .ashx .asmx .ascx .asax .config .ascx How do i do that? also it would be nice if i can make it so php still runs normally on other sites but thats not my concern right now. I need all urls to be able to run on this server/site

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  • Aging vs. Coding Skills

    - by Renan Malke Stigliani
    A little background, since it can be part of my point fo view. I'm a C#/Java programmer with age of 23, coding since my 18's. I started studying C and working with Cobol, and after 1 year I quickly moved to C#/Java Web Development, and have worked with it in about 3/4 companies. (I've just moved again) In my (brief) professional career I encountered some older programmers, all the times it was very hard to work with them, since I was way better programmer than they. And it is not about just the language skills, some of them had seriously problems understanding basic logic. Now I wonder how theese programmer get jobs on the market since (I imagine) they have more expenses, and thus have to make more money, and are really counter-productives. In theese examples, others project member have to constantly keep stoping for helping them out. All the times, they eventually quit... So I wonder... May the aging process slow down the learning rate and logic thinking? Does the programmer has to, or at least should, move to a management area before getting old? Please, my intention is not to be disrespectful with older persons. I am fully aware that this is NOT the case of all older programmers, I often see around very good old programmers on the net, I just never met them for close.

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  • Couldn't find package - But package is listed in the Packages file

    - by Chris
    (Quoted items are redacted elements) I am using a private repository and an currently trying to repackage some packages 3rd-party packages. I extract the package, make a few modifications (just the control files to fit with company policy - though sometimes file install locations though not in this case) and repackage (and usually rename). Normally I copy the files into a new blank debhelper project and reconstruct the package, however, with a recent one I attempting to convert and some libraries and stuff aren't linking properly (I did copy the postinst, postrm, and preinst files along with all DEDIAN files exactly), the original package worked, but my repackage doesn't, despite providing the same files in the same locations and the same postinst and preinst. So I was attempting to just modify the current packages control files (as the original package is not very good and will not list in our repository and getting a better one from the 3rd party is not an option). I also renamed the package. I did the following: dpkg-deb -R "directory" Modify DEBIAN/control dpkg-deb -b "directory" "package name I want" I did this and put it in our repository. The package shows up in the "Packages" file on the repository and running apt-get update on the client side shows the package in: /var/lib/apt/lists/"server"_"location"_Packages However when I do an apt-get install on the package name (as listed in the Packages file - I did a copy paste) it says it can't find the package. Same with an apt-cache search The Packages listings is as follow (name redacted): Package: "package name" Priority: extra Section: unknown Maintainer: "maintainer" Architecture: any Version: 1.0-lucid5 Depends: libc Filename: "directory"/"package_filename" Size: 2206292 MD5sum: "md5sum" SHA1: "sha key" SHA256: "sha256 key" Description: "description" I am running as sudo (and tried as root as well). I don't understand why apt-get won't see the package. Can you point out any flaws in what I have done, or perhaps some help on getting apt-get to properly see the package. Or perhaps an alternative. I am not even sure if this is a valid way to repackage something. Thanks.

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  • Why Standards Only Get You So Far

    - by Tim Murphy
    Over the years I have been exposed to a number of standards.  EDI was the first.  More recently it has been the CIECA standard for Insurance and now the embattled document standards of Open XML and ODF. Standards actually came up at the last CAG meeting.  The debate was over how effective they really are.  Even back in the late 80’s to early 90’s people found they had to customize these standards to get any work done.  I even had one vendor about a year ago tell me that they really weren’t standards, they were more of a guideline. The problem is that standards are created either by committee or by companies trying to sell a product.  They never fit all situations.  This is why most of them leave extension points in their definition.  Of course if you use those extension points everyone has to have custom code to know how to consume the new product. Standards increase reliability but they stifle innovation and slow the time to market cycle of products.  In this age of ever shortening windows of opportunity that could mean that a company could lose its competitive advantage. I believe that standards are not only good, but essential.  I also believe that they are not a silver bullet.  People who turn competing standards into a type of holy war are really missing the point.  I think we should make the best standards we can, whether that is for a product so that customers can use API, or by committee so that they cross products.  But they also need to be as feature rich and flexible as possible.  They can’t be just the lowest common denominator since this type of standard will be broken the day it is published.  In the end though, it is the market will vote with their dollars. del.icio.us Tags: Office Open XML,ODF,Standards,EDI

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  • GeForce 9600GT support for dual monitor setup

    - by Theo
    I have a NVIDIA GeForce 9600 GT (point of view, link) on an Asus M2V-MX motherboard. The card has one DVI, HDMI and S-Video output. The graphics card does not seem to support dual monitors: the driver control panel for the graphics card does not detect a second monitor that is attached via S-Video (which leads me to believe that it doesn't support dual monitors with DVI and the other connections). Would it be possible to use a VGA/DVI splitter to attach two monitors to the single DVI output on the graphics card? Would this allow for a dual monitor setup, or only mirroring? How do I know if the graphic card supports this? With this particular motherboard, would it be possible to use the onboard video for another monitor?

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  • How to use qcow2 disk image in Linux?

    - by sauparna
    I have a large qcow2 formatted disk image, which I use as storage. Often I need to move data to and from this disk image. I mount the disk using the qemu-nbd tool as follows: modprobe nbd max_part=63 qemu-nbd -c /dev/nbd0 /host/disk100G.img mount /dev/nbd0p1 /home/rup/disk But disk access fails every now and then in the midst of some I/O operation with an "Input/output error". At that point I have to manually unmount the disk and re-mount it so that I can run the program again: qemu-nbd -d /dev/nbd0 umount joborkhaki/ What could be the reason for this? Is there a better tool that I can use to maintain a qcow2 disk image?

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  • Abstract exception super type

    - by marcof
    If throwing System.Exception is considered so bad, why wasn't Exception made abstract in the first place? That way, it would not be possible to call: throw new Exception("Error occurred."); This would enforce using derived exceptions to provide more details about the error that occurred. For example, when I want to provide a custom exception hierarchy for a library, I usually declare an abstract base class for my exceptions: public abstract class CustomExceptionBase : Exception { /* some stuff here */ } And then some derived exception with a more specific purpose: public class DerivedCustomException : CustomExceptionBase { /* some more specific stuff here */ } Then when calling any library method, one could have this generic try/catch block to directly catch any error coming from the library: try { /* library calls here */ } catch (CustomExceptionBase ex) { /* exception handling */ } Is this a good practice? Would it be good if Exception was made abstract? EDIT : My point here is that even if an exception class is abstract, you can still catch it in a catch-all block. Making it abstract is only a way to forbid programmers to throw a "super-wide" exception. Usually, when you voluntarily throw an exception, you should know what type it is and why it happened. Thus enforcing to throw a more specific exception type.

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  • Oracle University Nouveaux cours (Week 35)

    - by swalker
    Parmi les nouveautés d’Oracle Université de ce mois-ci, vous trouverez : Fusion Middleware Oracle Directory Services 11g: Administration (5 days) Oracle SOA Suite 11g: Essential Concepts (Training on Demand) e-Business Suite R12 Oracle HRMS iRecruitment Fundamentals (Self-Study Course) R12 Oracle Payroll Fundamentals: Administration (Self-Study Course) R12 Oracle HRMS System Administration Fundamentals (Self-Study Course) R12 Oracle HRMS Self Service Fundamentals (Self-Study Course) R12 Oracle HRMS Implement and Use Fast Formula (Self-Study Course) R12 HRMS Work Structures Fundamentals (Self-Study Course) R12 HRMS Total Compensation Foundations (Self-Study Course) Siebel Siebel 8.1.x Chat and Voice Integration Using CCA (Self-Study Course) Siebel 8.1.x Search using Oracle Secure Enterprise Search (Self-Study Course) Siebel 8.1.x COM Web Services (Self-Study Course) Siebel 8.1.x COM Asset Based Order Management (Self-Study Course) Siebel 8.1.x COM: What is New in Product Configurator (Self-Study Course) Siebel 8.1.x COM Product Configurator Caching & Performance Management (Self-Study Course) Siebel 8.1.x COM PSP Engine Caching and Performance Management (Self-Study Course) Siebel 8.1.x Remote: Administration (Self-Study Course) Siebel 8.1.x Remote: Technical Foundations (Self-Study Course) Siebel Tools: Configuring Chart and Tree Applets (Self-Study Course) Sun - Server Administration SPARC SuperCluster Administration and Maintenance Seminar (2 days) OPN Only Sparc T4-Based Servers Installation Boot Camp (1 day) Primavera Primavera P6 Application Administration Rel 8.x (2 days) Oracle Retail Retail Merchandising System (RMS) Business Overview (Self-Study Course) Retail Invoice Matching (ReIM) Product Overview (Self-Study Course) Retail Invoice Matching (ReIM) Business Introduction (Self-Study Course) Retail Demand Forecasting: RDF Classic Product Overview (Self-Study Course) Retail Demand Forecasting Introduction (Self-Study Course) Retail Data Warehouse (RDW) Overview 13.1 (Self-Study Course) Oracle Retail Point-of-Service (POS) Product Overview (Self-Study Course) Retail Sales Audit (ReSA) Product Overview (Self-Study Course) Retail Price Management (RPM) Product Overview (Self-Study Course) Retail Merchandising System (RMS) Technical Introduction (Self-Study Course) Oracle Retail Integration Bus (RIB) Product Overview (Self-Study Course) Oracle Communiucations Unified Communications Suite Convergence Customization (2 days) OSM Foundations I: Tasks, Processes and Orders Contacter l’ équipe locale d’ Oracle University pour toute information et dates de cours. Restez connecté à Oracle University : LinkedIn OracleMix Twitter Facebook Google+

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  • SQL SERVER – Capturing Wait Types and Wait Stats Information at Interval – Wait Type – Day 5 of 28

    - by pinaldave
    Earlier, I have tried to cover some important points about wait stats in detail. Here are some points that we had covered earlier. DMV related to wait stats reset when we reset SQL Server services DMV related to wait stats reset when we manually reset the wait types However, at times, there is a need of making this data persistent so that we can take a look at them later on. Sometimes, performance tuning experts do some modifications to the server and try to measure the wait stats at that point of time and after some duration. I use the following method to measure the wait stats over the time. -- Create Table CREATE TABLE [MyWaitStatTable]( [wait_type] [nvarchar](60) NOT NULL, [waiting_tasks_count] [bigint] NOT NULL, [wait_time_ms] [bigint] NOT NULL, [max_wait_time_ms] [bigint] NOT NULL, [signal_wait_time_ms] [bigint] NOT NULL, [CurrentDateTime] DATETIME NOT NULL, [Flag] INT ) GO -- Populate Table at Time 1 INSERT INTO MyWaitStatTable ([wait_type],[waiting_tasks_count],[wait_time_ms],[max_wait_time_ms],[signal_wait_time_ms], [CurrentDateTime],[Flag]) SELECT [wait_type],[waiting_tasks_count],[wait_time_ms],[max_wait_time_ms],[signal_wait_time_ms], GETDATE(), 1 FROM sys.dm_os_wait_stats GO ----- Desired Delay (for one hour) WAITFOR DELAY '01:00:00' -- Populate Table at Time 2 INSERT INTO MyWaitStatTable ([wait_type],[waiting_tasks_count],[wait_time_ms],[max_wait_time_ms],[signal_wait_time_ms], [CurrentDateTime],[Flag]) SELECT [wait_type],[waiting_tasks_count],[wait_time_ms],[max_wait_time_ms],[signal_wait_time_ms], GETDATE(), 2 FROM sys.dm_os_wait_stats GO -- Check the difference between Time 1 and Time 2 SELECT T1.wait_type, T1.wait_time_ms Original_WaitTime, T2.wait_time_ms LaterWaitTime, (T2.wait_time_ms - T1.wait_time_ms) DiffenceWaitTime FROM MyWaitStatTable T1 INNER JOIN MyWaitStatTable T2 ON T1.wait_type = T2.wait_type WHERE T2.wait_time_ms > T1.wait_time_ms AND T1.Flag = 1 AND T2.Flag = 2 ORDER BY DiffenceWaitTime DESC GO -- Clean up DROP TABLE MyWaitStatTable GO If you notice the script, I have used an additional column called flag. I use it to find out when I have captured the wait stats and then use it in my SELECT query to SELECT wait stats related to that time group. Many times, I select more than 5 or 6 different set of wait stats and I find this method very convenient to find the difference between wait stats. In a future blog post, we will talk about specific wait stats. Read all the post in the Wait Types and Queue series. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL DMV, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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  • Multiple possible jsp views for a request

    - by Karl Walsh
    I'm looking to offer the user some way of changing how a single page looks based on some pre-defined jsps. i.e. Two or more jsp's contain similar information, and would be backed by a single controller method. The controller would decide which view to return. Is there a common way of achieving this? At the moment I have some administration screens where I control a list of possible views. The user can then choose which one to see from a drop-down. My current issue is that I don't know how to confirm (at the admin screen) that the view is valid. Is there a way of asking spring for all possible views so I can filter them and resent a drop-down on the admin screen rather than a free text field? If not is there a way of asking spring if a single view is valid? All these views will reside under a common directory, so it would probably be possible to scan recursively from that point and build a list of possible views. This goes beyond simply changing the css, since the page content might be different despite being backed by the same model.

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  • The future for Microsoft

    - by Scott Dorman
    Originally posted on: http://geekswithblogs.net/sdorman/archive/2013/10/16/the-future-for-microsoft.aspxMicrosoft is in the process of reinventing itself. While some may argue that it’s “too little, too late” or that their growing consumer-focused strategy is wrong, the truth of the situation is that Microsoft is reinventing itself into a new company. While Microsoft is now calling themselves a “devices and services” company, that’s not entirely accurate. Let’s look at some facts: Microsoft will always (for the long-term foreseeable future) be financially split into the following divisions: Windows/Operating Systems, which for FY13 made up approximately 24% of overall revenue. Server and Tools, which for FY13 made up approximately 26% of overall revenue. Enterprise/Business Products, which for FY13 made up approximately 32% of overall revenue. Entertainment and Devices, which for FY13 made up approximately 13% of overall revenue. Online Services, which for FY13 made up approximately 4% of overall revenue. It is important to realize that hardware products like the Surface fall under the Windows/Operating Systems division while products like the Xbox 360 fall under the Entertainment and Devices division. (Presumably other hardware, such as mice, keyboards, and cameras, also fall under the Entertainment and Devices division.) It’s also unclear where Microsoft’s recent acquisition of Nokia’s handset division will fall, but let’s assume that it will be under Entertainment and Devices as well. Now, for the sake of argument, let’s assume a slightly different structure that I think is more in line with how Microsoft presents itself and how the general public sees it: Consumer Products and Devices, which would probably make up approximately 9% of overall revenue. Developer Tools, which would probably make up approximately 13% of overall revenue. Enterprise Products and Devices, which would probably make up approximately 47% of overall revenue. Entertainment, which would probably make up approximately 13% of overall revenue. Online Services, which would probably make up approximately 17% of overall revenue. (Just so we’re clear, in this structure hardware products like the Surface, a portion of Windows sales, and other hardware fall under the Consumer Products and Devices division. I’m assuming that more of the income for the Windows division is coming from enterprise/volume licenses so 15% of that income went to the Enterprise Products and Devices division. Most of the enterprise services, like Azure, fall under the Online Services division so half of the Server and Tools income went there as well.) No matter how you look at it, the bulk of Microsoft’s income still comes from not just the enterprise but also software sales, and this really shouldn’t surprise anyone. So, now that the stage is set…what’s the future for Microsoft? The future I see for Microsoft (again, this is just my prediction based on my own instinct, gut-feel and publicly available information) is this: Microsoft is becoming a consumer-focused enterprise company. Let’s look at it a different way. Microsoft is an enterprise-focused company trying to create a larger consumer presence.  To a large extent, this is the exact opposite of Apple, who is really a consumer-focused company trying to create a larger enterprise presence. The major reason consumer-focused companies (like Apple) have started making in-roads into the enterprise is the “bring your own device” phenomenon. Yes, Apple has created some “game-changing” products but their enterprise influence is still relatively small. Unfortunately (for this blog post at least), Apple provides revenue in terms of hardware products rather than business divisions, so it’s not possible to do a direct comparison. However, in the interest of transparency, from Apple’s Quarterly Report (filed 24 July 2013), their revenue breakdown is: iPhone, which for the 3 months ending 29 June 2013 made up approximately 51% of revenue. iPad, which for the 3 months ending 29 June 2013 made up approximately 18% of revenue. Mac, which for the 3 months ending 29 June 2013 made up approximately 14% of revenue. iPod, which for the 3 months ending 29 June 2013 made up approximately 2% of revenue. iTunes, Software, and Services, which for the 3 months ending 29 June 2013 made up approximately 11% of revenue. Accessories, which for the 3 months ending 29 July 2013 made up approximately 3% of revenue. From this, it’s pretty clear that Apple is a consumer-and-hardware-focused company. At this point, you may be asking yourself “Where is all of this going?” The answer to that lies in Microsoft’s shift in company focus. They are becoming more consumer focused, but what exactly does that mean? The biggest change (at least that’s been in the news lately) is the pending purchase of Nokia’s handset division. This, in combination with their Surface line of tablets and the Xbox, will put Microsoft squarely in the realm of a hardware-focused company in addition to being a software-focused company. That can (and most likely will) shift the revenue split to looking at revenue based on software sales (both consumer and enterprise) and also hardware sales (mostly on the consumer side). If we look at things strictly from a Windows perspective, Microsoft clearly has a lot of irons in the fire at the moment. Discounting the various product SKUs available and painting the picture with broader strokes, there are currently 5 different Windows-based operating systems: Windows Phone Windows Phone 7.x, which runs on top of the Windows CE kernel Windows Phone 8.x+, which runs on top of the Windows 8 kernel Windows RT The ARM-based version of Windows 8, which runs on top of the Windows 8 kernel Windows (Pro) The Intel-based version of Windows 8, which runs on top of the Windows 8 kernel Xbox The Xbox 360, which runs it’s own proprietary OS. The Xbox One, which runs it’s own proprietary OS, a version of Windows running on top of the Windows 8 kernel and a proprietary “manager” OS which manages the other two. Over time, Windows Phone 7.x devices will fade so that really leaves 4 different versions. Looking at Windows RT and Windows Phone 8.x paints an interesting story. Right now, all mobile phone devices run on some sort of ARM chip and that doesn’t look like it will change any time soon. That means Microsoft has two different Windows based operating systems for the ARM platform. Long term, it doesn’t make sense for Microsoft to continue supporting that arrangement. I have long suspected (since the Surface was first announced) that Microsoft will unify these two variants of Windows and recent speculation from some of the leading Microsoft watchers lends credence to this suspicion. It is rumored that upcoming Windows Phone releases will include support for larger screen sizes, relax the requirement to have a hardware-based back button and will continue to improve API parity between Windows Phone and Windows RT. At the same time, Windows RT will include support for smaller screen sizes. Since both of these operating systems are based on the same core Windows kernel, it makes sense (both from a financial and development resource perspective) for Microsoft to unify them. The user interfaces are already very similar. So similar in fact, that visually it’s difficult to tell them apart. To illustrate this, here are two screen captures: Other than a few variations (the Bing News app, the picture shown in the Pictures tile and the spacing between the tiles) these are identical. The one on the left is from my Windows 8.1 laptop (which looks the same as on my Surface RT) and the one on the right is from my Windows Phone 8 Lumia 925. This pretty clearly shows that from a consumer perspective, there really is no practical difference between how these two operating systems look and how you interact with them. For the consumer, your entertainment device (Xbox One), phone (Windows Phone) and mobile computing device (Surface [or some other vendors tablet], laptop, netbook or ultrabook) and your desktop computing device (desktop) will all look and feel the same. While many people will denounce this consistency of user experience, I think this will be a good thing in the long term, especially for the upcoming generations. For example, my 5-year old son knows how to use my tablet, phone and Xbox because they all feature nearly identical user experiences. When Windows 8 was released, Microsoft allowed a Windows Store app to be purchased once and installed on as many as 5 devices. With Windows 8.1, this limit has been increased to over 50. Why is that important? If you consider that your phone, computing devices, and entertainment device will be running the same operating system (with minor differences related to physical hardware chipset), that means that I could potentially purchase my sons favorite Angry Birds game once and be able to install it on all of the devices I own. (And for those of you wondering, it’s only 7 [at the moment].) From an app developer perspective, the story becomes even more compelling. Right now there are differences between the different operating systems, but those differences are shrinking. The user interface technology for both is XAML but there are different controls available and different user experience concepts. Some of the APIs available are the same while some are not. You can’t develop a Windows Phone app that can also run on Windows (either Windows Pro or RT). With each release of Windows Phone and Windows RT, those difference become smaller and smaller. Add to this mix the Xbox One, which will also feature a Windows-based operating system and the same “modern” (tile-based) user interface and the visible distinctions between the operating systems will become even smaller. Unifying the operating systems means one set of APIs and one code base to maintain for an app that can run on multiple devices. One code base means it’s easier to add features and fix bugs and that those changes become available on all devices at the same time. It also means a single app store, which will increase the discoverability and reach of your app and consolidate revenue and app profile management. Now, the choice of what devices an app is available on becomes a simple checkbox decision rather than a technical limitation. Ultimately, this means more apps available to consumers, which is always good for the app ecosystem. Is all of this just rumor, speculation and conjecture? Of course, but it’s not unfounded. As I mentioned earlier, some of the prominent Microsoft watchers are also reporting similar rumors. However, Microsoft itself has even hinted at this future with their recent organizational changes and by telling developers “if you want to develop for Xbox One, start developing for Windows 8 now.” I think this pretty clearly paints the following picture: Microsoft is committed to the “modern” user interface paradigm. Microsoft is changing their release cadence (for all products, not just operating systems) to be faster and more modular. Microsoft is going to continue to unify their OS platforms both from a consumer perspective and a developer perspective. While this direction will certainly concern some people it will excite many others. Microsoft’s biggest failing has always been following through with a strong and sustained marketing strategy that presents a consistent view point and highlights what this unified and connected experience looks like and how it benefits consumers and enterprises. We’ve started to see some of this over the last few years, but it needs to continue and become more aggressive and consistent. In the long run, I think Microsoft will be able to pull all of these technologies and devices together into one seamless ecosystem. It isn’t going to happen overnight, but my prediction is that we will be there by the end of 2016. As both a consumer and a developer, I, for one, am excited about the future of Microsoft.

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  • Bind9 as a caching resolver fails with mismatch ID on localhost but not external IP

    - by argibbs
    I'm running Ubuntu 12.04 LTS on a machine on my private network. I have bind9 installed (v9.8.1-P1) via aptitude, so it appears to have put all the bits in the right places and the service starts automatically. I plan on adding some zones later, but first I'm just trying to get it working as a caching resolver. I installed bind, configured it, and starting using it. Initially I thought it was working ok, but then I found some sites weren't being resolved. I've pinned it down to being linked to the size of the result and bind failing-over to TCP mode. So: I'm trying to find out why bind is failing when I query for domain info and the result is 512 bytes (causing a truncation and retry on TCP). Specifically it fails with ID mismatches if I point dig at localhost, but works when I query the machine's own IP (192.168.0.2). This appears to be backwards to the problem that most people have when using bind (fails on external ip, works on localhost). If I do dig @localhost google.com (which has a response of <512 bytes) then it works; I get no warnings, and plenty of output. $ dig @localhost google.com ; <<>> DiG 9.8.1-P1 <<>> @localhost google.com [snip lots of output] ;; Query time: 39 msec ;; SERVER: 127.0.0.1#53(127.0.0.1) ;; WHEN: Thu Oct 17 23:08:34 2013 ;; MSG SIZE rcvd: 495 If I do dig @localhost play.google.com (which has a larger response) then I get back something like: $ dig @localhost play.google.com ;; Truncated, retrying in TCP mode. ;; ERROR: ID mismatch: expected ID 3696, got 27130 This seems to be standard, documented behaviour - when the UDP response is large (here 'large' == 512 bytes) it falls back to TCP. The ID mismatch is not expected though. If I do dig @192.168.0.2 play.google.com then I still get the warning about using TCP mode, but it otherwise works $ dig @192.168.0.2 play.google.com ;; Truncated, retrying in TCP mode. ; <<>> DiG 9.8.1-P1 <<>> @192.168.0.2 play.google.com [snip most of the output] ;; Query time: 5 msec ;; SERVER: 192.168.0.2#53(192.168.0.2) ;; WHEN: Thu Oct 17 23:05:55 2013 ;; MSG SIZE rcvd: 521 At the moment I've not set up any zones in my local instance, so it's just acting as a caching resolver. My options config is pretty much unchanged from standard, I've got the following set: options { directory "/var/cache/bind"; allow-query { 192.168/16; 127.0.0.1; }; forwarders { 8.8.8.8; 8.8.4.4; }; dnssec-validation auto; edns-udp-size 4096 ; allow-transfer { any; }; auth-nxdomain no; # conform to RFC1035 listen-on-v6 { any; }; }; And my /etc/resolv.conf is just nameserver 127.0.0.1 search .local The problem definitely seems linked to the failover to TCP mode: if I do dig +bufsize=4096 @localhost play.google.com then it works; no warning about failover to TCP, no ID mismatch, and a standard looking result. To be honest, if there was a way to force bind to use a much larger UDP buffer, that'd probably be good enough for me, but all I've been able to find mention of is max-udp-size 4096 and that doesn't change the behaviour in any way. I've also tried setting edns-udp-size 512 in case the problem is some weird EDNS issue with my router (which seems unlikely since the +bufsize=4096 flag works fine). I've also tried dig +trace @localhost play.google.com; this works. No truncation/TCP warning, and a full result. I've also tried changing the servers used in the forwarder (e.g. to OpenDNS), but that makes no difference. There's one last data point: if I repetitively do dig @localhost play.google.com I don't always get an ID mismatch, but sometimes a REFUSED error. I'm much more likely to get a REFUSED error if I dig the non-localhost IP (192.168.0.2) first: $ dig @localhost play.google.com ;; Truncated, retrying in TCP mode. ; <<>> DiG 9.8.1-P1 <<>> @localhost play.google.com ; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: REFUSED, id: 35104 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;play.google.com. IN A ;; Query time: 4 msec ;; SERVER: 127.0.0.1#53(127.0.0.1) ;; WHEN: Thu Oct 17 23:20:13 2013 ;; MSG SIZE rcvd: 33 Any insights or things to try would be much appreciated.

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  • apache2 force proxy for specific url on a subdomain

    - by Tony G.
    Hi, I have a site that has dynamic virtual subdomains using mod_rewrite, as defined like this: <VirtualHost *:80> ServerName example.com ServerAlias *.example.com DocumentRoot /var/www/example.com/www RewriteEngine on RewriteCond %{HTTP_HOST} ^[^.]+\.examle.com$ RewriteRule ^(.+) %{HTTP_HOST}$1 [C] RewriteRule ^([^.]+)\.example.com(.*) /var/www/example.com/$1$2 </VirtualHost> The problem is that I want a specific url, say subdomain.example.com/CONTROL/ to point back to www.example.com/ using a proxy (not url redirecting). I have tried adding: RewriteRule ^([^.]+)\.example.com/CONTROL(.*) /var/www/example.com/www$2 [P] But that didn't work. Any ideas?

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  • Render rivers in a grid.

    - by Gabriel A. Zorrilla
    I have created a random height map and now i want to create rivers. I've made an algorithm based on a* to make rivers flow from peaks to sea and now i'm in the quest of figuring out an elegant algorithm to render them. It's a 2D, square, mapgrid. The cells which the river pases has a simple integer value with this form :rivernumber && pointOrder. Ie: 10, 11, 12, 13, 14, 15, 16...1+N for the first river, 20,21,22,23...2+N for the second, etc. This is created in the map grid generation time and it's executed just once, when the world is generated. I wanted to treat each river as a vector, but there is a problem, if the same river has branches (because i put some noise to generate branches), i can not just connect the points in order. The second alternative is to generate a complex algorithm where analizes each point, checks if the next is not a branch, if so trigger another algorithm that take care of the branch then returns to the main river, etc. Very complex and inelegant. Perhaps there is a solution in the world generation algorithm or in the river rendering algorithm that is commonly used in these cases and i'm not aware of. Any tips? Thanks!!

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  • Q8300 Core-2 Quad vs X3360 Xeon

    - by alchemical
    I'm looking at this ABMX server, and trying to decide on the CPU. I'm purchasing 2 servers, to be used as dedicated web and DB servers for a web site that has low traffic now but could ramp up quickly. Just trying to decide if it is worth about $200 more (per server) for the Xeon vs the core-2. Passmark rates them at 3567 and 4153, which didn't seem that different. I'm not planning at this point to need virtualization. I did hear rumors that Xeon stands up better in a 24/7 server environment, but heard others say there wasn't that much difference. Planning to run Windows Server 2008, likely the R2 release, with 8GB RAM.

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  • transient DNS issues with certain sites in Snow Leopard

    - by ceejayoz
    I'm having a rather bizarre DNS issue with Snow Leopard. Certain sites - MSNBC.com being the most noticeable for me - have an odd issue with DNS, in all browsers. After not visiting the site after a while (30 minutes or so), the first attempt to access MSNBC.com results in a DNS error. Refreshing 1-5 times resolves the issue until the next ~30 minute period of inactivity. Seen this on three separate Macs at this point. One from-the-factory Snow Leopard install, two upgrades. Most sites are just fine. I Google and found other reports of the same thing with MSNBC, but no solutions.

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  • Solaris X86 64-bit Assembly Programming

    - by danx
    Solaris X86 64-bit Assembly Programming This is a simple example on writing, compiling, and debugging Solaris 64-bit x86 assembly language with a C program. This is also referred to as "AMD64" assembly. The term "AMD64" is used in an inclusive sense to refer to all X86 64-bit processors, whether AMD Opteron family or Intel 64 processor family. Both run Solaris x86. I'm keeping this example simple mainly to illustrate how everything comes together—compiler, assembler, linker, and debugger when using assembly language. The example I'm using here is a C program that calls an assembly language program passing a C string. The assembly language program takes the C string and calls printf() with it to print the string. AMD64 Register Usage But first let's review the use of AMD64 registers. AMD64 has several 64-bit registers, some special purpose (such as the stack pointer) and others general purpose. By convention, Solaris follows the AMD64 ABI in register usage, which is the same used by Linux, but different from Microsoft Windows in usage (such as which registers are used to pass parameters). This blog will only discuss conventions for Linux and Solaris. The following chart shows how AMD64 registers are used. The first six parameters to a function are passed through registers. If there's more than six parameters, parameter 7 and above are pushed on the stack before calling the function. The stack is also used to save temporary "stack" variables for use by a function. 64-bit Register Usage %rip Instruction Pointer points to the current instruction %rsp Stack Pointer %rbp Frame Pointer (saved stack pointer pointing to parameters on stack) %rdi Function Parameter 1 %rsi Function Parameter 2 %rdx Function Parameter 3 %rcx Function Parameter 4 %r8 Function Parameter 5 %r9 Function Parameter 6 %rax Function return value %r10, %r11 Temporary registers (need not be saved before used) %rbx, %r12, %r13, %r14, %r15 Temporary registers, but must be saved before use and restored before returning from the current function (usually with the push and pop instructions). 32-, 16-, and 8-bit registers To access the lower 32-, 16-, or 8-bits of a 64-bit register use the following: 64-bit register Least significant 32-bits Least significant 16-bits Least significant 8-bits %rax%eax%ax%al %rbx%ebx%bx%bl %rcx%ecx%cx%cl %rdx%edx%dx%dl %rsi%esi%si%sil %rdi%edi%di%axl %rbp%ebp%bp%bp %rsp%esp%sp%spl %r9%r9d%r9w%r9b %r10%r10d%r10w%r10b %r11%r11d%r11w%r11b %r12%r12d%r12w%r12b %r13%r13d%r13w%r13b %r14%r14d%r14w%r14b %r15%r15d%r15w%r15b %r16%r16d%r16w%r16b There's other registers present, such as the 64-bit %mm registers, 128-bit %xmm registers, 256-bit %ymm registers, and 512-bit %zmm registers. Except for %mm registers, these registers may not present on older AMD64 processors. Assembly Source The following is the source for a C program, helloas1.c, that calls an assembly function, hello_asm(). $ cat helloas1.c extern void hello_asm(char *s); int main(void) { hello_asm("Hello, World!"); } The assembly function called above, hello_asm(), is defined below. $ cat helloas2.s /* * helloas2.s * To build: * cc -m64 -o helloas2-cpp.s -D_ASM -E helloas2.s * cc -m64 -c -o helloas2.o helloas2-cpp.s */ #if defined(lint) || defined(__lint) /* ARGSUSED */ void hello_asm(char *s) { } #else /* lint */ #include <sys/asm_linkage.h> .extern printf ENTRY_NP(hello_asm) // Setup printf parameters on stack mov %rdi, %rsi // P2 (%rsi) is string variable lea .printf_string, %rdi // P1 (%rdi) is printf format string call printf ret SET_SIZE(hello_asm) // Read-only data .text .align 16 .type .printf_string, @object .printf_string: .ascii "The string is: %s.\n\0" #endif /* lint || __lint */ In the assembly source above, the C skeleton code under "#if defined(lint)" is optionally used for lint to check the interfaces with your C program--very useful to catch nasty interface bugs. The "asm_linkage.h" file includes some handy macros useful for assembly, such as ENTRY_NP(), used to define a program entry point, and SET_SIZE(), used to set the function size in the symbol table. The function hello_asm calls C function printf() by passing two parameters, Parameter 1 (P1) is a printf format string, and P2 is a string variable. The function begins by moving %rdi, which contains Parameter 1 (P1) passed hello_asm, to printf()'s P2, %rsi. Then it sets printf's P1, the format string, by loading the address the address of the format string in %rdi, P1. Finally it calls printf. After returning from printf, the hello_asm function returns itself. Larger, more complex assembly functions usually do more setup than the example above. If a function is returning a value, it would set %rax to the return value. Also, it's typical for a function to save the %rbp and %rsp registers of the calling function and to restore these registers before returning. %rsp contains the stack pointer and %rbp contains the frame pointer. Here is the typical function setup and return sequence for a function: ENTRY_NP(sample_assembly_function) push %rbp // save frame pointer on stack mov %rsp, %rbp // save stack pointer in frame pointer xor %rax, %r4ax // set function return value to 0. mov %rbp, %rsp // restore stack pointer pop %rbp // restore frame pointer ret // return to calling function SET_SIZE(sample_assembly_function) Compiling and Running Assembly Use the Solaris cc command to compile both C and assembly source, and to pre-process assembly source. You can also use GNU gcc instead of cc to compile, if you prefer. The "-m64" option tells the compiler to compile in 64-bit address mode (instead of 32-bit). $ cc -m64 -o helloas2-cpp.s -D_ASM -E helloas2.s $ cc -m64 -c -o helloas2.o helloas2-cpp.s $ cc -m64 -c helloas1.c $ cc -m64 -o hello-asm helloas1.o helloas2.o $ file hello-asm helloas1.o helloas2.o hello-asm: ELF 64-bit LSB executable AMD64 Version 1 [SSE FXSR FPU], dynamically linked, not stripped helloas1.o: ELF 64-bit LSB relocatable AMD64 Version 1 helloas2.o: ELF 64-bit LSB relocatable AMD64 Version 1 $ hello-asm The string is: Hello, World!. Debugging Assembly with MDB MDB is the Solaris system debugger. It can also be used to debug user programs, including assembly and C. The following example runs the above program, hello-asm, under control of the debugger. In the example below I load the program, set a breakpoint at the assembly function hello_asm, display the registers and the first parameter, step through the assembly function, and continue execution. $ mdb hello-asm # Start the debugger > hello_asm:b # Set a breakpoint > ::run # Run the program under the debugger mdb: stop at hello_asm mdb: target stopped at: hello_asm: movq %rdi,%rsi > $C # display function stack ffff80ffbffff6e0 hello_asm() ffff80ffbffff6f0 0x400adc() > $r # display registers %rax = 0x0000000000000000 %r8 = 0x0000000000000000 %rbx = 0xffff80ffbf7f8e70 %r9 = 0x0000000000000000 %rcx = 0x0000000000000000 %r10 = 0x0000000000000000 %rdx = 0xffff80ffbffff718 %r11 = 0xffff80ffbf537db8 %rsi = 0xffff80ffbffff708 %r12 = 0x0000000000000000 %rdi = 0x0000000000400cf8 %r13 = 0x0000000000000000 %r14 = 0x0000000000000000 %r15 = 0x0000000000000000 %cs = 0x0053 %fs = 0x0000 %gs = 0x0000 %ds = 0x0000 %es = 0x0000 %ss = 0x004b %rip = 0x0000000000400c70 hello_asm %rbp = 0xffff80ffbffff6e0 %rsp = 0xffff80ffbffff6c8 %rflags = 0x00000282 id=0 vip=0 vif=0 ac=0 vm=0 rf=0 nt=0 iopl=0x0 status=<of,df,IF,tf,SF,zf,af,pf,cf> %gsbase = 0x0000000000000000 %fsbase = 0xffff80ffbf782a40 %trapno = 0x3 %err = 0x0 > ::dis # disassemble the current instructions hello_asm: movq %rdi,%rsi hello_asm+3: leaq 0x400c90,%rdi hello_asm+0xb: call -0x220 <PLT:printf> hello_asm+0x10: ret 0x400c81: nop 0x400c85: nop 0x400c88: nop 0x400c8c: nop 0x400c90: pushq %rsp 0x400c91: pushq $0x74732065 0x400c96: jb +0x69 <0x400d01> > 0x0000000000400cf8/S # %rdi contains Parameter 1 0x400cf8: Hello, World! > [ # Step and execute 1 instruction mdb: target stopped at: hello_asm+3: leaq 0x400c90,%rdi > [ mdb: target stopped at: hello_asm+0xb: call -0x220 <PLT:printf> > [ The string is: Hello, World!. mdb: target stopped at: hello_asm+0x10: ret > [ mdb: target stopped at: main+0x19: movl $0x0,-0x4(%rbp) > :c # continue program execution mdb: target has terminated > $q # quit the MDB debugger $ In the example above, at the start of function hello_asm(), I display the stack contents with "$C", display the registers contents with "$r", then disassemble the current function with "::dis". The first function parameter, which is a C string, is passed by reference with the string address in %rdi (see the register usage chart above). The address is 0x400cf8, so I print the value of the string with the "/S" MDB command: "0x0000000000400cf8/S". I can also print the contents at an address in several other formats. Here's a few popular formats. For more, see the mdb(1) man page for details. address/S C string address/C ASCII character (1 byte) address/E unsigned decimal (8 bytes) address/U unsigned decimal (4 bytes) address/D signed decimal (4 bytes) address/J hexadecimal (8 bytes) address/X hexadecimal (4 bytes) address/B hexadecimal (1 bytes) address/K pointer in hexadecimal (4 or 8 bytes) address/I disassembled instruction Finally, I step through each machine instruction with the "[" command, which steps over functions. If I wanted to enter a function, I would use the "]" command. Then I continue program execution with ":c", which continues until the program terminates. MDB Basic Cheat Sheet Here's a brief cheat sheet of some of the more common MDB commands useful for assembly debugging. There's an entire set of macros and more powerful commands, especially some for debugging the Solaris kernel, but that's beyond the scope of this example. $C Display function stack with pointers $c Display function stack $e Display external function names $v Display non-zero variables and registers $r Display registers ::fpregs Display floating point (or "media" registers). Includes %st, %xmm, and %ymm registers. ::status Display program status ::run Run the program (followed by optional command line parameters) $q Quit the debugger address:b Set a breakpoint address:d Delete a breakpoint $b Display breakpoints :c Continue program execution after a breakpoint [ Step 1 instruction, but step over function calls ] Step 1 instruction address::dis Disassemble instructions at an address ::events Display events Further Information "Assembly Language Techniques for Oracle Solaris on x86 Platforms" by Paul Lowik (2004). Good tutorial on Solaris x86 optimization with assembly. The Solaris Operating System on x86 Platforms An excellent, detailed tutorial on X86 architecture, with Solaris specifics. By an ex-Sun employee, Frank Hofmann (2005). "AMD64 ABI Features", Solaris 64-bit Developer's Guide contains rules on data types and register usage for Intel 64/AMD64-class processors. (available at docs.oracle.com) Solaris X86 Assembly Language Reference Manual (available at docs.oracle.com) SPARC Assembly Language Reference Manual (available at docs.oracle.com) System V Application Binary Interface (2003) defines the AMD64 ABI for UNIX-class operating systems, including Solaris, Linux, and BSD. Google for it—the original website is gone. cc(1), gcc(1), and mdb(1) man pages.

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