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  • Documentation Changes in Solaris 11.1

    - by alanc
    One of the first places you can see Solaris 11.1 changes are in the docs, which have now been posted in the Solaris 11.1 Library on docs.oracle.com. I spent a good deal of time reviewing documentation for this release, and thought some would be interesting to blog about, but didn't review all the changes (not by a long shot), and am not going to cover all the changes here, so there's plenty left for you to discover on your own. Just comparing the Solaris 11.1 Library list of docs against the Solaris 11 list will show a lot of reorganization and refactoring of the doc set, especially in the system administration guides. Hopefully the new break down will make it easier to get straight to the sections you need when a task is at hand. Packaging System Unfortunately, the excellent in-depth guide for how to build packages for the new Image Packaging System (IPS) in Solaris 11 wasn't done in time to make the initial Solaris 11 doc set. An interim version was published shortly after release, in PDF form on the OTN IPS page. For Solaris 11.1 it was included in the doc set, as Packaging and Delivering Software With the Image Packaging System in Oracle Solaris 11.1, so should be easier to find, and easier to share links to specific pages the HTML version. Beyond just how to build a package, it includes details on how Solaris is packaged, and how package updates work, which may be useful to all system administrators who deal with Solaris 11 upgrades & installations. The Adding and Updating Oracle Solaris 11.1 Software Packages was also extended, including new sections on Relaxing Version Constraints Specified by Incorporations and Locking Packages to a Specified Version that may be of interest to those who want to keep the Solaris 11 versions of certain packages when they upgrade, such as the couple of packages that had functionality removed by an (unusual for an update release) End of Feature process in the 11.1 release. Also added in this release is a document containing the lists of all the packages in each of the major package groups in Solaris 11.1 (solaris-desktop, solaris-large-server, and solaris-small-server). While you can simply get the contents of those groups from the package repository, either via the web interface or the pkg command line, the documentation puts them in handy tables for easier side-by-side comparison, or viewing the lists before you've installed the system to pick which one you want to initially install. X Window System We've not had good X11 coverage in the online Solaris docs in a while, mostly relying on the man pages, and upstream X.Org docs. In this release, we've integrated some X coverage into the Solaris 11.1 Desktop Adminstrator's Guide, including sections on installing fonts for fontconfig or legacy X11 clients, X server configuration, and setting up remote access via X11 or VNC. Of course we continue to work on improving the docs, including a lot of contributions to the upstream docs all OS'es share (more about that another time). Security One of the things Oracle likes to do for its products is to publish security guides for administrators & developers to know how to build systems that meet their security needs. For Solaris, we started this with Solaris 11, providing a guide for sysadmins to find where the security relevant configuration options were documented. The Solaris 11.1 Security Guidelines extend this to cover new security features, such as Address Space Layout Randomization (ASLR) and Read-Only Zones, as well as adding additional guidelines for existing features, such as how to limit the size of tmpfs filesystems, to avoid users driving the system into swap thrashing situations. For developers, the corresponding document is the Developer's Guide to Oracle Solaris 11 Security, which has been the source for years for documentation of security-relevant Solaris API's such as PAM, GSS-API, and the Solaris Cryptographic Framework. For Solaris 11.1, a new appendix was added to start providing Secure Coding Guidelines for Developers, leveraging the CERT Secure Coding Standards and OWASP guidelines to provide the base recommendations for common programming languages and their standard API's. Solaris specific secure programming guidance was added via links to other documentation in the product doc set. In parallel, we updated the Solaris C Libary Functions security considerations list with details of Solaris 11 enhancements such as FD_CLOEXEC flags, additional *at() functions, and new stdio functions such as asprintf() and getline(). A number of code examples throughout the Solaris 11.1 doc set were updated to follow these recommendations, changing unbounded strcpy() calls to strlcpy(), sprintf() to snprintf(), etc. so that developers following our examples start out with safer code. The Writing Device Drivers guide even had the appendix updated to list which of these utility functions, like snprintf() and strlcpy(), are now available via the Kernel DDI. Little Things Of course all the big new features got documented, and some major efforts were put into refactoring and renovation, but there were also a lot of smaller things that got fixed as well in the nearly a year between the Solaris 11 and 11.1 doc releases - again too many to list here, but a random sampling of the ones I know about & found interesting or useful: The Privileges section of the DTrace Guide now gives users a pointer to find out how to set up DTrace privileges for non-global zones and what limitations are in place there. A new section on Recommended iSCSI Configuration Practices was added to the iSCSI configuration section when it moved into the SAN Configuration and Multipathing administration guide. The Managing System Power Services section contains an expanded explanation of the various tunables for power management in Solaris 11.1. The sample dcmd sources in /usr/demo/mdb were updated to include ::help output, so that developers like myself who follow the examples don't forget to include it (until a helpful code reviewer pointed it out while reviewing the mdb module changes for Xorg 1.12). The README file in that directory was updated to show the correct paths for installing both kernel & userspace modules, including the 64-bit variants.

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  • Oracle Cloud Applications: The Right Ingredients Baked In

    - by yaldahhakim
    v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} Normal 0 false false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} Oracle Cloud Applications: The Right Ingredients Baked In Eggs, flour, milk, and sugar. The magic happens when you mix these ingredients together. The same goes for the hottest technologies fast changing how IT impacts our organizations today: cloud, social, mobile, and big data. By themselves they’re pretty good; combining them with a great recipe is what unlocks real transformation power. Choosing the right cloud can be very similar to choosing the right cake. First consider comparing the core ingredients that go into baking a cake and the core design principles in building a cloud-based application. For instance, if flour is the base ingredient of a cake, then rich functionality that spans complete business processes is the base of an enterprise-grade cloud. Cloud computing is more than just consuming an "application as service", and having someone else manage it for you. Rather, the value of cloud is about making your business more agile in the marketplace, and shortening the time it takes to deliver and adopt new innovation. It’s also about improving not only the efficiency at which we communicate but the actual quality of the information shared as well. Data from different systems, like ingredients in a cake, must also be blended together effectively and evaluated through a consolidated lens. When this doesn’t happen, for instance when data in your sales cloud doesn't seamlessly connect with your order management and other “back office” applications, the speed and quality of information can decrease drastically. It’s like mixing ingredients in a strainer with a straw – you just can’t bring it all together without losing something. Mixing ingredients is similar to bringing clouds together, and co-existing cloud applications with traditional on premise applications. This is where a shared services  platform built on open standards and Service Oriented Architecture (SOA) is critical. It’s essentially a cloud recipe that calls for not only great ingredients, but also ingredients you can get locally or most likely already have in your kitchen (or IT shop.) Open standards is the best way to deliver a cost effective, durable application integration strategy – regardless of where your apps are deployed. It’s also the best way to build your own cloud applications, or extend the ones you consume from a third party. Just like using standard ingredients and tools you already have in your kitchen, a standards based cloud enables your IT resources to ensure a cloud works easily with other systems. Your IT staff can also make changes using tools they are already familiar with. Or even more ideal, enable business users to actually tailor their experience without having to call upon IT for help at all. This frees IT resources to focus more on developing new innovative services for the organization vs. run and maintain. Carrying the cake analogy forward, you need to add all the ingredients in before you bake it. The same is true with a modern cloud. To harness the full power of cloud, you can’t leave out some of the most important ingredients and just layer them on top later. This is what a lot of our niche competitors have done when it comes to social, mobile, big data and analytics, and other key technologies impacting the way we do business. The transformational power of these technology trends comes from having a strategy from the get-go that combines them into a winning recipe, and delivers them in a unified way. In looking at ways Oracle’s cloud is different from other clouds – not only is breadth of functionality rich across functional pillars like CRM, HCM, ERP, etc. but it embeds social, mobile, and rich intelligence capabilities where they make the most sense across business processes. This strategy enables the Oracle Cloud to uniquely deliver on all three of these dimensions to help our customers unlock the full power of these transformational technologies.

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  • Waiting for Windows 8: A Long, Hot Summer

    - by andrewbrust
    Microsoft has revealed some things about Windows 8, and revealed a part of the developer story for new Windows 8 “tailored,” “immersive” applications.  In retrospect, very little was shared.  The bit that was revealed to us is that those applications can be developed using a combination of HTML 5 and JavaScript.  Not much else was said, except that additional details would be revealed at Microsoft’s //Build/ conference in Anaheim, California in September. This has left a lot of people in suspense, and it seems that suspended state is going to last all summer.  The problem, of course, is that in the absence of hard information, people fill the void with Speculation, Rumor and Gloom.  That’s a bit like Fear, Uncertainty and Doubt, except that it’s self-imposed by the Microsoft community and not planted by Microsoft’s competitors. This is a less-than-perfect situation.  Not only is it causing developers to worry about the value of their skill sets, but I am already hearing from consulting shops that customers are getting nervous too and, in extreme cases, opting for non-Microsoft tools for their projects as a result.  I’m also hearing from dev tool ISVs that sales have suffered as a result. It’s quite possible that the customers moving off .NET wanted to do so anyway and it’s also possible that dev tool ISVs are suffering slower sales this year due a slowed rate of economic recovery. Without hard information, tend to people interpret things negatively.  Actually, that’s the major point in all of this. While there is multitude of opinions about what the Windows 8 development platform will look like once fully revealed, there is an emerging consensus around one thing: it sure would help if Microsoft revealed more of its strategy…just enough to quash absurd rumors, stabilize the .NET ecosystem and get people to stay calm. We’ve had some reassurances thus far: there will be a Windows desktop mode; we’ll still have Windows Explorer, we’ll still run Office, we’ll still have a task bar, and all the skills and tools we use now will still work there.  But with reassurances like that…people still feel insecure.  Because telling us that Windows 8 will have what is essentially a “classic” mode sure makes it sound like today’s skill sets will soon be “classic” too…and then maybe they’ll just become obsolete. Humans find change scary; it’s natural.  And when left alone with their fears – because no one is saying anything to dispel them – people can go from frightened to paranoid, and can start to viewing things in a downright conspiratorial light.  It would be great if Microsoft stepped into the void now and told us what is coming – especially because whatever they tell us is bound to be at least a little better than what people think they are going to hear. I don’t know what the announcements will be, but I do have it on authority, from a number of sources, that Microsoft isn’t gong to talk until //Build/.  That means no news until September September 13th.  Nothing until after Labor Day.  You get zippo until after the Back-to-School sales are done. What to do?  Try not to let the dark voices of gloom and doom fill your head.  Even in the absence of answers, we still have some important facts: The .NET developer community is huge. Microsoft’s customers have major investments in .NET, and in .NET skills. Political infighting in Redmond might make for irrational decisions, but ultimately public companies can’t just alienate their advocates and piss off their customers.  Spite doesn’t trump fiduciary responsibility. The computing device markets are changing, software is changing, software business models are changing and developers are changing.  Microsoft has to keep up. The HTML + JavaScript community is huge too, and it includes many of the “changed” developers. Public companies can’t ignore new markets nor the popular standards that can help them enter those new markets.  Loyalty doesn’t trump fiduciary responsibility either. If Microsoft can appeal to new developers, then it should. If Microsoft can keep catering to its existing developers and customers -- not just through legacy support, but also through empowering futures -- then it probably will. You don’t have to shove your old friends out into the rain to make room for new ones; you can bring those new constituents in under a bigger tent.  I hope Microsoft will enlarge the tent, and I have trouble imagining why it would not.

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  • Clouds, Clouds, Clouds Everywhere, Not a Drop of Rain!

    - by sxkumar
    At the recently concluded Oracle OpenWorld 2012, the center of discussion was clearly Cloud. Over the five action packed days, I got to meet a large number of customers and most of them had serious interest in all things cloud.  Public Cloud - particularly the Oracle Cloud - clearly got a lot of attention and interest. I think the use cases and the value proposition for public cloud is pretty straight forward. However, when it comes to private cloud, there were some interesting revelations.  Well, I shouldn’t really call them revelations since they are pretty consistent with what I have heard from customers at other conferences as well as during 1:1 interactions. While the interest in enterprise private cloud remains to be very high, only a handful of enterprises have truly embarked on a journey to create what the purists would call true private cloud - with capabilities such as self-service and chargeback/show back. For a large majority, today's reality is simply consolidation and virtualization - and they are quite far off from creating an agile, self-service and transparent IT infrastructure which is what the enterprise cloud is all about.  Even a handful of those who have actually implemented a close-to-real enterprise private cloud have taken an infrastructure centric approach and are seeing only limited business upside. Quite a few were frank enough to admit that chargeback and self-service isn’t something that they see an immediate need for.  This is in quite contrast to the picture being painted by all those surveys out there that show a large number of enterprises having already implemented an enterprise private cloud.  On the face of it, this seems quite contrary to the observations outlined above. So what exactly is the reality? Well, the reality is that there is undoubtedly a huge amount of interest among enterprises about transforming their legacy IT environment - which is often seen as too rigid, too fragmented, and ultimately too expensive - to something more agile, transparent and business-focused. At the same time however, there is a great deal of confusion among CIOs and architects about how to get there. This isn't very surprising given all the buzz and hype surrounding cloud computing. Every IT vendor claims to have the most unique solution and there isn't a single IT product out there that does not have a cloud angle to it. Add to this the chatter on the blogosphere, it will get even a sane mind spinning.  Consequently, most  enterprises are still struggling to fully understand the concept and value of enterprise private cloud.  Even among those who have chosen to move forward relatively early, quite a few have made their decisions more based on vendor influence/preferences rather than what their businesses actually need.  Clearly, there is a disconnect between the promise of the enterprise private cloud and the current adoption trends.  So what is the way forward?  I certainly do not claim to have all the answers. But here is a perspective that many cloud practitioners have found useful and thus worth sharing. To take a step back, the fundamental premise of the enterprise private cloud is IT transformation. It is the quest to create a more agile, transparent and efficient IT infrastructure that is driven more by business needs rather than constrained by operational and procedural inefficiencies. It is the new way of delivering and consuming IT services - where the IT organizations operate more like enablers of  strategic services rather than just being the gatekeepers of IT resources. In an enterprise private cloud environment, IT organizations are expected to empower the end users via self-service access/control and provide the business stakeholders a transparent view of how the resources are being used, what’s the cost of delivering a given service, how well are the customers being served, etc.  But the most important thing to note here is the enterprise private cloud is not just an IT project, rather it is a business initiative to create an IT setup that is more aligned with the needs of today's dynamic and highly competitive business environment. Surprised? You shouldn’t be. Just remember how the business users have been at the forefront of public cloud adoption within enterprises and private cloud is no exception.   Such a broad-based transformation makes cloud more than a technology initiative. It requires people (organizational) and process changes as well, and these changes are as critical as is the choice of right tools and technology. In my next blog,  I will share how essential it is for enterprise cloud technology to go hand-in hand with process re-engineering and organization changes to unlock true value of  enterprise cloud. I am sharing a short video from my session "Managing your private Cloud" at Oracle OpenWorld 2012. More videos from this session will be posted at the recently introduced Zero to Cloud resource page. Many other experts of Oracle enterprise private cloud solution will join me on this blog "Zero to Cloud"  and share best practices , deployment tips and information on how to plan, build, deploy, monitor, manage , meter and optimize the enterprise private cloud. We look forward to your feedback, suggestions and having an engaging conversion with you on this blog.

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  • The design of a generic data synchronizer, or, an [object] that does [actions] with the aid of [helpers]

    - by acheong87
    I'd like to create a generic data-source "synchronizer," where data-source "types" may include MySQL databases, Google Spreadsheets documents, CSV files, among others. I've been trying to figure out how to structure this in terms of classes and interfaces, keeping in mind (what I've read about) composition vs. inheritance and is-a vs. has-a, but each route I go down seems to violate some principle. For simplicity, assume that all data-sources have a header-row-plus-data-rows format. For example, assume that the first rows of Google Spreadsheets documents and CSV files will have column headers, a.k.a. "fields" (to parallel database fields). Also, eventually, I would like to implement this in PHP, but avoiding language-specific discussion would probably be more productive. Here's an overview of what I've tried. Part 1/4: ISyncable class CMySQL implements ISyncable GetFields() // sql query, pdo statement, whatever AddFields() RemFields() ... _dbh class CGoogleSpreadsheets implements ISyncable GetFields() // zend gdata api AddFields() RemFields() ... _spreadsheetKey _worksheetId class CCsvFile implements ISyncable GetFields() // read from buffer AddFields() RemFields() ... _buffer interface ISyncable GetFields() AddFields($field1, $field2, ...) RemFields($field1, $field2, ...) ... CanAddFields() // maybe the spreadsheet is locked for write, or CanRemFields() // maybe no permission to alter a database table ... AddRow() ModRow() RemRow() ... Open() Close() ... First Question: Does it make sense to use an interface, as above? Part 2/4: CSyncer Next, the thing that does the syncing. class CSyncer __construct(ISyncable $A, ISyncable $B) Push() // sync A to B Pull() // sync B to A Sync() // Push() and Pull() only differ in direction; factor. // Sync()'s job is to make sure that the fields on each side // match, to add fields where appropriate and possible, to // account for different column-orderings, etc., and of // course, to add and remove rows as necessary to sync. ... _A _B Second Question: Does it make sense to define such a class, or am I treading dangerously close to the "Kingdom of Nouns"? Part 3/4: CTranslator? ITranslator? Now, here's where I actually get lost, assuming the above is passable. Sometimes, two ISyncables speak different "dialects." For example, believe it or not, Google Spreadsheets (accessed through the Google Data API "list feed") returns column headers lower-cased and stripped of all spaces and symbols! That is, sys_TIMESTAMP is systimestamp, as far as my code can tell. (Yes, I am aware that the "cell feed" does not strip the name so; however cell-by-cell manipulation is too slow for what I'm doing.) One can imagine other hypothetical examples. Perhaps even the data itself can be in different "dialects." But let's take it as given for now, and not argue this if possible. Third Question: How would you implement "translation"? Note: Taking all this as an exercise, I'm more interested in the "idealized" design, rather than the practical one. (God knows that shipped sailed when I began this project.) Part 4/4: Further Thought Here's my train of thought to demonstrate I've thunk, albeit unfruitfully: First, I thought, primitively, "I'll just modify CMySQL::GetFields() to lower-case and strip field names so they're compatible with Google Spreadsheets." But of course, then my class should really be called, CMySQLForGoogleSpreadsheets, and that can't be right. So, the thing which translates must exist outside of an ISyncable implementor. And surely it can't be right to make each translation a method in CSyncer. If it exists outside of both ISyncable and CSyncer, then what is it? (Is it even an "it"?) Is it an abstract class, i.e. abstract CTranslator? Is it an interface, since a translator only does, not has, i.e. interface ITranslator? Does it even require instantiation? e.g. If it's an ITranslator, then should its translation methods be static? (I learned what "late static binding" meant, today.) And, dear God, whatever it is, how should a CSyncer use it? Does it "have" it? Is it, "it"? Who am I? ...am I, "I"? I've attempted to break up the question into sub-questions, but essentially my question is singular: How does one implement an object A that conceptually "links" (has) two objects b1 and b2 that share a common interface B, where certain pairs of b1 and b2 require a helper, e.g. a translator, to be handled by A? Something tells me that I've overcomplicated this design, or violated a principle much higher up. Thank you all very much for your time and any advice you can provide.

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  • Quadratic Programming with Oracle R Enterprise

    - by Jeff Taylor-Oracle
         I wanted to use quadprog with ORE on a server running Oracle Solaris 11.2 on a Oracle SPARC T-4 server For background, see: Oracle SPARC T4-2 http://docs.oracle.com/cd/E23075_01/ Oracle Solaris 11.2 http://www.oracle.com/technetwork/server-storage/solaris11/overview/index.html quadprog: Functions to solve Quadratic Programming Problems http://cran.r-project.org/web/packages/quadprog/index.html Oracle R Enterprise 1.4 ("ORE") 1.4 http://www.oracle.com/technetwork/database/options/advanced-analytics/r-enterprise/ore-downloads-1502823.html Problem: path to Solaris Studio doesn't match my installation: $ ORE CMD INSTALL quadprog_1.5-5.tar.gz * installing to library \u2018/u01/app/oracle/product/12.1.0/dbhome_1/R/library\u2019 * installing *source* package \u2018quadprog\u2019 ... ** package \u2018quadprog\u2019 successfully unpacked and MD5 sums checked ** libs /opt/SunProd/studio12u3/solarisstudio12.3/bin/f95 -m64   -PIC  -g  -c aind.f -o aind.o bash: /opt/SunProd/studio12u3/solarisstudio12.3/bin/f95: No such file or directory *** Error code 1 make: Fatal error: Command failed for target `aind.o' ERROR: compilation failed for package \u2018quadprog\u2019 * removing \u2018/u01/app/oracle/product/12.1.0/dbhome_1/R/library/quadprog\u2019 $ ls -l /opt/solarisstudio12.3/bin/f95 lrwxrwxrwx   1 root     root          15 Aug 19 17:36 /opt/solarisstudio12.3/bin/f95 -> ../prod/bin/f90 Solution: a symbolic link: $ sudo mkdir -p /opt/SunProd/studio12u3 $ sudo ln -s /opt/solarisstudio12.3 /opt/SunProd/studio12u3/ Now, it is all good: $ ORE CMD INSTALL quadprog_1.5-5.tar.gz * installing to library \u2018/u01/app/oracle/product/12.1.0/dbhome_1/R/library\u2019 * installing *source* package \u2018quadprog\u2019 ... ** package \u2018quadprog\u2019 successfully unpacked and MD5 sums checked ** libs /opt/SunProd/studio12u3/solarisstudio12.3/bin/f95 -m64   -PIC  -g  -c aind.f -o aind.o /opt/SunProd/studio12u3/solarisstudio12.3/bin/ cc -xc99 -m64 -I/usr/lib/64/R/include -DNDEBUG -KPIC  -xlibmieee  -c init.c -o init.o /opt/SunProd/studio12u3/solarisstudio12.3/bin/f95 -m64  -PIC -g  -c -o solve.QP.compact.o solve.QP.compact.f /opt/SunProd/studio12u3/solarisstudio12.3/bin/f95 -m64  -PIC -g  -c -o solve.QP.o solve.QP.f /opt/SunProd/studio12u3/solarisstudio12.3/bin/f95 -m64   -PIC  -g  -c util.f -o util.o /opt/SunProd/studio12u3/solarisstudio12.3/bin/ cc -xc99 -m64 -G -o quadprog.so aind.o init.o solve.QP.compact.o solve.QP.o util.o -xlic_lib=sunperf -lsunmath -lifai -lsunimath -lfai -lfai2 -lfsumai -lfprodai -lfminlai -lfmaxlai -lfminvai -lfmaxvai -lfui -lfsu -lsunmath -lmtsk -lm -lifai -lsunimath -lfai -lfai2 -lfsumai -lfprodai -lfminlai -lfmaxlai -lfminvai -lfmaxvai -lfui -lfsu -lsunmath -lmtsk -lm -L/usr/lib/64/R/lib -lR installing to /u01/app/oracle/product/12.1.0/dbhome_1/R/library/quadprog/libs ** R ** preparing package for lazy loading ** help *** installing help indices   converting help for package \u2018quadprog\u2019     finding HTML links ... done     solve.QP                                html      solve.QP.compact                        html  ** building package indices ** testing if installed package can be loaded * DONE (quadprog) ====== Here is an example from http://cran.r-project.org/web/packages/quadprog/quadprog.pdf > require(quadprog) > Dmat <- matrix(0,3,3) > diag(Dmat) <- 1 > dvec <- c(0,5,0) > Amat <- matrix(c(-4,-3,0,2,1,0,0,-2,1),3,3) > bvec <- c(-8,2,0) > solve.QP(Dmat,dvec,Amat,bvec=bvec) $solution [1] 0.4761905 1.0476190 2.0952381 $value [1] -2.380952 $unconstrained.solution [1] 0 5 0 $iterations [1] 3 0 $Lagrangian [1] 0.0000000 0.2380952 2.0952381 $iact [1] 3 2 Here, the standard example is modified to work with Oracle R Enterprise require(ORE) ore.connect("my-name", "my-sid", "my-host", "my-pass", 1521) ore.doEval(   function () {     require(quadprog)   } ) ore.doEval(   function () {     Dmat <- matrix(0,3,3)     diag(Dmat) <- 1     dvec <- c(0,5,0)     Amat <- matrix(c(-4,-3,0,2,1,0,0,-2,1),3,3)     bvec <- c(-8,2,0)    solve.QP(Dmat,dvec,Amat,bvec=bvec)   } ) $solution [1] 0.4761905 1.0476190 2.0952381 $value [1] -2.380952 $unconstrained.solution [1] 0 5 0 $iterations [1] 3 0 $Lagrangian [1] 0.0000000 0.2380952 2.0952381 $iact [1] 3 2 Now I can combine the quadprog compute algorithms with the Oracle R Enterprise Database engine functionality: Scale to large datasets Access to tables, views, and external tables in the database, as well as those accessible through database links Use SQL query parallel execution Use in-database statistical and data mining functionality

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  • Tech Talk: Managing Cloud Integration

    - by Tanu Sood
    Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Cloud computing solutions are widely hailed as a way to reduce capital expenditures yet organizations are realizing they need to also consider all of the nuances of integrating cloud applications with existing information systems.Cloud integration, after all, has a direct impact on your costs, maintenance and upgrade efforts. Catch this conversation on Tech Talk with Oracle Vice President, Amit Zavery, to understand how Oracle Fusion Middleware provides a simple and consistent method to maintaining integration interfaces across disparate systems across cloud and on-premise applications. Simplify your IT infrastructure and seamlessly manage data and application integration across your applications with Oracle solutions. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} For other Fusion Middleware talks, subscribe to Fusion Middleware Radio today and visit us on oracle.com Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Photo courtesy: www.cloudtweaks.com

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  • Using Subjects to Deploy Queries Dynamically

    - by Roman Schindlauer
    In the previous blog posting, we showed how to construct and deploy query fragments to a StreamInsight server, and how to re-use them later. In today’s posting we’ll integrate this pattern into a method of dynamically composing a new query with an existing one. The construct that enables this scenario in StreamInsight V2.1 is a Subject. A Subject lets me create a junction element in an existing query that I can tap into while the query is running. To set this up as an end-to-end example, let’s first define a stream simulator as our data source: var generator = myApp.DefineObservable(     (TimeSpan t) => Observable.Interval(t).Select(_ => new SourcePayload())); This ‘generator’ produces a new instance of SourcePayload with a period of t (system time) as an IObservable. SourcePayload happens to have a property of type double as its payload data. Let’s also define a sink for our example—an IObserver of double values that writes to the console: var console = myApp.DefineObserver(     (string label) => Observer.Create<double>(e => Console.WriteLine("{0}: {1}", label, e)))     .Deploy("ConsoleSink"); The observer takes a string as parameter which is used as a label on the console, so that we can distinguish the output of different sink instances. Note that we also deploy this observer, so that we can retrieve it later from the server from a different process. Remember how we defined the aggregation as an IQStreamable function in the previous article? We will use that as well: var avg = myApp     .DefineStreamable((IQStreamable<SourcePayload> s, TimeSpan w) =>         from win in s.TumblingWindow(w)         select win.Avg(e => e.Value))     .Deploy("AverageQuery"); Then we define the Subject, which acts as an observable sequence as well as an observer. Thus, we can feed a single source into the Subject and have multiple consumers—that can come and go at runtime—on the other side: var subject = myApp.CreateSubject("Subject", () => new Subject<SourcePayload>()); Subject are always deployed automatically. Their name is used to retrieve them from a (potentially) different process (see below). Note that the Subject as we defined it here doesn’t know anything about temporal streams. It is merely a sequence of SourcePayloads, without any notion of StreamInsight point events or CTIs. So in order to compose a temporal query on top of the Subject, we need to 'promote' the sequence of SourcePayloads into an IQStreamable of point events, including CTIs: var stream = subject.ToPointStreamable(     e => PointEvent.CreateInsert<SourcePayload>(e.Timestamp, e),     AdvanceTimeSettings.StrictlyIncreasingStartTime); In a later posting we will show how to use Subjects that have more awareness of time and can be used as a junction between QStreamables instead of IQbservables. Having turned the Subject into a temporal stream, we can now define the aggregate on this stream. We will use the IQStreamable entity avg that we defined above: var longAverages = avg(stream, TimeSpan.FromSeconds(5)); In order to run the query, we need to bind it to a sink, and bind the subject to the source: var standardQuery = longAverages     .Bind(console("5sec average"))     .With(generator(TimeSpan.FromMilliseconds(300)).Bind(subject)); Lastly, we start the process: standardQuery.Run("StandardProcess"); Now we have a simple query running end-to-end, producing results. What follows next is the crucial part of tapping into the Subject and adding another query that runs in parallel, using the same query definition (the “AverageQuery”) but with a different window length. We are assuming that we connected to the same StreamInsight server from a different process or even client, and thus have to retrieve the previously deployed entities through their names: // simulate the addition of a 'fast' query from a separate server connection, // by retrieving the aggregation query fragment // (instead of simply using the 'avg' object) var averageQuery = myApp     .GetStreamable<IQStreamable<SourcePayload>, TimeSpan, double>("AverageQuery"); // retrieve the input sequence as a subject var inputSequence = myApp     .GetSubject<SourcePayload, SourcePayload>("Subject"); // retrieve the registered sink var sink = myApp.GetObserver<string, double>("ConsoleSink"); // turn the sequence into a temporal stream var stream2 = inputSequence.ToPointStreamable(     e => PointEvent.CreateInsert<SourcePayload>(e.Timestamp, e),     AdvanceTimeSettings.StrictlyIncreasingStartTime); // apply the query, now with a different window length var shortAverages = averageQuery(stream2, TimeSpan.FromSeconds(1)); // bind new sink to query and run it var fastQuery = shortAverages     .Bind(sink("1sec average"))     .Run("FastProcess"); The attached solution demonstrates the sample end-to-end. Regards, The StreamInsight Team

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  • Computer science undergraduate project ideas

    - by Mehrdad Afshari
    Hopefully, I'm going to finish my undergraduate studies next semester and I'm thinking about the topic of my final project. And yes, I've read the questions with duplicate title. I'm asking this from a bit different viewpoint, so it's not an exact dupe. I've spent at least half of my life coding stuff in different languages and frameworks so I'm not looking at this project as a way to learn much about coding and preparing for real world apps or such. I've done lots of those already. But since I have to do it to complete my degree, I felt I should spend my time doing something useful instead of throwing the whole thing out. I'm planning to make it an open source project or a hosted Web app (depending on the type) if I can make a high quality thing out of it, so I decided to ask StackOverflow what could make a useful project. Situation I've plenty of freedom about the topic. They also require 30-40 pages of text describing the project. I have the following points in mind (the more satisfied, the better): Something useful for software development Something that benefits the community Having academic value is great Shouldn't take more than a month of development (I know I'm lazy). Shouldn't be related to advanced theoretical stuff (soft computing, fuzzy logic, neural networks, ...). I've been a business-oriented software developer. It should be software oriented. While I love hacking microcontrollers and other fun embedded electronic things, I'm not really good at soldering and things like that. I'm leaning toward a Web application (think StackOverflow, PasteBin, NerdDinner, things like those). Technology It's probably going to be done in .NET (C#, F#) and Windows platform. If I really like the project (cool low level hacking), I might actually slip to C/C++. But really, C# is what I'm efficient at. Ideas Programming language, parsing and compiler related stuff: Designing a domain specific programming language and compiler Templating language compiled to C# or IL Database tools and related code generation stuff Web related technologies: ASP.NET MVC View engine doing something cool (don't know what exactly...) Specific-purpose, small, fast ASP.NET-based Web framework Applications: Visual Studio plugin to integrate with Bazaar (it's too much work, I think). ASP.NET based, jQuery-powered issue tracker (and possibly, project lifecycle management as a whole - poor man's TFS) Others: Something related to GPGPU Looking forward for great ideas! Unfortunately, I can't help on a currently existing project. I need to start my own to prevent further problems (as it's an undergrad project, nevertheless).

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  • Problem with AquaTerm on Snow Leopard

    - by cheetah
    When i try to install AquaTerm on Snow leopard from MacPorts i got this: ---> Computing dependencies for aquaterm ---> Building aquaterm Error: Target org.macports.build returned: shell command "cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_ports_aqua_aquaterm/work/aquaterm" && /usr/bin/xcodebuild -target "AquaTerm" -configuration Deployment build OBJROOT=build/ SYMROOT=build/ MACOSX_DEPLOYMENT_TARGET=10.6 ARCHS=x86_64 SDKROOT= USER_APPS_DIR=/Applications/MacPorts FRAMEWORKS_DIR=/opt/local/Library/Frameworks" returned error 1 Command output: [WARN]Warning: The Copy Bundle Resources build phase contains this target's Info.plist file 'AquaTerm.framework-Info.plist'. CopyPlistFile build/Deployment/AquaTerm.framework/Versions/A/Resources/AquaTerm.framework-Info.plist AquaTerm.framework-Info.plist cd /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_ports_aqua_aquaterm/work/aquaterm /Developer/Library/Xcode/Plug-ins/CoreBuildTasks.xcplugin/Contents/Resources/copyplist AquaTerm.framework-Info.plist --outdir /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_ports_aqua_aquaterm/work/aquaterm/build/Deployment/AquaTerm.framework/Versions/A/Resources error: can't exec '/Developer/Library/Xcode/Plug-ins/CoreBuildTasks.xcplugin/Contents/Resources/copyplist' (No such file or directory) Command /Developer/Library/Xcode/Plug-ins/CoreBuildTasks.xcplugin/Contents/Resources/copyplist failed with exit code 71 Command /Developer/Library/Xcode/Plug-ins/CoreBuildTasks.xcplugin/Contents/Resources/copyplist failed with exit code 71 === BUILD NATIVE TARGET AquaTerm OF PROJECT AquaTerm WITH CONFIGURATION Deployment === Check dependencies Warning: Multiple build commands for output file /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_ports_aqua_aquaterm/work/aquaterm/build/Deployment/AquaTerm.app/Contents/Resources/help.html [WARN]Warning: Multiple build commands for output file /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_ports_aqua_aquaterm/work/aquaterm/build/Deployment/AquaTerm.app/Contents/Resources/help.html CopyTiffFile build/Deployment/AquaTerm.app/Contents/Resources/Cross.tiff English.lproj/Cross.tiff cd /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_ports_aqua_aquaterm/work/aquaterm /Developer/Library/Xcode/Plug-ins/CoreBuildTasks.xcplugin/Contents/Resources/copytiff English.lproj/Cross.tiff --outdir /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_ports_aqua_aquaterm/work/aquaterm/build/Deployment/AquaTerm.app/Contents/Resources error: can't exec '/Developer/Library/Xcode/Plug-ins/CoreBuildTasks.xcplugin/Contents/Resources/copytiff' (No such file or directory) Command /Developer/Library/Xcode/Plug-ins/CoreBuildTasks.xcplugin/Contents/Resources/copytiff failed with exit code 71 Command /Developer/Library/Xcode/Plug-ins/CoreBuildTasks.xcplugin/Contents/Resources/copytiff failed with exit code 71 ** BUILD FAILED ** The following build commands failed: AQTFwk: CopyPlistFile /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_ports_aqua_aquaterm/work/aquaterm/build/Deployment/AquaTerm.framework/Versions/A/Resources/AquaTerm.framework-Info.plist AquaTerm.framework-Info.plist AquaTerm: CopyTiffFile /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_ports_aqua_aquaterm/work/aquaterm/build/Deployment/AquaTerm.app/Contents/Resources/Cross.tiff English.lproj/Cross.tiff (2 failures) Error: Status 1 encountered during processing. Before reporting a bug, first run the command again with the -d flag to get complete output. How i can solve this problem?

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  • Resizing QT's QTextEdit to Match Text Height: maximumViewportSize()

    - by Aaron
    I am trying to use a QTextEdit widget inside of a form containing several QT widgets. The form itself sits inside a QScrollArea that is the central widget for a window. My intent is that any necessary scrolling will take place in the main QScrollArea (rather than inside any widgets), and any widgets inside will automatically resize their height to hold their contents. I have tried to implement the automatic resizing of height with a QTextEdit, but have run into an odd issue. I created a sub-class of QTextEdit and reimplemented sizeHint() like this: QSize OperationEditor::sizeHint() const { QSize sizehint = QTextBrowser::sizeHint(); sizehint.setHeight(this->fitted_height); return sizehint; } this-fitted_height is kept up-to-date via this slot that is wired to the QTextEdit's "contentsChanged()" signal: void OperationEditor::fitHeightToDocument() { this->document()->setTextWidth(this->viewport()->width()); QSize document_size(this->document()->size().toSize()); this->fitted_height = document_size.height(); this->updateGeometry(); } The size policy of the QTextEdit sub-class is: this->setSizePolicy(QSizePolicy::MinimumExpanding, QSizePolicy::Preferred); I took this approach after reading this post. Here is my problem: As the QTextEdit gradually resizes to fill the window, it stops getting larger and starts scrolling within the QTextEdit, no matter what height is returned from sizeHint(). If I initially have sizeHint() return some large constant number, then the QTextEdit is very big and is contained nicely within the outer QScrollArea, as one would expect. However, if sizeHint gradually adjusts the size of the QTextEdit rather than just making it really big to start, then it tops out when it fills the current window and starts scrolling instead of growing. I have traced this problem to be that, no matter what my sizeHint() returns, it will never resize the QTextEdit larger than the value returned from maximumViewportSize(), which is inherited from QAbstractScrollArea. Note that this is not the same number as viewport()-maximumSize(). I am unable to figure out how to set that value. Looking at QT's source code, maximumViewportSize() is returning "the size of the viewport as if the scroll bars had no valid scrolling range." This value is basically computed as the current size of the widget minus (2 * frameWidth + margins) plus any scrollbar widths/heights. This does not make a lot of sense to me, and it's not clear to me why that number would be used anywhere in a way that supercede's the sub-class's sizeHint() implementation. Also, it does seem odd that the single "frameWidth" integer is used in computing both the width and the height. Can anyone please shed some light on this? I suspect that my poor understanding of QT's layout engine is to blame here.

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  • How do I verify a DKIM signature in PHP?

    - by angrychimp
    I'll admit I'm not very adept at key verification. What I have is a script that downloads messages from a POP3 server, and I'm attempting to verify the DKIM signatures in PHP. I've already figured out the body hash (bh) validation check, but I can't figure out the header validation. http://www.dkim.org/specs/rfc4871-dkimbase.html#rfc.section.6.1.3 Below is an example of my message headers. I've been able to use the Mail::DKIM package to validate the signature in Perl, so I know it's good. I just can't seem to figure out the instructions in the RFC and translate them into PHP code. DomainKey-Signature: q=dns; a=rsa-sha1; c=nofws; s=angrychimp-1.bh; d=angrychimp.net; h=From:X-Outgoing; b=RVkenibHQ7GwO5Y3tun2CNn5wSnooBSXPHA1Kmxsw6miJDnVp4XKmA9cUELwftf9 nGiRCd3rLc6eswAcVyNhQ6mRSsF55OkGJgDNHiwte/pP5Z47Lo/fd6m7rfCnYxq3 DKIM-Signature: v=1; a=rsa-sha1; d=angrychimp.net; s=angrychimp-1.bh; c=relaxed/simple; q=dns/txt; [email protected]; t=1268436255; h=From:Subject:X-Outgoing:Date; bh=gqhC2GEWbg1t7T3IfGMUKzt1NCc=; b=ZmeavryIfp5jNDIwbpifsy1UcavMnMwRL6Fy6axocQFDOBd2KjnjXpCkHxs6yBZn Wu+UCFeAP+1xwN80JW+4yOdAiK5+6IS8fiVa7TxdkFDKa0AhmJ1DTHXIlPjGE4n5; To: [email protected] Message-ID: From: DKIM Tester Reply-To: [email protected] Subject: Automated DKIM Testing (angrychimp.net) X-Outgoing: dhaka Date: Fri, 12 Mar 2010 15:24:15 -0800 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline MIME-Version: 1.0 Return-Path: [email protected] X-OriginalArrivalTime: 12 Mar 2010 23:25:50.0326 (UTC) FILETIME=[5A0ED160:01CAC23B] I can extract the public key from my DNS just fine, and I believe I'm canonicalizing the headers correctly, but I just can't get the signature validated. I don't think I'm preparing my key or computing the signature validation correctly. Is this something that's possible (do I need pear extensions or something?) or is manually validating a DKIM signature in PHP just not feasible?

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  • Use bug tracker to get things done and manage personal tasks?

    - by Frank
    This is slightly off-topic, but can only be answered by programmers and is useful to many programmers: Do you think it is useful to use a bug tracking system to keep track of personal todo items and to Get Things Done? I have not tried that; in fact, I don't have much experience with bug tracking systems. For my todo lists, I have played around with Google Tasks and Remember The Milk, but both of them have shortcomings: Google Tasks: I like that you can create todo lists easily, can reorder items in the list and easily create hierarchies. But it is way too simplistic and does not allow to tag tasks or move tasks from one list to another. Remember The Milk: It is nice and sleek, but you cannot create hierarchies of tasks, cannot arbitrarily reorder tasks and cannot set dependencies of tasks. That's where a bug tracking system should come in: Since I think (maybe too much?) like a programmer, my tasks have a natural hierarchy and a tree of dependencies, like in a Makefile. Here are two examples: The task of writing my thesis is done when several milestones are done. Some of these milestones can run in parallel (writing background chapter, running experiments A, running experiments B), others depend on each other (writing main chapter depends on first getting results from experiments A). The same is true for more personal goals: I want to host a dinner party, which requires finding a good date, finishing the guest list, making invitations, finding nice recipes, cooking, ... For me, all these tasks involve hierarchical dependencies and milestones that bug tracking systems should be able to handle? Here is an article that explains how to do advanced GTD with Remember The Milk, but he has to use several workarounds: (1) add a general tag 'wait' to tasks that are waiting for others to be completed but you cannot enter the IDs of the tasks that they are waiting for, (2) starting some special tasks with "." so that they are at the top of the alphabetically sorted list and signal that others are 'below' it as subgoals. Bug tracking systems should be able to handle these things much more naturally? Does anyone have experience and can recommend a lightweight bug tracking system that might be good for this? Other requirements: Should run as web app, should allow me to tag a task with several tags (like 'work', 'fun', 'short-task', 'errands', ...).

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  • Resultant of a polynomial with x^n–1

    - by devin.omalley
    Resultant of a polynomial with x^n–1 (mod p) I am implementing the NTRUSign algorithm as described in http://grouper.ieee.org/groups/1363/lattPK/submissions/EESS1v2.pdf , section 2.2.7.1 which involves computing the resultant of a polynomial. I keep getting a zero vector for the resultant which is obviously incorrect. private static CompResResult compResMod(IntegerPolynomial f, int p) { int N = f.coeffs.length; IntegerPolynomial a = new IntegerPolynomial(N); a.coeffs[0] = -1; a.coeffs[N-1] = 1; IntegerPolynomial b = new IntegerPolynomial(f.coeffs); IntegerPolynomial v1 = new IntegerPolynomial(N); IntegerPolynomial v2 = new IntegerPolynomial(N); v2.coeffs[0] = 1; int da = a.degree(); int db = b.degree(); int ta = da; int c = 0; int r = 1; while (db > 0) { c = invert(b.coeffs[db], p); c = (c * a.coeffs[da]) % p; IntegerPolynomial cb = b.clone(); cb.mult(c); cb.shift(da - db); a.sub(cb, p); IntegerPolynomial v2c = v2.clone(); v2c.mult(c); v2c.shift(da - db); v1.sub(v2c, p); if (a.degree() < db) { r *= (int)Math.pow(b.coeffs[db], ta-a.degree()); r %= p; if (ta%2==1 && db%2==1) r = (-r) % p; IntegerPolynomial temp = a; a = b; b = temp; temp = v1; v1 = v2; v2 = temp; ta = db; } da = a.degree(); db = b.degree(); } r *= (int)Math.pow(b.coeffs[0], da); r %= p; c = invert(b.coeffs[0], p); v2.mult(c); v2.mult(r); v2.mod(p); return new CompResResult(v2, r); } There is pseudocode in http://www.crypto.rub.de/imperia/md/content/texte/theses/da_driessen.pdf which looks very similar. Why is my code not working? Are there any intermediate results I can check? I am not posting the IntegerPolynomial code because it isn't too interesting and I have unit tests for it that pass. CompResResult is just a simple "Java struct".

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  • Unable to verify body hash for DKIM

    - by Joshua
    I'm writing a C# DKIM validator and have come across a problem that I cannot solve. Right now I am working on calculating the body hash, as described in Section 3.7 Computing the Message Hashes. I am working with emails that I have dumped using a modified version of EdgeTransportAsyncLogging sample in the Exchange 2010 Transport Agent SDK. Instead of converting the emails when saving, it just opens a file based on the MessageID and dumps the raw data to disk. I am able to successfully compute the body hash of the sample email provided in Section A.2 using the following code: SHA256Managed hasher = new SHA256Managed(); ASCIIEncoding asciiEncoding = new ASCIIEncoding(); string rawFullMessage = File.ReadAllText(@"C:\Repositories\Sample-A.2.txt"); string headerDelimiter = "\r\n\r\n"; int headerEnd = rawFullMessage.IndexOf(headerDelimiter); string header = rawFullMessage.Substring(0, headerEnd); string body = rawFullMessage.Substring(headerEnd + headerDelimiter.Length); byte[] bodyBytes = asciiEncoding.GetBytes(body); byte[] bodyHash = hasher.ComputeHash(bodyBytes); string bodyBase64 = Convert.ToBase64String(bodyHash); string expectedBase64 = "2jUSOH9NhtVGCQWNr9BrIAPreKQjO6Sn7XIkfJVOzv8="; Console.WriteLine("Expected hash: {1}{0}Computed hash: {2}{0}Are equal: {3}", Environment.NewLine, expectedBase64, bodyBase64, expectedBase64 == bodyBase64); The output from the above code is: Expected hash: 2jUSOH9NhtVGCQWNr9BrIAPreKQjO6Sn7XIkfJVOzv8= Computed hash: 2jUSOH9NhtVGCQWNr9BrIAPreKQjO6Sn7XIkfJVOzv8= Are equal: True Now, most emails come across with the c=relaxed/relaxed setting, which requires you to do some work on the body and header before hashing and verifying. And while I was working on it (failing to get it to work) I finally came across a message with c=simple/simple which means that you process the whole body as is minus any empty CRLF at the end of the body. (Really, the rules for Body Canonicalization are quite ... simple.) Here is the real DKIM email with a signature using the simple algorithm (with only unneeded headers cleaned up). Now, using the above code and updating the expectedBase64 hash I get the following results: Expected hash: VnGg12/s7xH3BraeN5LiiN+I2Ul/db5/jZYYgt4wEIw= Computed hash: ISNNtgnFZxmW6iuey/3Qql5u6nflKPTke4sMXWMxNUw= Are equal: False The expected hash is the value from the bh= field of the DKIM-Signature header. Now, the file used in the second test is a direct raw output from the Exchange 2010 Transport Agent. If so inclined, you can view the modified EdgeTransportLogging.txt. At this point, no matter how I modify the second email, changing the start position or number of CRLF at the end of the file I cannot get the files to match. What worries me is that I have been unable to validate any body hash so far (simple or relaxed) and that it may not be feasible to process DKIM through Exchange 2010.

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  • Which mobile operating system should I code for?

    - by samgoody
    It seems as though mobile computing has fully arrived. I would like to rewrite two of our programs for mobile devices, but am a bit lost as to which platform to target. Complicating this decision: I would need to learn the relevant languages and IDEs - my coding to date has been almost all web based (PHP, JS, Actionscript, etc. Some ASPX). Most users seem to be religious about their mobile decision, so oral conversations leave me more confused then enlightened. I do not yet own a smartphone - will have to buy one once I know which platform to be aiming for. Both of my programs are more for business users, (one is only useful for C.P.A.s). I am a single developer, and cannot develop for more than one platform at a time. Getting it right is important. Based on what I've found on the web, I would've expected RIM to be a shoo-in, and the general order to be as follows: RIM Blackberry - More of them than any other brand. Despite naysayers, they've had double the sales (or perhaps 5X the sales) of any other smartphone, and have continued to grow. And, they have business users. Android - According to Schmidt, they have outsold everyone else except RIM (though I can't find where I read that now), and they are just getting started. According to Comscore, they are already at 8% of the market and expected to hit Shcmidt's claims within six months. Nokia - The largest worldwide. If they would just make up between Maemo or Symbian, I would be far less confused. iPhone - Much more competition by other apps, fewer sales to be had, and a overlord that can delay or cancel my app at any time. Is Cocoa hard to learn? Windows Mobile - Word is that version 7 will not be backwards compatible and losing market share. Palm WebOS - Perhaps this should go first, as it is the only one that offers tools to make my life easy as a web application developer. No competition in marketplace. But not very many users either. However, a search on StackOverflow shows a hugely disproportionate number of iPhone questions versus Blackberry. Likewise, there are clearly more apps on iPhone, so it must be getting developer love. What is the one platform I should develop for? Please back up your answer with the logic.

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  • ImageMagick on Mac OSX Snow Leopard. Is there any way to get it to work?

    - by ?????
    It seems that I have more trouble getting standard Unix things to run on Snow Leopard than any other platform--including Windows cygwin For the past couple of days, I've been trying to get ImageMagick to run on Snow Leopard. The most obvious way, Mac Ports, fails: tppllc-Mac-Pro:ImageMagick-sl swirsky$ sudo port install imagemagick ---> Computing dependencies for p5-locale-gettext ---> Configuring p5-locale-gettext Error: Target org.macports.configure returned: configure failure: shell command " cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_ports_perl_p5-locale-gettext/work/gettext-1.05" && /opt/local/bin/perl Makefile.PL INSTALLDIRS=vendor " returned error 2 Command output: checking for gettext... no checking for gettext in -I/opt/local/include -arch i386 -L/opt/local/lib -lintl...gettext function not found. Please install libintl at Makefile.PL line 18. no Error: Unable to upgrade port: 1 Error: Unable to execute port: upgrade xorg-libXt failed Before reporting a bug, first run the command again with the -d flag to get complete output. tppllc-Mac-Pro:ImageMagick-sl swirsky$ Not wanting to spend another two days figuring out why my libintl doesn't have a "gettext" function, I tried a different route: the script mentioned here: http://github.com/masterkain/ImageMagick-sl This script downloads and installs an ImageMagic independently of MacPorts issues tppllc-Mac-Pro:ImageMagick-sl swirsky$ /usr/local/bin/convert dyld: Library not loaded: /opt/local/lib/libiconv.2.dylib Referenced from: /opt/local/lib/libfontconfig.1.dylib Reason: Incompatible library version: libfontconfig.1.dylib requires version 8.0.0 or later, but libiconv.2.dylib provides version 7.0.0 Trace/BPT trap It downloads everything and compiles fine, but fails when I try to run it, with the message above. So now I'm two steps away from ImageMagick, trying to get a newer libiconv on my machine. I downloaded the latest libiconv, compiled and built it. I put the resulting library in /opt/local/lib, and I still get the same error message: tppllc-Mac-Pro:.libs swirsky$ sudo mv libiconv.2.dylib /opt/local/lib/libiconv.2.dylib tppllc-Mac-Pro:.libs swirsky$ convert dyld: Library not loaded: /opt/local/lib/libiconv.2.dylib Referenced from: /opt/local/lib/libfontconfig.1.dylib Reason: Incompatible library version: libfontconfig.1.dylib requires version 8.0.0 or later, but libiconv.2.dylib provides version 7.0.0 Trace/BPT trap So here's my question: Is it possible to get ImageMagick to run on OSX Snow Leopard? Are there any binary distributions that have static libraries baked in so I don't have to worry about these issue/

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  • How to split HTML code with javascript or JQuery

    - by Dean
    Hi I'm making a website using JSP and servlets and I have to now break up a list of radio buttons to insert a textarea and a button. I have got the button and textarea to hide and show when you click on the radio button it shows the text area and button. But this only appears at the top and when there are hundreds on the page this will become awkward so i need a way for it to appear underneath. Here is what my HTML looks like when complied: <form action="addSpotlight" method="POST"> <table> <tr><td><input type="radio" value="29" name="publicationIDs" ></td><td>A System For Dynamic Server Allocation in Application Server Clusters, IEEE International Symposium on Parallel and Distributed Processsing with Applications, 2008</td> </tr> <tr><td><input type="radio" value="30" name="publicationIDs" ></td><td>Analysing BitTorrent's Seeding Strategies, 7th IEEE/IFIP International Conference on Embedded and Ubiquitous Computing (EUC-09), 2009</td> </tr> <tr><td><input type="radio" value="31" name="publicationIDs" ></td><td>The Effect of Server Reallocation Time in Dynamic Resource Allocation, UK Performance Engineering Workshop 2009, 2009</td> </tr> <tr><td><input type="radio" value="32" name="publicationIDs" ></td><td>idk, hello, 1992</td> </tr> <tr><td><input type="radio" value="33" name="publicationIDs" ></td><td>sad, safg, 1992</td> </tr> <div class="abstractWriteup"><textarea name="abstract"></textarea> <input type="submit" value="Add Spotlight"></div> </table> </form> Now here is what my JSP looks like: <form action="addSpotlight" method="POST"> <table> <%int i = 0; while(i<ids.size()){%> <tr><td><input type="radio" value="<%=ids.get(i)%>" name="publicationIDs" ></td><td><%=info.get(i)%></td> </tr> <%i++; }%> <div class="abstractWriteup"><textarea name="abstract"></textarea> <input type="submit" value="Add Spotlight"></div> </table> </form> Thanks in Advance Dean

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  • Advice for Architecture Design Logic for software application

    - by Prasad
    Hi, I have a framework of basic to complex set of objects/classes (C++) running into around 500. With some rules and regulations - all these objects can communicate with each other and hence can cover most of the common queries in the domain. My Dream: I want to provide these objects as icons/glyphs (as I learnt recently) on a workspace. All these objects can be dragged/dropped into the workspace. They have to communicate only through their methods(interface) and in addition to few iterative and conditional statements. All these objects are arranged finally to execute a protocol/workflow/dataflow/process. After drawing the flow, the user clicks the Execute/run button. All the user interaction should be multi-touch enabled. The best way to show my dream is : Jeff Han's Multitouch Video. consider Jeff is playing with my objects instead of the google maps. :-) it should be like playing a jigsaw puzzle. Objective: how can I achieve the following while working on this final product: a) the development should be flexible to enable provision for web services b) the development should enable easy web application development c) The development should enable client-server architecture - d) further it should also enable mouse based drag/drop desktop application like Adobe programs etc. I mean to say: I want to economize on investments. Now I list my efforts till now in design : a) Created an Editor (VB) where the user writes (manually) the object / class code b) On Run/Execute, the code is copied into a main() function and passed to interpreter. c) Catch the output and show it in the console. The interpreter can be separated to become a server and the Editor can become the client. This needs lot of standard client-server architecture work. But some how I am not comfortable in the tightness of this system. Without interpreter is there much faster and better embeddable solution to this? - other than writing a special compiler for these objects. Recently learned about AXIS-C++ can help me - looks like - a friend suggested. Is that the way to go ? Here are my questions: (pl. consider me a self taught programmer and NOT my domain) a) From the stage of C++ objects to multi-touch product, how can I make sure I will develop the parallel product/service models as well.? What should be architecture aspects I should consider ? b) What technologies are best suited for this? c) If I am thinking of moving to Cloud Computing, how difficult/ how redundant / how unnecessary my efforts will be ? d) How much time in months would it take to get the first beta ? I take the liberty to ask if any of the experts here are interested in this project, please email me: [email protected] Thank you for any help. Looking forward.

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  • How do I correct "Commit Failed. File xxx is out of date. xxx path not found."

    - by Ryan Taylor
    I have recently run into a particularly sticky issue regarding committing the result of a merge in subversion. Our Subversion server is @ 1.5.0 and my TortoiseSVN client is now @ 1.6.1. I am trying to merge a feature branch back into my trunk. The merge appears to work okay; however, the commit fails with the following error message. Commit failed (details follow): File 'flex/src/com/penbay/invision/portal/services/http/soap/ReportServices/GetAllBldgsParamsByRegionBySiteResultEvent.as' is out of date '/svn/ibis/!svn/wrk/531d459d-80fa-ea46-bfb4-940d79ee6d2e/visualization/trunk/source/flex/src/com/penbay/invision/portal/services/http/soap/ReportServices/GetAllBldgsParamsByRegionBySiteResultEvent.as' path not found You have to update your working copy first. My working trunk is up to date. I have even checked out a new one into a different folder to make sure there wasn't any local cruft messing with the merge. I have done some more research into this and I think part of the problem is user error. I think our problems are: We had some developers committing work with a subversion client before 1.5 and some after. I believe this has the potential to corrupt the merge info. In other branches we have performed partial merges. That is, we did not always perform merges at the root of the branch. This was to facilitate updating Flex and .NET efforts within the same branch. We performed cyclic (reflexive) merges on our branch. This was done because we had multiple parallel branches and we wanted to periodically update our branch with the latest code in trunk. All of these things are explicitly not recommended by the Subversion book/team. We have learned our lesson and now know the best practices. However, we first need to merge and commit our latest branch. What it the best way to correct the problems we are encountering? Would deleting all the merge info in the trunk and branch be a viable solution? No. I have done this but it does not resolve the error that I am getting above.

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  • fit a ellipse in Python given a set of points xi=(xi,yi)

    - by Gianni
    I am computing a series of index from a 2D points (x,y). One index is the ratio between minor and major axis. To fit the ellipse i am using the following post when i run these function the final results looks strange because the center and the axis length are not in scale with the 2D points center = [ 560415.53298363+0.j 6368878.84576771+0.j] angle of rotation = (-0.0528033467597-5.55111512313e-17j) axes = [0.00000000-557.21553487j 6817.76933256 +0.j] thanks in advance for help import numpy as np from numpy.linalg import eig, inv def fitEllipse(x,y): x = x[:,np.newaxis] y = y[:,np.newaxis] D = np.hstack((x*x, x*y, y*y, x, y, np.ones_like(x))) S = np.dot(D.T,D) C = np.zeros([6,6]) C[0,2] = C[2,0] = 2; C[1,1] = -1 E, V = eig(np.dot(inv(S), C)) n = np.argmax(np.abs(E)) a = V[:,n] return a def ellipse_center(a): b,c,d,f,g,a = a[1]/2, a[2], a[3]/2, a[4]/2, a[5], a[0] num = b*b-a*c x0=(c*d-b*f)/num y0=(a*f-b*d)/num return np.array([x0,y0]) def ellipse_angle_of_rotation( a ): b,c,d,f,g,a = a[1]/2, a[2], a[3]/2, a[4]/2, a[5], a[0] return 0.5*np.arctan(2*b/(a-c)) def ellipse_axis_length( a ): b,c,d,f,g,a = a[1]/2, a[2], a[3]/2, a[4]/2, a[5], a[0] up = 2*(a*f*f+c*d*d+g*b*b-2*b*d*f-a*c*g) down1=(b*b-a*c)*( (c-a)*np.sqrt(1+4*b*b/((a-c)*(a-c)))-(c+a)) down2=(b*b-a*c)*( (a-c)*np.sqrt(1+4*b*b/((a-c)*(a-c)))-(c+a)) res1=np.sqrt(up/down1) res2=np.sqrt(up/down2) return np.array([res1, res2]) if __name__ == '__main__': points = [(560036.4495758876, 6362071.890493258), (560036.4495758876, 6362070.890493258), (560036.9495758876, 6362070.890493258), (560036.9495758876, 6362070.390493258), (560037.4495758876, 6362070.390493258), (560037.4495758876, 6362064.890493258), (560036.4495758876, 6362064.890493258), (560036.4495758876, 6362063.390493258), (560035.4495758876, 6362063.390493258), (560035.4495758876, 6362062.390493258), (560034.9495758876, 6362062.390493258), (560034.9495758876, 6362061.390493258), (560032.9495758876, 6362061.390493258), (560032.9495758876, 6362061.890493258), (560030.4495758876, 6362061.890493258), (560030.4495758876, 6362061.390493258), (560029.9495758876, 6362061.390493258), (560029.9495758876, 6362060.390493258), (560029.4495758876, 6362060.390493258), (560029.4495758876, 6362059.890493258), (560028.9495758876, 6362059.890493258), (560028.9495758876, 6362059.390493258), (560028.4495758876, 6362059.390493258), (560028.4495758876, 6362058.890493258), (560027.4495758876, 6362058.890493258), (560027.4495758876, 6362058.390493258), (560026.9495758876, 6362058.390493258), (560026.9495758876, 6362057.890493258), (560025.4495758876, 6362057.890493258), (560025.4495758876, 6362057.390493258), (560023.4495758876, 6362057.390493258), (560023.4495758876, 6362060.390493258), (560023.9495758876, 6362060.390493258), (560023.9495758876, 6362061.890493258), (560024.4495758876, 6362061.890493258), (560024.4495758876, 6362063.390493258), (560024.9495758876, 6362063.390493258), (560024.9495758876, 6362064.390493258), (560025.4495758876, 6362064.390493258), (560025.4495758876, 6362065.390493258), (560025.9495758876, 6362065.390493258), (560025.9495758876, 6362065.890493258), (560026.4495758876, 6362065.890493258), (560026.4495758876, 6362066.890493258), (560026.9495758876, 6362066.890493258), (560026.9495758876, 6362068.390493258), (560027.4495758876, 6362068.390493258), (560027.4495758876, 6362068.890493258), (560027.9495758876, 6362068.890493258), (560027.9495758876, 6362069.390493258), (560028.4495758876, 6362069.390493258), (560028.4495758876, 6362069.890493258), (560033.4495758876, 6362069.890493258), (560033.4495758876, 6362070.390493258), (560033.9495758876, 6362070.390493258), (560033.9495758876, 6362070.890493258), (560034.4495758876, 6362070.890493258), (560034.4495758876, 6362071.390493258), (560034.9495758876, 6362071.390493258), (560034.9495758876, 6362071.890493258), (560036.4495758876, 6362071.890493258)] a_points = np.array(points) x = a_points[:, 0] y = a_points[:, 1] from pylab import * plot(x,y) show() a = fitEllipse(x,y) center = ellipse_center(a) phi = ellipse_angle_of_rotation(a) axes = ellipse_axis_length(a) print "center = ", center print "angle of rotation = ", phi print "axes = ", axes from pylab import * plot(x,y) plot(center[0:1],center[1:], color = 'red') show() each vertex is a xi,y,i point plot of 2D point and center of fit ellipse

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  • C++ Unlocking a std::mutex before calling std::unique_lock wait

    - by Sant Kadog
    I have a multithreaded application (using std::thread) with a manager (class Tree) that executes some piece of code on different subtrees (embedded struct SubTree) in parallel. The basic idea is that each instance of SubTree has a deque that store objects. If the deque is empty, the thread waits until a new element is inserted in the deque or the termination criteria is reached. One subtree can generate objects and push them in the deque of another subtree. For convenience, all my std::mutex, std::locks and std::variable_condition are stored in a struct called "locks". The class Tree creates some threads that run the following method (first attempt) : void Tree::launch(SubTree & st, Locks & locks ) { /* some code */ std::lock_guard<std::mutex> deque_lock(locks.deque_mutex_[st.id_]) ; // lock the access to the deque of subtree st if (st.deque_.empty()) // check that the deque is still empty { // some threads are still running, wait for them to terminate std::unique_lock<std::mutex> wait_lock(locks.restart_mutex_[st.id_]) ; locks.restart_condition_[st.id_].wait(wait_lock) ; } /* some code */ } The problem is that "deque_lock" is still locked while the thread is waiting. Hence no object can be added in the deque of the current thread by a concurrent one. So I turned the lock_guard into a unique_lock and managed the lock/unlock manually : void launch(SubTree & st, Locks & locks ) { /* some code */ std::unique_lock<std::mutex> deque_lock(locks.deque_mutex_[st.id_]) ; // lock the access to the deque of subtree st if (st.deque_.empty()) // check that the deque is still empty { deque_lock.unlock() ; // unlock the access to the deque to enable the other threads to add objects // DATA RACE : nothing must happen to the unprotected deque here !!!!!! // some threads are still running, wait for them to terminate std::unique_lock<std::mutex> wait_lock(locks.restart_mutex_[st.id_]) ; locks.restart_condition_[st.id_].wait(wait_lock) ; } /* some code */ } The problem now, is that there is a data race, and I would like to make sure that the "wait" instruction is performed directly after the "deque_lock.unlock()" one. Would anyone know a way to create such a critical instruction sequence with the standard library ? Thanks in advance.

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  • ImageMagick on Mac OSX Snow Leopard. Is there any way to get it to compile and run?

    - by ?????
    It seems that I have more trouble getting standard Unix things to run on Snow Leopard than any other platform--including Windows cygwin For the past couple of days, I've been trying to get ImageMagick to run on Snow Leopard. The most obvious way, Mac Ports, fails: tppllc-Mac-Pro:ImageMagick-sl swirsky$ sudo port install imagemagick ---> Computing dependencies for p5-locale-gettext ---> Configuring p5-locale-gettext Error: Target org.macports.configure returned: configure failure: shell command " cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_ports_perl_p5-locale-gettext/work/gettext-1.05" && /opt/local/bin/perl Makefile.PL INSTALLDIRS=vendor " returned error 2 Command output: checking for gettext... no checking for gettext in -I/opt/local/include -arch i386 -L/opt/local/lib -lintl...gettext function not found. Please install libintl at Makefile.PL line 18. no Error: Unable to upgrade port: 1 Error: Unable to execute port: upgrade xorg-libXt failed Before reporting a bug, first run the command again with the -d flag to get complete output. tppllc-Mac-Pro:ImageMagick-sl swirsky$ Not wanting to spend another two days figuring out why my libintl doesn't have a "gettext" function, I tried a different route: the script mentioned here: http://github.com/masterkain/ImageMagick-sl This script downloads and installs an ImageMagic independently of MacPorts issues tppllc-Mac-Pro:ImageMagick-sl swirsky$ /usr/local/bin/convert dyld: Library not loaded: /opt/local/lib/libiconv.2.dylib Referenced from: /opt/local/lib/libfontconfig.1.dylib Reason: Incompatible library version: libfontconfig.1.dylib requires version 8.0.0 or later, but libiconv.2.dylib provides version 7.0.0 Trace/BPT trap It downloads everything and compiles fine, but fails when I try to run it, with the message above. So now I'm two steps away from ImageMagick, trying to get a newer libiconv on my machine. I downloaded the latest libiconv, compiled and built it. I put the resulting library in /opt/local/lib, and I still get the same error message: tppllc-Mac-Pro:.libs swirsky$ sudo mv libiconv.2.dylib /opt/local/lib/libiconv.2.dylib tppllc-Mac-Pro:.libs swirsky$ convert dyld: Library not loaded: /opt/local/lib/libiconv.2.dylib Referenced from: /opt/local/lib/libfontconfig.1.dylib Reason: Incompatible library version: libfontconfig.1.dylib requires version 8.0.0 or later, but libiconv.2.dylib provides version 7.0.0 Trace/BPT trap Now here's something interesting. The error message shows it's looking in /opt/local/lib/libiconv.2.dylib. otools -L shows that this does implement 8.0.0: tppllc-Mac-Pro:.libs swirsky$ otool -L /opt/local/lib/libiconv.2.dylib /opt/local/lib/libiconv.2.dylib: /usr/local/lib/libiconv.2.dylib (compatibility version 8.0.0, current version 8.0.0) /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 125.0.0) tppllc-Mac-Pro:.libs swirsky$ And, for good measure, I set the DYLD_LIBRARY_PATH to make sure this directory is the one for dynamic libraries. So even though I do have a library that provides 8.0.0, it's being seen as 7.0.0! Any ideas why this would happen? So here's my question: Is it possible to get ImageMagick to run on OSX Snow Leopard? Are there any binary distributions that have static libraries baked in so I don't have to worry about these issue/

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  • how to implement a "soft barrier" in multithreaded c++

    - by Jason
    I have some multithreaded c++ code with the following structure: do_thread_specific_work(); update_shared_variables(); //checkpoint A do_thread_specific_work_not_modifying_shared_variables(); //checkpoint B do_thread_specific_work_requiring_all_threads_have_updated_shared_variables(); What follows checkpoint B is work that could have started if all threads have reached only checkpoint A, hence my notion of a "soft barrier". Typically multithreading libraries only provide "hard barriers" in which all threads must reach some point before any can continue. Obviously a hard barrier could be used at checkpoint B. Using a soft barrier can lead to better execution time, especially since the work between checkpoints A and B may not be load-balanced between the threads (i.e. 1 slow thread who has reached checkpoint A but not B could be causing all the others to wait at the barrier just before checkpoint B). I've tried using atomics to synchronize things and I know with 100% certainty that is it NOT guaranteed to work. For example using openmp syntax, before the parallel section start with: shared_thread_counter = num_threads; //known at compile time #pragma omp flush Then at checkpoint A: #pragma omp atomic shared_thread_counter--; Then at checkpoint B (using polling): #pragma omp flush while (shared_thread_counter > 0) { usleep(1); //can be removed, but better to limit memory bandwidth #pragma omp flush } I've designed some experiments in which I use an atomic to indicate that some operation before it is finished. The experiment would work with 2 threads most of the time but consistently fail when I have lots of threads (like 20 or 30). I suspect this is because of the caching structure of modern CPUs. Even if one thread updates some other value before doing the atomic decrement, it is not guaranteed to be read by another thread in that order. Consider the case when the other value is a cache miss and the atomic decrement is a cache hit. So back to my question, how to CORRECTLY implement this "soft barrier"? Is there any built-in feature that guarantees such functionality? I'd prefer openmp but I'm familiar with most of the other common multithreading libraries. As a workaround right now, I'm using a hard barrier at checkpoint B and I've restructured my code to make the work between checkpoint A and B automatically load-balancing between the threads (which has been rather difficult at times). Thanks for any advice/insight :)

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  • How to catch 'exceptions' for out of order execution in Workflow Foundation 4?

    - by Alex Key
    Hi, I am attempting to model a worklfow using a "WCF Workflow Service" in .net / vs 2010 that needs to handle out of order execution gracefully (but not allow it - if thath makes sense!?) For example I have 2 receive activities one called Initialize and the other called GetValue inside a FlowChart. In most cases Initialize should be called first and GetValue after (as modled in the flow chart). However if GetValue is executed before Initialize I do not want to return an "out of order" exception (although when I look at the WCF test client, I can't actually see an exception). But instead a custom exception saying something like "you must initialize first". In theory I could model this with lots of parallel activities and conditions to check if Initialized / Running / Terminated etc. But the business process I am modelling if very very similar to a state machine... except it must handle people executing things in the wrong order. Ideally I would like to catch the "out of order" exception (thought I don't think it's really an exception as such), check the 'exception' to see which function was attempted to run and then handle it. I have done some research around enabling AllowBufferedReceive. However I don't want to be able to execute out of order (I don't think), but instead give a detailed response if it does happen. I've looked at the new beta state machine template for WF 4 - but i'm not sure if it does what i'm after? I'm not sure if I have the wrong end of the stick, so any help would be greatly appreciated. [EDIT] To help clarify... Sorry it's a tricky one to explain. The standard I am trying to implement (the e-learning standard SCORM RTE) is structured like a state machine i.e. certain functions can only be executed in certain states. However the standard specifies that if the calling clients tries to execute a function that it is not meant to, then a warning should be issued... for example "you cannot use GetValue(), because you have not yet Initialized". Ideally I'd like to structure the workflow as the theoretical state machine and not need to have to use multiple if/else's to handle all the scenarios where something could be executed out-of-order. I'd like to catch a out-of-order exception (but I don't think there is such an exception - as it's not in the debugger) and rethrow it.

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