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  • Install problem on UEFI, Windows 8 new desktop

    - by albuquerque mat
    I just bought an HP desktop, p6-2326s, which has windows 8 installed. I have tried booting a Ubuntu live disc but the machine won't boot it. When I bring up the UEFI boot menu it offers a selection of UEFI BOOT SOURCES, windows boot manager, dvd drive, IP4 Ethernet controller, or IP6 Ethernet controller. If I select the dvd drive with the CD in it I get the message "Secure boot violation, Invalid structure detected. Check secure boot policy in setup." With all other selections it just boots into windows. So where do I go from here?

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  • Brevets : Microsoft gagne contre Motorola en Allemagne, les terminaux Android du constructeur interdits de ventes sur le territoire

    Brevets : Microsoft gagne contre Motorola en Allemagne les terminaux Android du constructeur interdits de ventes sur le territoire Les procès Android se poursuivent avec leurs lots de rebondissements, et laissent peu à peu place à des décisions de justice. Après le verdict de l'affaire Google contre Oracle pour violation de brevets Java dans Android, dont le géant de la recherche en est sorti vainqueur, c'est au tour d'un autre gros feuilleton IT qui dure depuis plus d'un an de livrer sa sentence. Un tribunal régional de Munich en Allemagne a arrêté que les téléphones Android de Motorola Mobility violent les brevets de Microsoft. Plus précisément, ces dispositifs empièten...

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  • Using XA Transactions in Coherence-based Applications

    - by jpurdy
    While the costs of XA transactions are well known (e.g. increased data contention, higher latency, significant disk I/O for logging, availability challenges, etc.), in many cases they are the most attractive option for coordinating logical transactions across multiple resources. There are a few common approaches when integrating Coherence into applications via the use of an application server's transaction manager: Use of Coherence as a read-only cache, applying transactions to the underlying database (or any system of record) instead of the cache. Use of TransactionMap interface via the included resource adapter. Use of the new ACID transaction framework, introduced in Coherence 3.6.   Each of these may have significant drawbacks for certain workloads. Using Coherence as a read-only cache is the simplest option. In this approach, the application is responsible for managing both the database and the cache (either within the business logic or via application server hooks). This approach also tends to provide limited benefit for many workloads, particularly those workloads that either have queries (given the complexity of maintaining a fully cached data set in Coherence) or are not read-heavy (where the cost of managing the cache may outweigh the benefits of reading from it). All updates are made synchronously to the database, leaving it as both a source of latency as well as a potential bottleneck. This approach also prevents addressing "hot data" problems (when certain objects are updated by many concurrent transactions) since most database servers offer no facilities for explicitly controlling concurrent updates. Finally, this option tends to be a better fit for key-based access (rather than filter-based access such as queries) since this makes it easier to aggressively invalidate cache entries without worrying about when they will be reloaded. The advantage of this approach is that it allows strong data consistency as long as optimistic concurrency control is used to ensure that database updates are applied correctly regardless of whether the cache contains stale (or even dirty) data. Another benefit of this approach is that it avoids the limitations of Coherence's write-through caching implementation. TransactionMap is generally used when Coherence acts as system of record. TransactionMap is not generally compatible with write-through caching, so it will usually be either used to manage a standalone cache or when the cache is backed by a database via write-behind caching. TransactionMap has some restrictions that may limit its utility, the most significant being: The lock-based concurrency model is relatively inefficient and may introduce significant latency and contention. As an example, in a typical configuration, a transaction that updates 20 cache entries will require roughly 40ms just for lock management (assuming all locks are granted immediately, and excluding validation and writing which will require a similar amount of time). This may be partially mitigated by denormalizing (e.g. combining a parent object and its set of child objects into a single cache entry), at the cost of increasing false contention (e.g. transactions will conflict even when updating different child objects). If the client (application server JVM) fails during the commit phase, locks will be released immediately, and the transaction may be partially committed. In practice, this is usually not as bad as it may sound since the commit phase is usually very short (all locks having been previously acquired). Note that this vulnerability does not exist when a single NamedCache is used and all updates are confined to a single partition (generally implying the use of partition affinity). The unconventional TransactionMap API is cumbersome but manageable. Only a few methods are transactional, primarily get(), put() and remove(). The ACID transactions framework (accessed via the Connection class) provides atomicity guarantees by implementing the NamedCache interface, maintaining its own cache data and transaction logs inside a set of private partitioned caches. This feature may be used as either a local transactional resource or as logging XA resource. However, a lack of database integration precludes the use of this functionality for most applications. A side effect of this is that this feature has not seen significant adoption, meaning that any use of this is subject to the usual headaches associated with being an early adopter (greater chance of bugs and greater risk of hitting an unoptimized code path). As a result, for the moment, we generally recommend against using this feature. In summary, it is possible to use Coherence in XA-oriented applications, and several customers are doing this successfully, but it is not a core usage model for the product, so care should be taken before committing to this path. For most applications, the most robust solution is normally to use Coherence as a read-only cache of the underlying data resources, even if this prevents taking advantage of certain product features.

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  • "// ..." comments at end of code block after } - good or bad?

    - by gablin
    I've often seen such comments be used: function foo() { ... } // foo while (...) { ... } // while if (...) { ... } // if and sometimes even as far as if (condition) { ... } // if (condition) I've never understood this practice and thus never applied it. If your code is so long that you need to know what this ending } is then perhaps you should consider splitting it up into separate functions. Also, most developers tools are able to jump to the matching bracket. And finally the last is, for me, a clear violation to the DRY principle; if you change the condition you would have to remember to change the comment as well (or else it could get messy for the maintainer, or even for you). So why do people use this? Should we use it, or is it bad practice?

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  • Is there any complications or side effects for changing final field access/visibility modifier from private to protected?

    - by Software Engeneering Learner
    I have a private final field in one class and then I want to address that field in a subclass. I want to change field access/visibility modifier from private to protected, so I don't have to call getField() method from subclass and I can instead address that field directly (which is more clear and cohessive). Will there be any side effects or complications if I change private to protected for a final field? UPDATE: from logical point of view, it's obvious that descendant should be able to directly access all predecessor fields, right? But there are certain constraints that are imposed on private final fields by JVM, like 100% initialization guarantee after construction phase(useful for concurrency) and so on. So I would like to know, by changing from private to protected, won't that or any other constraints be compromised?

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  • Pooling (Singleton) Objects Against Connection Pools

    - by kolossus
    Given the following scenario A canned enterprise application that maintains its own connection pool A homegrown client application to the enterprise app. This app is built using Spring framework, with the DAO pattern While I may have a simplistic view of this, I think the following line of thinking is sound: Having a fixed pool of DAO objects, holding on to connection objects from the pool. Clearly, the pool should be capable of scaling up (or down depending on need) and the connection objects must outnumber the DAOs by a healthy margin. Good Instantiating brand new DAOs for every request to access the enterprise app; each DAO will attempt to grab a connection from the pool and release it when it's done. Bad Since these are service objects, there will be no (mutable) state held by the objects (reduced risk of concurrency issues) I also think that with #1, there should be little to no resource contention, while in #2, there'll almost always be a DAO waiting to be serviced. Is my thinking correct and what could go wrong?

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  • Law of Demeter in MVC regarding Controller-View communication

    - by Antonio MG
    The scenario: Having a Controller that controls a view composed of complex subviews. Each one of those subviews is a separated class in a separate file. For example, one of those subviews is called ButtonsView, and has a bunch of buttons. The Controller has to access those buttons. Would accessing those buttons like this: controllerMainView.buttonsView.firstButton.state(); be a violation of the LOD? On one hand, it could be yes because the controller is accessing the inner hierarchy of the view. On the other, a Controller should be aware of what happens inside the view and how is composed. Any thoughts?

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  • The architecture and technologies to use for a secure, fast, reliable and easily scalable web application

    - by DSoul
    ^ For actual questions, skip to the lists down below I understand, that his is a vague topic, but please, before you turn the other way and disregard me, hear me out. I am currently doing research for a web application(I don't know if application is the correct word for it, but I will proceed w/ that for now), that one day might need to be everything mentioned in the title. I am bound by nothing. That means that every language, OS and framework is acceptable, but only if it proves it's usefulness. And if you are going to say, that scalability and speed depend on the code I write for this application, then I agree, but I am just trying to find something, that wouldn't stand in my way later on. I have done quite a bit reading on this subject, but I still don't have a clear picture, to what suits my needs, so I come to you, StackOverflow, to give me directions. I know you all must be wondering what I'm building, but I assure you, that it doesn't matter. I have heard of 12 factor app though, if you have any similar guidelines or what is, to suggest the please, go ahead. For the sake of keeping your answers as open as possible, I'm not gonna provide you my experience regarding anything written in this question. ^ Skippers, start here First off - the weights of the requirements are probably something like that (on a scale of 10): Security - 10 Speed - 5 Reliability (concurrency) - 7.5 Scalability - 10 Speed and concurrency are not a top priority, in the sense, that the program can be CPU intensive, and therefore slow, and only accept a not-that-high number of concurrent users, but both of these factors must be improvable by scaling the system Anyway, here are my questions: How many layers should the application have, so it would be future-proof and could best fulfill the aforementioned requirements? For now, what I have in mind is the most common version: Completely separated front end, that might be a web page or an MMI application or even both. Some middle-ware handling communication between the front and the back end. This is probably a server that communicates w/ the front end via HTTP. How the communication w/ the back end should be handled is probably dependent on the back end. The back end. Something that handles data through resources like DB and etc. and does various computations w/ the data. This, as the highest priority part of the software, must be easily spread to multiple computers later on and have no known security holes. I think ideally the middle-ware should send a request to a queue from where one of the back end processes takes this request, chops it up to smaller parts and buts these parts of the request back onto the same queue as the initial request, after what these parts will be then handled by other back end processes. Something *map-reduce*y, so to say. What frameworks, languages and etc. should these layers use? The technologies used here are not that important at this moment, you can ignore this part for now I've been pointed to node.js for this part. Do you guys know any better alternatives, or have any reasons why I should (not) use node.js for this particular job. I actually have no good idea, what to use for this job, there are too many options out there, so please direct me. This part (and the 2. one also, I think) depend a lot on the OS, so suggest any OSs alongside w/ the technologies/frameworks. Initially, all computers (or 1 for starters) hosting the back end are going to be virtual machines. Please do give suggestions to any part of the question, that you feel you have comprehensive knowledge and/or experience of. And also, point out if you feel that any part of the current set-up means an instant (or even distant) failure or if I missed a very important aspect to consider. I'm not looking for a definitive answer for how to achieve my goals, because there certainly isn't one, for I haven't provided you w/ all the required information. I'm just looking for recommendations and directions on what to look into. Also, bare in mind, that this isn't something that I have to get done quickly, to sell and let it be re-written by the new owner (which, I've been told for multiple times, is what I should aim for). I have all the time in the world and I really just want to learn doing something really high-end. Also, excuse me if my language isn't the best, I'm not a native. Anyway. Thanks in advance to anyone, who takes the time to help me out here. PS. When I do seem to come up w/ a good architecture/design for this project, I will certainly make it an open project and keep you guys up to date w/ it's development. As in what you could have told me earlier and etc. For obvious reasons the very same question got closed on SO, but could you guys still help me?.

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  • De plus en plus d'employeurs exigent les identifiants Facebook des candidats d'après Reuters, une pratique légale aux USA

    De plus en plus d'employeurs exigent les identifiants Facebook des candidats D'après Reuters, une violation de la vie privée qui serait tout à fait légale aux Etats-Unis [IMG]http://blog.developpez.com/media/facebook_128.png[/IMG] Aux Etats-Unis, les personnes à la recherche d'un emploi se retrouvent confrontées à un tout nouveau problème selon l'agence de presse Reuters. Certains employeurs exigeraient durant les entretiens d'embauche que les candidats dévoilent leurs identifiants Facebook. Plusieurs études ont démontré que Facebook pouvait être un outil de recrutement utile. Passer 5 à 10 minutes sur le profil d'un candidat permet à l'employeur d'en apprendre beaucou...

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  • Adopt a Java EE 7 JSR!

    - by reza_rahman
    Broad community participation is key to the success of any technology worth it's salt. The Adopt-a-JSR program was launched in recognition of this fact. It is an initiative by some key JUG leaders around the World to encourage JUG members to get involved in a JSR and to evangelize that JSR to their JUG and the wider Java community, in order to increase grass roots participation. There are a number of JUGs that have already jumped in like the Chennai JUG, SouJava, London Java Community, BeJUG, GoJava, Morrocco JUG, Campinas JUG and ItpJava. Note that any developer can participate, there isn't a need to be a JUG leader. There are a number of Java EE 7 JSRs that could use your help right now including WebSocket, JSON, Caching, Concurrency for EE, JAX-RS2 and JMS2. Find out more here.

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  • Database Context and Singleton injection with IoC

    - by zaitsman
    All of the below relates to a ASP.NET c# app. I have a Singleton Settings MemoryCache that reads values from database on first access and caches these, then invalidates them using SQL Service Broker message and re-reads as required. For the purposes of standard controllers, i create my Db Context in a request scope. However, this obviously means that i can't use the same context in the Settings Cache class, since that is a singleton and we have a scope collision. At the moment, i ended up with two db contexts - the Controllers get it via IoC container, whereas a Singleton just creates it's own. However, i am not satisfied with this approach (mostly due to the way i feel about two contexts, the cache doesn't set anything on the db hence concurrency is not an issue as much). What is a better way to do it?

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  • Android : la plainte d'Oracle risque de perdre de l'ampleur, l'organisme officiel chargé des brevets rejette 17 demandes d'Oracle

    Android : La plainte d'Oracle contre Google risque de perdre de l'ampleur L'organisme officiel chargé des brevets rejette 17 demandes d'Oracle Mise à jour du 23/06/11 L'organisme officiel américain chargé des brevets vient d'entrer en jeu dans l'affaire entre Oracle et Google sur l'utilisation de Java dans Android. Oracle accuse Google de violation de 7 de ses brevets (ou plus exactement de brevets dont il a hérité avec le rachat de Sun). Pour chaucun, les avocats d'Oracle ont déposé plusieurs demandes (des « claims »). Après examen du premier brevet, le US Patent and Trademark Office (USPTO) vient d'invalider 17 des 21 demandes d'Oracle...

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  • Deleting a game object

    - by Balls
    I tried doing this but it cause an access violation. void GameObjectFactory::Update() { for( std::list<GameObject*>::iterator it=gameObjectList.begin() ..... (*it)->Update(); } void Bomb::Update() { if( time == 2.0f ) { gameObjectFactory->Remove( this ); } } void GameObjectFactory::Remove( ... ) { gameObjectList.remove( ... ); } My thoughts would be to mark the object to be dead then let the factory handle it the on next frame for deletion. Is it the best and fastest way? What do you think?

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  • Designing a hierarchical structure with lots of reads and writes?

    - by JD01
    I am in the process of working on a video on demand system part of it involves the management of a hierarchical tree structure (think windows explorer) which allows users to upload videos, move folders around, create new folders etc. User action will be allowed depending on which permissions they have. In addition to managing the structure (creating folders and uploading videos), subscribers will be viewing content (read access). The number of reads will be significantly more than the writes. My question (and it is big one) is should I store the data in a database (for the writes) and also have some sort of cache which will be used for the reads? or do I use two databases? or is there a better solution? Also I will have to resolve concurrency issues which I think optimistic locking on the database will resolve. I have a fair bit about CQRS over the last few months but not sure if this is the way to go. Any ideas?

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  • Brevets : Motorola gagne à son tour contre Microsoft, un tribunal allemand tranche en faveur du constructeur dans l'affaire Android

    Brevets : Microsoft gagne contre Motorola en Allemagne les terminaux Android du constructeur interdits de ventes sur le territoire Les procès Android se poursuivent avec leurs lots de rebondissements, et laissent peu à peu place à des décisions de justice. Après le verdict de l'affaire Google contre Oracle pour violation de brevets Java dans Android, dont le géant de la recherche en est sorti vainqueur, c'est au tour d'un autre gros feuilleton IT qui dure depuis plus d'un an de livrer sa sentence. Un tribunal régional de Munich en Allemagne a arrêté que les téléphones Android de Motorola Mobility violent les brevets de Microsoft. Plus précisément, ces dispositifs empièten...

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  • how to enrich my programming background? [on hold]

    - by city
    I am not sure whether I post my question in right place. I am a master student in computer science and I will graduate next year.Recently, I failed in an interview. Because (at least I think) the interviewer did not think my background strong enough although I finished 5 courses projects and currently working on other 2 projects in graduate school. It seems that nowadays, recruiters like these candidates who finish some projects out of school/work. So I wanna enrich my background. So, I hope you guys recommend some java/C++ projects to me, which I can finish in two or three months. And it would be better if concurrency programming or other fancy skills are needed.

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  • Tomcat threads vs Java threads

    - by black666
    When using java threads, one has to take care of the basic problems that come with concurrency through synchronization etc. AFAIK Tomcat also works with threads to handle its workload. Why is it, that I don't have to think about making my code threadsafe when it is running in Tomcat?

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  • Link error in Borland

    - by Oren
    Hello Got Link error (Fatal: Access violation. Link terminated) in Borland 6.0. How do I know what is the cause of it ? Is there any output file that I can open and get more informative message ? Thanks in advance.

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  • Multiple NSOperationQueues?

    - by Infinity
    Hello! I would like to use NSOperations in my application to resolve threading problems. I have read some tutorials and now I know what I have to do, but I have a problem. There is a must to have the same NSOperationQueue in each class. What if I use a new NSOperationQueue in each class. There will be concurrency problems?

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  • Object database for website

    - by Damian
    I was planning to use db4o for a website. It's a microblog site with small posts and comments developed in java. The thing is I contacted db4o support asking if db4o would be suitable for a website, and they answered me that only for websites with low concurrency. That means with few requests? So, now I think db4o will not be a good choice. Do you know if there is any object database for java suitable for a website?

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  • Reading value at an address

    - by user146780
    I'm trying to make a program that reads the value at a certain address. I have this: int _tmain(int argc, _TCHAR* argv[]) { int *address; address = (int*)0x00000021; cout << *address; return 0; } But this gives a read violation error. What am I doing wrong? Thanks

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  • How fast is Berkeley DB SQL compared to SQLite?

    - by dan04
    Oracle recently released a Berkeley DB back-end to SQLite. I happen to have a hundreds-of-megabytes SQLite database that could very well benefit from "improved performance, concurrency, scalability, and reliability", but Oracle's site appears to lack any measurements of the improvements. Has anyone here done some benchmarking?

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