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• .NET development on a Retina MacBook Pro with Windows 8

  - by Jeff

  I remember sitting in Building 5 at Microsoft with some of my coworkers, when one of them came in with a shiny new 11” MacBook Air. It was nearly two years ago, and we found it pretty odd that the OEM’s building Windows machines sucked at industrial design in a way that defied logic. While Dell and HP were in a race to the bottom building commodity crap, Apple was staying out of the low-end market completely, and focusing on better design. In the process, they managed to build machines people actually wanted, and maintain an insanely high margin in the process. I stopped buying the commodity crap and custom builds in 2006, when Apple went Intel. As a .NET guy, I was still in it for Microsoft’s stack of development tools, which I found awesome, but had back to back crappy laptops from HP and Dell. After that original 15” MacBook Pro, I also had a Mac Pro tower (that I sold after three years for $1,500!), a 27” iMac, and my favorite, a 17” MacBook Pro (the unibody style) with an SSD added from OWC. The 17” was a little much to carry around because it was heavy, but it sure was nice getting as much as eight hours of battery life, and the screen was amazing. When the rumors started about a 15” model with a “retina” screen inspired by the Air, I made up my mind I wanted one, and ordered it the day it came out. I sold my 17”, after three years, for $750 to a friend who is really enjoying it. I got the base model with the upgrade to 16 gigs of RAM. It feels solid for being so thin, and if you’ve used the third generation iPad or the newer iPhone, you’ll be just as thrilled with the screen resolution. I’m typically getting just over six hours of battery life while running a VM, but Parallels 8 allegedly makes some power improvements, so we’ll see what happens. (It was just released today.) The nice thing about VM’s are that you can run more than one at a time. Primarily I run the Windows 8 VM with four cores (the laptop is quad-core, but has 8 logical cores due to hyperthreading or whatever Intel calls it) and 8 gigs of RAM. I also have a Windows Server 2008 R2 VM I spin up when I need to test stuff in a “real” server environment, and I give it two cores and 4 gigs of RAM. The Windows 8 VM spins up in about 8 seconds. Visual Studio 2012 takes a few more seconds, but count part of that as the “ReSharper tax” as it does its startup magic. The real beauty, the thing I looked most forward to, is that beautifully crisp C# text. Consolas has never looked as good as it does at 10pt. as it does on this display. You know how it looks great at 80pt. when conference speakers demo stuff on a projector? Think that sharpness, only tiny. It’s just gorgeous. Beyond that, everything is just so responsive and fast. Builds of large projects happen in seconds, hundreds of unit tests run in seconds… you just don’t spend a lot of time waiting for stuff. It’s kind of painful to go back to my 27” iMac (which would be better if I put an SSD in it before its third birthday). Are there negatives? A few minor issues, yes. As is the case with OS X, not everything scales right. You’ll see some weirdness at times with splash screens and icons and such. Chrome’s text rendering (in Windows) is apparently not aware of how to deal with higher DPI’s, so text is fuzzy (the OS X version is super sharp, however). You’ll also have to do some fiddling with keyboard settings to use the Windows 8 keyboard shortcuts. Overall, it’s as close to a no-compromise development experience as I’ve ever had. I’m not even going to bother with Boot Camp because the VM route already exceeds my expectations. You definitely get what you pay for. If this one also lasts three years and I can turn around and sell it, it’s worth it for something I use every day.

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• Defaulting the HLSL Vertex and Pixel Shader Levels to Feature Level 9_1 in VS 2012

  - by Michael B. McLaughlin

  I love Visual Studio 2012. But this is not a post about that. This is a post about tweaking one particular parameter that I’ve found a bit annoying. Disclaimer: You will be modifying important MSBuild files. If you screw up you will break your build tools. And maybe your computer will catch fire. I’m not responsible. No warranties or guaranties of any sort. This info is provided “as is”. By default, if you add a new vertex shader or pixel shader item to a project, it will be set to build with shader profile 4.0_level_9_3. If you need 9_3 functionality, this is all well and good. But (especially for Windows Store apps) you really want to target the lowest shader profile possible so that your game will run on as many computers as possible. So it’s a good idea to default to 9_1. To do this you could add in new HLSL files via “Add->New Item->Visual C++->HLSL->______ Shader File (.hlsl)” and then edit the shader files’ properties to set them manually to use 9_1 via “Properties->HLSL Compiler->General->Shader Model”. This is fine unless you forget to do this once and then submit your game with 9_3 shaders instead of 9_1 shaders to the Windows Store or to some other game store. Then you’d wind up with either rejection or angry “this doesn’t work on my computer! ripoff!” messages. There’s another option though. In “Program Files (x86)\Microsoft Visual Studio 11.0\Common7\IDE\ItemTemplates\VC\HLSL\1033\VertexShader” (note the path might vary slightly for you if you are using a 32-bit system or have a non-ENU version of Visual Studio 2012) you will find a “VertexShader.vstemplate” file. If you open this file in a text editor (e.g. Notepad++), then inside the CustomParameters tag within the TemplateContent tag you should see a CustomParameter tag for the ShaderType, i.e.: <CustomParameter Name="$ShaderType$" Value="Vertex"/> On a new line, we are going to add another CustomParameter tag to the CustomParameters tag. It will look like this: <CustomParameter Name="$ShaderModel$" Value="4.0_level_9_1"/> such that we now have:     <CustomParameters>       <CustomParameter Name="$ShaderType$" Value="Vertex"/>       <CustomParameter Name="$ShaderModel$" Value="4.0_level_9_1"/>     </CustomParameters> You can then save the file (you will need to be an Administrator or have Administrator access). Back in the 1033 directory (or whatever the number is for your language), go into the “PixelShader” directory. Edit the “PixelShader.vstemplate” file and make the same change (note that this time $ShaderType$ is “Pixel” not “Vertex”; you shouldn’t be changing that line anyway, but if you were to just copy and replace the above four lines then you will wind up creating pixel shaders that the HLSL compiler would try to compile as vertex shaders, with all sort of weird errors as a result). Once you’ve added the $ShaderModel$ line to “PixelShader.vstemplate” and have saved it, everything should be done. Since Feature Level 9_1 and 9_3 don’t support any of the other shader types, those are set to default to their appropriate minimums already (Compute and Geometry are set to “4.0” and Domain and Hull are set to “5.0”, which are their respective minimums (though not all 4.0 cards support Compute shaders; they were an optional feature added with DirectX 10.1 and only became required for DirectX 11 hardware). In case you are wondering where these magic values come from, you can find them all in the “fxc.xml” file in the “\Program Files (x86)\MSBuild\Microsoft.CPP\v4.0\V110\1033” directory (or whatever your language number is; 1033 is ENU and various other product languages have their own respective numbers (see: http://msdn.microsoft.com/en-us/goglobal/bb964664.aspx ) such that Japanese is 1041 (for example), though for all I know MSBuild tasks might be 1033 for everyone). If, like me, you installed VS 2012 to a drive other than the C:\ drive, you will find the vstemplate files in the drive to which you installed VS 2012 (D:\ in my case) but you will find the fxc.xml file on the C:\ drive. You should not edit fxc.xml. You will almost definitely break things by doing that; it’s just something you can look through to see all the other options that the FXC task takes such that you could, if needed, add further CustomParameter tags if you wanted to default to other supported options. I haven’t tried any others though so I don’t have any advice on how to set them.

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• Oracle Romania Summer School

  - by Maria Sandu

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 What would you say about a Summer School within a corporation where you can learn, play and practice? You might think that this is something usually uncommon for a company and you would be right. However, Oracle’s main value being innovation, we came up with a new project for Romanian students and graduates. We organised Oracle Summer School , offering them the opportunity to develop their soft skills and gain valuable business knowledge and exposure. How was Oracle Summer School programme organised? We focused on students and graduates’ needs and combined business experience with training and practice. The twenty four participants had different backgrounds, being interested in Software, Hardware, Finance, Marketing or other areas. The programme fulfilled each of these needs, bringing them in contact with Specialists and Managers. The first two weeks were dedicated to the company visits, business presentations and networking. The participants got an insight about employees’ activities and projects. Storytelling was also part of the program and people from different departments spent a couple of hours with the participants, sharing their experiences, knowledge and interesting stories. The Recruitment team delivered a training about the job interview skills in order to make the participants feel better prepared for a Recruitment process. The second module consisted of two weeks of Soft Skills trainings delivered by professional trainers from different departments. The participants gained useful insight on the competencies required within a business environment. The evenings were dedicated to social activities and it not very long until they started feel part of a team. The third module will take place at the end of September and will put the participants in contact with senior people from the business who will become their Mentors. What do the participants say about Oracle Summer School? “ As a fresh computer science graduate, Oracle Summer School gave me the opportunity of finding what are the technical and nontechnical skills required in a large multinational company. It was a great way of seeing how the theoretical knowledge I received during college is applied in real-life scenarios and what skills I still need to develop. “  (Cosmin Radu) “ When arriving at Oracle I had high expectations, but did not know exactly what was going to unfold because of the program's lack of precedence. Right after the first day, my feedback outgrew the initial forecast and the following weeks continued to build upon it. I had the pleasure to acquaint with brilliant people. The program was outlined on various profiles, delivering a comprehensive experience. It was very engaging, informative and nevertheless fun. “ (Vlad Manciu) „ Oracle Summer School is by far the best summer school that I have ever attended. For me it has been a great experience so far, because I’ve learned not only how to use soft skills in a corporate environment, but I’ve learned a great deal about myself as well. However, the most valuable asset of this 3-week period were the people that I’ve met: great individuals and great professionals, whom I really grew fond of.” (Alexandru Purcarea) “Applying to Oracle Summer School has been the best decision I took in regard to how to spend my summer holiday. I had the chance to do job shadowing at some of the departments I was interested in and I attended great trainings on various subjects such as time management and emotional intelligence. Moreover, I made friends with the other participants and we enjoyed going out together after “classes”.(Andreea Tudor) If you are interested in joining our team and attending our events please follow us on https://campus.oracle.com/campus/HR/emea_main.html /* 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:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-family:"Calibri","sans-serif"; mso-ascii- mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi- mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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• Level of detail algorithm not functioning correctly

  - by Darestium

  I have been working on this problem for months; I have been creating Planet Generator of sorts, after more than 6 months of work I am no closer to finishing it then I was 4 months ago. My problem; The terrain does not subdivide in the correct locations properly, it almost seems as if there is a ghost camera next to me, and the quads subdivide based on the position of this "ghost camera". Here is a video of the broken program: http://www.youtube.com/watch?v=NF_pHeMOju8 The best example of the problem occurs around 0:36. For detail limiting, I am going for a chunked LOD approach, which subdivides the terrain based on how far you are away from it. I use a "depth table" to determine how many subdivisions should take place. void PQuad::construct_depth_table(float distance) { tree[0] = -1; for (int i = 1; i < MAX_DEPTH; i++) { tree[i] = distance; distance /= 2.0f; } } The chuncked LOD relies on the child/parent structure of quads, the depth is determined by a constant e.g: if the constant is 6, there are six levels of detail. The quads which should be drawn go through a distance test from the player to the centre of the quad. void PQuad::get_recursive(glm::vec3 player_pos, std::vector<PQuad*>& out_children) { for (size_t i = 0; i < children.size(); i++) { children[i].get_recursive(player_pos, out_children); } if (this->should_draw(player_pos) || this->depth == 0) { out_children.emplace_back(this); } } bool PQuad::should_draw(glm::vec3 player_position) { float distance = distance3(player_position, centre); if (distance < tree[depth]) { return true; } return false; } The root quad has four children which could be visualized like the following: [] [] [] [] Where each [] is a child. Each child has the same amount of children up until the detail limit, the quads which have are 6 iterations deep are leaf nodes, these nodes have no children. Each node has a corresponding Mesh, each Mesh structure has 16x16 Quad-shapes, each Mesh's Quad-shapes halves in size each detail level deeper - creating more detail. void PQuad::construct_children() { // Calculate the position of the Quad based on the parent's location calculate_position(); if (depth < (int)MAX_DEPTH) { children.reserve((int)NUM_OF_CHILDREN); for (int i = 0; i < (int)NUM_OF_CHILDREN; i++) { children.emplace_back(PQuad(this->face_direction, this->radius)); PQuad *child = &children.back(); child->set_depth(depth + 1); child->set_child_index(i); child->set_parent(this); child->construct_children(); } } else { leaf = true; } } The following function creates the vertices for each quad, I feel that it may play a role in the problem - I just can't determine what is causing the problem. void PQuad::construct_vertices(std::vector<glm::vec3> *vertices, std::vector<Color3> *colors) { vertices->reserve(quad_width * quad_height); for (int y = 0; y < quad_height; y++) { for (int x = 0; x < quad_width; x++) { switch (face_direction) { case YIncreasing: vertices->emplace_back(glm::vec3(position.x + x * element_width, quad_height - 1.0f, -(position.y + y * element_width))); break; case YDecreasing: vertices->emplace_back(glm::vec3(position.x + x * element_width, 0.0f, -(position.y + y * element_width))); break; case XIncreasing: vertices->emplace_back(glm::vec3(quad_width - 1.0f, position.y + y * element_width, -(position.x + x * element_width))); break; case XDecreasing: vertices->emplace_back(glm::vec3(0.0f, position.y + y * element_width, -(position.x + x * element_width))); break; case ZIncreasing: vertices->emplace_back(glm::vec3(position.x + x * element_width, position.y + y * element_width, 0.0f)); break; case ZDecreasing: vertices->emplace_back(glm::vec3(position.x + x * element_width, position.y + y * element_width, -(quad_width - 1.0f))); break; } // Position the bottom, right, front vertex of the cube from being (0,0,0) to (-16, -16, 16) (*vertices)[vertices->size() - 1] -= glm::vec3(quad_width / 2.0f, quad_width / 2.0f, -(quad_width / 2.0f)); colors->emplace_back(Color3(255.0f, 255.0f, 255.0f, false)); } } switch (face_direction) { case YIncreasing: this->centre = glm::vec3(position.x + quad_width / 2.0f, quad_height - 1.0f, -(position.y + quad_height / 2.0f)); break; case YDecreasing: this->centre = glm::vec3(position.x + quad_width / 2.0f, 0.0f, -(position.y + quad_height / 2.0f)); break; case XIncreasing: this->centre = glm::vec3(quad_width - 1.0f, position.y + quad_height / 2.0f, -(position.x + quad_width / 2.0f)); break; case XDecreasing: this->centre = glm::vec3(0.0f, position.y + quad_height / 2.0f, -(position.x + quad_width / 2.0f)); break; case ZIncreasing: this->centre = glm::vec3(position.x + quad_width / 2.0f, position.y + quad_height / 2.0f, 0.0f); break; case ZDecreasing: this->centre = glm::vec3(position.x + quad_width / 2.0f, position.y + quad_height / 2.0f, -(quad_height - 1.0f)); break; } this->centre -= glm::vec3(quad_width / 2.0f, quad_width / 2.0f, -(quad_width / 2.0f)); } Any help in discovering what is causing this "subdivding in the wrong place" would be greatly appreciated.

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• #OOW 2012 @PARIS...talking Oracle and Clouds, and Optimized Datacenter

  - by Eric Bezille

  For those of you who want to get most out of Oracle technologies to evolve your IT to the Next Wave, I encourage you to register to the up coming Oracle Optimized Datacenter event that will take place in Paris on November 28th. You will get the opportunity to exchange with Oracle experts and customers having successfully evolve their IT by leveraging Oracle technologies. You will also get the latest news on some of the Oracle systems announcements made during OOW 2012. During this event we will make an update about Oracle and Clouds, from private to public and hybrid models. So in preparing this session, I thought it was a good start to make a status of Cloud Computing in France, and CIO requirements in particular. Starting in 2009 with the first Cloud Camp in Paris, the market has evolved, but the basics are still the same : think hybrid. From Traditional IT to Clouds One size doesn't fit all, and for big companies having already an IT in place, there will be parts eligible to external (public) cloud, and parts that would be required to stay inside the firewalls, so ability to integrate both side is key.  None the less, one of the major impact of Cloud Computing trend on IT, reported by Forrester, is the pressure it makes on CIO to evolve towards the same model that end-users are now used to in their day to day life, where self-service and flexibility are paramount. This is what is driving IT to transform itself toward "a Global Service Provider", or for some as "IT "is" the Business" (see : Gartner Identifies Four Futures for IT and CIO), and for both models toward a Private Cloud Service Provider. In this journey, there is still a big difference between most of existing external Cloud and a firm IT : the number of applications that a CIO has to manage. Most cloud providers today are overly specialized, but at the end of the day, there are really few business processes that rely on only one application. So CIOs has to combine everything together external and internal. And for the internal parts that they will have to make them evolve to a Private Cloud, the scope can be very large. This will often require CIOs to evolve from their traditional approach to more disruptive ones, the time has come to introduce new standards and processes, if they want to succeed. So let's have a look at the different Cloud models, what type of users they are addressing, what value they bring and most importantly what needs to be done by the  Cloud Provider, and what is left over to the user. IaaS, PaaS, SaaS : what's provided and what needs to be done First of all the Cloud Provider will have to provide all the infrastructure needed to deliver the service. And the more value IT will want to provide, the more IT will have to deliver and integrate : from disks to applications. As we can see in the above picture, providing pure IaaS, left a lot to cover for the end-user, that’s why the end-user targeted by this Cloud Service is IT people. If you want to bring more value to developers, you need to provide to them a development platform ready to use, which is what PaaS is standing for, by providing not only the processors power, storage and OS, but also the Database and Middleware platform. SaaS being the last mile of the Cloud, providing an application ready to use by business users, the remaining part for the end-users being configuring and specifying the application for their specific usage. In addition to that, there are common challenges encompassing all type of Cloud Services : Security : covering all aspect, not only of users management but also data flows and data privacy Charge back : measuring what is used and by whom Application management : providing capabilities not only to deploy, but also to upgrade, from OS for IaaS, Database, and Middleware for PaaS, to a full Business Application for SaaS. Scalability : ability to evolve ALL the components of the Cloud Provider stack as needed Availability : ability to cover “always on” requirements Efficiency : providing a infrastructure that leverage shared resources in an efficient way and still comply to SLA (performances, availability, scalability, and ability to evolve) Automation : providing the orchestration of ALL the components in all service life-cycle (deployment, growth & shrink (elasticity), upgrades,...) Management : providing monitoring, configuring and self-service up to the end-users Oracle Strategy and Clouds For CIOs to succeed in their Private Cloud implementation, means that they encompass all those aspects for each component life-cycle that they selected to build their Cloud. That’s where a multi-vendors layered approach comes short in terms of efficiency. That’s the reason why Oracle focus on taking care of all those aspects directly at Engineering level, to truly provide efficient Cloud Services solutions for IaaS, PaaS and SaaS. We are going as far as embedding software functions in hardware (storage, processor level,...) to ensure the best SLA with the highest efficiency. The beauty of it, as we rely on standards, is that the Oracle components that you are running today in-house, are exactly the same that we are using to build Clouds, bringing you flexibility, reversibility and fast path to adoption. With Oracle Engineered Systems (Exadata, Exalogic & SPARC SuperCluster, more specifically, when talking about Cloud), we are delivering all those components hardware and software already engineered together at Oracle factory, with a single pane of glace for the management of ALL the components through Oracle Enterprise Manager, and with high-availability, scalability and ability to evolve by design. To give you a feeling of what does that bring in terms just of implementation project timeline, for example with Oracle SPARC SuperCluster, we have a consistent track of record to have the system plug into existing Datacenter and ready in a week. This includes Oracle Database, OS, virtualization, Database Storage (Exadata Storage Cells in this case), Application Storage, and all network configuration. This strategy enable CIOs to very quickly build Cloud Services, taking out not only the complexity of integrating everything together but also taking out the automation and evolution complexity and cost. I invite you to discuss all those aspect in regards of your particular context face2face on November 28th.

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• Accelerating 2d object collision with other objects [on hold]

  - by Silent Cave

  Making my very first attempt at game programming with SDL/OpenGL. So I made an object Actor witch can move in all four sides with acceleration. And there are bunch of other rectangles to collide to. the image Movement and collision detection alghorythms work just fine by itself, but when combined to prevent the green rectangle from crossing black rectangles, it gives me a kind of funny resault. Let me show you the code first: from Actor.h class Actor{ public: SDL_Rect * dim; alphaColor * col; float speed; float xlGrav, xrGrav, yuGrav, ydGrav; float acceleration; bool left,right,up,down; Actor(SDL_Rect * dim,alphaColor * col, float speed, float acceleration); bool colides(const SDL_Rect & rect); bool check_for_collisions(const std::vector<SDL_Rect*> & gameObjects ); }; from actor.cpp bool Actor::colides(const SDL_Rect & rect){ if (dim->x + dim->w < rect.x) return false; if (dim->x > rect.x + rect.w) return false; if (dim->y + dim->h < rect.y) return false; if (dim->y > rect.y + rect.h) return false; return true; } movement logic from main.cpp if (actor->left){ if(actor->xlGrav < actor->speed){ actor->xlGrav += actor->speed*actor->acceleration; }else actor->xlGrav = actor->speed; actor->dim->x -= actor->xlGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->x += actor->xlGrav; actor->xlGrav = 0; } } if (!actor->left){ if(actor->xlGrav - actor->speed*actor->acceleration > 0){ actor->xlGrav -= actor->speed*actor->acceleration; }else actor->xlGrav = 0; actor->dim->x -= actor->xlGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->x += actor->xlGrav; actor->xlGrav = 0; } } if (actor->right){ if(actor->xrGrav < actor->speed){ actor->xrGrav += actor->speed*actor->acceleration; }else actor->xrGrav = actor->speed; actor->dim->x += actor->xrGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->x -= actor->xrGrav; actor->xrGrav = 0; } } if (!actor->right){ if(actor->xrGrav - actor->speed*actor->acceleration > 0){ actor->xrGrav -= actor->speed*actor->acceleration; }else actor->xrGrav = 0; actor->dim->x += actor->xrGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->x -= actor->xrGrav; actor->xrGrav = 0; } } if (actor->up){ if(actor->yuGrav < actor->speed){ actor->yuGrav += actor->speed*actor->acceleration; }else actor->yuGrav = actor->speed; actor->dim->y -= actor->yuGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->y += actor->yuGrav; actor->yuGrav = 0; } } if (!actor->up){ if(actor->yuGrav - actor->speed*actor->acceleration > 0){ actor->yuGrav -= actor->speed*actor->acceleration; }else actor->yuGrav = 0; actor->dim->y -= actor->yuGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->y += actor->yuGrav; actor->yuGrav = 0; } } if (actor->down){ if(actor->ydGrav < actor->speed){ actor->ydGrav += actor->speed*actor->acceleration; }else actor->ydGrav = actor->speed; actor->dim->y += actor->ydGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->y -= actor->ydGrav; actor->ydGrav = 0; } } if (!actor->down){ if(actor->ydGrav - actor->speed*actor->acceleration > 0){ actor->ydGrav -= actor->speed*actor->acceleration; }else actor->ydGrav = 0; actor->dim->y += actor->ydGrav; if(actor->check_for_collisions(gameObjects)){ actor->dim->y -= actor->ydGrav; actor->ydGrav = 0; } } So, if the green box approaches an obstacle from up or left, everything goes as planned - object stops, and it's acceleration drops to zero. But if it comes from bottom or right, it enters into obstacles inner space and starts strangely dance, I'd rather say move in inverted controls. What do I fail to see?

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• Remote Workers...We're Not That Bad!

  - by user12601034

  I work from home a lot – my team is located in different cities and countries, my manager is in a different city, and most of our work is done via conference calls, email and collaboration through Oracle Social Network. We’ve figured out how to be effective and involve team members, regardless of where we are all located. When I mention that I work from home, a lot of my friends will laugh, roll their eyes or use their fingers to make quotation marks around “work from home.” Their belief is that I’m sitting at home, eating bon-bons and watching television. The attempts at humor only multiply when they know that my husband also mostly works from home. So, it was with great joy that I read the Lifehacker article Why Remote Workers Are More (Yes, More) Engaged. I’m not going to re-write the article for you, but four highlights from the article include: Proximity breeds complacency –because communicating with employees sitting next to you is so easy, you may not do it well. Absence makes people try harder to connect – because you have to make an effort to connect to your team, you tend to pay better attention when you do connect Leaders of virtual team make better use of tools – when working remotely, you will use technology (many different forms of it) to connect with your team. This daily use of the tools makes you more proficient with those tools Leaders of far-flung teams maximize the time spent together – getting together takes effort, time and money, so leaders tend to filter out distractions when teams do get together. These points made me happy because I’ve seen the same things play out in my team located around the world. And I’m not saying that a virtual team is more effective than a co-located team – but my virtual team doesn’t have the option of filing into a conference room for a face-to-face meeting whenever we want. Instead, we have to figure out how to work effectively without meeting face-to-face. Am I more engaged as a remote worker? I’d like to think that I am. I’ve been on calls with colleagues at 3am – this would never happen if my only option was to be in the office. I can leave my “office” to pick up my kids from school…and I’m willingly back online after kids are in bed to finish up anything I need to. Oracle Social Network lets me use my iPad to engage with my teammates when I’m waiting at music lessons, the doctor’s office or any place else with a network connection. I feel like I’m more connected with my team, and I feel like I’m more connected with my family life. So yes, I am a remote worker, and I am engaged. If you lead a virtual team, I challenge you to increase the ways that you communicate to effectively engage your team. If you are on a virtual team, I challenge you to think about how you might interact with team members to keep both them and yourself engaged in your work. And if you have some great ideas on how to make virtual teams (and workers) effective and engaged, please share those ideas in the comments! Now, if you’ll excuse me, I need to go get a bon-bon...   :) 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-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-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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• Subterranean IL: The ThreadLocal type

  - by Simon Cooper

  I came across ThreadLocal<T> while I was researching ConcurrentBag. To look at it, it doesn't really make much sense. What's all those extra Cn classes doing in there? Why is there a GenericHolder<T,U,V,W> class? What's going on? However, digging deeper, it's a rather ingenious solution to a tricky problem. Thread statics Declaring that a variable is thread static, that is, values assigned and read from the field is specific to the thread doing the reading, is quite easy in .NET: [ThreadStatic] private static string s_ThreadStaticField; ThreadStaticAttribute is not a pseudo-custom attribute; it is compiled as a normal attribute, but the CLR has in-built magic, activated by that attribute, to redirect accesses to the field based on the executing thread's identity. TheadStaticAttribute provides a simple solution when you want to use a single field as thread-static. What if you want to create an arbitary number of thread static variables at runtime? Thread-static fields can only be declared, and are fixed, at compile time. Prior to .NET 4, you only had one solution - thread local data slots. This is a lesser-known function of Thread that has existed since .NET 1.1: LocalDataStoreSlot threadSlot = Thread.AllocateNamedDataSlot("slot1"); string value = "foo"; Thread.SetData(threadSlot, value); string gettedValue = (string)Thread.GetData(threadSlot); Each instance of LocalStoreDataSlot mediates access to a single slot, and each slot acts like a separate thread-static field. As you can see, using thread data slots is quite cumbersome. You need to keep track of LocalDataStoreSlot objects, it's not obvious how instances of LocalDataStoreSlot correspond to individual thread-static variables, and it's not type safe. It's also relatively slow and complicated; the internal implementation consists of a whole series of classes hanging off a single thread-static field in Thread itself, using various arrays, lists, and locks for synchronization. ThreadLocal<T> is far simpler and easier to use. ThreadLocal ThreadLocal provides an abstraction around thread-static fields that allows it to be used just like any other class; it can be used as a replacement for a thread-static field, it can be used in a List<ThreadLocal<T>>, you can create as many as you need at runtime. So what does it do? It can't just have an instance-specific thread-static field, because thread-static fields have to be declared as static, and so shared between all instances of the declaring type. There's something else going on here. The values stored in instances of ThreadLocal<T> are stored in instantiations of the GenericHolder<T,U,V,W> class, which contains a single ThreadStatic field (s_value) to store the actual value. This class is then instantiated with various combinations of the Cn types for generic arguments. In .NET, each separate instantiation of a generic type has its own static state. For example, GenericHolder<int,C0,C1,C2> has a completely separate s_value field to GenericHolder<int,C1,C14,C1>. This feature is (ab)used by ThreadLocal to emulate instance thread-static fields. Every time an instance of ThreadLocal is constructed, it is assigned a unique number from the static s_currentTypeId field using Interlocked.Increment, in the FindNextTypeIndex method. The hexadecimal representation of that number then defines the specific Cn types that instantiates the GenericHolder class. That instantiation is therefore 'owned' by that instance of ThreadLocal. This gives each instance of ThreadLocal its own ThreadStatic field through a specific unique instantiation of the GenericHolder class. Although GenericHolder has four type variables, the first one is always instantiated to the type stored in the ThreadLocal<T>. This gives three free type variables, each of which can be instantiated to one of 16 types (C0 to C15). This puts an upper limit of 4096 (163) on the number of ThreadLocal<T> instances that can be created for each value of T. That is, there can be a maximum of 4096 instances of ThreadLocal<string>, and separately a maximum of 4096 instances of ThreadLocal<object>, etc. However, there is an upper limit of 16384 enforced on the total number of ThreadLocal instances in the AppDomain. This is to stop too much memory being used by thousands of instantiations of GenericHolder<T,U,V,W>, as once a type is loaded into an AppDomain it cannot be unloaded, and will continue to sit there taking up memory until the AppDomain is unloaded. The total number of ThreadLocal instances created is tracked by the ThreadLocalGlobalCounter class. So what happens when either limit is reached? Firstly, to try and stop this limit being reached, it recycles GenericHolder type indexes of ThreadLocal instances that get disposed using the s_availableIndices concurrent stack. This allows GenericHolder instantiations of disposed ThreadLocal instances to be re-used. But if there aren't any available instantiations, then ThreadLocal falls back on a standard thread local slot using TLSHolder. This makes it very important to dispose of your ThreadLocal instances if you'll be using lots of them, so the type instantiations can be recycled. The previous way of creating arbitary thread-static variables, thread data slots, was slow, clunky, and hard to use. In comparison, ThreadLocal can be used just like any other type, and each instance appears from the outside to be a non-static thread-static variable. It does this by using the CLR type system to assign each instance of ThreadLocal its own instantiated type containing a thread-static field, and so delegating a lot of the bookkeeping that thread data slots had to do to the CLR type system itself! That's a very clever use of the CLR type system.

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• EM CLI, diving in and beyond!

  - by Maureen Byrne

  v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} Doing more in less time… Isn’t that what we all strive to do? With this in mind, I put together two screen watches on Oracle Enterprise Manager 12c command line interface, or EM CLI as it is also known. There is a wealth of information on any topic that you choose to read about, from manual pages to coding documents…might I even say blog posts? In our busy lives it is so nice to just sit back with a short video, watch and learn enough to dive in. Doing more in less time, is the essence of EM CLI. It enables you to script fundamental and complex administrative tasks in an elegant way, thanks to the Jython scripting language. Repetitive tasks can be scripted and reused again and again. Sure, a Graphical User Interface provides a more intuitive step by step approach to tasks, and it provides a way of quickly becoming familiar with a product and its many features, and it is definitely the way to go when viewing performance data and historical trending…but for repetitive and complex tasks, scripting is the way to go! Lets us take the everyday task of creating an administrator. Using EM CLI in interactive mode the command could look like this.. emcli>create_user(name='jan.doe', type='EXTERNAL_USER') This command creates an administrator called jan.doe which is an externally authenticated user, possibly LDAP or SSO, defined by the EXTERNAL_USER tag. The create_user procedure takes many arguments; see the documentation for more information. Now, where EM CLI really shines and shows power is in creating multiple users. Regardless of the number, tens or thousands, the effort is the same. With the use of a standard programming construct, a loop, you can place your create_user() procedure within it. Using a loop allows you to iterate through a previously created list, creating new users until the list is complete. Using EM CLI in Script mode, your Jython loop would look something like this… for user in list_of_users:       create_user(name=user, expire=’true’, password=’welcome123’) This Jython code snippet iterates through a previously defined list of names, list_of_users, and iterates through the list, taking each name, user in this case, and creates an administrator sets the password to welcome123, but forces the user to reset it when they first login. This is only one of over four hundred procedures created to expose Oracle Enterprise Manager 12c functionality in a powerful and programmatic way. It is a few months since we released EM CLI with scripting option. We are seeing many users adapt to this fun and powerful way of using Oracle Enterprise Manager 12c. What are the first steps? Watch these screen watches, and dive in. The first screen watch steps you through where and how to download and install and how to run your first few commands. The Second screen watch steps you through a few scripts. Next time, I am going to show you the basic building blocks to writing a Jython script to perform Oracle Enterprise Manager 12c administrative tasks. Join this growing group of EM CLI users…. Dive in! 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-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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• JavaDay Taipei 2014 Trip Report

  - by reza_rahman

  JavaDay Taipei 2014 was held at the Taipei International Convention Center on August 1st. Organized by Oracle University, it is one of the largest Java developer events in Taiwan. This was another successful year for JavaDay Taipei with a fully sold out venue packed with youthful, energetic developers (this was my second time at the event and I have already been invited to speak again next year!). In addition to Oracle speakers like me, Steve Chin and Naveen Asrani, the event also featured a bevy of local speakers including Taipei Java community leaders. Topics included Java SE, Java EE, JavaFX, cloud and Big Data. It was my pleasure and privilege to present one of the opening keynotes for the event. I presented my session on Java EE titled "JavaEE.Next(): Java EE 7, 8, and Beyond". I covered the changes in Java EE 7 as well as what's coming in Java EE 8. I demoed the Cargo Tracker Java EE BluePrints. I also briefly talked about Adopt-a-JSR for Java EE 8. The slides for the keynote are below (click here to download and view the actual PDF): It appears your Web browser is not configured to display PDF files. No worries, just click here to download the PDF file. In the afternoon I did my JavaScript + Java EE 7 talk titled "Using JavaScript/HTML5 Rich Clients with Java EE 7". This talk is basically about aligning EE 7 with the emerging JavaScript ecosystem (specifically AngularJS). The talk was completely packed. The slide deck for the talk is here: JavaScript/HTML5 Rich Clients Using Java EE 7 from Reza Rahman The demo application code is posted on GitHub. The code should be a helpful resource if this development model is something that interests you. Do let me know if you need help with it but the instructions should be fairly self-explanatory. I am delivering this material at JavaOne 2014 as a two-hour tutorial. This should give me a little more bandwidth to dig a little deeper, especially on the JavaScript end. I finished off Java Day Taipei with my talk titled "Using NoSQL with ~JPA, EclipseLink and Java EE" (this was the last session of the conference). The talk covers an interesting gap that there is surprisingly little material on out there. The talk has three parts -- a birds-eye view of the NoSQL landscape, how to use NoSQL via a JPA centric facade using EclipseLink NoSQL, Hibernate OGM, DataNucleus, Kundera, Easy-Cassandra, etc and how to use NoSQL native APIs in Java EE via CDI. The slides for the talk are here: Using NoSQL with ~JPA, EclipseLink and Java EE from Reza Rahman The JPA based demo is available here, while the CDI based demo is available here. Both demos use MongoDB as the data store. Do let me know if you need help getting the demos up and running. After the event the Oracle University folks hosted a reception in the evening which was very well attended by organizers, speakers and local Java community leaders. I am extremely saddened by the fact that this otherwise excellent trip was scarred by terrible tragedy. After the conference I joined a few folks for a hike on the Maokong Mountain on Saturday. The group included friends in the Taiwanese Java community including Ian and Robbie Cheng. Without warning, fatal tragedy struck on a remote part of the trail. Despite best efforts by us, the excellent Taiwanese Emergency Rescue Team and World class Taiwanese physicians we were unable to save our friend Robbie Cheng's life. Robbie was just thirty-four years old and is survived by his younger brother, mother and father. Being the father of a young child myself, I can only imagine the deep sorrow that this senseless loss unleashes. Robbie was a key member of the Taiwanese Java community and a Java Evangelist at Sun at one point. Ironically the only picture I was able to take of the trail was mere moments before tragedy. I thought I should place him in that picture in profoundly respectful memoriam: Perhaps there is some solace in the fact that there is something inherently honorable in living a bright life, dying young and meeting one's end on a beautiful remote mountain trail few venture to behold let alone attempt to ascend in a long and tired lifetime. Perhaps I'd even say it's a fate I would not entirely regret facing if it were my own. With that thought in mind it seems appropriate to me to quote some lyrics from the song "Runes to My Memory" by legendary Swedish heavy metal band Amon Amarth idealizing a fallen Viking warrior cut down in his prime: "Here I lie on wet sand I will not make it home I clench my sword in my hand Say farewell to those I love When I am dead Lay me in a mound Place my weapons by my side For the journey to Hall up high When I am dead Lay me in a mound Raise a stone for all to see Runes carved to my memory" I submit my deepest condolences to Robbie's family and hope my next trip to Taiwan ends in a less somber note.

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• Breaking 1NF to model subset constraints. Does this sound sane?

  - by Chris Travers

  My first question here. Appologize if it is in the wrong forum but this seems pretty conceptual. I am looking at doing something that goes against conventional wisdom and want to get some feedback as to whether this is totally insane or will result in problems, so critique away! I am on PostgreSQL 9.1 but may be moving to 9.2 for this part of this project. To re-iterate: Does it seem sane to break 1NF in this way? I am not looking for debugging code so much as where people see problems that this might lead. The Problem In double entry accounting, financial transactions are journal entries with an arbitrary number of lines. Each line has either a left value (debit) or a right value (credit) which can be modelled as a single value with negatives as debits and positives as credits or vice versa. The sum of all debits and credits must equal zero (so if we go with a single amount field, sum(amount) must equal zero for each financial journal entry). SQL-based databases, pretty much required for this sort of work, have no way to express this sort of constraint natively and so any approach to enforcing it in the database seems rather complex. The Write Model The journal entries are append only. There is a possibility we will add a delete model but it will be subject to a different set of restrictions and so is not applicable here. If and when we allow deletes, we will probably do them using a simple ON DELETE CASCADE designation on the foreign key, and require that deletes go through a dedicated stored procedure which can enforce the other constraints. So inserts and selects have to be accommodated but updates and deletes do not for this task. My Proposed Solution My proposed solution is to break first normal form and model constraints on arrays of tuples, with a trigger that breaks the rows out into another table. CREATE TABLE journal_line ( entry_id bigserial primary key, account_id int not null references account(id), journal_entry_id bigint not null, -- adding references later amount numeric not null ); I would then add "table methods" to extract debits and credits for reporting purposes: CREATE OR REPLACE FUNCTION debits(journal_line) RETURNS numeric LANGUAGE sql IMMUTABLE AS $$ SELECT CASE WHEN $1.amount < 0 THEN $1.amount * -1 ELSE NULL END; $$; CREATE OR REPLACE FUNCTION credits(journal_line) RETURNS numeric LANGUAGE sql IMMUTABLE AS $$ SELECT CASE WHEN $1.amount > 0 THEN $1.amount ELSE NULL END; $$; Then the journal entry table (simplified for this example): CREATE TABLE journal_entry ( entry_id bigserial primary key, -- no natural keys :-( journal_id int not null references journal(id), date_posted date not null, reference text not null, description text not null, journal_lines journal_line[] not null ); Then a table method and and check constraints: CREATE OR REPLACE FUNCTION running_total(journal_entry) returns numeric language sql immutable as $$ SELECT sum(amount) FROM unnest($1.journal_lines); $$; ALTER TABLE journal_entry ADD CONSTRAINT CHECK (((journal_entry.running_total) = 0)); ALTER TABLE journal_line ADD FOREIGN KEY journal_entry_id REFERENCES journal_entry(entry_id); And finally we'd have a breakout trigger: CREATE OR REPLACE FUNCTION je_breakout() RETURNS TRIGGER LANGUAGE PLPGSQL AS $$ BEGIN IF TG_OP = 'INSERT' THEN INSERT INTO journal_line (journal_entry_id, account_id, amount) SELECT NEW.id, account_id, amount FROM unnest(NEW.journal_lines); RETURN NEW; ELSE RAISE EXCEPTION 'Operation Not Allowed'; END IF; END; $$; And finally CREATE TRIGGER AFTER INSERT OR UPDATE OR DELETE ON journal_entry FOR EACH ROW EXECUTE_PROCEDURE je_breaout(); Of course the example above is simplified. There will be a status table that will track approval status allowing for separation of duties, etc. However the goal here is to prevent unbalanced transactions. Any feedback? Does this sound entirely insane? Standard Solutions? In getting to this point I have to say I have looked at four different current ERP solutions to this problems: Represent every line item as a debit and a credit against different accounts. Use of foreign keys against the line item table to enforce an eventual running total of 0 Use of constraint triggers in PostgreSQL Forcing all validation here solely through the app logic. My concerns are that #1 is pretty limiting and very hard to audit internally. It's not programmer transparent and so it strikes me as being difficult to work with in the future. The second strikes me as being very complex and required a series of contraints and foreign keys against self to make work, and therefore it strikes me as complex, hard to sort out at least in my mind, and thus hard to work with. The fourth could be done as we force all access through stored procedures anyway and this is the most common solution (have the app total things up and throw an error otherwise). However, I think proof that a constraint is followed is superior to test cases, and so the question becomes whether this in fact generates insert anomilies rather than solving them. If this is a solved problem it isn't the case that everyone agrees on the solution....

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• What Counts For a DBA: Fitness

  - by Louis Davidson

  If you know me, you can probably guess that physical exercise is not really my thing. There was a time in my past when it a larger part of my life, but even then never in the same sort of passionate way as a number of our SQL friends.  For me, I find that mental exercise satisfies what I believe to be the same inner need that drives people to run farther than I like to drive on most Saturday mornings, and it is certainly just as addictive. Mental fitness shares many common traits with physical fitness, especially the need to attain it through repetitive training. I only wish that mental training burned off a bacon cheeseburger in the same manner as does jogging around a dewy park on Saturday morning. In physical training, there are at least two goals, the first of which is to be physically able to do a task. The second is to train the brain to perform the task without thinking too hard about it. No matter how long it has been since you last rode a bike, you will be almost certainly be able to hop on and start riding without thinking about the process of pedaling or balancing. If you’ve never ridden a bike, you could be a physics professor /Olympic athlete and still crash the first few times you try, even though you are as strong as an ox and your knowledge of the physics of bicycle riding makes the concept child’s play. For programming tasks, the process is very similar. As a DBA, you will come to know intuitively how to backup, optimize, and secure database systems. As a data programmer, you will work to instinctively use the clauses of Transact-SQL DML so that, when you need to group data three ways (and not four), you will know to use the GROUP BY clause with GROUPING SETS without resorting to a search engine.  You have the skill. Making it naturally then requires repetition and experience is the primary requirement, not just simply learning about a topic. The hardest part of being really good at something is this difference between knowledge and skill. I have recently taken several informative training classes with Kimball University on data warehousing and ETL. Now I have a lot more knowledge about designing data warehouses than before. I have also done a good bit of data warehouse designing of late and have started to improve to some level of proficiency with the theory. Yet, for all of this head knowledge, it is still a struggle to take what I have learned and apply it to the designs I am working on.  Data warehousing is still a task that is not yet deeply ingrained in my brain muscle memory. On the other hand, relational database design is something that no matter how much or how little I may get to do it, I am comfortable doing it. I have done it as a profession now for well over a decade, I teach classes on it, and I also have done (and continue to do) a lot of mental training beyond the work day. Sometimes the training is just basic education, some reading blogs and attending sessions at PASS events.  My best training comes from spending time working on other people’s design issues in forums (though not nearly as much as I would like to lately). Working through other people’s problems is a great way to exercise your brain on problems with which you’re not immediately familiar. The final bit of exercise I find useful for cultivating mental fitness for a data professional is also probably the nerdiest thing that I will ever suggest you do.  Akin to running in place, the idea is to work through designs in your head. I have designed more than one database system that would revolutionize grocery store operations, sales at my local Target store, the ordering process at Amazon, and ways to improve Disney World operations to get me through a line faster (some of which they are starting to implement without any of my help.) Never are the designs truly fleshed out, but enough to work through structures and processes.  On “paper”, I have designed database systems to catalog things as trivial as my Lego creations, rental car companies and my audio and video collections. Once I get the database designed mentally, sometimes I will create the database, add some data (often using Red-Gate’s Data Generator), and write a few queries to see if a concept was realistic, but I will rarely fully flesh out the database since I have no desire to do any user interface programming anymore.  The mental training allows me to keep in practice for when the time comes to do the work I love the most for real…even if I have been spending most of my work time lately building data warehouses.  If you are really strong of mind and body, perhaps you can mix a mental run with a physical run; though don’t run off of a cliff while contemplating how you might design a database to catalog the trees on a mountain…that would be contradictory to the purpose of both types of exercise.

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• Take Two: Comparing JVMs on ARM/Linux

  - by user12608080

  Although the intent of the previous article, entitled Comparing JVMs on ARM/Linux, was to introduce and highlight the availability of the HotSpot server compiler (referred to as c2) for Java SE-Embedded ARM v7,  it seems, based on feedback, that everyone was more interested in the OpenJDK comparisons to Java SE-E.  In fact there were two main concerns: The fact that the previous article compared Java SE-E 7 against OpenJDK 6 might be construed as an unlevel playing field because version 7 is newer and therefore potentially more optimized. That the generic compiler settings chosen to build the OpenJDK implementations did not put those versions in a particularly favorable light. With those considerations in mind, we'll institute the following changes to this version of the benchmarking: In order to help alleviate an additional concern that there is some sort of benchmark bias, we'll use a different suite, called DaCapo.  Funded and supported by many prestigious organizations, DaCapo's aim is to benchmark real world applications.  Further information about DaCapo can be found at http://dacapobench.org. At the suggestion of Xerxes Ranby, who has been a great help through this entire exercise, a newer Linux distribution will be used to assure that the OpenJDK implementations were built with more optimal compiler settings.  The Linux distribution in this instance is Ubuntu 11.10 Oneiric Ocelot. Having experienced difficulties getting Ubuntu 11.10 to run on the original D2Plug ARMv7 platform, for these benchmarks, we'll switch to an embedded system that has a supported Ubuntu 11.10 release.  That platform is the Freescale i.MX53 Quick Start Board.  It has an ARMv7 Coretex-A8 processor running at 1GHz with 1GB RAM. We'll limit comparisons to 4 JVM implementations: Java SE-E 7 Update 2 c1 compiler (default) Java SE-E 6 Update 30 (c1 compiler is the only option) OpenJDK 6 IcedTea6 1.11pre 6b23~pre11-0ubuntu1.11.10.2 CACAO build 1.1.0pre2 OpenJDK 6 IcedTea6 1.11pre 6b23~pre11-0ubuntu1.11.10.2 JamVM build-1.6.0-devel Certain OpenJDK implementations were eliminated from this round of testing for the simple reason that their performance was not competitive.  The Java SE 7u2 c2 compiler was also removed because although quite respectable, it did not perform as well as the c1 compilers.  Recall that c2 works optimally in long-lived situations.  Many of these benchmarks completed in a relatively short period of time.  To get a feel for where c2 shines, take a look at the first chart in this blog. The first chart that follows includes performance of all benchmark runs on all platforms.  Later on we'll look more at individual tests.  In all runs, smaller means faster.  The DaCapo aficionado may notice that only 10 of the 14 DaCapo tests for this version were executed.  The reason for this is that these 10 tests represent the only ones successfully completed by all 4 JVMs.  Only the Java SE-E 6u30 could successfully run all of the tests.  Both OpenJDK instances not only failed to complete certain tests, but also experienced VM aborts too. One of the first observations that can be made between Java SE-E 6 and 7 is that, for all intents and purposes, they are on par with regards to performance.  While it is a fact that successive Java SE releases add additional optimizations, it is also true that Java SE 7 introduces additional complexity to the Java platform thus balancing out any potential performance gains at this point.  We are still early into Java SE 7.  We would expect further performance enhancements for Java SE-E 7 in future updates. In comparing Java SE-E to OpenJDK performance, among both OpenJDK VMs, Cacao results are respectable in 4 of the 10 tests.  The charts that follow show the individual results of those four tests.  Both Java SE-E versions do win every test and outperform Cacao in the range of 9% to 55%. For the remaining 6 tests, Java SE-E significantly outperforms Cacao in the range of 114% to 311% So it looks like OpenJDK results are mixed for this round of benchmarks.  In some cases, performance looks to have improved.  But in a majority of instances, OpenJDK still lags behind Java SE-Embedded considerably. Time to put on my asbestos suit.  Let the flames begin...

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• XNA - Use Mouse To Rotate & Arrow Keys To Scroll A Linearly Wrapped Texture:

  - by The Thing

  Using XNA I'm working on my first, relatively simple, videogame for the PC. At the moment my game window is 1024 X 768 and I have a 'Starfield' linearly wrapped background texture 1280 X 1280 in size whose origin has been set to its center point (width / 2, height / 2). This texture is drawn onscreen using (graphics.PreferredBackBufferWidth / 2, graphics.PreferredBackBufferHeight / 2) to place the origin in the center of the window. I want to be able to use the horizontal movement of the mouse to rotate my texture left or right and use the arrow keys to scroll the texture in four directions. From my own related coding experiments I have found that once I rotate the texture it no longer scrolls in the direction I want, it's as if somehow the XNA framework's 'sense of direction' has been 'rotated' along with the texture. As an example of what I've described above lets say I rotate the texture 45 degrees to the right, then pressing the up arrow key results in the texture scrolling diagonally from top-right to bottom-left. This is not what I want, regardless of the degree or direction of rotation I want my texture to scroll straight up, straight down, or to the left or right depending on which arrow key was pressed. How do I go about accomplishing this? Any help or guidance is appreciated. To finish up there are two points I'd like to clarify: [1] The reason I'm using linear wrapping on my starfield texture is that it gives a nice impression of an endless starfield. [2] Using a texture at least 1280 X 1280 in conjunction with a game window of 1024 X 768 means that at no point in it's rotation will the edges of the texture become visible. Thanks for reading..... Update # 1 - as requested by RCIX: The code below is what I was referring to earlier when I mentioned 'related coding experiments'. As you can see I am scrolling a linearly wrapped texture in the direction I've moved the mouse relative to the center of the screen. This works perfectly if I don't rotate the texture, but once I do rotate it the direction of the scrolling gets messed up for some reason. public class Game1 : Microsoft.Xna.Framework.Game { GraphicsDeviceManager graphics; SpriteBatch spriteBatch; int x; int y; float z = 250f; Texture2D Overlay; Texture2D RotatingBackground; Rectangle? sourceRectangle; Color color; float rotation; Vector2 ScreenCenter; Vector2 Origin; Vector2 scale; Vector2 Direction; SpriteEffects effects; float layerDepth; public Game1() { graphics = new GraphicsDeviceManager(this); Content.RootDirectory = "Content"; } protected override void Initialize() { graphics.PreferredBackBufferWidth = 1024; graphics.PreferredBackBufferHeight = 768; graphics.ApplyChanges(); Direction = Vector2.Zero; IsMouseVisible = true; ScreenCenter = new Vector2(graphics.PreferredBackBufferWidth / 2, graphics.PreferredBackBufferHeight / 2); Mouse.SetPosition((int)graphics.PreferredBackBufferWidth / 2, (int)graphics.PreferredBackBufferHeight / 2); sourceRectangle = null; color = Color.White; rotation = 0.0f; scale = new Vector2(1.0f, 1.0f); effects = SpriteEffects.None; layerDepth = 1.0f; base.Initialize(); } protected override void LoadContent() { spriteBatch = new SpriteBatch(GraphicsDevice); Overlay = Content.Load<Texture2D>("Overlay"); RotatingBackground = Content.Load<Texture2D>("Background"); Origin = new Vector2((int)RotatingBackground.Width / 2, (int)RotatingBackground.Height / 2); } protected override void UnloadContent() { } protected override void Update(GameTime gameTime) { float timePassed = (float)gameTime.ElapsedGameTime.TotalSeconds; MouseState ms = Mouse.GetState(); Vector2 MousePosition = new Vector2(ms.X, ms.Y); Direction = ScreenCenter - MousePosition; if (Direction != Vector2.Zero) { Direction.Normalize(); } x += (int)(Direction.X * z * timePassed); y += (int)(Direction.Y * z * timePassed); //No rotation = texture scrolls as intended, With rotation = texture no longer scrolls in the direction of the mouse. My update method needs to somehow compensate for this. //rotation += 0.01f; base.Update(gameTime); } protected override void Draw(GameTime gameTime) { spriteBatch.Begin(SpriteSortMode.Deferred, null, SamplerState.LinearWrap, null, null); spriteBatch.Draw(RotatingBackground, ScreenCenter, new Rectangle(x, y, RotatingBackground.Width, RotatingBackground.Height), color, rotation, Origin, scale, effects, layerDepth); spriteBatch.Draw(Overlay, Vector2.Zero, Color.White); spriteBatch.End(); base.Draw(gameTime); } }

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• Separating text strings into a table of individual words in SQL via XML.

  - by Phil Factor

  p.MsoNormal {margin-top:0cm; margin-right:0cm; margin-bottom:10.0pt; margin-left:0cm; line-height:115%; font-size:11.0pt; font-family:"Calibri","sans-serif"; } Nearly nine years ago, Mike Rorke of the SQL Server 2005 XML team blogged ‘Querying Over Constructed XML Using Sub-queries’. I remember reading it at the time without being able to think of a use for what he was demonstrating. Just a few weeks ago, whilst preparing my article on searching strings, I got out my trusty function for splitting strings into words and something reminded me of the old blog. I’d been trying to think of a way of using XML to split strings reliably into words. The routine I devised turned out to be slightly slower than the iterative word chop I’ve always used in the past, so I didn’t publish it. It was then I suddenly remembered the old routine. Here is my version of it. I’ve unwrapped it from its obvious home in a function or procedure just so it is easy to appreciate. What it does is to chop a text string into individual words using XQuery and the good old nodes() method. I’ve benchmarked it and it is quicker than any of the SQL ways of doing it that I know about. Obviously, you can’t use the trick I described here to do it, because it is awkward to use REPLACE() on 1…n characters of whitespace. I’ll carry on using my iterative function since it is able to tell me the location of each word as a character-offset from the start, and also because this method leaves punctuation in (removing it takes time!). However, I can see other uses for this in passing lists as input or output parameters, or as return values.   if exists (Select * from sys.xml_schema_collections where name like 'WordList')   drop XML SCHEMA COLLECTION WordList go create xml schema collection WordList as ' <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"> <xs:element name="words">        <xs:simpleType>               <xs:list itemType="xs:string" />        </xs:simpleType> </xs:element> </xs:schema>'   go   DECLARE @string VARCHAR(MAX) –we'll get some sample data from the great Ogden Nash Select @String='This is a song to celebrate banks, Because they are full of money and you go into them and all you hear is clinks and clanks, Or maybe a sound like the wind in the trees on the hills, Which is the rustling of the thousand dollar bills. Most bankers dwell in marble halls, Which they get to dwell in because they encourage deposits and discourage withdrawals, And particularly because they all observe one rule which woe betides the banker who fails to heed it, Which is you must never lend any money to anybody unless they don''t need it. I know you, you cautious conservative banks! If people are worried about their rent it is your duty to deny them the loan of one nickel, yes, even one copper engraving of the martyred son of the late Nancy Hanks; Yes, if they request fifty dollars to pay for a baby you must look at them like Tarzan looking at an uppity ape in the jungle, And tell them what do they think a bank is, anyhow, they had better go get the money from their wife''s aunt or ungle. But suppose people come in and they have a million and they want another million to pile on top of it, Why, you brim with the milk of human kindness and you urge them to accept every drop of it, And you lend them the million so then they have two million and this gives them the idea that they would be better off with four, So they already have two million as security so you have no hesitation in lending them two more, And all the vice-presidents nod their heads in rhythm, And the only question asked is do the borrowers want the money sent or do they want to take it withm. Because I think they deserve our appreciation and thanks, the jackasses who go around saying that health and happi- ness are everything and money isn''t essential, Because as soon as they have to borrow some unimportant money to maintain their health and happiness they starve to death so they can''t go around any more sneering at good old money, which is nothing short of providential. '   –we now turn it into XML declare @xml_data xml(WordList)  set @xml_data='<words>'+ replace(@string,'&', '&amp;')+'</words>'    select T.ref.value('.', 'nvarchar(100)')  from (Select @xml_data.query('                      for $i in data(/words) return                      element li { $i }               '))  A(list) cross apply A.List.nodes('/li') T(ref)     …which gives (truncated, of course)…

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• How You Helped Shape Java EE 7...

  - by reza_rahman

  I have been working with the JCP in various roles since EJB 3/Java EE 5 (much of it on my own time), eventually culminating in my decision to accept my current role at Oracle (despite it's inevitable set of unique challenges, a role I find by and large positive and fulfilling). During these years, it has always been clear to me that pretty much everyone in the JCP genuinely cares about openness, feedback and developer participation. Perhaps the most visible sign to date of this high regard for grassroots level input is a survey on Java EE 7 gathered a few months ago. The survey was designed to get open feedback on a number of critical issues central to the Java EE 7 umbrella specification including what APIs to include in the standard. When we started the survey, I don't think anyone was certain what the level of participation from developers would really be. I also think everyone was pleasantly surprised that a large number of developers (around 1100) took the time out to vote on these very important issues that could impact their own professional life. And it wasn't just a matter of the quantity of responses. I was particularly impressed with the quality of the comments made through the survey (some of which I'll try to do justice to below). With Java EE 7 under our belt and the horizons for Java EE 8 emerging, this is a good time to thank everyone that took the survey once again for their thoughts and let you know what the impact of your voice actually was. As an aside, you may be happy to know that we are working hard behind the scenes to try to put together a similar survey to help kick off the agenda for Java EE 8 (although this is by no means certain). I'll break things down by the questions asked in the survey, the responses and the resulting change in the specification. APIs to Add to Java EE 7 Full/Web Profile The first question in the survey asked which of four new candidate APIs (WebSocket, JSON-P, JBatch and JCache) should be added to the Java EE 7 Full and Web profile respectively. Developers by and large wanted all the new APIs added to the full platform. The comments expressed particularly strong support for WebSocket and JCache. Others expressed dissatisfaction over the lack of a JSON binding (as opposed to JSON processing) API. WebSocket, JSON-P and JBatch are now part of Java EE 7. In addition, the long-awaited Java EE Concurrency Utilities API was also included in the Full Profile. Unfortunately, JCache was not finalized in time for Java EE 7 and the decision was made not to hold up the Java EE release any longer. JCache continues to move forward strongly and will very likely be included in Java EE 8 (it will be available much sooner than Java EE 8 to boot). An emergent standard for JSON-B is also a strong possibility for Java EE 8. When it came to the Web Profile, developers were supportive of adding WebSocket and JSON-P, but not JBatch and JCache. Both WebSocket and JSON-P are now part of the Web Profile, now also including the already popular JAX-RS API. Enabling CDI by Default The second question asked whether CDI should be enabled in Java EE by default. The overwhelming majority of developers supported the default enablement of CDI. In addition, developers expressed a desire for better CDI/Java EE alignment (with regards to EJB and JSF in particular). Some developers expressed legitimate concerns over the performance implications of enabling CDI globally as well as the potential conflict with other JSR 330 implementations like Spring and Guice. CDI is enabled by default in Java EE 7. Respecting the legitimate concerns, CDI 1.1 was very careful to add additional controls around component scanning. While a lot of work was done in Java EE 6 and Java EE 7 around CDI alignment, further alignment is under serious consideration for Java EE 8. Consistent Usage of @Inject The third question was around using CDI/JSR 330 @Inject consistently vs. allowing JSRs to create their own injection annotations (e.g. @BatchContext). A majority of developers wanted consistent usage of @Inject. The comments again reflected a strong desire for CDI/Java EE alignment. A lot of emphasis in Java EE 7 was put into using @Inject consistently. For example, the JBatch specification is focused on using @Inject wherever possible. JAX-RS remains an exception with it's existing custom injection annotations. However, the JAX-RS specification leads understand the importance of eventual convergence, hopefully in Java EE 8. Expanding the Use of @Stereotype The fourth question was about expanding CDI @Stereotype to cover annotations across Java EE beyond just CDI. A solid majority of developers supported the idea of making @Stereotype more universal in Java EE. The comments maintained the general theme of strong support for CDI/Java EE alignment Unfortunately, there was not enough time and resources in Java EE 7 to implement this fairly pervasive feature. However, it remains a serious consideration for Java EE 8. Expanding Interceptor Use The final set of questions was about expanding interceptors further across Java EE. Developers strongly supported the concept. Along with injection, interceptors are now supported across all Java EE 7 components including Servlets, Filters, Listeners, JAX-WS endpoints, JAX-RS resources, WebSocket endpoints and so on. I hope you are encouraged by how your input to the survey helped shape Java EE 7 and continues to shape Java EE 8. Participating in these sorts of surveys is of course just one way of contributing to Java EE. Another great way to stay involved is the Adopt-A-JSR Program. A large number of developers are already participating through their local JUGs. You could of course become a Java EE JSR expert group member or observer. You should stay tuned to The Aquarium for the progress of Java EE 8 JSRs if that's something you want to look into...

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• rotate player based off of joystick

  - by pengume

  Hey everyone I have this game that i am making in android and I have a touch screen joystick that moves the player around based on the joysticks position. I cant figure out how to also get the player to rotate at the same angle of the joystick. so when the joystick is to the left the players bitmap is rotated to the left as well. Maybe someone here has some sample code I could look at here is the joysticks class that I am using. `public class GameControls implements OnTouchListener { public float initx = DroidzActivity.screenWidth - 45; //255; // 320 og 425 public float inity = DroidzActivity.screenHeight - 45;//425; // 480 og 267 public Point _touchingPoint = new Point( DroidzActivity.screenWidth - 45, DroidzActivity.screenHeight - 45); public Point _pointerPosition = new Point(DroidzActivity.screenWidth - 100, DroidzActivity.screenHeight - 100); // ogx 220 ogy 150 private Boolean _dragging = false; private boolean attackMode = false; @Override public boolean onTouch(View v, MotionEvent event) { update(event); return true; } private MotionEvent lastEvent; public boolean ControlDragged; private static double angle; public void update(MotionEvent event) { if (event == null && lastEvent == null) { return; } else if (event == null && lastEvent != null) { event = lastEvent; } else { lastEvent = event; } // drag drop if (event.getAction() == MotionEvent.ACTION_DOWN) { if ((int) event.getX() > 0 && (int) event.getX() < 50 && (int) event.getY() > DroidzActivity.screenHeight - 160 && (int) event.getY() < DroidzActivity.screenHeight - 0) { setAttackMode(true); } else { _dragging = true; } } else if (event.getAction() == MotionEvent.ACTION_UP) { if(isAttackMode()){ setAttackMode(false); } _dragging = false; } if (_dragging) { ControlDragged = true; // get the pos _touchingPoint.x = (int) event.getX(); _touchingPoint.y = (int) event.getY(); // Log.d("GameControls", "x = " + _touchingPoint.x + " y = " //+ _touchingPoint.y); // bound to a box if (_touchingPoint.x < DroidzActivity.screenWidth - 75) { // og 400 _touchingPoint.x = DroidzActivity.screenWidth - 75; } if (_touchingPoint.x > DroidzActivity.screenWidth - 15) {// og 450 _touchingPoint.x = DroidzActivity.screenWidth - 15; } if (_touchingPoint.y < DroidzActivity.screenHeight - 75) {// og 240 _touchingPoint.y = DroidzActivity.screenHeight - 75; } if (_touchingPoint.y > DroidzActivity.screenHeight - 15) {// og 290 _touchingPoint.y = DroidzActivity.screenHeight - 15; } // get the angle setAngle(Math.atan2(_touchingPoint.y - inity, _touchingPoint.x - initx) / (Math.PI / 180)); // Move the ninja in proportion to how far // the joystick is dragged from its center _pointerPosition.y += Math.sin(getAngle() * (Math.PI / 180)) * (_touchingPoint.x / 70); // og 180 70 _pointerPosition.x += Math.cos(getAngle() * (Math.PI / 180)) * (_touchingPoint.x / 70); // make the pointer go thru if (_pointerPosition.x > DroidzActivity.screenWidth) { _pointerPosition.x = 0; } if (_pointerPosition.x < 0) { _pointerPosition.x = DroidzActivity.screenWidth; } if (_pointerPosition.y > DroidzActivity.screenHeight) { _pointerPosition.y = 0; } if (_pointerPosition.y < 0) { _pointerPosition.y = DroidzActivity.screenHeight; } } else if (!_dragging) { ControlDragged = false; // Snap back to center when the joystick is released _touchingPoint.x = (int) initx; _touchingPoint.y = (int) inity; // shaft.alpha = 0; } } public void setAttackMode(boolean attackMode) { this.attackMode = attackMode; } public boolean isAttackMode() { return attackMode; } public void setAngle(double angle) { this.angle = angle; } public static double getAngle() { return angle; } }` I should also note that the player has animations based on when he is moving or attacking. EDIT: I got the angle and am rotating the sprite around in the correct angle however it rotates on the wrong spot. My sprite is one giant bitmap that gets cut into four pieces and only one shown at a time to animate walking. here is the code I am using to rotate him right now. ` public void draw(Canvas canvas,int pointerX, int pointerY) { Matrix m; if (setRotation){ // canvas.save(); m = new Matrix(); m.reset(); // spriteWidth and spriteHeight are for just the current frame showed //m.setTranslate(spriteWidth / 2, spriteHeight / 2); //get and set rotation for ninja based off of joystick m.preRotate((float) GameControls.getRotation()); //create the rotated bitmap flipedSprite = Bitmap.createBitmap(bitmap , 0, 0,bitmap.getWidth(),bitmap.getHeight() , m, true); //set new bitmap to rotated ninja setBitmap(flipedSprite); setRotation = false; // canvas.restore(); Log.d("Ninja View", "angle of rotation= " +(float) GameControls.getRotation()); } ` And then the draw method // create the destination rectangle for the ninjas current animation frame // pointerX and pointerY are from the joystick moving the ninja around destRect = new Rect(pointerX, pointerY, pointerX + spriteWidth, pointerY + spriteHeight); canvas.drawBitmap(bitmap, getSourceRect(), destRect, null);

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• From the Classroom to the Boardroom

  - by Maria Sandu

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Pens and Paper...these are the only things being a student and being a graduate / professional have in common. Walking in to the offices of Oracle South Africa as a graduate the first thing you notice is how polished and sleek all the people who work here look. 80% of the ladies wear sky-scraper heels and walk with the greatest grace. This was the first of many rude awakenings to remind me that I am no longer a student but a graduate. My first struggle was having to wake up at wee hours of the morning to prepare for work. As a student going to class was almost an optional thing, if you missed a morning class you could always attend an evening class to make up for it or simply attend with another group. But in the workplace, you HAVE to show up every single morning at the same time, with no option of coming in when it suits you and there is definitely no coming in with the evening class/shift. As a student, the earliest hour I ever woke up was 7:00am, anything earlier than that was considered inhumane torture. My reason for waking up every morning as a student was “you have a degree to go get” but as a graduate having to go to work I have to say to myself “here’s to a new day of learning and growing”. My second struggle has come in having to change my beloved wardrobe. Everyone who knows me knows how passionate I am about fashion and shopping. For me Shopping is a BASIC HUMAN RIGHT, that should not be messed with. Therefore it was with great sadness that I swopped my rippled skinny jeans for pin-striped formal pants, my long chandelier earrings for simple studs, my flat shoes for heels, my sheer blouses for crisp white shirts, even my beloved wild hair had to make way for a simple ponytail. Our looks as ladies also came under great scrutiny, we had to acquaint ourselves with some serious grooming tools: the mascara, blush, lip-gloss, blush, a touch of lipstick and a manicure set. Language was a struggle of its own as well. Being a student you learn to relate to your peers in a informal way. In the workplace you have to address everyone with the same respect, including your peers. Words like “Hey buddy” had to make way for “good morning friend”. The month long winter school holiday was one of the things I looked forward to as a student. This was a time where we got to be at home and avoid the coldest month of the year, July. It was the most amazing thing ever, just sleeping and snuggling up to all sorts of warm things but sadly it is now a thing of the past. It is currently winter in South Africa and going to work has become the most unfashionable thing with all the jackets, boots, scarves and gloves. But summer is coming and I will miss those holidays too. As a student the school holidays were like a gift for us to catch a break and not think for a while which was why it was imaginable how someone would go on for the entire year without a break, with only the promise of a mere 21 days annual leave!! Right now I am sure we are all looking forward to taking that annual leave when the time is right. The worst rude awakening I must say, has to be presenting in front of clients and managers. As a student you have the same class mates for almost four years therefore presenting in front of them becomes the norm over the years and your lecturer will always go gently on you. What they don’t tell you at University is that in the real world, time is money and clients pay money to see you present therefore there is no room for error. Clients are not there to give you a score and boost your ego, they expect nothing less than 100% and they will let you know without a second thought. For a graduate this can feel like you are being fed to the sharks, you either get eaten or you swim for your life. At the end of the day, it is all an experience that is meant to groom us into better professional and make us a part of the Red Team. All the sacrifices are worth it and they lead us to being better and more polished professionals. So if you are interested in joining the ECEMEA Sales and Presales Internship Programme, please have a look at http://campus.oracle.com for more information and for our latest vacancies and internships. /* 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:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; 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; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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• Coherence Data Guarantees for Data Reads - Basic Terminology

  - by jpurdy

  When integrating Coherence into applications, each application has its own set of requirements with respect to data integrity guarantees. Developers often describe these requirements using expressions like "avoiding dirty reads" or "making sure that updates are transactional", but we often find that even in a small group of people, there may be a wide range of opinions as to what these terms mean. This may simply be due to a lack of familiarity, but given that Coherence sits at an intersection of several (mostly) unrelated fields, it may be a matter of conflicting vocabularies (e.g. "consistency" is similar but different in transaction processing versus multi-threaded programming). Since almost all data read consistency issues are related to the concept of concurrency, it is helpful to start with a definition of that, or rather what it means for two operations to be concurrent. Rather than implying that they occur "at the same time", concurrency is a slightly weaker statement -- it simply means that it can't be proven that one event precedes (or follows) the other. As an example, in a Coherence application, if two client members mutate two different cache entries sitting on two different cache servers at roughly the same time, it is likely that one update will precede the other by a significant amount of time (say 0.1ms). However, since there is no guarantee that all four members have their clocks perfectly synchronized, and there is no way to precisely measure the time it takes to send a given message between any two members (that have differing clocks), we consider these to be concurrent operations since we can not (easily) prove otherwise. So this leads to a question that we hear quite frequently: "Are the contents of the near cache always synchronized with the underlying distributed cache?". It's easy to see that if an update on a cache server results in a message being sent to each near cache, and then that near cache being updated that there is a window where the contents are different. However, this is irrelevant, since even if the application reads directly from the distributed cache, another thread update the cache before the read is returned to the application. Even if no other member modifies a cache entry prior to the local near cache entry being updated (and subsequently read), the purpose of reading a cache entry is to do something with the result, usually either displaying for consumption by a human, or by updating the entry based on the current state of the entry. In the former case, it's clear that if the data is updated faster than a human can perceive, then there is no problem (and in many cases this can be relaxed even further). For the latter case, the application must assume that the value might potentially be updated before it has a chance to update it. This almost aways the case with read-only caches, and the solution is the traditional optimistic transaction pattern, which requires the application to explicitly state what assumptions it made about the old value of the cache entry. If the application doesn't want to bother stating those assumptions, it is free to lock the cache entry prior to reading it, ensuring that no other threads will mutate the entry, a pessimistic approach. The optimistic approach relies on what is sometimes called a "fuzzy read". In other words, the application assumes that the read should be correct, but it also acknowledges that it might not be. (I use the qualifier "sometimes" because in some writings, "fuzzy read" indicates the situation where the application actually sees an original value and then later sees an updated value within the same transaction -- however, both definitions are roughly equivalent from an application design perspective). If the read is not correct it is called a "stale read". Going back to the definition of concurrency, it may seem difficult to precisely define a stale read, but the practical way of detecting a stale read is that is will cause the encompassing transaction to roll back if it tries to update that value. The pessimistic approach relies on a "coherent read", a guarantee that the value returned is not only the same as the primary copy of that value, but also that it will remain that way. In most cases this can be used interchangeably with "repeatable read" (though that term has additional implications when used in the context of a database system). In none of cases above is it possible for the application to perform a "dirty read". A dirty read occurs when the application reads a piece of data that was never committed. In practice the only way this can occur is with multi-phase updates such as transactions, where a value may be temporarily update but then withdrawn when a transaction is rolled back. If another thread sees that value prior to the rollback, it is a dirty read. If an application uses optimistic transactions, dirty reads will merely result in a lack of forward progress (this is actually one of the main risks of dirty reads -- they can be chained and potentially cause cascading rollbacks). The concepts of dirty reads, fuzzy reads, stale reads and coherent reads are able to describe the vast majority of requirements that we see in the field. However, the important thing is to define the terms used to define requirements. A quick web search for each of the terms in this article will show multiple meanings, so I've selected what are generally the most common variations, but it never hurts to state each definition explicitly if they are critical to the success of a project (many applications have sufficiently loose requirements that precise terminology can be avoided).

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• Concurrency Utilities for Java EE Early Draft (JSR 236)

  - by arungupta

  Concurrency Utilities for Java EE is being worked as JSR 236 and has released an Early Draft. It provides concurrency capabilities to Java EE application components without compromising container integrity. Simple (common) and advanced concurrency patterns are easily supported without sacrificing usability. Using Java SE concurrency utilities such as java.util.concurrent API, java.lang.Thread and java.util.Timer in a Java EE application component such as EJB or Servlet are problematic since the container and server have no knowledge of these resources. JSR 236 enables concurrency largely by extending the Concurrency Utilities API developed under JSR-166. This also allows a consistency between Java SE and Java EE concurrency programming model. There are four main programming interfaces available: ManagedExecutorService ManagedScheduledExecutorService ContextService ManagedThreadFactory ManagedExecutorService is a managed version of java.util.concurrent.ExecutorService. The implementations of this interface are provided by the container and accessible using JNDI reference: <resource-env-ref>  <resource-env-ref-name>    concurrent/BatchExecutor  </resource-env-ref-name>  <resource-env-ref-type>    javax.enterprise.concurrent.ManagedExecutorService  </resource-env-ref-type><resource-env-ref> and available as: @Resource(name="concurrent/BatchExecutor")ManagedExecutorService executor; Its recommended to bind the JNDI references in the java:comp/env/concurrent subcontext. The asynchronous tasks that need to be executed need to implement java.lang.Runnable or java.util.concurrent.Callable interface as: public class MyTask implements Runnable { public void run() { // business logic goes here }} OR public class MyTask2 implements Callable<Date> {  public Date call() { // business logic goes here   }} The task is then submitted to the executor using one of the submit method that return a Future instance. The Future represents the result of the task and can also be used to check if the task is complete or wait for its completion. Future<String> future = executor.submit(new MyTask(), String.class);. . .String result = future.get(); Another example to submit tasks is: class MyTask implements Callback<Long> { . . . }class MyTask2 implements Callback<Date> { . . . }ArrayList<Callable> tasks = new ArrayList<();tasks.add(new MyTask());tasks.add(new MyTask2());List<Future<Object>> result = executor.invokeAll(tasks); The ManagedExecutorService may be configured for different properties such as: Hung Task Threshold: Time in milliseconds that a task can execute before it is considered hung Pool Info Core Size: Number of threads to keep alive Maximum Size: Maximum number of threads allowed in the pool Keep Alive: Time to allow threads to remain idle when # of threads > Core Size Work Queue Capacity: # of tasks that can be stored in inbound buffer Thread Use: Application intend to run short vs long-running tasks, accordingly pooled or daemon threads are picked ManagedScheduledExecutorService adds delay and periodic task running capabilities to ManagedExecutorService. The implementations of this interface are provided by the container and accessible using JNDI reference: <resource-env-ref>  <resource-env-ref-name>    concurrent/BatchExecutor  </resource-env-ref-name>  <resource-env-ref-type>    javax.enterprise.concurrent.ManagedExecutorService  </resource-env-ref-type><resource-env-ref> and available as: @Resource(name="concurrent/timedExecutor")ManagedExecutorService executor; And then the tasks are submitted using submit, invokeXXX or scheduleXXX methods. ScheduledFuture<?> future = executor.schedule(new MyTask(), 5, TimeUnit.SECONDS); This will create and execute a one-shot action that becomes enabled after 5 seconds of delay. More control is possible using one of the newly added methods: MyTaskListener implements ManagedTaskListener {  public void taskStarting(...) { . . . }  public void taskSubmitted(...) { . . . }  public void taskDone(...) { . . . }  public void taskAborted(...) { . . . } }ScheduledFuture<?> future = executor.schedule(new MyTask(), 5, TimeUnit.SECONDS, new MyTaskListener()); Here, ManagedTaskListener is used to monitor the state of a task's future. ManagedThreadFactory provides a method for creating threads for execution in a managed environment. A simple usage is: @Resource(name="concurrent/myThreadFactory")ManagedThreadFactory factory;. . .Thread thread = factory.newThread(new Runnable() { . . . }); concurrent/myThreadFactory is a JNDI resource. There is lot of interesting content in the Early Draft, download it, and read yourself. The implementation will be made available soon and also be integrated in GlassFish 4 as well. Some references for further exploring ... Javadoc Early Draft Specification concurrency-ee-spec.java.net [email protected]

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• What to leave when you're leaving

  - by BuckWoody

  There's already a post on this topic - sort of. I read this entry, where the author did a good job on a few steps, but I found that a few other tips might be useful, so if you want to check that one out and then this post, you might be able to put together your own plan for when you leave your job.  I once took over the system administrator (of which the Oracle and SQL Server servers were a part) at a mid-sized firm. The outgoing administrator had about a two- week-long scheduled overlap with me, but was angry at the company and told me "hey, I know this is going to be hard on you, but I want them to know how important I was. I'm not telling you where anything is or what the passwords are. Good luck!" He then quit that day. It took me about three days to find all of the servers and crack the passwords. Yes, the company tried to take legal action against the guy and all that, but he moved back to his home country and so largely got away with it. Obviously, this isn't the way to leave a job. Many of us have changed jobs in the past, and most of us try to be very professional about the transition to a new team, regardless of the feelings about a particular company. I've been treated badly at a firm, but that is no reason to leave a mess for someone else. So here's what you should put into place at a minimum before you go. Most of this is common sense - which of course isn't very common these days - and another good rule is just to ask yourself "what would I want to know"? The article I referenced at the top of this post focuses on a lot of documentation of the systems. I think that's fine, but in actuality, I really don't need that. Even with this kind of documentation, I still perform a full audit on the systems, so in the end I create my own system documentation. There are actually only four big items I need to know to get started with the systems: 1. Where is everything/everybody?The first thing I need to know is where all of the systems are. I mean not only the street address, but the closet or room, the rack number, the IU number in the rack, the SAN luns, all that. A picture here is worth a thousand words, which is why I really like Visio. It combines nice graphics, full text and all that. But use whatever you have to tell someone the physical locations of the boxes. Also, tell them the physical location of the folks in charge of those boxes (in case you aren't) or who share that responsibility. And by "where" in this case, I mean names and phones.  2. What do they do?For both the servers and the people, tell them what they do. If it's a database server, detail what each database does and what application goes to that, and who "owns" that application. In my mind, this is one of hte most important things a Data Professional needs to know. In the case of the other administrtors or co-owners, document each person's responsibilities.   3. What are the credentials?Logging on/in and gaining access to the buildings are things that the new Data Professional will need to do to successfully complete their job. This means service accounts, certificates, all of that. The first thing they should do, of course, is change the passwords on all that, but the first thing they need is the ability to do that!  4. What is out of the ordinary?This is the most tricky, and perhaps the next most important thing to know. Did you have to use a "special" driver for that video card on server X? Is the person that co-owns an application with you mentally unstable (like me) or have special needs, like "don't talk to Buck before he's had coffee. Nothing will make any sense"? Do you have service pack requirements for a specific setup? Write all that down. Anything that took you a day or longer to make work is probably a candidate here. This is my short list - anything you care to add? Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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• Revisiting the Generations

  - by Row Henson

  I was asked earlier this year to contribute an article to the IHRIM publication – Workforce Solutions Review.  My topic focused on the reality of the Gen Y population 10 years after their entry into the workforce.  Below is an excerpt from that article: It seems like yesterday that we were all talking about the entry of the Gen Y'ers into the workforce and what a radical change that would have on how we attract, retain, motivate, reward, and engage this new, younger segment of the workforce.  We all heard and read that these youngsters would be more entrepreneurial than their predecessors – the Gen X'ers – who were said to be more loyal to their profession than their employer. And, we heard that these “youngsters” would certainly be far less loyal to their employers than the Baby Boomers or even earlier Traditionalists. It was also predicted that – at least for the developed parts of the world – they would be more interested in work/life balance than financial reward; they would need constant and immediate reinforcement and recognition and we would be lucky to have them in our employment for two to three years. And, to keep them longer than that we would need to promote them often so they would be continuously learning since their long-term (10-year) goal would be to own their own business or be an independent consultant.  Well, it occurred to me recently that the first of the Gen Y'ers are now in their early 30s and it is time to look back on some of these predictions. Many really believed the Gen Y'ers would enter the workforce with an attitude – expect everything to be easy for them – have their employers meet their demands or move to the next employer, and I believe that we can now say that, generally, has not been the case. Speaking from personal experience, I have mentored a number of Gen Y'ers and initially felt that with a 40-year career in Human Resources and Human Resources Technology – I could share a lot with them. I found out very quickly that I was learning at least as much from them! Some of the amazing attributes I found from these under-30s was their fearlessness, ease of which they were able to multi-task, amazing energy and great technical savvy. They were very comfortable with collaborating with colleagues from both inside the company and peers outside their organization to problem-solve quickly. Most were eager to learn and willing to work hard.  This brings me to the generation that will follow the Gen Y'ers – the Generation Z'ers – those born after 1998. We have come full circle. If we look at the Silent Generation or Traditionalists, we find a workforce that preceded the television and even very early telephones. We Baby Boomers (as I fall right squarely in this category) remembered the invention of the television and telephone – but laptop computers and personal digital assistants (PDAs) were a thing of “StarTrek” and other science fiction movies and publications. Certainly, the Gen X'ers and Gen Y'ers grew up with the comfort of these devices just as we did with calculators. But, what of those under the age of 10 – how will the workplace look in 15 more years and what type of workforce will be required to operate in the mobile, global, virtual world. I spoke to a friend recently who had her four-year-old granddaughter for a visit. She said she found her in the den in front of the TV trying to use her hand to get the screen to move! So, you see – we have come full circle. The under-70 Traditionalist grew up in a world without TV and the Generation Z'er may never remember the TV we knew just a few years ago. As with every generation – we spend much time generalizing on their characteristics. The most important thing to remember is every generation – just like every individual – is different. The important thing for those of us in Human Resources to remember is that one size doesn’t fit all. What motivates one employee to come to work for you and stay there and be productive is very different than what the next employee is looking for and the organization that can provide this fluidity and flexibility will be the survivor for generations to come. And, finally, just when we think we have it figured out, a multitude of external factors such as the economy, world politics, industries, and technologies we haven’t even thought about will come along and change those predictions. As I reach retirement age – I do so believing that our organizations are in good hands with the generations to follow – energetic, collaborative and capable of working hard while still understanding the need for balance at work, at home and in the community! 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• Determining the angle to fire a shot when target and shooter moves, and bullet moves with shooter velocity added in

  - by Azaral

  I saw this question: Predicting enemy position in order to have an object lead its target and followed the link in the answer to stack overflow. In the stack overflow page I used the 2nd answer, the one that is a large mathematical derivation. My situation is a little different though. My first question though is will the answer provided in the stack overflow page even work to begin with, assuming the original circumstances of moving target and stationary shooter. My situation is a little different than that situation. My target moves, the shooter moves, and the bullets from the shooter start off with the velocities in x and y added to the bullets' x and y velocities. If you are sliding to the right, the bullets will remain in front of you as you move so as long as your velocity remains constant. What I'm trying to do is to get the enemy to be able to determine where they need to shoot in order to hit the player. Unless the player and enemy is stationary, the velocity from the ship adding to the velocity of the bullets will cause a miss. I'd rather like to prevent that. I used the formula in the stack overflow answer and did what I thought were the appropriate adjustments. I've been banging at this for the last four hours and I just can't make it click. It is probably something really simple and boneheaded that I am missing (that seems to be a lot of my problems lately). Here is the solution presented from the stack overflow answer: It boils down to solving a quadratic equation of the form: a * sqr(x) + b * x + c == 0 Note that by sqr I mean square, as opposed to square root. Use the following values: a := sqr(target.velocityX) + sqr(target.velocityY) - sqr(projectile_speed) b := 2 * (target.velocityX * (target.startX - cannon.X) + target.velocityY * (target.startY - cannon.Y)) c := sqr(target.startX - cannon.X) + sqr(target.startY - cannon.Y) Now we can look at the discriminant to determine if we have a possible solution. disc := sqr(b) - 4 * a * c If the discriminant is less than 0, forget about hitting your target -- your projectile can never get there in time. Otherwise, look at two candidate solutions: t1 := (-b + sqrt(disc)) / (2 * a) t2 := (-b - sqrt(disc)) / (2 * a) Note that if disc == 0 then t1 and t2 are equal. If there are no other considerations such as intervening obstacles, simply choose the smaller positive value. (Negative t values would require firing backward in time to use!) Substitute the chosen t value back into the target's position equations to get the coordinates of the leading point you should be aiming at: aim.X := t * target.velocityX + target.startX aim.Y := t * target.velocityY + target.startY Here is my code, after being corrected by Sam Hocevar (thank you again for your help!). It still doesn't work. For some reason it never enters the section of code inside the if(disc = 0) (obviously because it is always less than zero but...). However, if I plug the numbers from my game log on the enemy and player positions and velocities it outputs a valid firing solution. I have looked at the code side by side a couple of times now and I can't find any differences. There has got to be something simple I'm missing here. If someone else could look at this code and determine what is going on here I'd appreciate it. I know it's not going through that section because if it were, shouldShoot would become true and the enemy would be blasting away at the player. This section calls the function in question, CalculateShootHeading() if(shouldMove) { UseEngines(); } x += xVelocity; y += yVelocity; CalculateShootHeading(); if(shouldShoot) { ShootWeapons(); } UpdateWeapons(); This is CalculateShootHeading(). This is inside the enemy class so x and y are the enemy's x and y and the same with velocity. One output from my game log gives Player X = 2108, Player Y = -180.956, Player X velocity = 10.9949, Player Y Velocity = -6.26017, Enemy X = 1988.31, Enemy Y = -339.051, Enemy X velocity = 1.81666, Enemy Y velocity = -9.67762, 0 enemy projectiles. The output from the console tester is Bullet position = 2210.49, -239.313 and Player Position = 2210.49, -239.313. This doesn't make any sense. The only thing that could be different is the code or the input into my function in the game and I've checked that and I don't think that it is wrong as it's updated before this and never changed. float const bulletSpeed = 30.f; float const dx = playerX - x; float const dy = playerY - y; float const vx = playerXVelocity - xVelocity; float const vy = playerYVelocity - yVelocity; float const a = vx * vx + vy * vy - bulletSpeed * bulletSpeed; float const b = 2.f * (vx * dx + vy * dy); float const c = dx * dx + dy * dy; float const disc = b * b - 4.f * a * c; shouldShoot = false; if (disc >= 0.f) { float t0 = (-b - std::sqrt(disc)) / (2.f * a); float t1 = (-b + std::sqrt(disc)) / (2.f * a); if (t0 < 0.f || (t1 < t0 && t1 >= 0.f)) { t0 = t1; } if (t0 >= 0.f) { float shootx = vx + dx / t0; float shooty = vy + dy / t0; heading = std::atan2(shooty, shootx) * RAD2DEGREE; } shouldShoot = true; }

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• WPF Formatting Issues - Automatically stretching and resizing?

  - by Adam S

  I'm very new to WPF and XAML. I am trying to design a basic data entry form. I have used a stack panel holding four more stack panels to get the layout I want. Perhaps a grid would be better for this, I am not sure. Here is an image of my form in action: http://yfrog.com/7gscreenshot1impp And here is the XAML code that generates it: <Window x:Class="Test1.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="Window1" Height="224" Width="536.762"> <StackPanel Height="Auto" Name="stackPanel1" Width="Auto" Orientation="Horizontal"> <StackPanel Height="Auto" Name="stackPanel2" Width="Auto"> <Label Height="Auto" Name="label1" Width="Auto">Patient Name:</Label> <Label Height="Auto" Name="label2" Width="Auto">Physician:</Label> <Label Height="Auto" Name="label3" Width="Auto">Insurance:</Label> <Label Height="Auto" Name="label4" Width="Auto">Therapy Goals:</Label> </StackPanel> <StackPanel Height="Auto" Name="stackPanel3" Width="Auto"> <TextBox Height="Auto" Name="textBox1" Width="Auto" Padding="3" Margin="1" /> <TextBox Height="Auto" Name="textBox2" Width="Auto" Padding="3" Margin="1" /> <TextBox Height="Auto" Name="textBox3" Width="Auto" Padding="3" Margin="1" /> <TextBox Height="Auto" Name="textBox4" Width="Auto" Padding="3" Margin="1" /> </StackPanel> <StackPanel Height="Auto" Name="stackPanel4" Width="Auto"> <Label Height="Auto" Name="label5" Width="Auto">Date:</Label> <Label Height="Auto" Name="label6" Width="Auto">Patient Phone:</Label> <Label Height="Auto" Name="label7" Width="Auto">Facility:</Label> <Label Height="Auto" Name="label8" Width="Auto">Referring Physician:</Label> </StackPanel> <StackPanel Height="Auto" Name="stackPanel5" Width="Auto"> <TextBox Height="Auto" Name="textBox5" Width="Auto" Padding="3" Margin="1" /> <TextBox Height="Auto" Name="textBox6" Width="Auto" Padding="3" Margin="1" /> <TextBox Height="Auto" Name="textBox7" Width="Auto" Padding="3" Margin="1" /> <TextBox Height="Auto" Name="textBox8" Width="Auto" Padding="3" Margin="1" /> </StackPanel> </StackPanel> </Window> What I really want is for the text boxes to stretch equally to fill up the space horizontally. I would also like for the controls in each vertical stackpanel to 'spread out' evenly as the window is resized vertically. Can any of you experts out there help me out?

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• Javascript Noob: How to emulate slideshow on front page by automatically cycling through existing ho

  - by Zildjoms

  hey everyone. hope you could help me out am working on this website and i've finished all the hover effects i like - they're exactly how i want them to be: http://s5ent.brinkster.net/beta3.asp - try hovering over the four links and you'll see a very simple fade effect at work, which degrades into a regular css hover without javascript. what i plan to do is to make the page look like it had a fancy slideshow going on upon loading and while idle, and i wanted to achieve that by capitalizing on the existing hover styling/behavior of the main page links instead of using another script to create the effect from scratch. to do this i imagined i'll need a script that emulates a hover action on each link at regular time intervals once the page has loaded, starting from left to right (footcare, lawn & equipment, about us, contact us), looping through all 4 links indefinitely (footcare, lawn & equipment, about us, contact us, footcare, lawn& equipment, etc.) but pauses when any of them have been actually hovered over by a viewer and resumes from wherever the user left off upon mouseout. hope you get my drift... i also want to achieve this without unnecessarily disrupting the current html. so i guess everything will have to be done by scripting as much as possible.. i'm very new to javascript and jquery. as you can see at s5ent.brinkster.net/beta3.1-autohover.asp, the following script i made works wrong: it hovers-on all of them at the same time and doesn't hover-out anymore. when you try to actually hover into and out of each link the link just comes back on: <script type="text/javascript"> $(document).ready(function () { var speed = 5000; var run = setInterval('rotate()', speed); }); function rotate() { $('.lilevel1 a').each(function(i) { $(this).mouseover(); }); } </script> it's just gross. aside from the fact that this last bit of script isn't even working in ie. could you please help me make this thing happen? that'd be really sweet, guys. i know there are tonsa geniuses out there who could whip this up in no time. or if you have a better way to go about it by all means kindly lemme know. thanks guys, hope you're all havin a blast.

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