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• Overriding classes/functions from a .dll.

  - by Jeff

  Say I have class A and class B. B inherits from class A, and implements a few virtual functions. The only problem is that B is defined in a .dll. Right now, I have a function that returns an instance of class A, but it retrieves that from a static function in the .dll that returns an instance of class B. My plan is to call the created object, and hopefully, have the functions in the .dll executed instead of the functions defined in class A. For some reason, I keep getting restricted memory access errors. Is there something I don't understand that will keep this plan from working?

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• VEMap Pan triggers VEMap.onclick

  - by Jason

  I'm using the Virtual Earth (or Bing!...) SDK and need to attach an event when someone clicks the map. Unfortunately panning the map also triggers the onclick event. Does anyone know of a work around? function GetMap(){ map = new VEMap('dvMap'); map.LoadMap(new VELatLong(35.576916524038616,-80.9410858154297), 11, 'h',false); mapIsInit = true; map.AttachEvent('onclick', MapClick); } function MapClick(e){ var clickPnt = map.PixelToLatLong(new VEPixel(e.mapX,e.mapY)); Message('Map X: ' + clickPnt.Longitude + '\nMap Y: ' + clickPnt.Latitude + '\nZoom: ' + e.zoomLevel); }

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• Is there a way to extracting semantic informations from PDF? (converting PDF to pure XHTML)

  - by Eonil

  Hi. I'm finding a way to extract semantic structural informations (like title, heading, paragraph or lists) from PDF. Because I want to get a pure structural data from PDF. Finally, I want to create an pure XHTML from the PDF. With only structural informations. No design or layout. I know, PDF can be created without any structural information. I don't consider those PDFs. Only regularly well-structured PDFs are considered. I'm new to PDF. So I don't know it offers regular semantic structure or not. If it exists, it's library will offer it. So I want to know whether PDF spec has those information, and best way to get those information if exists.

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• Run Windows XP on a usb drive virtually on Windows XP?

  - by Russell

  I am sick of not being able to run and install certain applications on my work computer due to admin restrictions (eg: Adobe AIR) . I have heard of smaller versions of Windows running on a usb thumb drive and have looked into it but can't find anything on running windows virtually from a usb drive. I would like to be able to login to this particular computer, insert my usb drive and then open up another version of windows installed on the thumb drive while still being able to use the windows I logged in on (literally be able to alt+tab between the main desktop and the virtual desktop from the usb drive). Is this even possible? For further clarification: The version of windows has to be Windows XP and there is no other option available for what I want to do. Looking forward to a response.

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• Why does GetClusterShape return null when the cluster specification was retrieved through the GetClu

  - by Markus Olsson

  Suppose I have a virtual earth shape layer called shapeLayer1 (my creative energy is apparently at an alltime low). When i call the GetClusteredShapes method I get an array of VEClusterSpecification objects that represent each and every one of my currently visible clusters; no problem there. But when I call the GetClusterShape() method it returns null... null! Why on earth would it do that? I used firebug to confirm that the private variable of the VEClusterSpecification that's supposed to hold a reference to the shape is indeed null so it's not the method that's causing the problem. Some have suggested that this is actually documented behavior Returns null if a VEClusterSpecification object was returned from the VEShapeLayer.GetClusteredShapes Method But looking at the current MSDN documentation for the VEShape class it says: Returns if a VEClusterSpecification object was returned from the VEShapeLayer.GetClusteredShapes Method Is this a bug or a feature? Is there any known workarounds or (if it is a bug) some plan on when they are going to fix it?

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• How does one use dynamic recompilation?

  - by acidzombie24

  It came to my attention some emulators and virtual machines use dynamic recompilation. How do they do that? In C i know how to call a function in ram using typecasting (although i never tried) but how does one read opcodes and generate code for it? Does the person need to have premade assembly chunks and copy/batch them together? is the assembly written in C? If so how do you find the length of the code? How do you account for system interrupts?

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• Pure Java open-source libraries for portfolio selection (= constrained, non-linear optimization)?

  - by __roland__

  Does anyone know or has experience with a pure Java library to select portfolios or do some similar kinds of quadratic programming with constraints? There seems to be a lot of tools, as already discussed elsewhere - but what I would like to use is a pure Java implementation. Since I want to call the library from within another open-source software with a BSD-ish license I would prefer LGPL over GPL. Any help is appreciated. If you don't know such libraries, which is the most simple algorithm you would suggest to implement? It has to cope with an inequality constraint (all x_i = 0) and an equality constraint (sum of all x_i = 1).

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• What's the best example of pure show-off code you've seen?

  - by Damovisa

  Let's face it, programmers can be show-offs. I've seen a lot of code that was only done a particular way to prove how smart the person who wrote it was. What's the best example of pure show-off code you've seen (or been responsible for) in your time? For me, it'd have to be the guy who wrote FizzBuzz in one line on a whiteboard during a programming interview. Not really that impressive in the scheme of things, but completely unnecessary and pure, "look-what-I-can-do". I've lost the original code, but I think it was something like this (linebreaks for readability): Enumerable.Range(1,100).ToList().ForEach( n => Console.WriteLine( (n%3==0) ? (n%5==0) ? "FizzBuzz" : "Fizz" : (n%5==0) ? "Buzz" : n ) );

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• Tutorial/resource for implementing VM

  - by zaharpopov

  Hello, I want self-education purpose implement a simple virtual machine for a dynamic language, prefer in C language. Something like the Lua VM, or Parrot, or Python VM, but simpler. Are there any good resources/tutorials on achieving this, apart from looking at code and design documentations of the existing VMs? Thanks in advance for your answers and ideas Edit: why close vote? I don't understand - is this not programming. Please comment if there is specific problem with my question.

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• Android Apps Not Showing Up In AVD

  - by Mike

  I recently started messing with Android Apps, but I have had nothing but problems trying to get them into the Virtual Device for testing. For some reason, they never seem to show up in the AVD. It has worked one time, but that's it out of hours spent just trying to test one or two very simple apps. I've redone the AVD setup many, many times, trying different settings and what not to no avail. I've followed multiple guides and tutorials to the letter to get it working, but they just refuse to show up in the list. :( Any insight would be appreciated, thank you.

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• imported vm gives "failed to open/create network" error

  - by Colleen

  steps: 1. created a vm in windows 2. partitioned drive and installed ubuntu 3. exported the vm I created 4. mounted windows drive in ubuntu 5. imported the vm from the export, in the mounted drive 6. tried to start vm, got the following error: "Failed to open a session for the virtual machine XXXX. Failed to open/create the internal network 'HostInterfaceNetworking-Intel(R) 82579LM Gigabit Network Connection' (you might need to modprobe vboxnetflt to make it accessible) (VERR_INTNET_FLT_IF_NOT_FOUND). Result Code: NS_ERROR_FAILURE (0x80004005) Component: Console Interface: IConsole {1968b7d3-e3bf-4ceb-99e0-cb7c913317bb} " Network settings: Adapter 1: PCnet-FAST III (Bridged adapter, Intel(R) 82579LM Gigabit Network Connection)

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• How to change the app name in OSX menubar in a pure-Python application bundle?

  - by gyim

  I am trying to create a pure-Python application bundle for a wxPython app. I created the .app directory with the files described in Apple docs, with an Info.plist file etc. The only difference between a "normal" app and this bundle is that the entry point (CFBundleExecutable) is a script which starts with the following line: #!/usr/bin/env python2.5 Everything works fine except that the application name in the OSX menubar is still "Python" although I have set the CFBundleName in Info.plist (I copied the result of py2app, actually). The full Info.plist can be viewed here: http://tinyurl.com/32qgpjt How can I change this? I have read everywhere that the menubar name is only determined by CFBundleName. How is it possible that the Python interpreter can change this in runtime? Note: I was using py2app before, but the result was too large (50 MB instead of the current 100KB) and it was not even portable between Leopard and Snow Leopard... so it seems to be much easier to create a pure-Python app bundle "by hand" than transforming the output of py2app.

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• Force download menu for remote files

  - by o-logn

  Hey, I would like users to upload links on my site. When another user clicks on the link (e.g. PDF file), then I would like the download popup to show instead of actually displaying the PDF in browser. I know I can use Response.AddHeader/Response.WriteFile to achieve this, but the WriteFile method required a virtual path. However, the links uploaded by the user will be pointing to external servers. Can I still force the download popup to show and, if so, what would be the most efficient way of doing it? Thanks for any advice

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• Wastage of resources in Virtualization

  - by Sabeen Malik

  I am not sure if this is the write place to ask the question. However i hope it is. When looking for a VPS earlier today, I was trying to understand how each container would work in the background. Keeping in mind the fact that the operating system uses most of the power and power on a system, wouldn't having multiple operating systems in the same machine mean more wastage of resources. For instance if i was running centOS on a dedicated box and it was running lets say 20 background OS level processes. Then i go and install a virtualization platform and install 5 more centOS virtual machines in the same system which are exactly the same as the host operating system. Doesn't this mean duplication of those 20 processes 6 times? So internally the context switching is happening between 120 processes instead of 20?

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• Is there any LAME c++ wraper\simplifier (working on Linux Mac and Win from pure code)?

  - by Ole Jak

  So I want to create simple pcm to mp3 C++ project. I want it to use LAME. I love LAME but It is realy biiig. so I need some kind of OpenSource working from pure code with pure lame code workflow simplifier. So to say I give it File with PCM and DEST file. Call something like LameSimple.ToMP3(file with PCM, File with MP3 , 44100, 16, MP3, VBR); ore such thing in 4 - 5 lines (examples ofcourse should exist) and I have vhat I needed It should be light, simple, powerfool, opensource, crossplatform. Is there any thing like this?!?

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• Configure multiple keystores in JBoss depending on requested hostname

  - by Mo

  Hello, I have my J2EE application deployed into a JBossAS. My Application has to respond to two different hostnames (https://foo.com/myApp and https://bar.com/myApp). It is the same instance of the app serving those two hostnames. But I don't know how to configure the keystores. I need different keystores for each hostname. Is there a way to tie a virtual host in JBoss' server.xml to a specific connector? Or do I have to use two different IP-addresses and create a connector for each? A solution that does not require a second IP-address would be greatly appreciated.

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• IIS serving corrupted MSI

  - by CF_Maintainer

  Hello, I am trying to put an .msi for download in a virtual directory setup with IIS. The download works fine but when I try and install the .msi, it says it is missing a _cabinet file. Me and a coworker had this issue will the installer downloaded fine & ran correctly on another coworker's machine. Am I missing anything? Is it a better approach to send the .msi as a byte[] via a webservice and assemble it on the client side?

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• Rackspace Ubuntu 12.04 server stuck in initramfs after kernel upgrade

  - by Znarkus

  Can't boot after I did a aptitude full-upgrade and let it update menu.lst (did a diff first and it looked good). This is what I've done so far in the BusyBox shell: mkdir /tmp/xvda1 mount /dev/xvda1 /tmp/xvda1 chroot /dev/xvda1 nano /boot/grub/menu.lst This file looks like this: title Ubuntu 12.04.1 LTS, kernel 3.2.0-31-virtual root(hd0,0) kernel /boot/vmlinuz-3.2.0-31-virtual root=UUID=/dev/xvda1 ro quiet splash initrd /boot/initrd.img-3.2.0-31-virtual title Ubuntu 12.04.1 LTS, kernel 3.2.0-31-virtual (recovery mode) root(hd0,0) kernel /boot/vmlinuz-3.2.0-31-virtual root=UUID=/dev/xvda1 ro single initrd /boot/initrd.img-3.2.0-31-virtual titleUbuntu 12.04.1 LTS, kernel 3.2.0-24-virtual root(hd0,0) kernel/boot/vmlinuz-3.2.0-24-virtual root=UUID=/dev/xvda1 ro quiet splash initrd/boot/initrd.img-3.2.0-24-virtual titleUbuntu 12.04.1 LTS, kernel 3.2.0-24-virtual (recovery mode) root(hd0,0) kernel/boot/vmlinuz-3.2.0-24-virtual root=UUID=/dev/xvda1 ro single initrd/boot/initrd.img-3.2.0-24-virtual titleUbuntu 12.04.1 LTS, kernel 3.2.0-24-generic root(hd0,0) kernel/boot/vmlinuz-3.2.0-24-generic root=UUID=/dev/xvda1 ro quiet splash initrd/boot/initrd.img-3.2.0-24-generic titleUbuntu 12.04.1 LTS, kernel 3.2.0-24-generic (recovery mode) root(hd0,0) kernel/boot/vmlinuz-3.2.0-24-generic root=UUID=/dev/xvda1 ro single initrd/boot/initrd.img-3.2.0-24-generic titleChainload into GRUB 2 root(hd0,0) kernel/boot/grub/core.img titleUbuntu 12.04.1 LTS, memtest86+ root(hd0,0) kernel/boot/memtest86+.bin From what I remember, the upgrade added the UUID= string. Should I remove these? Or rather, how do I get my system back online again? Thanks. Update: Seems like I can't even edit the file. [ Error writing /boot/grub/menu.lst: Read-only file system ]

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• setting up Ubuntu 10.10 as paravirtualized guest in Xen on RHEL5 host - what kernel?

  - by kostmo

  I've discovered the tool ubuntu-vm-builder, which I've installed and then invoked on an Ubuntu workstation as: sudo vmbuilder xen ubuntu --suite maverick --flavour virtual --arch amd64 --mem=512 --rootsize 8192 This workstation is not the intended target host of the virtual machine, however; I would like to host the guest on a Red Hat Enterprise Linux 5 machine that is running Xen 3.0.3. The output of this command appears to be a folder named ubuntu-xen containing three files: tmpXXXXXX, a very large file which I assume is the root partition image tmpYYYYYY, a somewhat large file which I assume is the swap partition image xen.conf, a text file I have copied the xen.conf file to the RHEL server's /etc/xen directory under the new name newvm, adjusting the paths of tempXXXXXX and tempYYYYYYin the file after also copying them from my local workstation to the RHEL server. When I launch the Virtual Machine Manager virt-manager, I can see the newvm virtual machine listed underneath the Dom0 machine. When I try to start newvm, I get the error: Error starting domain: virDomainCreate() failed POST operation failed: (xend.err 'Error creating domain: Kernel image does not exist: None') Indeed, there exists an entry kernel = 'None' in the xen.conf file. How do I find out what the path of the kernel should be? Is this path supposed to be to a kernel stored on the local filesystem of the RHEL5 host, or is it supposed to be a path inside the guest image? I see that the vmbuilder command provides for a --xen-kernel option, along with a --xen-ramdisk option, but I'm not sure what to use for either. I think I should be able to get this to work, since Ubuntu is said to be supported as a Xen guest, even though the Xen 4.0.1 docs state support for only a limited set of distributions, Ubuntu excluded. Update 1 When running vmbuilder on my local workstation, I did observe an output line saying: Calling hook: install_kernel and later, output lines saying: update-initramfs: Generating /boot/initrd.img-2.6.35-23-virtual [...] run-parts: executing /etc/kernel/postinst.d/initramfs-tools 2.6.35-23-virtual /boot/vmlinuz-2.6.35-23-virtual So in the xen.conf file, I tried setting the lines: kernel = '/boot/vmlinuz-2.6.35-23-virtual' ramdisk = '/boot/initrd.img-2.6.35-23-virtual' When trying to start the VM, I got an error similar to last time: Error starting domain: virDomainCreate() failed POST operation failed: (xend.err 'Error creating domain: Kernel image does not exist: /boot/vmlinuz-2.6.35-23-virtual') This makes me think that the RHEL5 machine is looking for local files, rather than a file within the binary guest disk image. After running sudo updatedb on my workstation, neither of those files were found. If the vmbuilder tool had tried to install them, it must have failed. Update 2 I was able to extract the kernel and initrd images from the guest disk binary by mounting it: mkdir mnt_tmp sudo mount ubuntu-xen/tmpXXXXXX mnt_tmp/ -o loop cp mnt_tmp/boot/vmlinuz-2.6.35-23-virtual virtual_kernel_ubuntu cp mnt_tmp/boot/initrd.img-2.6.35-23-virtual virtual_initrd_ubuntu These two files I copied to the RHEL5 server, and edited the xen.conf file to point to them as kernel and ramdisk. With this done, I could "run" the newvm virtual machine from within virt-manager, but was met with the message Console Not Configured For Guest when I double clicked the entry to open the Virtual Machine Console. As suggested by a forum, I then added the line vfb = [ 'type=vnc' ] to the configuration file, recreated the virtual machine (a ~10 min process), and this time got the message: Connecting to console for guest This remained indefinitely; after selecting View - Serial Console, I found a kernel panic: [5442621.272173] Kernel panic - not syncing: Attempted to kill the idle task! [5442621.272179] Pid: 0, comm: swapper Tainted: G D 2.6.35-23-virtual #41-Ubuntu [5442621.272184] Call Trace: [5442621.272191] [<ffffffff815a1b81>] panic+0x90/0x111 [5442621.272199] [<ffffffff810652ee>] do_exit+0x3be/0x3f0 [5442621.272204] [<ffffffff815a5e20>] oops_end+0xb0/0xf0 [5442621.272211] [<ffffffff8100ddeb>] die+0x5b/0x90 [5442621.272216] [<ffffffff815a56c4>] do_trap+0xc4/0x170 [5442621.272221] [<ffffffff8100ba35>] do_invalid_op+0x95/0xb0 [5442621.272227] [<ffffffff8130851c>] ? intel_idle+0xac/0x180 [5442621.272232] [<ffffffff810072bf>] ? xen_restore_fl_direct_end+0x0/0x1 [5442621.272239] [<ffffffff815a48fe>] ? _raw_spin_unlock_irqrestore+0x1e/0x30 [5442621.272247] [<ffffffff8108dfb7>] ? tick_broadcast_oneshot_control+0xc7/0x120 [5442621.272253] [<ffffffff8100ad5b>] invalid_op+0x1b/0x20 [5442621.272259] [<ffffffff8130851c>] ? intel_idle+0xac/0x180 [5442621.272264] [<ffffffff813084e0>] ? intel_idle+0x70/0x180 [5442621.272269] [<ffffffff810072bf>] ? xen_restore_fl_direct_end+0x0/0x1 [5442621.272275] [<ffffffff8148a147>] cpuidle_idle_call+0xa7/0x140 [5442621.272281] [<ffffffff81008d93>] cpu_idle+0xb3/0x110 [5442621.272286] [<ffffffff815873aa>] rest_init+0x8a/0x90 [5442621.272291] [<ffffffff81b04c9d>] start_kernel+0x387/0x390 [5442621.272297] [<ffffffff81b04341>] x86_64_start_reservations+0x12c/0x130 [5442621.272303] [<ffffffff81b08002>] xen_start_kernel+0x55d/0x561 Update 3 I tried an i386 architecture instead of amd64, but got the same kernel panic. Also, it seems the Virtual Machine Manager pays attention to the format of the filename of the kernel; for the same kernel binary, I tried simply naming it vmlinuz-virtual, which threw out an error box about an invalid kernel. When I named it vmlinuz-2.6.35-23-virtual, it did not throw the error, but it did still result in the kernel panic shortly thereafter.

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• Get JVM to grow memory demand as needed up to size of VM limit?

  - by Ira Baxter

  We ship a Java application whose memory demand can vary quite a lot depending on the size of the data it is processing. If you don't set the max VM (virtual memory) size, quite often the JVM quits with an GC failure on big data. What we'd like to see, is the JVM requesting more memory, as GC fails to provide enough, until the total available VM is exhausted. e.g., start with 128Mb, and increase geometrically (or some other step) whenever the GC failed. The JVM ("Java") command line allows explicit setting of max VM sizes (various -Xm* commands), and you'd think that would be designed to be adequate. We try to do this in a .cmd file that we ship with the application. But if you pick any specific number, you get one of two bad behaviors: 1) if your number is small enough to work on most target systems (e.g., 1Gb), it isn't big enough for big data, or 2) if you make it very large, the JVM refuses to run on those systems whose actual VM is smaller than specified. How does one set up Java to use the available VM when needed, without knowing that number in advance, and without grabbing it all on startup?

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• VEMap and a GeoRSS feed(hosted separately)

  - by Alexis Abril

  The scenario is as follows: A WCF web service exists that outputs a valid GeoRSS feed. This lives in its own domain as a number of different applications have access to it. A web page(on a different site) has been created with an instance of a VEMap(Bing/Virtual Earth map object). Now, VEMap can accept an input feed in this format via the following: var layer = new VEShapeLayer(); var veLayerSpec = new VEShapeSourceSpecification(VEDataType.GeoRSS, "someurl", layer); map.ImportShapeLayerData(veLayerSpec, onComplete, true); onComplete is a callback function I'm using to replace the default pin graphic with something custom. The question is in regards to "someurl", which is a path to a local xml file containing the geographic information(georss simple format). I've realized this feed and the map must be hosted in the same domain, so I've created a generic handler that reads the remote feed and returns it in the same format. var veLayerSpec = new VEShapeSourceSpecification(VEDataType.GeoRSS, "/somelocalhandler.ashx", layer); When I do this, I get the VEMap error("z is null"). This is the same error one would receive when trying to access a remote feed. When I copy the feed into a local xml file(ie, "feed.xml") there is no error. The order of operations is currently: remote feed - local handler - VEMap import If I'm over complicating this procedure, let me know! I'm a bit new to the Bing Maps API and might have missed something. Any assistance is appreciated.

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• Pointer Implementation Details in C

  - by Will Bickford

  I would like to know architectures which violate the assumptions I've listed below. Also I would like to know if any of the assumptions are false for all architectures (i.e. if any of them are just completely wrong). sizeof(int *) == sizeof(char *) == sizeof(void *) == sizeof(func_ptr *) The in-memory representation of all pointers for a given architecture is the same regardless of the data type pointed to. The in-memory representation of a pointer is the same as an integer of the same bit length as the architecture. Multiplication and division of pointer data types are only forbidden by the compiler. NOTE: Yes I know this is nonsensical. What I mean is - is there hardware support to forbid this incorrect usage? All pointer values can be casted to a single integer. In other words, what architectures still make use of segments and offsets? Incrementing a pointer is equivalent to adding sizeof(the pointed data type) to the memory address stored by the pointer. If p is an int32* then p+1 is equal to the memory address 4 bytes after p. I'm most used to pointers being used in a contiguous, virtual memory space. For that usage, I can generally get by thinking of them as addresses on a number line. See (http://stackoverflow.com/questions/1350471/pointer-comparison/1350488#1350488).

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• Is there a way to automaticly call all versions of an inherited method?

  - by Eric

  I'm writing a plug-in for a 3D modeling program. I have a custom class that wraps instances of elements in the 3D model, and in turn derives it's properties from the element it wraps. When the element in the model changes I want my class(es) to update their properties based on the new geometry. In the simplified example below. I have classes AbsCurveBasd, Extrusion, and Shell which are all derived from one another. Each of these classes implement a RefreshFromBaseShape() method which updates specific properties based on the current baseShape the class is wrapping. I can call base.RefreshFromBaseShape() in each implementation of RefreshFromBaseShape() to ensure that all the properties are updated. But I'm wondering if there is a better way where I don't have to remember to do this in every implementation of RefershFromBaseShape()? For example because AbsCurveBased does not have a parameterless constructor the code wont even compile unless the constructors call the base class constructors. public abstract class AbsCurveBased { internal Curve baseShape; double Area{get;set;} public AbsCurveBased(Curve baseShape) { this.baseShape = baseShape; RefreshFromBaseShape(); } public virtual void RefreshFromBaseShape() { //sets the Area property from the baseShape } } public class Extrusion : AbsCurveBased { double Volume{get;set;} double Height{get;set;} public Extrusion(Curve baseShape):base(baseShape) { this.baseShape = baseShape; RefreshFromBaseShape(); } public override void RefreshFromBaseShape() { base.RefreshFromBaseShape(); //sets the Volume property based on the area and the height } } public class Shell : Extrusion { double ShellVolume{get;set;} double ShellThickness{get;set;} public Shell(Curve baseShape): base(baseShape) { this.baseShape = baseShape; RefreshFromBaseShape(); } public void RefreshFromBaseShape() { base.RefreshFromBaseShape(); //sets this Shell Volume from the Extrusion properties and ShellThickness property } }

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• Writing a VM - well formed bytecode?

  - by David Titarenco

  Hi, I'm writing a virtual machine in C just for fun. Lame, I know, but luckily I'm on SO so hopefully no one will make fun :) I wrote a really quick'n'dirty VM that reads lines of (my own) ASM and does stuff. Right now, I only have 3 instructions: add, jmp, end. All is well and it's actually pretty cool being able to feed lines (doing it something like write_line(&prog[1], "jmp", regA, regB, 0); and then running the program: while (machine.code_pointer <= BOUNDS && DONE != true) { run_line(&prog[machine.cp]); } I'm using an opcode lookup table (which may not be efficient but it's elegant) in C and everything seems to be working OK. My question is more of a "best practices" question but I do think there's a correct answer to it. I'm making the VM able to read binary files (storing bytes in unsigned char[]) and execute bytecode. My question is: is it the VM's job to make sure the bytecode is well formed or is it just the compiler's job to make sure the binary file it spits out is well formed? I only ask this because what would happen if someone would edit a binary file and screw stuff up (delete arbitrary parts of it, etc). Clearly, the program would be buggy and probably not functional. Is this even the VM's problem? I'm sure that people much smarter than me have figured out solutions to these problems, I'm just curious what they are!

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• Preventing a heavy process from sinking in the swap file

  - by eran

  Our service tends to fall asleep during the nights on our client's server, and then have a hard time waking up. What seems to happen is that the process heap, which is sometimes several hundreds of MB, is moved to the swap file. This happens at night, when our service is not used, and others are scheduled to run (DB backups, AV scans etc). When this happens, after a few hours of inactivity the first call to the service takes up to a few minutes (consequent calls take seconds). I'm quite certain it's an issue of virtual memory management, and I really hate the idea of forcing the OS to keep our service in the physical memory. I know doing that will hurt other processes on the server, and decrease the overall server throughput. Having that said, our clients just want our app to be responsive. They don't care if nightly jobs take longer. I vaguely remember there's a way to force Windows to keep pages on the physical memory, but I really hate that idea. I'm leaning more towards some internal or external watchdog that will initiate higher-level functionalities (there is already some internal scheduler that does very little, and makes no difference). If there were a 3rd party tool that provided that kind of service is would have been just as good. I'd love to hear any comments, recommendations and common solutions to this kind of problem. The service is written in VC2005 and runs on Windows servers.

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