Search Results

Search found 15637 results on 626 pages for 'memory efficient'.

Page 461/626 | < Previous Page | 457 458 459 460 461 462 463 464 465 466 467 468  | Next Page >

• Someone is using the struct name as a variable name too. What does the code really say? (c++)

  - by EvilTeach

  This morning we found an old chunk of code that was causing a library call to crash. struct fred { int a; int b; int c; }; fred fred[MAX_SIZE+1]; memset( fred, 0, sizeof(fred) * MAX_SIZE+1 ); It appears that the sizeof(fred) may have been the full array size, rather than the structure size, as it was overwriting a great deal of memory. The fact that it compiled without warning on several different systems seemed odd. Is there a correct semantic for this case where the type and variable name are colliding? or is this some sort of undefined behavior? or just a defect? I haven't been been clever enough to find anything on Google or our language help. Thanks Evil

  Read the article

• How can I get this code involving unique_ptr to compile?!

  - by Neil G

  #include <vector> #include <memory> using namespace std; class A { public: A(): i(new int) {} A(A const& a) = delete; A(A &&a): i(move(a.i)) {} unique_ptr<int> i; }; class AGroup { public: void AddA(A &&a) { a_.emplace_back(move(a)); } vector<A> a_; }; int main() { AGroup ag; ag.AddA(A()); return 0; } does not compile... (says that unique_ptr's copy constructor is deleted) I tried replacing move with forward. Not sure if I did it right, but it didn't work for me.

  Read the article

• Application crash when using an NSTimer and pushViewController

  - by Cesar

  I'm using an NSTimer to implement a 3 seconds splash screen. If a don't use a timer the view it's correctly pushed but if I use the timer for adding a little delay the application crash with a EXC_BAD_ACCESS. I'm pretty sure the answer contains "memory management" but I can't get the point... @interface RootViewController : UIViewController { NSTimer *timer; } -(void)changeView:(NSTimer*)theTimer; @property(nonatomic,retain) NSTimer *timer; ... @implementation RootViewController @synthesize timer; - (void)viewDidAppear:(BOOL)animated { [super viewDidAppear:animated]; [[self navigationController] setNavigationBarHidden:YES]; timer = [NSTimer scheduledTimerWithTimeInterval:3.0 target:self selector:@selector(changeView:) userInfo:nil repeats:NO]; } -(void)changeView:(NSTimer*)theTimer { NSLog(@"timer fired"); //Crash here, but only if called using a timer [[self navigationController] pushViewController:list animated:YES]; }

  Read the article

• Optimizing a large iteration of PHP objects (EAV-based)

  - by Aron Rotteveel

  I am currently working on a project that utilizes the EAV model. This turns out to work quite well, but like many others I am now stumbling upon some performance issues. The data set in this particular case consists of aproximately 2500 entities, each with aprox. 150 attributes. Each entity and each attribute is represented by a PHP-object. Since most parts of the application only iterate through a filtered set of entities, we have not had very large issues yet. Now, however, I am working on an algorithm that requires iteration over the entire dataset, which causes a major impact on performance. This information is perhaps not very much to work with, but since this is an architectural problem, I am hoping for a architectural pattern to help me on the way as well. Each entity, including it's attributes takes up aprox. 500KB of memory.

  Read the article

• Advanced Java book in the lines of CLR via c# or C# in Depth?

  - by devoured elysium

  I want to learn about how things work in depth in Java. Coming from a c# background, there were a couple of very good books that go really deep in c# (C# in depth, CLR via c#, just to name the most popular). Is there anything like that in Java? I searched it up on amazon but nothing seemed to go that deep in Java as the two above go in c#. I don't want to know more about specific classes, or how to use this library or that other library, I want to learn how the objects are created on memory, how they get created on the stack, heap, etc. A more fundamental knowledge, let's say. I've read some chapters of Effective Java and The Java Programming Language but they don't seem to go so deep as I'd want them to go. Maybe there are other people that know both c# and Java that have read any of the referred books and know any that might be useful? Thanks

  Read the article

• C++ Static array vs. Dynamic array?

  - by user69514

  What is the difference between a static array and a dynamic array in C++? I have to do an assignment for my class and it says not to use static arrays, only dynamic arrays. I've looked in the book and online, but I don't seem to understand. I thought static was created at compile time and dynamic at runtime, but I might be mistaken this with memory allocation. Can you explain to me the difference between static array and dynamic array in C++? Thnaks.

  Read the article

• HTTP status code for "success with errors"?

  - by Richard Levasseur

  I've poked around a bit, but I don't see an HTTP status code for when a request's succeeds, but there is an error after the "point of no return". e.g., Say you process a request, its committed to the database, but while returning the result you run of memory, or encounter a NPE, or what have you. It would have been a 200 response, but now, internally, you aren't able to return the proper, well-formed response. 202 Accepted doesn't seem to fit since we've already processed the request. What status code means "Success, but errors"? Does one even exist?

  Read the article

• Piping SoX in Python - subprocess alternative?

  - by Cochise Ruhulessin

  I use SoX in an application. The application uses it to apply various operations on audiofiles, such as trimming. This works fine: from subprocess import Popen, PIPE kwargs = {'stdin': PIPE, 'stdout': PIPE, 'stderr': PIPE} pipe = Popen(['sox','-t','mp3','-', 'test.mp3','trim','0','15'], **kwargs) output, errors = pipe.communicate(input=open('test.mp3','rb').read()) if errors: raise RuntimeError(errors) This will cause problems on large files hower, since read() loads the complete file to memory; which is slow and may cause the pipes' buffer to overflow. A workaround exists: from subprocess import Popen, PIPE import tempfile import uuid import shutil import os kwargs = {'stdin': PIPE, 'stdout': PIPE, 'stderr': PIPE} tmp = os.path.join(tempfile.gettempdir(), uuid.uuid1().hex + '.mp3') pipe = Popen(['sox','test.mp3', tmp,'trim','0','15'], **kwargs) output, errors = pipe.communicate() if errors: raise RuntimeError(errors) shutil.copy2(tmp, 'test.mp3') os.remove(tmp) So the question stands as follows: Are there any alternatives to this approach, aside from writing a Python extension to the Sox C API?

  Read the article

• How does a virtual machine work?

  - by Martin

  I've been looking into how programming languages work, and some of them have a so-called virtual machines. I understand that this is some form of emulation of the programming language within another programming language, and that it works like how a compiled language would be executed, with a stack. Did I get that right? With the proviso that I did, what bamboozles me is that many non-compiled languages allow variables with "liberal" type systems. In Python for example, I can write this: x = "Hello world!" x = 2**1000 Strings and big integers are completely unrelated and occupy different amounts of space in memory, so how can this code even be represented in a stack-based environment? What exactly happens here? Is x pointed to a new place on the stack and the old string data left unreferenced? Do these languages not use a stack? If not, how do they represent variables internally?

  Read the article

• Vertical Scroll not working, are the guides but the screen does not scroll.

  - by Leandro

  package com.lcardenas.infoberry; import net.rim.device.api.system.DeviceInfo; import net.rim.device.api.system.GPRSInfo; import net.rim.device.api.system.Memory; import net.rim.device.api.ui.MenuItem; import net.rim.device.api.ui.component.Dialog; import net.rim.device.api.ui.component.LabelField; import net.rim.device.api.ui.component.Menu; import net.rim.device.api.ui.component.SeparatorField; import net.rim.device.api.ui.container.MainScreen; import net.rim.device.api.ui.container.VerticalFieldManager; import net.rim.device.api.ui.decor.Background; import net.rim.device.api.ui.decor.BackgroundFactory; public class vtnprincipal extends MainScreen { //llamamos a la clase principal private InfoBerry padre; //variables para el menu private MenuItem mnubateria; private MenuItem mnuestado; private MenuItem mnuacerca; public vtnprincipal(InfoBerry padre) { super(); this.padre = padre; } public void incventana(){ VerticalFieldManager _ventana = new VerticalFieldManager(VerticalFieldManager.VERTICAL_SCROLL | VerticalFieldManager.VERTICAL_SCROLLBAR); double tmemoria =((DeviceInfo.getTotalFlashSize()/1024)/1024.00); double fmemoria = ((Memory.getFlashFree()/1024)/1024.00); Background cyan = BackgroundFactory.createSolidBackground(0x00E0FFFF); Background gris = BackgroundFactory.createSolidBackground(0x00DCDCDC ); //Borramos todos de la pantalla this.deleteAll(); //llamamos al menu incMenu(); //DIBUJAMOS LA VENTANA try{ LabelField title = new LabelField("Info Berry", LabelField.FIELD_HCENTER | LabelField.USE_ALL_HEIGHT ); setTitle(title); _ventana.add(new LabelField("Información del Dispositivo", LabelField.FIELD_HCENTER |LabelField.RIGHT | LabelField.USE_ALL_HEIGHT | LabelField.NON_FOCUSABLE )); _ventana.add(new SeparatorField()); _ventana.add(new SeparatorField()); txthorizontal modelo = new txthorizontal("Modelo:", DeviceInfo.getDeviceName()); modelo.setBackground(gris); _ventana.add(modelo); txthorizontal pin = new txthorizontal("PIN:" , Integer.toHexString(DeviceInfo.getDeviceId()).toUpperCase()); pin.setBackground(cyan); _ventana.add(pin); txthorizontal imeid = new txthorizontal("IMEID:" , GPRSInfo.imeiToString(GPRSInfo.getIMEI())); imeid.setBackground(gris); _ventana.add(imeid); txthorizontal version= new txthorizontal("SO Versión:" , DeviceInfo.getSoftwareVersion()); version.setBackground(cyan); _ventana.add(version); txthorizontal plataforma= new txthorizontal("SO Plataforma:" , DeviceInfo.getPlatformVersion()); plataforma.setBackground(gris); _ventana.add(plataforma); txthorizontal numero= new txthorizontal("Numero Telefonico: " , "Hay que firmar"); numero.setBackground(cyan); _ventana.add(numero); _ventana.add(new SeparatorField()); _ventana.add(new SeparatorField()); _ventana.add(new LabelField("Memoria", LabelField.FIELD_HCENTER | LabelField.USE_ALL_HEIGHT | LabelField.NON_FOCUSABLE)); _ventana.add(new SeparatorField()); txthorizontal totalm= new txthorizontal("Memoria app Total:" , mmemoria(tmemoria) + " Mb"); totalm.setBackground(gris); _ventana.add(totalm); txthorizontal disponiblem= new txthorizontal("Memoria app Disponible:" , mmemoria(fmemoria) + " Mb"); disponiblem.setBackground(cyan); _ventana.add(disponiblem); ///txthorizontal estadoram = new txthorizontal("Memoria RAM:" , mmemoria(prueba) + " Mb"); //estadoram.setBackground(gris); //add(estadoram); _ventana.add(new SeparatorField()); _ventana.add(new SeparatorField()); this.add(_ventana); }catch(Exception e){ Dialog.alert("Excepción en clase vtnprincipal: " + e.toString()); } } //DIBUJAMOS EL MENU private void incMenu() { MenuItem.separator(30); mnubateria = new MenuItem("Bateria",40, 10) { public void run() { bateria(); } }; mnuestado = new MenuItem("Estado de Red", 50, 10) { public void run() { estado(); } }; mnuacerca = new MenuItem("Acerca de..", 60, 10) { public void run() { acerca(); } }; MenuItem.separator(70); }; // public void makeMenu(Menu menu, int instance) { if (!menu.isDisplayed()) { menu.deleteAll(); menu.add(MenuItem.separator(30)); menu.add(mnubateria); menu.add(mnuestado); menu.add(mnuacerca); menu.add(MenuItem.separator(60)); } } public void bateria(){ padre.vtnbateria.incventana(); padre.pushScreen(padre.vtnbateria); } public void estado(){ padre.vtnestado.incventana(); padre.pushScreen(padre.vtnestado); } public void acerca(){ padre.vtnacerca.incventana(); padre.pushScreen(padre.vtnacerca); } public boolean onClose(){ Dialog.alert("Hasta Luego"); System.exit(0); return true; } public double mmemoria(double x) { if ( x > 0 ) return Math.floor(x * 100) / 100; else return Math.ceil(x * 100) / 100; } }

  Read the article

• Why can final object be modified?

  - by Matt McCormick

  I came across the following code in a code base I am working on: public final class ConfigurationService { private static final ConfigurationService INSTANCE = new ConfigurationService(); private List providers; private ConfigurationService() { providers = new ArrayList(); } public static void addProvider(ConfigurationProvider provider) { INSTANCE.providers.add(provider); } ... INSTANCE is declared as final. Why can objects be added to INSTANCE? Shouldn't that invalidate the use of final. (It doesn't). I'm assuming the answer has to do something with pointers and memory but would like to know for sure.

  Read the article

• How do laziness and I/O work together in Haskell?

  - by Bill

  I'm trying to get a deeper understanding of laziness in Haskell. I was imagining the following snippet today: data Image = Image { name :: String, pixels :: String } image :: String -> IO Image image path = Image path <$> readFile path The appeal here is that I could simply create an Image instance and pass it around; if I need the image data it would be read lazily - if not, the time and memory cost of reading the file would be avoided: main = do image <- image "file" putStrLn $ length $ pixels image But is that how it actually works? How is laziness compatible with IO? Will readFile be called regardless of whether I access pixels image or will the runtime leave that thunk unevaluated if I never refer to it? If the image is indeed read lazily, then isn't it possible I/O actions could occur out of order? For example, what if immediately after calling image I delete the file? Now the putStrLn call will find nothing when it tries to read.

  Read the article

• Problem with SqlServer 2005 when opening connections

  - by Jose Obregon

  I have a Winforms application and I use EntLib to connect to a SQL Server 2005 DB. The application is working ok, but sometimes, and lately more often, we have started receiving this error from the db when opening the connection: A connection was successfully established with the server, but then an error occurred during the login process. (provider: Shared Memory Provider, error: 0 - No process is on the other end of the pipe.) (Microsoft SQL Server, Error: 233) The problem is intermittent. The user works well for a couple of hours and then suddenly the exception is thrown. Sometimes it happens when we run a small process that loads a file and then inserts the data to the db.

  Read the article

• Android OpenGl Renderer finish event

  - by Eu Vid

  In OpenGL Renderer onDrawFrame is called several time, until the page is completely rendered. I cannot find an event that my page is completeley rendered in order to take a snapshot of the OpenGL page and animate it. I have the solution to take snapshot on at the animation trigger (specific button), but this will imply a specific delay, until Bitmap is created, such as i would like to keep in memory a mutable copy of every page. Do you know other way to animate GLSurfaceView with rendered content? Snippet for triggering snapshot. glSurfaceView.queueEvent(new Runnable() { @Override public void run() { glSurfaceView.getRenderer().takeGlSnapshot(); } }); EGLContext for passing the GL11 object. public void takeGlSnapshot() { EGL10 egl = (EGL10) EGLContext.getEGL(); GL11 gl = (GL11) egl.eglGetCurrentContext().getGL(); takeSnapshot(gl); } onDrawFrame(Gl10 gl) { //is last call for this page event ????????????

  Read the article

• A cross between std::multimap and std::vector?

  - by Milan Babuškov

  I'm looking for a STL container that works like std::multimap, but has constant access time to random n-th element. I need this because I have such structure in memory that is std::multimap for many reasons, but items stored in it have to be presented to the user in a listbox. Since amount of data is huge, I'm using list box with virtual items (i.e. list control polls for value at line X). As a workaround I'm currently using additional std::vector to store "indexes" into std::map, and I fill it like this: std::vector<MMap::data_type&> vec; for (MMap::iterator it = mmap.begin(); it != mmap.end(); ++it) vec.push_back((*it).second); But this is not very elegant solution. Is there some such containter?

  Read the article

• How to prevent a globally overridden "new" operator from being linked in from external library

  - by mprudhom

  In our iPhone XCode 3.2.1 project, we're linking in 2 external static C++ libraries, libBlue.a and libGreen.a. libBlue.a globally overrides the "new" operator for it's own memory management. However, when we build our project, libGreen.a winds up using libBlue's new operator, which results in a crash (presumably because libBlue.a is making assumptions about the kinds of structures being allocated). Both libBlue.a and libGreen.a are provided by 3rd parties, so we can't change any of their source code or build options. When we remove libBlue.a from the project, libGreen.a doesn't have any issues. However, no amount of shuffling the linking order of the libraries seems to fix the problem, nor does any experimentation with the various linking flags. Is there some way to tell XCode to tell the linker to "have libGreen's use of the new operator use the standard C++ new operator rather than the one redefined by libBlue"?

  Read the article

• BigDecimal precision not persisted with javax.persistence annotations

  - by dkaczynski

  I am using the javax.persistence API and Hibernate to create annotations and persist entities and their attributes in an Oracle 11g Express database. I have the following attribute in an entity: @Column(precision = 12, scale = 9) private BigDecimal weightedScore; The goal is to persist a decimal value with a maximum of 12 digits and a maximum of 9 of those digits to the right of the decimal place. After calculating the weightedScore, the result is 0.1234, but once I commit the entity with the Oracle database, the value displays as 0.12. I can see this by either by using an EntityManager object to query the entry or by viewing it directly in the Oracle Application Express (Apex) interface in a web browser. How should I annotate my BigDecimal attribute so that the precision is persisted correctly? Note: We use an in-memory HSQL database to run our unit tests, and it does not experience the issue with the lack of precision, with or without the @Column annotation.

  Read the article

• How to serialize a collection of base type and see the concrete types in easy to read XML

  - by Jason Coyne

  I have a List which is populated with objects of various concrete types which subclass BaseType I am using the WCF DataContractSerializer <Children> <BaseType xmlns:d3p1="http://schemas.datacontract.org/2004/07/Tasks" i:type="d3p1:ConcreteTypeA"></BaseType> <BaseType xmlns:d3p1="http://schemas.datacontract.org/2004/07/Tasks" i:type="d3p1:ConcreteTypeB"></BaseType> </Children> Is there any way to get this to generate <Children> <ConcreteTypeA/> <ConcreteTypeB/> </Children> ? The real goal is to let users generate some XML to load into memory, and the users are of a skill level that asking them for the original XML is not going to be successful.

  Read the article

• Make compiler copy characters using movsd

  - by Suma

  I would like to copy a relatively short sequence of memory (less than 1 KB, typically 2-200 bytes) in a time critical function. The best code for this on CPU side seems to be rep movsd. However I somehow cannot make my compiler to generate this code. I hoped (and I vaguely remember seeing so) using memcpy would do this using compiler built-in instrinsic, but based on disassembly and debugging it seems compiler is using call to memcpy/memmove library implementation instead. I also hoped the compiler might be smart enough to recognize following loop and use rep movsd on its own, but it seems it does not. char *dst; const char *src; // ... for (int r=size; --r>=0; ) *dst++ = *src++; Is there some way to make the Visual Studio compiler to generate rep movsd sequence other than using inline assembly?

  Read the article

• The speed of .NET in numerical computing

  - by Yin Zhu

  In my experience, .net is 2 to 3 times slower than native code. (I implemented L-BFGS for multivariate optimization). I have traced the ads on stackoverflow to http://www.centerspace.net/products/ the speed is really amazing, the speed is close to native code. How can they do that? They said that: Q. Is NMath "pure" .NET? A. The answer depends somewhat on your definition of "pure .NET". NMath is written in C#, plus a small Managed C++ layer. For better performance of basic linear algebra operations, however, NMath does rely on the native Intel Math Kernel Library (included with NMath). But there are no COM components, no DLLs--just .NET assemblies. Also, all memory allocated in the Managed C++ layer and used by native code is allocated from the managed heap. Can someone explain more to me? Thanks!

  Read the article

• Processing potentially large STDIN data, more than once

  - by d11wtq

  I'd like to provide an accessor on a class that provides an NSInputStream for STDIN, which may be several hundred megabytes (or gigabytes, though unlikely, perhaps) of data. When I caller gets this NSInputStream it should be able to read from it without worrying about exhausting the data it contains. In other words, another block of code may request the NSInputStream and will expect to be able to read from it. Without first copying all of the data into an NSData object which (I assume) would cause memory exhaustion, what are my options for handling this? The returned NSInputStream does not have to be the same instance, it simply needs to provide the same data. The best I can come up with right now is to copy STDIN to a temporary file and then return NSInputStream instances using that file. Is this pretty much the only way to handle it? Is there anything I should be cautious of if I go the temporary file route?

  Read the article

• Copy Structure To Another Program

  - by Steven

  Long story, long: I am adding a web interface (ASPX.NET: VB) to a data acquisition system developed with LabVIEW which outputs raw data files. These raw data files are the binary representation of a LabVIEW cluster (essentially a structure). LabVIEW provides functions to instantiate a class or structure or call a method defined in a .NET DLL file. I plan to create a DLL file containing a structure definition and a class with methods to transfer the structure. When the webpage requests data, it would call a LabVIEW executable with a filename parameter. The LabVIEW code would instantiate the structure, populate the structure from the data file, then call the method to transfer the data back to the website. Long story, short: How do you recommend I transfer (copy) an instance of a structure from one .NET program to a VB.NET program? Ideas considered: sockets, temp file, xml file, config file, web services, CSV, some type of serialization, shared memory

  Read the article

• LNK1106 with big binary resource

  - by E Dominique

  I have a rather huge .dat-file (896MB) included as a BIN resource in my project. Now I get a LNK1106 link error ("fatal error LNK1106: invalid file or disk full: cannot seek to 0x382A3920".) I use Visual Studio 2005 under Windows XP, and have tried on a 4GB RAM machine with high Virtual Memory settings and lots of disk space. I have tried a number of different optimization flags, but to no avail. Does anyone have a clue? EDIT: I have narrowed it down to a specific size of the compiled resource. If the .res file is 544078588 bytes (about 518.9MB) or larger, the error occurs. If it is smaller it works just fine. Still no solution, though...

  Read the article

• On Windows XP, programmatically set Pagefile to "No Paging File" on single c: drive

  - by NBPC77

  I'm trying to write a C#/.NET application that optimizes the hard drives for our XP workstations Set pagefile to "No paging file" Reboot Run a defrag utility to optimize the data and apps Create a contiguous page file Reboot, run pagedefrag from Sysinternals I'm really struggling with #1. I delete the following key: SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PagingFiles Upon reboot, the System Control Panel shows "No page file", but c:\pagefile.sys still exists and its in use by the SYSTEM process so I can't delete it and I can't optimize HD. I tried using PendingFileRenamingOperations and that bombs out too. I tried using WMI: Win32_PageFileSetting, but that only lets you set sizes (not zero--defaults to 2MB). Of course, if I do the manual steps outlined above, it works. I think I need an API call to make this happen.

  Read the article

• SQL CE not loading from network share

  - by David Veeneman

  I installed VS 2010 RC yesterday, and suddenly, SQL Server CE isn't loading files from a network share. In projects compiled with VS 2008, if I try to open a SQL CE file located on a network share, I get an error that reads like this: Internal error: Cannot open the shared memory region. If I try to create a data connection in VS 2010 to a SQL CE file on a network share, I get this error: SQL Server Compact does not support opening database files on a network share. Can anyone shed any light on what's going on? Thanks.

  Read the article

< Previous Page | 457 458 459 460 461 462 463 464 465 466 467 468  | Next Page >