Search Results

Search found 12872 results on 515 pages for 'memory alignment'.

Page 391/515 | < Previous Page | 387 388 389 390 391 392 393 394 395 396 397 398  | Next Page >

  • How can I ensure that a Java object (containing cryptographic material) is zeroized?

    - by Jeremy Powell
    My concern is that cryptographic keys and secrets that are managed by the garbage collector may be copied and moved around in memory without zeroization. As a possible solution, is it enough to: public class Key { private char[] key; // ... protected void finalize() throws Throwable { try { for(int k = 0; k < key.length; k++) { key[k] = '\0'; } } catch (Exception e) { //... } finally { super.finalize(); } } // ... }

    Read the article

  • Are there any Python reference counting/garbage collection gotchas when dealing with C code?

    - by Jason Baker
    Just for the sheer heck of it, I've decided to create a Scheme binding to libpython so you can embed Python in Scheme programs. I'm already able to call into Python's C API, but I haven't really thought about memory management. The way mzscheme's FFI works is that I can call a function, and if that function returns a pointer to a PyObject, then I can have it automatically increment the reference count. Then, I can register a finalizer that will decrement the reference count when the Scheme object gets garbage collected. I've looked at the documentation for reference counting, and don't see any problems with this at first glance (although it may be sub-optimal in some cases). Are there any gotchas I'm missing? Also, I'm having trouble making heads or tails of the cyclic garbage collector documentation. What things will I need to bear in mind here? In particular, how do I make Python aware that I have a reference to something so it doesn't collect it while I'm still using it?

    Read the article

  • What interprocess locking calls should I monitor?

    - by Matt Joiner
    I'm monitoring a process with strace/ltrace in the hope to find and intercept a call that checks, and potentially activates some kind of globally shared lock. While I've dealt with and read about several forms of interprocess locking on Linux before, I'm drawing a blank on what to calls to look for. Currently my only suspect is futex() which comes up very early on in the process' execution. Update0 There is some confusion about what I'm after. I'm monitoring an existing process for calls to persistent interprocess memory or equivalent. I'd like to know what system and library calls to look for. I have no intention call these myself, so naturally futex() will come up, I'm sure many libraries will implement their locking calls in terms of this, etc. Update1 I'd like a list of function names or a link to documentation, that I should monitor at the ltrace and strace levels (and specifying which). Any other good advice about how to track and locate the global lock in mind would be great.

    Read the article

  • Find Loding performance of the Website

    - by pandora
    How to find the site performance, there is a tools like YSLOW, Speed traker in google that shows the speed of the website. I have done a php project on LMS with Zend Framework, Everything is in live. When user post contents for a subject that may be size 200K and submitted to the server takes too slow. Sometime server may get DOWN. I login to server(PUTTY) and checked i found that there is more resource occupied in my server. It uses full memory on the server. When i cleared the resource the site loads well. Site is in Dedicated server with 3 more domains with 4GB Ram. Because of this LMS website all the website gets down. I need to check what is wrong in my website. How do i Start?

    Read the article

  • dangling pointer, reason for value change after free()?

    - by Aman Jain
    In the following code segment, after free(x), why does y becomes 0? As per my understanding, the memory in the heap that was being pointed to by x, and is still being pointed by y, hasn't been allocated to someone else, so how can it change to 0? And moreover, I don't think it is free(x) that changed it to 0. Any comments? #include <stdio.h> int main ( int argc, char *argv[] ) { int *y = NULL; int *x = NULL; x = malloc(4); *x = 5; y = x; printf("[%d]\n", *y); //prints 5 free(x); printf("[%d]\n", *y); //why doesn't print 5?, prints 0 instead return 0; }

    Read the article

  • Why is autorelease especially dangerous/expensive for iPhone applications?

    - by e.James
    I'm looking for a primary source (or a really good explanation) to back up the claim that the use of autorelease is dangerous or overly expensive when writing software for the iPhone. Several developers make this claim, and I have even heard that Apple does not recommend it, but I have not been able to turn up any concrete sources to back it up. SO references: autorelease-iphone Why does this create a memory leak (iPhone)? Note: I can see, from a conceptual point of view, that autorelease is slightly more expensive than a simple call to release, but I don't think that small penalty is enough to make Apple recommend against it. What's the real story?

    Read the article

  • What are some best practices for making sure your .NET code will scale well?

    - by billmaya
    Last week I interviewed for a position at a TripleA MMORPG game company here in NE. I didn't get the job but one of the areas that came up during the interview was the about the scalability of the code that you write and how it should be considered early on in the design of your architecture and classes. Sadly to say I've never thought very much about the scalability of the .NET code that I've written (I work with single user desktop and mobile applications and our major concerns are usually with device memory and rates of data transmission). I'm interested in learning more about writing code that scales up well so it can handle a wide range of remote users in a client server environment, specifically MMORPGs. Are there any books, web sites, best practices, etc. that could get me started researching this topic?

    Read the article

  • Is there any kind of standard for 8086 multiprocessing?

    - by Earlz
    Back when I made an 8086 emulator I noticed that there was the LOCK prefix intended for synchonization in a multiprocessor environment. Yet the only multitasking I know of for the x86 arch. involves use of the APIC which didn't come around until either the Pentiums or 486s. Was there any kind of standard for 8086 multitasking or was it done by some manufacturer specific extensions to the instruction set and/or special ports? By standard, I mean things like: How do you separate the 2 processors if they both use the same memory? This is impossible without some kind of way to make each processor execute a different piece of code. (or cause an interrupt on only one processor)

    Read the article

  • can QuickGraph support these requirements? (includes database persistence support)

    - by Greg
    Hi, Would QuickGraph be able to help me out with my requirements below? (a) want to model a graph of nodes and directional relationships between nodes - for example to model web pages/files linked under a URL, or modeling IT infrastructure and dependencies between hardware/software. The library would include methods such as * Node.GetDirectParents() //i.e. there could be more than one direct parent for a node * Node.GetRootParents() //i.e. traverse the tree to the top root parent(s) for the given node * Node.GetDirectChildren() * Node.GetAllChildren() (b) have to persist the data to a database - so it should support SQL Server and ideally SQLite as well. If it does support these requirement then I'd love to hear: any pointers to any parts of QuickGraph to dig into? what is the best concept re it's usage in terms of how to use database persistence - is it a simpler design to assume every search/method works directly on the database, or does QuickGraph support smarts to be able to work in memory and the "save" to database all changes at an appropriate point in time (e.g. like ADO.net does with DataTable etc) Thanks in advance

    Read the article

  • Worths to spend $100 to create a browser based game ?

    - by coolboycsaba
    I'm creating a browser based games and I've calculated that it will cost me something like $100 for the domain name and the host. The game uses almost no resources (bandwidth, space, memory). The problem is that I don't know how to find the players, and how many players I need to get a profit. I`m planning to use BuySellAds and Google Adsense. I think the game is pretty good, but I think I will have just a little amount of unique visitors, because each player is counted as unique only once. So what do you think, it will worth ?

    Read the article

  • Interface Builder only allows one button to be "touchable"

    - by STLMikey
    I'm making a clone of the classic game simon, the memory matching game. My (iPad) app will load fine, i tap start, the game screen loads, and only one of my four buttons will respond to touch commands. To troubleshoot, I tried creating a second unrelated nib and just populating it with four buttons not linked to anything. However, only one of those four buttons would respond to touch! There are no IBActions being called, nothing. Both the view itself, and all four buttons are touch enabled in the inspector...I'm stumped. I'm moreso asking if anyone has encountered anything simillar, as I'd rather not burden potential help with app-specific questions if it's avoidable. Thank you!

    Read the article

  • Add C pointer to NSMutableArray

    - by Georges Oates Larsen
    I am writing an Objective-C program that deals with low level image memory. I am using ANSI-C structs for my data storage -- Full blown objects seem overkill seeing as the data I am storing is 100% data, with no methods to operate on that data. Specifically, I am writing a customizable posterization algorithm which relies on an array of colors -- This is where things get tricky. I am storing my colors as structs of three floats, and an integer flag (related to the posterization algorithm specifically). Everyhting is going well, except for one thing... [actual question] I can't figure out how to add pointers to an NSMutableArray! I know how to add an object, but adding a pointer to a struct seems to be more difficult -- I do not want NSMutableArray dereferencing my pointer and treating the struct as some sort of strange object. I want NSMutableArray to add the pointer its self to its collection. How do I go about doing this? Thanks in advance, G

    Read the article

  • Browser back button broken between hidden div's

    - by Linda
    First of all, these pages will never be on the web but will be in internal memory. They are a group of linked documents---an ebook. http://www.anmldr.com/testdivs When I click on the link in the first div, the second div becomes visible and the first div is hidden. The problem is with the browser's back button. If you then click on the back button, the URL updates but the first div does not show again. How can I correct the back button so that the first div shows? The link from the second div to the first div works fine but it is the browser back button that I do not know how to work with. Thanks, Linda P.S. These are using CSS3 so it is better to use a WebKit based browser.

    Read the article

  • Clone LINQ To SQL object Extension Method throws object dispose exception....

    - by gtas
    Hello all, I have this extension method for cloning my LINQ To SQL objects: public static T CloneObjectGraph<T>(this T obj) where T : class { var serializer = new DataContractSerializer(typeof(T), null, int.MaxValue, false, true, null); using (var ms = new System.IO.MemoryStream()) { serializer.WriteObject(ms, obj); ms.Position = 0; return (T)serializer.ReadObject(ms); } } But while i carry objects with not all references loaded, while qyuerying with DataLoadOptions, sometimes it throws the object disposed exception, but thing is I don't ask for references that is not loaded (null). e.g. I have Customer with many references and i just need to carry on memory the Address reference EntityRef< and i don't Load anything else. But while i clone the object this exception forces me to load all the EntitySet< references with the Customer object, which might be too much and slow down the application speed. Any suggestions?

    Read the article

  • Algorithms for modern hardware?

    - by Jurily
    Once again, I find myself with a set of broken assumptions. The article itself is about a 10x performance gain by modifying a proven-optimal algorithm to account for virtual memory: What good is an O(log2(n)) algorithm if those operations cause page faults and slow disk operations? For most relevant datasets an O(n) or even an O(n^2) algorithm, which avoids page faults, will run circles around it. Are there more such algorithms around? Should we re-examine all those fundamental building blocks of our education? What else do I need to watch out for when writing my own?

    Read the article

  • How do I implement something like pointers in javascript?

    - by Shaun
    I know that javascript doesn't have pointers in terms of a variable referring to a place in memory but what I have is a number of variables which are subject to change and dependent on each other. For example: Center (x,y) = (offsetLeft + width/scale , offsetTop + height/scale) As of now I have rewritten the equation in terms of each individual variable and after any changes I call the appropriate update function. For example: If scale changes, then then the center, height, and width stay the same. So I call updateoffset() { offsetLeft = centerx - width/scale; offsetTop = centery - height/scale; } Is this the easiest way to update each of these variables when any of them changes?

    Read the article

  • How to force programs out of swap file when a resources-intensive batch finishes?

    - by sharptooth
    We use employees' desktops for CPU-intensive simulation during the night. Desktops run Windows - usually Windows XP. Employees don't log off, they just lock the desktops, switch off their monitors and go. Every employee has a configuration file which he can edit to specify when he is most likely out of office. When that time comes a background program grabs data for simulation from the server, spawns worker processes, watches them, gets results and sends them to the server. When the time specified by the employee elapses simulation stops so that normal desktop usage is not interfered. The problem is that simuation consumes a lot of memory, so when the worker processes run they force other programs into the swap file. So when the employee comes all the programs he left are luggish and slow until he opens them one by one so that they are unswapped. Is there a way the program can force other programs out of swap file when it stops simulation so that they again run smoothly?

    Read the article

  • ASP.NET application stopping event?

    - by Barguast
    I have a ASP.NET application which implements a custom in-memory cache. I'm using this as opposed to ASP.NET's caching mechanism as I needed a more complex way to handle what to drop from the cache. Part of this custom cache is a separate thread which occasionally searches for data to drop from the cache whenever it gets too large. What I need to do is signal this cache maintenance thread to stop whenever the ASP.NET application 'exits'. I guess this basically amounts to when the web site is stopped in IIS. Is there a pre-existing event I can utilise to do this? Thanks.

    Read the article

  • Screen scraping C application without using OCR or DOM?

    - by Mrgreen
    We have a legacy system that is essentially a glorified telnet interface. We cannot use an alternative telnet client program to connect to the system since there are special features built into the client software they have provided us. I want to be able to screen scrape from this program, however that's proving very difficult. I have tried using WindowSpy and Spy++ to check the window text and it comes up blank. It's a custom C program written by the vendor (they have even disabled selecting text). I'm really looking for a free option and something I may perhaps be able to use in conjuction with a scripting language. It seems the only ways to grab text is directly from the Windows GDI or from memory, but that seems a little extreme. Can anyone recommend any software/DLLs that might be able to accomplish this? I'd be extremely appreciative.

    Read the article

  • C inline assembly of x96 fbstp instruction

    - by David HUnter
    Was wondering how to inline a usage of fbstp on a 32 bit I86 architecture. I tried something like int main( ) { double foo = 100.0; long bar = 0; asm( "pushl %1; fbstp %0" : "=m"(bar) : "r"(foo) ); ... But bar is unchanged. I have tried reading everything I can find on this but most example simply do things like add two integers together. I can’t find any that talk about pushing operands onto the stack and what I should be doing when an instruction like fbstp writes 80 bits of data back to memory ( i.e. what C type to use ) and how to specify it in the asm syntax. Also on x86-64 there seems to be a pushq and no pushl but fbstp still exists whereas fbstq does not. Is there some other magic for 64 bit.

    Read the article

  • Is it OK to pass SQLCommand as a parameter?

    - by TooFat
    I have a Business Layer that passes a Conn string and a SQLCommand to a Data Layer like so public void PopulateLocalData() { System.Data.SqlClient.SqlCommand cmd = new System.Data.SqlClient.SqlCommand(); cmd.CommandType = System.Data.CommandType.StoredProcedure; cmd.CommandText = "usp_PopulateServiceSurveyLocal"; DataLayer.DataProvider.ExecSQL(ConnString, cmd); } The DataLayer then just executes the sql like so public static int ExecSQL(string sqlConnString, System.Data.SqlClient.SqlCommand cmd) { int rowsAffected; using (SqlConnection conn = new SqlConnection(sqlConnString)) { conn.Open(); cmd.Connection = conn; rowsAffected = cmd.ExecuteNonQuery(); cmd.Dispose(); } return rowsAffected; } Is it OK for me to pass the SQLCommand as a parameter like this or is there a better more accepted way of doing it. One of my concerns is if an error occurs when executing the query the cmd.dispose line will never execute. Does that mean it will continue to use up memory that will never be released?

    Read the article

  • JavaME FileConnection url

    - by Trimack
    Hi there, I want to save data to my Sony Ericsson K750i. I know the phone implements FileConnection version 1.0. The list of roots taken from FileSystemRegistry.listRoots(); returns single element named "c:/". I want to save a file.txt just about anywhere, but preferably to the memory stick attached. Unfortunately, it doesn't seem to work. It throws an IOException without any message. I tried opening the fileconnection on numerous roots like c:/, C:/, /, ./, root1/, SDCard/, CFCard/, MemoryStick/ and perhaps some more but without any luck. The exception is thrown right after this line for any of those roots: FileConnection filecon = (FileConnection) Connector.open("file:///MemoryStick/file.txt"); Please, what URL should i use?

    Read the article

  • Why might different computers calculate different arithmetic results in VB.NET?

    - by Eyal
    I have some software written in VB.NET that performs a lot of calculations, mostly extracting jpegs to bitmaps and computing calculations on the pixels like convolutions and matrix multiplication. Different computers are giving me different results despite having identical inputs. What might be the reason? Edit: I can't provide the algorithm because it's proprietary but I can provide all the relevant operations: ULong \ ULong (Turuncating division) Bitmap.Load("filename.bmp') (Load a bitmap into memory) Bitmap.GetPixel(Integer, Integer) (Get a pixel's brightness) Double + Double Double * Double Math.Sqrt(Double) Math.PI Math.Cos(Double) ULong - ULong ULong * ULong ULong << ULong List.OrderBy(Of Double)(Func) Hmm... Is it possible that OrderBy is using a non-stable QuickSort and that QuickSort is using a random pivot? Edit: Just tested, nope. The sort is stable.

    Read the article

  • how come we need not close the handle returned by ShellExecute ?

    - by fred-hh
    On success, ShellExecute returns a handle. Do we need to close this handle, and if so, how ? According to examples published my Microsoft, we need not close this handle. But the doc of ShellExecute itself is mute on the subject. Can you confirm we indeed do not need to close this handle ? But then, how can a handle be valid and in no need of being closed ??? Which of the following statements is/are true: the handle is invalid and we can't do anything with it; the handle is never freed and there is a (Microsoft-sponsored) memory leak (until the caller program ends); the handle is automatically freed by the system at some time and never reused afterwards (- another kind of resource leak). Only on trying to use it can we know whether it still points to something. what else ?

    Read the article

  • Tips for a successful AppStore submission?

    - by Andrew Grant
    In a day or two I'll be ready to submit my iPhone app to the AppStore and I'm curious whether people who have gone through this process have any tips / suggestions for a smooth submission process. Here's things I've covered; No memory leaks Tested performance on an actual device Doesn't crash :) Using correct certificates / profile What I'm a little unsure about are how to configure the "Bundle Display Name" /"Bundle Identifier" and "Bundle Name" in info.plist. I understand the first is the text that's shown on the iPhone itself, but what about the last? Does this have to match Bundle Identifier? Are there any other things I should add to the info.plist? I've noticed that when built for Adhoc distribution my app does not have any author/title information in iTunes.

    Read the article

< Previous Page | 387 388 389 390 391 392 393 394 395 396 397 398  | Next Page >