Search Results

Search found 23084 results on 924 pages for 'jeff main'.

Page 771/924 | < Previous Page | 767 768 769 770 771 772 773 774 775 776 777 778  | Next Page >

• Beginner error in CUDA

  - by Dimitri

  Hi folks, first all i want to wish you a merry christmas. I am writing a small program in CUDA and i have the following errors : contraste.cu(167): error: calling a host function from a __device__/__global__ function is not allowed I don't understand why. Can you please help me and show me my errors. It seems that my program is correct. Here is a the bunch of code causing the problems : __global__ void kernel_contraste(float power, unsigned char tab_in[], unsigned char tab_out[], int nbl, int nbc) { int x = threadIdx.x; printf("I am the thread %d\n", x); } Part of my main program : unsigned char *dimg, *dimg_res; ..... cudaMalloc((void **)dimg, h * w * sizeof(char)); cudaMemcpy(dimg, r.data, h*w*sizeof(char), cudaMemcpyHostToDevice); cudaMalloc((void **)dimg_res, h*w*sizeof(char)); dim3 nbThreadparBloc(256); dim3 numblocs(1); kernel_contraste<<<numblocs, nbThreadparBloc >>>(puissance, dimg, dimg_res, h, w); cudaThreadSynchronize(); ..... cudaFree(dimg); cudaFree(dimg_res); The line 167 is the line where i call the printf in function kernel_contraste. For information, this program takes an image as an input( a sun Rasterfile ) and a power then it calculates the contraste of that image. Thanks !!

  Read the article

• Memory increases with Java UDP Server

  - by Trevor

  I have a simple UDP server that creates a new thread for processing incoming data. While testing it by sending about 100 packets/second I notice that it's memory usage continues to increase. Is there any leak evident from my code below? Here is the code for the server. public class UDPServer { public static void main(String[] args) { UDPServer server = new UDPServer(15001); server.start(); } private int port; public UDPServer(int port) { this.port = port; } public void start() { try { DatagramSocket ss = new DatagramSocket(this.port); while(true) { byte[] data = new byte[1412]; DatagramPacket receivePacket = new DatagramPacket(data, data.length); ss.receive(receivePacket); new DataHandler(receivePacket.getData()).start(); } } catch (IOException e) { e.printStackTrace(); } } } Here is the code for the new thread that processes the data. For now, the run() method doesn't do anything. public class DataHandler extends Thread { private byte[] data; public DataHandler(byte[] data) { this.data = data; } @Override public void run() { System.out.println("run"); } }

  Read the article

• Would there be a market for this idea (cross platform VM for iPhone OS)

  - by Tzury Bar Yochay

  For a long time I wondered if the following idea worth a nickel or just a waste of time and energy. I am willing to start a project which will provide a kind of a VM for all iPxxx apps - so developed once for iPxxx can run on a Macbook, iMac, Linux, Android and windows (desktop and mobile). You get the idea, right? I want to do to the current iPhone SDK, the same as what Mono did to Microsoft .Net and perhaps a more complete set of implementation. I tend to believe that if overnight all apps on appstore become available on the android market as well that would be a mini revolution. Think about running iPad apps on every tablet that will come out to the market in the future. Wouldn't it be fantastic to all the developers, which from now on, can write once and sell everywhere? The main questions which I ask myself repeatedly is: "Is This Legal?" - I mean, say I have done this, would apple's lawyers will start sending me all kinds of nasty emails? I am willing to hear your opinion about this idea as well as if some of you willing and able to join forces and start this open source project.

  Read the article

• LINQ - 'Could not translate expression' with previously used and proven query condition

  - by tomfumb

  I am fairly new to LINQ and can't get my head around some inconsistency in behaviour. Any knowledgeable input would be much appreciated. I see similar issues on SO and elsewhere but they don't seem to help. I have a very simple setup - a company table and an addresses table. Each company can have 0 or more addresses, and if 0 one must be specified as the main address. I'm trying to handle the cases where there are 0 addresses, using an outer join and altering the select statement accordingly. Please note I'm currently binding the output straight to a GridView so I would like to keep all processing within the query. The following DOES work IQueryable query = from comp in context.Companies join addr in context.Addresses on comp.CompanyID equals addr.CompanyID into outer // outer join companies to addresses table to include companies with no address from addr in outer.DefaultIfEmpty() where (addr.IsMain == null ? true : addr.IsMain) == true // if a company has no address ensure it is not ruled out by the IsMain condition - default to true if null select new { comp.CompanyID, comp.Name, AddressID = (addr.AddressID == null ? -1 : addr.AddressID), // use -1 to represent a company that has no addresses MainAddress = String.Format("{0}, {1}, {2} {3} ({4})", addr.Address1, addr.City, addr.Region, addr.PostalCode, addr.Country) }; but this displays an empty address in the GridView as ", , ()" So I updated the MainAddress field to be MainAddress = (addr.AddressID == null ? "" : String.Format("{0}, {1}, {2} {3} ({4})", addr.Address1, addr.City, addr.Region, addr.PostalCode, addr.Country)) and now I'm getting the Could not translate expression error and a bunch of spewey auto-generated code in the error which means very little to me. The condition I added to MainAddress is no different to the working condition on AddressID, so can anybody tell me what's going on here? Any help greatly appreciated.

  Read the article

• C++ Problem: Class Promotion using derived class

  - by Michael Fitzpatrick

  I have a class for Float32 that is derived from Float32_base class Float32_base { public: // Constructors Float32_base(float x) : value(x) {}; Float32_base(void) : value(0) {}; operator float32(void) {return value;}; Float32_base operator =(float x) {value = x; return *this;}; Float32_base operator +(float x) const { return value + x;}; protected: float value; } class Float32 : public Float32_base { public: float Tad() { return value + .01; } } int main() { Float32 x, y, z; x = 1; y = 2; // WILL NOT COMPILE! z = (x + y).Tad(); // COMPILES OK z = ((Float32)(x + y)).Tad(); } The issue is that the + operator returns a Float32_base and Tad() is not in that class. But 'x' and 'y' are Float32's. Is there a way that I can get the code in the first line to compile without having to resort to a typecast like I did on the next line?

  Read the article

• Generics in a bidirectional association

  - by Verhoevenv

  Let's say I have two classes A and B, with B a subtype of A. This is only part of a richer type hierarchy, obviously, but I don't think that's relevant. Assume A is the root of the hierarchy. There is a collection class C that keeps track of a list of A's. However, I want to make C generic, so that it is possible to make an instance that only keeps B's and won't accept A's. class A(val c: C[A]) { c.addEntry(this) } class B(c: C[A]) extends A(c) class C[T <: A]{ val entries = new ArrayBuffer[T]() def addEntry(e: T) { entries += e } } object Generic { def main(args : Array[String]) { val c = new C[B]() new B(c) } } The code above obviously give the error 'type mismatch: found C[B], required C[A]' on the new B(c) line. I'm not sure how this can be fixed. It's not possible to make C covariant in T (like C[+T <: A]) because the ArrayBuffer is non-variantly typed in T. It's not possible to make the constructor of B require a C[B] because C can't be covariant. Am I barking up the wrong tree here? I'm a complete Scala newbie, so any ideas and tips might be helpful. Thank you! EDIT: Basically, what I'd like to have is that the compiler accepts both val c = new C[B]() new B(c) and val c = new C[A]() new B(c) but would reject val c = new C[B]() new A(c) It's probably possible to relax the typing of the ArrayBuffer in C to be A instead of T, and thus in the addEntry method as well, if that helps.

  Read the article

• Retrieve nested list from XDocument with LINQ

  - by twreid

  Ok I want my link query to return a list of users. Below is the XML <section type="Users"> <User type="WorkerProcessUser"> <default property="UserName" value="Main"/> <default property="Password" value=""/> <default property="Description" value=""/> <default property="Group" value=""/> </User> <User type="AnonymousUser"> <default property="UserName" value="Second"/> <default property="Password" value=""/> <default property="Description" value=""/> <default property="Group" value=""/> </User> </section> And my current LINQ Query that doesn't work. doc is an XDocument var users = (from iis in doc.Descendants("section") where iis.Attribute("type").Value == "Users" from user in iis.Elements("User") from prop in user.Descendants("default") select new { Type = user.Attribute("type").Value, UserName = prop.Attribute("UserName").Value }); This does not work can anyone tell me what I need to fix? Here is my second attempt after fixing for the wrong property name. However this one does not seem to enumerate the UserName value for me when I try to use it or at least when I try to write it to the console. Also this returns 8 total results I should only have 2 results as I only have 2 users. (from iis in doc.Descendants("section") where iis.Attribute("type").Value == "Users" from user in iis.Elements("User") from prop in user.Descendants("default") select new { Type = user.Attribute("type").Value, UserName = (from name in prop.Attributes("property") where name.Value == "UserName" select name.NextAttribute.Value).ToString() });

  Read the article

• Does jquery live slow down websites?

  - by chobo2

  Hi I have a problem I am using jquery U.I tabs that load everything with ajax. Now I have it right now everytime you click on a tab a partial view is loaded up into that tab. Now in this partial view their are javascript files that use jquery to bind all the events that are needed in that tab plus some jquery plugins I am using. Now every time that tab is loaded up all those scripts are loaded up. If it is clicked 10 times then those scripts are loaded 10times up meaing now each of say my buttons will now have 10 of the same events on it mean if someone clicks on that button 10 events will all fire off to and do the same thing. So I need to find some solution to either move all the script out and have it on the main page and use jquery.live or some other solution. I tried to do use jquery caching for the U.I tabs but this won't work since some things in say Tab A when changed effect Tab B meaning I need Tab B to be reloaded but the scripts can't reload otherwise I run into the same problem as now.

  Read the article

• How to construct objects based on XML code?

  - by the_drow

  I have XML files that are representation of a portion of HTML code. Those XML files also have widget declarations. Example XML file: <message id="msg"> <p> <Widget name="foo" type="SomeComplexWidget" attribute="value"> inner text here, sets another attribute or inserts another widget to the tree if needed... </Widget> </p> </message> I have a main Widget class that all of my widgets inherit from. The question is how would I create it? Here are my options: Create a compile time tool that will parse the XML file and create the necessary code to bind the widgets to the needed objects. Advantages: No extra run-time overhead induced to the system. It's easy to bind setters. Disadvantages: Adds another step to the build chain. Hard to maintain as every widget in the system should be added to the parser. Use of macros to bind the widgets. Complex code Find a method to register all widgets into a factory automatically. Advantages: All of the binding is done completely automatically. Easier to maintain then option 1 as every new widget will only need to call a WidgetFactory method that registers it. Disadvantages: No idea how to bind setters without introducing a maintainability nightmare. Adds memory and run-time overhead. Complex code What do you think is better? Can you guys suggest a better solution?

  Read the article

• Overlaying several CLR reference fields with each other in explicit struct?

  - by thr

  Edit: I'm well aware of that this works very well with value types, my specific question is about using this for reference types. I've been tinkering around with structs in .NET/C#, and I just found out that you can do this: using System; using System.Runtime.InteropServices; namespace ConsoleApplication1 { class Foo { } class Bar { } [StructLayout(LayoutKind.Explicit)] struct Overlaid { [FieldOffset(0)] public object AsObject; [FieldOffset(0)] public Foo AsFoo; [FieldOffset(0)] public Bar AsBar; } class Program { static void Main(string[] args) { var overlaid = new Overlaid(); overlaid.AsObject = new Bar(); Console.WriteLine(overlaid.AsBar); overlaid.AsObject = new Foo(); Console.WriteLine(overlaid.AsFoo); Console.ReadLine(); } } } Basically circumventing having to do dynamic casting during runtime by using a struct that has an explicit field layout and then accessing the object inside as it's correct type. Now my question is: Can this lead to memory leaks somehow, or any other undefined behavior inside the CLR? Or is this a fully supported convention that is usable without any issues? I'm aware that this is one of the darker corners of the CLR, and that this technique is only a viable option in very few specific cases.

  Read the article

• Memory allocation patterns in C++

  - by Mahatma

  I am confused about the memory allocation in C++ in terms of the memory areas such as Const data area, Stack, Heap, Freestore, Heap and Global/Static area. I would like to understand the memory allocation pattern in the following snippet. Can anyone help me to understand this. If there any thing more apart from the variable types mentioned in the example to help understand the concept better please alter the example. class FooBar { int n; //Stored in stack? public: int pubVar; //stored in stack? void foo(int param) //param stored in stack { int *pp = new int; //int is allocated on heap. n = param; static int nStat; //Stored in static area of memory int nLoc; //stored in stack? string str = "mystring"; //stored in stack? .. if(CONDITION) { static int nSIf; //stored in static area of memory int loopvar; //stored in stack .. } } } int main(int) { Foobar bar; //bar stored in stack? or a part of it? Foobar *pBar; //pBar is stored in stack pBar = new Foobar(); //the object is created in heap? What part of the object is stored on heap } EDIT: What confuses me is, if pBar = new Foobar(); stores the object on the heap, how come int nLoc; and int pubVar;, that are components of the object stored on stack? Sounds contradictory to me. Shouldn't the lifetime of pubvar and pBar be the same?

  Read the article

• Looking forward to a programming future but confused where to start.

  - by Kraivyne

  Hi there, I am very new to this site and to programming. I started doing some basic programming with python a few weeks ago and recently, messing around with Java basics. My main problem is that I am completely overwhelmed and haven't got the slightest clue where I should be starting. I want to learn programming because I really enjoy doing it, the simple applications that I have managed to conjure up put a smile on my face. My plan is to eventually (by eventually I'm talking about 6 years+) go into games programming. I have been informed that C++ is the best way to go about this but haven't got the slightest clue what book/sight is optimal for someone who is still learning the very basics. These are my questions: I have been to the Definitive C++ Book Guide but am still unsure which book is best to start of with. Should I stick with Python or Java instead of moving on to C++? Is there any advice you would give to a beginner programmer? Thanks again for all your help.

  Read the article

• Why should I prefer OSGi Services over exported packages?

  - by Jens

  Hi, I am trying to get my head around OSGi Services. The main question I keep asking myself is: What's the benefit of using services instead of working with bundles and their exported packages? As far as I know it seems the concept of Late Binding has something to do with it. Bundle dependencies are wired together at bundle start, so they are pretty fixed I guess. But with services it seems to be almost the same. A bundle starts and registers services or binds to services. Of course services can come and go whenever they want and you have to keep track of these chances. But the core idea doesn't seem that different to me. Another aspect to this seems to be that services are more flexible. There could be many implementations for one specific Interface. On the other hand there can be a lot of different implementations for a specific exported package too. In another text I read that the disadvantage of using exported packages is that they make the application more fragile than services. The author wrote that if you remove one bundle from the dependency graph other dependencies would no longer be met, thus possibly causing a domino effect on the whole graph. But couldn't the same happen if a service would go offline? To me it looks like service dependencies are no better than bundle dependencies. So far I could not find a blog post, book or presentation that could clearly describe why services are better than just exposing functionality by exporting and importing packages. To sum my questions up: What are the key benefits of using OSGi Services that make them superior to exporting and importing packages?

  Read the article

• help me to parse JSON value using JSONTouch

  - by EquinoX

  I have the following json: http://www.adityaherlambang.me/webservice.php?user=2&num=10&format=json I would like to get all the name in this data by the following code, but it gives an error. How can I fix it? NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding]; NSDictionary *results = [responseString JSONValue]; NSDictionary *users = [results objectForKey:@"users"] objectForKey:@"user"]; for (NSDictionary *user in users){ //NSLog(@"key:%@, value:%@", user, [user objectForKey:user]); NSString *title = [users objectForKey:@"NAME"]; NSLog(@"%@", title); } Error: 2011-01-29 00:18:50.386 NeighborMe[7763:207] -[__NSArrayM objectForKey:]: unrecognized selector sent to instance 0xb618840 2011-01-29 00:18:50.388 NeighborMe[7763:207] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSArrayM objectForKey:]: unrecognized selector sent to instance 0xb618840' *** Call stack at first throw: ( 0 CoreFoundation 0x027d9b99 __exceptionPreprocess + 185 1 libobjc.A.dylib 0x0292940e objc_exception_throw + 47 2 CoreFoundation 0x027db6ab -[NSObject(NSObject) doesNotRecognizeSelector:] + 187 3 CoreFoundation 0x0274b2b6 ___forwarding___ + 966 4 CoreFoundation 0x0274ae72 _CF_forwarding_prep_0 + 50 5 NeighborMe 0x0000bd75 -[NeighborListViewController connectionDidFinishLoading:] + 226 6 Foundation 0x0007cb96 -[NSURLConnection(NSURLConnectionReallyInternal) sendDidFinishLoading] + 108 7 Foundation 0x0007caef _NSURLConnectionDidFinishLoading + 133 8 CFNetwork 0x02d8d72f _ZN19URLConnectionClient23_clientDidFinishLoadingEPNS_26ClientConnectionEventQueueE + 285 9 CFNetwork 0x02e58fcf _ZN19URLConnectionClient26ClientConnectionEventQueue33processAllEventsAndConsumePayloadEP20XConnectionEventInfoI12XClientEvent18XClientEventParamsEl + 389 10 CFNetwork 0x02e5944b _ZN19URLConnectionClient26ClientConnectionEventQueue33processAllEventsAndConsumePayloadEP20XConnectionEventInfoI12XClientEvent18XClientEventParamsEl + 1537 11 CFNetwork 0x02d82968 _ZN19URLConnectionClient13processEventsEv + 100 12 CFNetwork 0x02d827e5 _ZN17MultiplexerSource7performEv + 251 13 CoreFoundation 0x027bafaf __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 15 14 CoreFoundation 0x0271939b __CFRunLoopDoSources0 + 571 15 CoreFoundation 0x02718896 __CFRunLoopRun + 470 16 CoreFoundation 0x02718350 CFRunLoopRunSpecific + 208 17 CoreFoundation 0x02718271 CFRunLoopRunInMode + 97 18 GraphicsServices 0x030b800c GSEventRunModal + 217 19 GraphicsServices 0x030b80d1 GSEventRun + 115 20 UIKit 0x002e9af2 UIApplicationMain + 1160 21 NeighborMe 0x00001c34 main + 102 22 NeighborMe 0x00001bc5 start + 53 23 ??? 0x00000001 0x0 + 1 ) terminate called after throwing an instance of 'NSException' I really just wanted to be able to iterate through the names

  Read the article

• What is the fastest way to insert 100 000 records from one database to another?

  - by Pentium10

  I have a mobile application. My client has a large data set ~100.000 records. It's updated frequently. When we sync we need to copy from one database to another. I have attached the second database to the main, and run an insert into table select * from sync.table. This is extremely slow, it takes about 10 minutes I think. I noticed that the journal file gets increased step by step. How can I speed this up? EDITED 1 I have indexes off, and I have journal off. Using insert into table select * from sync.table it still takes 10 minutes. EDITED 2 If I run a query like select id,invitem,invid,cost from inventory where itemtype = 1 order by invitem limit 50 it takes 15-20 seconds. The table schema is: CREATE TABLE inventory ('id' INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, 'serverid' INTEGER NOT NULL DEFAULT 0, 'itemtype' INTEGER NOT NULL DEFAULT 0, 'invitem' VARCHAR, 'instock' FLOAT NOT NULL DEFAULT 0, 'cost' FLOAT NOT NULL DEFAULT 0, 'invid' VARCHAR, 'categoryid' INTEGER DEFAULT 0, 'pdacategoryid' INTEGER DEFAULT 0, 'notes' VARCHAR, 'threshold' INTEGER NOT NULL DEFAULT 0, 'ordered' INTEGER NOT NULL DEFAULT 0, 'supplier' VARCHAR, 'markup' FLOAT NOT NULL DEFAULT 0, 'taxfree' INTEGER NOT NULL DEFAULT 0, 'dirty' INTEGER NOT NULL DEFAULT 1, 'username' VARCHAR, 'version' INTEGER NOT NULL DEFAULT 15 ) Indexes are created like CREATE INDEX idx_inventory_categoryid ON inventory (pdacategoryid); CREATE INDEX idx_inventory_invitem ON inventory (invitem); CREATE INDEX idx_inventory_itemtype ON inventory (itemtype); I am wondering, the insert into ... select * from isn't the fastest built-in way to do massive data copy? EDITED 3 SQLite is serverless, so please stop voting a particular answer, because that is not the answer I'm sure.

  Read the article

• Mongodb, linq driver. How to construct Contains with variable or statements

  - by Syska

  I'm using the LINQ Driver for C#, works great. Sorting a lot of properties but heres a problem I can't solve, its probebly simple. var identifierList = new []{"10", "20", "30"}; var newList = list.Where(x => identifierList.Contains(x.Identifier)); This is NOT supported ... So I could do something like: var newList = list.Where(x => x.Identifier == "10" || x.Identifier == "20" || x.Identifier == "30"); But since the list is variable ... how do I construct the above? Or are there even better alternatives? The list is of type IQueryable<MyCustomClass> For information ... this is used as a filter of alot of properties. In SQL I could have a parent - child relationship. But as I can't as the parent for the main ID I need to take all the ID's out and then construct it like this. Hopes this makes sense. If needed I will explain more.

  Read the article

• What's the steps for SQL optimization and changes without reflect live system ?

  - by Space Cracker

  we have a big portal that build using SharePoint 2007 , asp.net 3.5 , SQL Server 2005 .. many developers work in it since 01/2008 and we are now doing huge analysis for current SQL Databases [not share-point DB ] to optimize and enhance it. The main db have about 330 table and 1720 stored procedure (SP) created from 01/2008 till now Many table names / Columns is very long and we want to short it we found SP names is written in 25 format :( , some of them are very complex and also we want to rename many SP parameters need to be renamed one of the biggest table is Registered user table, that will be spitted in more than one table for some optimization, many columns name will be changed I searched for the way that i can rename table names ,columns and i found SQL refactor tool but i still trying it .. my questions : Is SQl Refactor is the best tool for renaming ? or is there any other one ? if i want to make it manually, is there any references or best practice for that ? How can i do such changes in fast and stable way .. i search for recommendations and case studies if exist ?

  Read the article

• Any workarounds for non-static member array initialization?

  - by TomiJ

  In C++, it's not possible to initialize array members in the initialization list, thus member objects should have default constructors and they should be properly initialized in the constructor. Is there any (reasonable) workaround for this apart from not using arrays? [Anything that can be initialized using only the initialization list is in our application far preferable to using the constructor, as that data can be allocated and initialized by the compiler and linker, and every CPU clock cycle counts, even before main. However, it is not always possible to have a default constructor for every class, and besides, reinitializing the data again in the constructor rather defeats the purpose anyway.] E.g. I'd like to have something like this (but this one doesn't work): class OtherClass { private: int data; public: OtherClass(int i) : data(i) {}; // No default constructor! }; class Foo { private: OtherClass inst[3]; // Array size fixed and known ahead of time. public: Foo(...) : inst[0](0), inst[1](1), inst[2](2) {}; }; The only workaround I'm aware of is the non-array one: class Foo { private: OtherClass inst0; OtherClass inst1; OtherClass inst2; OtherClass *inst[3]; public: Foo(...) : inst0(0), inst1(1), inst2(2) { inst[0]=&inst0; inst[1]=&inst1; inst[2]=&inst2; }; }; Edit: It should be stressed that OtherClass has no default constructor, and that it is very desirable to have the linker be able to allocate any memory needed (one or more static instances of Foo will be created), using the heap is essentially verboten. I've updated the examples above to highlight the first point.

  Read the article

• Interview question: C program to sort a binary array in O(n)

  - by Zacky112

  I've comeup with the following program to do it, but it does not seem to work and goes into infinite loop. Its working is similar to quicksort. int main() { int arr[] = {1,1,0,1,0,0,0,1,0,1,0,1,0,1,0,1,0,1}; int N = 18; int *front, *last; front = arr; last = arr + N; while(front <= last) { while( (front < last) && (*front == 0) ) front++; while( (front < last) && (*last == 1) ) last--; if( front < last) { int temp = *front; *front = *last; *last = temp; front ++; last--; } } for(int i=0;i<N;i++) printf("%d ",arr[i]); return 0; }

  Read the article

• Core Data Errors vs Exceptions Part 3

  - by John Gallagher

  My question is similar to this one. Background I'm creating a large number of objects in a core data store using NSOperations to speed things up. I've followed all the Core Data multithreading rules - I've got a single persistent store coordinator and a managed object context per thread that on save is merging back to the main managed object context. The Problem When the number of threads running at once is more than 1, I get the exception logged on save of my core data store: NSExceptionHandler has recorded the following exception: NSInternalInconsistencyException -- optimistic locking failure What I've Tried My code that creates new entities is quite complex - it makes entities that have relationships with other entities that could be being created in a separate thread. If I replace my object creation routine with some very simple code just making non-related entries, everything works perfectly. Initially, as well as the exceptions, I was getting a save error saying core data couldn't save due to the merge failing. I read the docs and realised I needed a merge policy on the Managed Object Context I was saving to. I set this up and as this question states, the save error goes away, but the exception remains. My Question Do I need to worry about these exceptions? If I do need to get rid of the exceptions, any ideas on how I do it?

  Read the article

• Binary Search Tree, cannot do traversal

  - by ihm

  Please see BST codes below. It only outputs "5". what did I do wrong? #include <iostream> class bst { public: bst(const int& numb) : root(new node(numb)) {} void insert(const int& numb) { root->insert(new node(numb), root); } void inorder() { root->inorder(root); } private: class node { public: node(const int& numb) : left(NULL), right(NULL) { value = numb; } void insert(node* insertion, node* position) { if (position == NULL) position = insertion; else if (insertion->value > position->value) insert(insertion, position->right); else if (insertion->value < position->value) insert(insertion, position->left); } void inorder(node* tree) { if (tree == NULL) return; inorder(tree->left); std::cout << tree->value << std::endl; inorder(tree->right); } private: node* left; node* right; int value; }; node* root; }; int main() { bst tree(5); tree.insert(4); tree.insert(2); tree.insert(10); tree.insert(14); tree.inorder(); return 0; }

  Read the article

• Followed the official android documentations but still could not use SQLite in app

  - by user366539

  My DBHelper class public class DBHelper extends SQLiteOpenHelper { public DBHelper(Context context) { super(context,"SIMPLE_DB",null,1); } @Override public void onCreate(SQLiteDatabase db) { db.execSQL("CREATE TABLE SIMPLE_TABLE ( " + "ID INTEGER PRIMARY KEY " + "DESC TEXT);"); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { } } Activity class public class SimpleDatabase extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); DBHelper dbHelper = new DBHelper(this); SQLiteDatabase db = dbHelper.getReadableDatabase(); db.execSQL("INSERT INTO SIMPLE_TABLE VALUES (NULL, 'test');"); Cursor cursor = db.rawQuery("SELECT * FROM SIMPLE_TABLE", null); TextView text = (TextView)findViewById(R.id.textbox); text.setText(cursor.getString(0)); } } I figure it crashed (application has stopped unexpectedly!) at SQLiteDatabase db = ... because if I commented the code out from there to the end then it worked fine. But I have no idea whatsoever why it does that. Any help would be appreciated.

  Read the article

• creating a vector with references to some of the elements of another vector

  - by memC

  hi, I have stored instances of class A in a std:vector, vec_A as vec_A.push_back(A(i)). The code is shown below. Now, I want to store references some of the instances of class A (in vec_A) in another vector or another array. For example, if the A.getNumber() returns 4, 7, 2 , I want to put a reference to that instance of A in another vector, say std:vector<A*> filtered_A or an array. Can someone sow me how to do this?? Thanks! class A { public: int getNumber(); A(int val); ~A(){}; private: int num; }; A::A(int val){ num = val; }; int A::getNumber(){ return num; }; int main(){ int i =0; int num; std::vector<A> vec_A; for ( i = 0; i < 10; i++){ vec_A.push_back(A(i)); } std::cout << "\nPress RETURN to continue..."; std::cin.get(); return 0; }

  Read the article

• How to achieve to following C++ output formatting?

  - by Yan Cheng CHEOK

  I wish to print out double as the following rules : 1) No scietific notation 2) Maximum decimal point is 3 3) No trailing 0. For example : 0.01 formated to "0.01" 2.123411 formatted to "2.123" 2.11 formatted to "2.11" 2.1 formatted to "2.1" 0 formatted to "0" By using .precision(3) and std::fixed, I can only achieve rule 1) and rule 2), but not rule 3) 0.01 formated to "0.010" 2.123411 formatted to "2.123" 2.11 formatted to "2.110" 2.1 formatted to "2.100" 0 formatted to "0" Code example is as bellow : #include <iostream> int main() { std::cout.precision(3); std::cout << std::fixed << 0.01 << std::endl; std::cout << std::fixed << 2.123411 << std::endl; std::cout << std::fixed << 2.11 << std::endl; std::cout << std::fixed << 2.1 << std::endl; std::cout << std::fixed << 0 << std::endl; getchar(); } any idea?

  Read the article

• c++ STL vector is not acccepting the copy constructor

  - by prabhakaran

  I wrote a code ( c++,visual studio 2010) which is having a vector, even I though copy const is declared, but is still showing that copy const is not declared Here the code #include<iostream> #include<vector> using namespace std; class A { public: A(){cout << "Default A is acting" << endl ;} A(A &a){cout << "Copy Constructor of A is acting" << endl ;} }; int main() { A a; A b=a; vector<A> nothing; nothing.push_back(a); int n; cin >> n; } The error I got is Error 1 error C2558: class 'A' : no copy constructor available or copy constructor is declared 'explicit' c:\program files\microsoft visual studio 10.0\vc\include\xmemory 48 1 delete Anybody please help me

  Read the article

< Previous Page | 767 768 769 770 771 772 773 774 775 776 777 778  | Next Page >