Search Results

Search found 12281 results on 492 pages for 'memory fences'.

Page 53/492 | < Previous Page | 49 50 51 52 53 54 55 56 57 58 59 60  | Next Page >

  • multiple C++ deletion of a memory pointed by multiple objects

    - by elgcom
    Another c++ pointer deletion question is in the following example: class Foo { public: int *p; ~Foo() { delete p; p = NULL; } }; Foo *f1 = new Foo(); Foo *f2 = new Foo(); f1->p = new int(1); f2->p = f1->p; delete f2; // ok delete f1; // no error? Why I did not get error when calling "delete f1"? didn't I delete the same address (*p) twice? If I directly delete the pointers in the last 2 lines of code, I will get error. delete f2->p; // ok delete f1->p; // error!! *** glibc detected *** double free or corruption (fasttop) ***

    Read the article

  • Implicit Memory Barriers

    - by foo
    let's say i have variables A, B and C that two threads (T1, T2) share. i have the following code: //T1 //~~ A = 1; B = 1; C = 1; InterlockedExchange(ref Foo, 1); //T2 (executes AFTER T1 calls InterlockedExchange) //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ InterlockedExchange(ref Bar, 1); WriteLine(A); WriteLine(B); WriteLine(C); Question: does calling InterlockedExchange (implicit full fence) on T1 and T2, gurentess that T2 will "See" the write done by T1 before the fence? (A, B and C variables), even though those variables are not plance on the same cache-line as Foo and Bar?

    Read the article

  • Is there a memory leak here?

    - by TheLearner
    Please see my comments in code: -(id)initWithCoordinate:(CLLocationCoordinate2D)c title:(NSString *)t { [super init]; coordinate = c; NSDate *today = [NSDate date]; NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init]; [dateFormatter setDateStyle:NSDateFormatterLongStyle]; NSString* formattedDate = [NSString stringWithFormat:@"%@ %@", [dateFormatter stringFromDate:today], t]; [self setTitle:formattedDate]; //Why does the app crash when I try and release formattedDate? I have after all passed its reference to the title property? [dateFormatter release]; //I need to release the dateformatter because I have finished using it and I have not passed on a reference to it return self; }

    Read the article

  • android low memory issue

    - by Faisal khan
    1.Start Andorid app in my app there are 10 screens i navigate b/w the screens after that i press home button my app goes on the background now i play with other applications which cause system to run GC press home button select my app come back to my app when i press back button it throws exception and crashes. any idea for quick fix ?

    Read the article

  • How are two-dimensional arrays formatted in memory?

    - by Chris Cooper
    In C, I know I can dynamically allocate a two-dimensional array on the heap using the following code: int** someNumbers = malloc(arrayRows*sizeof(int*)); for (i = 0; i < arrayRows; i++) { someNumbers[i] = malloc(arrayColumns*sizeof(int)); } Clearly, this actually creates a one-dimensional array of pointers to a bunch of separate one-dimensional arrays of integers, and "The System" can figure you what I mean when I ask for: someNumbers[4][2]; But when I statically declare a 2D array, as in the following line...: int someNumbers[ARRAY_ROWS][ARRAY_COLUMNS]; ...does a similar structure get created on the stack, or is it of another form completely? (i.e. is it a 1D array of pointers? If not, what is it, and how do references to it get figured out?) Also, when I said, "The System," what is actually responsible for figuring that out? The kernel? Or does the C compiler sort it out while compiling?

    Read the article

  • has anyone produced an in-memory GIT repository?

    - by Andrew Matthews
    I would like to be able to take advantage of the benefits of GIT (and its workflows), but without the cost of disk access - I just would like to leverage the distributed revision control capabilities of GIT to produce something like a hybrid of memcached and GIT. (preferably in .NET) Is there such a beast out there?

    Read the article

  • Custom UIButton Memory Management in dealloc

    - by ddawber
    I am hoping to clarify the processes going on here. I have created a subclass of UIButton whose init method looks like this: - (id)initWithTitle:(NSString *)title frame:(CGRect)btnFrame { self = [UIButton buttonWithType:UIButtonTypeCustom]; [self setTitle:title forState:UIControlStateNormal]; self.frame = btnFrame; return self; } In my view controller I am creating one of these buttons and adding it as a subview: myButton = [[CustomButton alloc] initWithTitle:@"Title" frame:someFrame]; [self.view addSubview:myButton]; In the view controller's dealloc method I log the retain count of my button: - (void)dealloc { NSLog(@"RC: %d", [myButton retainCount]); //RC = 2 [super dealloc]; NSLog(@"RC: %d", [myButton retainCount]); //RC = 1 } The way I understand it, myButton is not actually retained, even though I invoked it using alloc, because in my subclass I created an autorelease button (using buttonWithType:). In dealloc, does this mean that, when dealloc is called the superview releases the button and its retain count goes down to 1? The button has not yet been autoreleased? Or do I need to get that retain count down to zero after calling [super dealloc]? Cheers.

    Read the article

  • How to debug memory allocation issues?

    - by amitabh
    Hi I am writing an iPhone app that that is trying to create a second a view when the user clicks on an element in UITableView. The code looks like ReplyToViewController *reply = [[ReplyToViewController alloc] initWithNibName:@"ReplyTo" bundle:nil]; reply.delegate = self; Message *message = [resultData objectAtIndex:indexPath.row]; int dbid = [message.bizid intValue]; NSLog(@"dbid=%d",dbid); reply.currentMessage = message; reply.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal; [self presentModalViewController:reply animated:YES]; The reply object gets created properly and the view is proper. Last line in above code segment calls some framework code which eventually calls the viewDidLoad method of the ReplyToViewController. Address of the reply object in the above code and the address of the object in viewDidLoad is not same. Any idea where this new object is coming from? How do I debug? I also added init method the following method in ReplyToViewController hoping that it will get called and I can find who is creating this new object. But it does not stop in this method. Any help will be greatly appreciated. - (id) init { /* first initialize the base class */ self = [super init]; return self; } // Following gets called from the 1st code segment. - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil { if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) { // Custom initialization } return self; } - (void)viewDidLoad { [super viewDidLoad]; NSLog(currentMessage.text]; // THIS returns nil and the program fails later in the code. }

    Read the article

  • Copy a function in memory and execute it

    - by Elinghton
    Hi everybody, I would like to know how in C in can copy the content of a function into memroy and the execute it? I'm trying to do something like this: typedef void(*FUN)(int *); char * myNewFunc; char *allocExecutablePages (int pages) { template = (char *) valloc (getpagesize () * pages); if (mprotect (template, getpagesize (), PROT_READ|PROT_EXEC|PROT_WRITE) == -1) { perror ("mprotect"); } } void f1 (int *v) { *v = 10; } // allocate enough spcae but how much ?? myNewFunc = allocExecutablePages(...) /* Copy f1 somewere else * (how? assume that i know the size of f1 having done a (nm -S foo.o)) */ ((FUN)template)(&val); printf("%i",val); Thanks for your answers

    Read the article

  • What things must I know about OpenAL memory management?

    - by mystify
    I am playing sound with OpenAL, and it seems to increase memory footprint dramatically for every little sound I play. It seems that OpenAL never frees memory itself and that playing a Source causes memory footprint to grow. I couldn't find any good resources about OpenAL memory management, but I bet I must do a lot of stuff myself. Maybe someone knows a ressource for that?

    Read the article

  • Android -- Object Creation/Memory Allocation vs. Performance

    - by borg17of20
    Hello all, This is probably an easy one. I have about 20 TextViews/ImageViews in my current project that I access like this: ((TextView)multiLayout.findViewById(R.id.GameBoard_Multi_Answer1_Text)).setText(""); //or ((ImageView)multiLayout.findViewById(R.id.GameBoard_Multi_Answer1_Right)).setVisibility(View.INVISIBLE); My question is this, am I better off, from a performance standpoint, just assigning these object variables? Further, am I losing some performance to the constant "search" process that goes on as a part of the findViewById(...) method? (i.e. Does findsViewById(...) use some sort of hashtable/hashmap for look-ups or does it implement an iterative search over the view hierarchy?) At present, my program never uses more than 2.5MB of RAM, so will assigning 20 or so more object variables drastically affect this? I don't think so, but I figured I'd ask. Thanks.

    Read the article

  • Memory allocation for a matrix in C

    - by Snogzvwtr
    Why is the following code resulting in Segmentation fault? (I'm trying to create two matrices of the same size, one with static and the other with dynamic allocation) #include <stdio.h> #include <stdlib.h> //Segmentation fault! int main(){ #define X 5000 #define Y 6000 int i; int a[X][Y]; int** b = (int**) malloc(sizeof(int*) * X); for(i=0; i<X; i++){ b[i] = malloc (sizeof(int) * Y); } } Weirdly enough, if I comment out one of the matrix definitions, the code runs fine. Like this: #include <stdio.h> #include <stdlib.h> //No Segmentation fault! int main(){ #define X 5000 #define Y 6000 int i; //int a[X][Y]; int** b = (int**) malloc(sizeof(int*) * X); for(i=0; i<X; i++){ b[i] = malloc (sizeof(int) * Y); } } or #include <stdio.h> #include <stdlib.h> //No Segmentation fault! int main(){ #define X 5000 #define Y 6000 int i; int a[X][Y]; //int** b = (int**) malloc(sizeof(int*) * X); //for(i=0; i<X; i++){ // b[i] = malloc (sizeof(int) * Y); //} } I'm running gcc on Linux on a 32-bit machine.

    Read the article

  • iphone memory management: alloc and retain properties.

    - by Jonathan
    According to the docs, you do one release per alloc or retain (etc) However what about when using retain propertys? eg: HEADER @property(retain)UIView *someView; IMPLEMENTATION /*in some method*/ UIView *tempView = [[UIView alloc] init]; //<<<<<ALLOC - retain count = +1 [tempView setBackgroundColor:[UIColor redColor]]; self.someView = tempView; ///<<<<<RETAIN - retain count = +2 [tempView release]; ///should I do this? or a different version of the IMPLEMENTATION self.someView = [[UIView alloc] init]; //<<<<<ALLOC & RETAIN - retain count = +2 //now what??? [self.someView release]; ???? EDIT: I didn't make it clear, but I meant what to do in both circumstances, not just the first.

    Read the article

  • iPhone memory management: a release after setting self.someProperty = nil

    - by ddawber
    I am reading the LazyTableImages code that Apple have released and they do something to this effect (in an NSOperation subclass): - (void)dealloc { [myProperty release]; [myProperty2 release]; } - (void)main { // // Parse operation undertaken here // self.myProperty = nil; self.myProperty2 = nil; } My thinking is that they do this in case dealloc is called before setting properties to nil. Is my thinking correct here? Are the releases unnecessary, as self.myProperty = nil effectively releases myProperty? One thing I have noticed in this code is that they don't release all retained objects in dealloc, only some of them, which is really the cause for my confusion. Cheers

    Read the article

  • C - fork() and sharing memory

    - by Ben
    I need my parent and child process to both be able to read and write the same variable (of type int) so it is "global" between the two processes. I'm assuming this would use some sort of cross-process communication and have one variable on one process being updated. I did a quick google and IPC and various techniques come up but I don't know which is the most suitable for my situation. So what technique is best and could you provide a link to a noobs tutorial for it. Thanks.

    Read the article

  • Simple Obj-C Memory Management Question

    - by yar
    This is from some sample code from a book // On launch, create a basic window - (void)applicationDidFinishLaunching:(UIApplication *)application { UIWindow *window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]; UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:[[HelloController alloc] init]]; [window addSubview:nav.view]; [window makeKeyAndVisible]; } But a release is never called for window nor for nav. Release should be called since alloc was called, right? If #1 is right, then I would need to store a reference to each of these in an instance variable in order to release them in the dealloc? Perhaps I'm wrong all around...

    Read the article

  • Memory Management iOS dev app doesn't work after a few detail items

    - by user1434846
    I am working on a project with a tableView controller and the detail views contains CMMotionManager.When i open 5 or 6 detailViews all goes well,but after a while the app goes slow and finally crashes.On instruments the only leak is on main.m , also i must say that I'm using ARC and i can't dealloc or realese the instances. Here is the code: First the table view: - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib. self.title = @"Movement";//Master View Controller title bar UIImage *image = [UIImage imageNamed:@"jg_navibar.png"]; [self.navigationController.navigationBar setBackgroundImage:image forBarMetrics:UIBarMetricsDefault]; //Init the array with data bodypartsMutableArray = [NSMutableArray arrayWithCapacity:26]; BodypartData *part1 = [[BodypartData alloc] init]; part1.bodypartname = @"Shoulder"; part1.movementname = @"Flexion"; part1.fullimageStartingPosition=[UIImage imageNamed:@"2_shoulder_flexion_end_position.jpg"]; part1.fullimageEndedPosition=[UIImage imageNamed:@"2_shoulder_flexion_end_position.jpg"]; part1.thumbimage=[UIImage imageNamed:@"1_shoulder_flexion_landmarks_thumb.jpg"]; [bodypartsMutableArray addObject:part1]; ......... } then the cell: - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"MyBasicCell"]; BodypartData *part = [self.bodypartsMutableArray objectAtIndex:indexPath.row]; cell.textLabel.text =[NSString stringWithFormat:part.movementname]; cell.detailTextLabel.text =[NSString stringWithFormat:part.bodypartname]; cell.imageView.image =part.thumbimage; return cell; } and the the detailViewdid load: - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib. // Init motionManager object and set the Update Interval _motionManager = [[CMMotionManager alloc]init]; _motionManager.deviceMotionUpdateInterval=1/60; //60 Hz [_motionManager startGyroUpdates]; if (_motionManager.gyroAvailable) { _motionManager.gyroUpdateInterval = 1.0/60.0; [_motionManager startDeviceMotionUpdatesToQueue:[NSOperationQueue currentQueue] withHandler: ^(CMDeviceMotion *motion, NSError *error) { CMAttitude *attitude = motion.attitude; //Calculation with rotationMatrix m11 = [NSString stringWithFormat:@"%.02f", attitude.rotationMatrix.m11]; m12 = [NSString stringWithFormat:@"%.02f", attitude.rotationMatrix.m12]; m13 = [NSString stringWithFormat:@"%.02f", attitude.rotationMatrix.m13]; ......... }

    Read the article

  • how does memory stacks work in javascript

    - by user227353
    When we have code like: function a(){ var x =0; this.add=function(){ alert(x++); } } var test = new a(); test.add(); // alert 0 test.add(); // alert 1 test.add(); // alert 2 How does this work? Doesn't that the value of 'x' in a() should be 'gone' as soon as test = new a() is complete? The stack contains x should also be gone as well, right? Or, does javascript always keep all the stacks ever created in case they will be referenced in future? But that wouldn't be nice, would it...?

    Read the article

  • iphone: memory problems after refactor

    - by agilpwc
    I had a NIB with several view controllers in it. I modified the code and used Interface Builder decomose interface to get all the view controllers in their own Nib. But now with empty core data database, I'm getting "message sent to deallocated instance" errors. Here is the code flow: From the RootViewController this is called: if (self.dogController == nil) { DogViewController *controller = [[DogViewController alloc] initWithNibName:@"DogViewController" bundle:nil]; self.dogController = controller; [controller release]; } self.dogController.managedObjectContext = self.managedObjectContext; [self.navigationController pushViewController:self.dogController animated:YES]; Then in a dogController a button is pressed to insert a new object and the following code is excuted and the error hits on the save, according to the trace NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext]; NSEntityDescription *entity = [[self.fetchedResultsController fetchRequest] entity]; NSManagedObject *newManagedObject = [NSEntityDescription insertNewObjectForEntityForName:[entity name] inManagedObjectContext:context]; // If appropriate, configure the new managed object. [newManagedObject setValue:[NSDate date] forKey:@"birthDate"]; [newManagedObject setValue:@"-" forKey:@"callName"]; // Save the context. NSError *error = nil; if (![context save:&error]) { Then the error produced in the console is * -[JudgeViewController numberOfSectionsInTableView:]: message sent to deallocated instance 0x598e580 I'm racking my brain for hours and I can't figure out where my minor changes made something messed up. Any ideas?

    Read the article

  • memory management objective c - returning objects from methods

    - by geeth
    Hi, Please clarify, how to deal with returned objects from methods? Below, I get employee details from GeEmployeetData function with autorelease, 1. Do I have to retain the returned object in Process method? 2. Can I release *emp in Process fucntion? -(void) Process { Employee *emp = [self GeEmployeetData] } +(Employee*) GeEmployeetData{ Employee *emp = [[Employee alloc]init]; //fill entity return [emp autorelease]; }

    Read the article

  • Question about memory usage

    - by sudo rm -rf
    Hi there. I have the following method: +(NSMutableDictionary *)getTime:(float)lat :(float)lon { NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; NSMutableDictionary *dictionary = [[NSMutableDictionary alloc] init]; [dictionary setObject:hour forKey:@"hour"]; [dictionary setObject:minute forKey:@"minute"]; [dictionary setObject:ampm forKey:@"ampm"]; return dictionary; } A lot of the method is chopped off, so I think I need the pool for some other stuff in the method. Here's my question. I know that I need to release the following objects: [dictionary release]; [pool release]; However, I can't release the dictionary before I return it, but as soon as I return it the rest of the method isn't performed. What should I do?

    Read the article

< Previous Page | 49 50 51 52 53 54 55 56 57 58 59 60  | Next Page >