Is there a way to find out what the maximum number of bytes available is when using malloc in c?
Or do you just have to do it and check errno and/or the pointer to see if you succeeded? ...
memory-management
Do you still trap memory allocation failures in your C++ program
I am writing some guidelines for the company and I need to answer some tough questions. This one is quite difficult. The solution can be: Not track at all. Make sure that objects are allocated using new which will throws an exception when allocation failed. The application will die, and it is not a big deal. PRO - code usually can be...
Region based memory management
I'm designing a high level language, and I want it to have the speed of C++ (it will use LLVM), but be safe and high level like C#. Garbage collection is slow, and new/delete is unsafe. I decided to try to use "region based memory management" (there are a few papers about it on the web, mostly for functional languages). The only "useful"...
Objective-C memory management--best practices when returning objects?
Suppose I have a function like this: - (NSSet *) someFunction { //code... return [[[NSSet alloc] initWithObjets:obj1, obj2, nil] autorelease]; } When I call this function, do I need to do retain/release the return value? I'm assuming I do. However, what if I don't do autorelease, so someFunction now looks like this: - (NSSet...
Patterns for freeing memory in C?
I'm currently working on a C based application am a bit stuck on freeing memory in a non-antipattern fashion. I am a memory-management amateur. My main problem is I declare memory structures in various different scopes, and these structures get passed around by reference to other functions. Some of those functions may throw errors and e...
How to release MPMoviePlayerController?
I have a couple of views that access the movie player. I've put the following code in a method in AppDelegate for these views. They send in the filename to play. The code works fine but I know a release is required somewhere. If I add the last line as a release or autorelease, the app will crash once the user presses done on the movi...
In copyWithZone:, should I use zone for all allocs or just for the returned object?
Suppose I have a class like this: @interface SomeClass : NSObject<NSCopying> { SomeOtherClass *obj; } In the definition of copyWithZone:, I do this: SomeClass *someCopy = [[SomeClass allocWithZone:zone] init]; So my question is, if I want to make a copy of obj, which of these is correct/recommended? option A: objCopy = [obj c...
Why is the destructor not called for the returned object from the function?
I was thinking that when a function returns an object on the stack to the calling function, the calling function gets a copy of the original object but the original object's destructor is called as soon as the stack unwinds. But in the following program, the destructor is getting called only once. I expected it to be called twice. #incl...
.NET Collections and the Large Object Heap (LOH)
Are .NET collections with large number of items apt to be stored in the LOH? I'm curious about List and Dictionary specifically. In my code, I store a large number (40k+) of relatively small objects (lets say 1k) in temporary Lists and Dictionarys for processing. Does the number of items in these collections increase the likelihood of b...
Memory Allocation Profiling in C++
I am writing an application and am surprised to see its total memory usage is already too high. I want to profile the dynamic memory usage of my application: How many objects of each kind are there in the heap, and which functions created these objects? Also, how much memory is used by each of the object? Is there a simple way to do thi...
Is it safe to store objects of a class which has an std::auto_ptr as its member variable in std::vector?
I can't use shared_ptr in my project, no boost :( So, I'm having a class roughly similar to the one below: class MyClass { private: std::auto_ptr<MyOtherClass> obj; }; Now, I want to store the instances of above class in std::vector. Is it safe? I've read here that it's wrong to use std::auto_ptr with STL containers. Does it apply ...
UITabBarController Memory management problem inside UINavigationController
I have to use a UITabBarController inside UINavigationController. Everything seems to be right, but if i log the dealloc calls of the tabs some strange thing happens. If I don't touch eanything just the back button, all dealloc of each tabs are called. If I switch to any other tab and than I tap the back button the dealloc of the first ...
Will an empty delegate eat up memory?
public sealed class FtpManager { public event EventHandler LoggingIn = delegate { }; private void OnLoggingIn(object sender, EventArgs e) { var handler = LoggingIn; handler(sender, e); } // ... } In the above code, I have initialized LoggingIn event handler with an empty delegate. Will that affect memory...
Using RSLs with Adobe AIR
Does anyone know how exactly RSLs work with AIR? I have a terminal server that runs several instances of a very large AIR application, which unfortunately has 100M RAM on startup and 200 after a bit of use. This is obviously not really workable, and I'm thinking that RSLs may be a solution if they're cached on the machine. However I have...
would this cause an memory leak in iPhone?
- (void)viewDidLoad { [super viewDidLoad]; landscape.image = [UIImage imageNamed:@"tenerife1.png"]; } I assign that new UIImage to the image property of an UIImageView object. I am not sure if that would result in an memory leak? ...
Where are the best explanations of memory management for iPhone?
I am looking for good explanations out there. I have a 1000 pages book about objective-c, but unfortunately the part about memory management, retain counting, is described pretty bad and hard to understand. ...
How to help java tomcat processes to regain used memory?
We are running an web application that is using Java 64bit 5 gigs of -Xmx of maximum heap size. We have no control over the java code. We can only tweak configuration parameters. The situation that we are facing is that the java processes after it takes the full heap allocated at start up, it starts acting very responding very slow to...
safe way of allocating memory for a list node
In a simple list, ex : struct Node { Node *next; void *data; } is there any problem if i allocate Node and Data in a single allocation (provided i know the size), like Node * t = (Node*)malloc(sizeof(Node) + DataSize)); and always assign data at the end of allocated chunk, t->data = (BYTE*)t+ sizeof(Node); /* BYTE...
Alloca implementation
How does one implement alloca() using inline x86 assembler in languages like D, C, and C++? I want to create a slightly modified version of it, but first I need to know how the standard version is implemented. Reading the disassembly from compilers doesn't help because they perform so many optimizations, and I just want the canonical f...
NSArray with Custom Objects in NSTableDataSource
I am trying to make NSTableDataSource compatible object and give this object to NSTableView as DataSource, however when table tries to display data, it crashes. @interface NSArrayDataSource : NSObject{ NSArray* internalArray; } -(id) initWithArray: (NSArray*) objects; -(int)numberOfRowsInTableView:(NSTableView *)aTableView; -(id)ta...