I've painfully learned during last few days a lot about programming in c++. I love it :) I know I should release memory - the golden "each malloc=free" or "each new=delete" rules exist now in my world, but I'm using them to rather simple objects. What about vector ? Wherever I can, I'm using vector.clear() but that clearly isn't enough, ...
I need some pointers on how to diagnose and fix this problem. I don't know if this is a simple server setup problem or an application design problem (or both). Once or twice every few months this Oracle XE database reports ORA-4031 errors. It doesn't point to any particular part of the sga consistently. A recent example is: ORA-04031: ...
I know that a language like Python does garbage collection for you, but for any applications/optimizations or even security, is it important to understand how memory management works? I am very familiar, but I am going to start teaching a student soon, and I'm curious to know whether that's something we should go over. Note: this questi...
In other languages you have a number of possibilities usually for memory reclamation: Mark objects and then remove them Explicit retain and release Count references to objects Internal heap disposition How does Ruby work? ...
I'm getting my feet wet in Objective-C and Cocoa (I know, probably late, but hey I have to start somewhere) and I noticed that all objects are allocated out of the heap. Is there any reason why this is the standard in Objective-C? I tried looked everywhere (and yes, even on StackOverflow), but I couldn't find any explicit reason, except...
Hello, I've been trying to use the time command /usr/bin/time to measure the peak memory consumption of a program on a linux system. Independently of what executable I experiment with, I get the correct answer for what regards running time, but memory usage figures are always 0. the typical output from time is something like: 8.68use...
I'm working on learning Objective-C, and I'm trying to get a feel for the memory management. I'm fairly familiar with C memory management, but I'm trying to figure out how different ObjC is. Let's say I have a class called Complex that is used for holding complex numbers, which has a method -(Complex*)add:(Complex*)c; that adds the pass...
[I've read the Lua manual, but it did not provide solid answers.] Let's say I have a Lua Table, acting as an indexed array: local myArray = {}; myArray[1] = "Foo"; myArray[2] = "Bar"; How do I best dispose of this Table? Do I just set myArray to nil? Or do I have to iterate through array and set each indexed element to nil? Simila...
I'm just starting to learn programming. And as of now, I know a tad bit of memory management in Objective-C. It wasn't easy learning it. So, just out of curiosity, is the memory management employed in major languages like C, C++, Java, etc., in any way similar to what I've learned? ...
I am a new Objective-C programmer coming from a C#, VB.NET, Etc. These are all garbage collected languages and for the most part the worst thing you can do is abuse memory usage, because when your program shuts down the memory is reclaimed by the runtime. However, I am not clear about Objective-C. I get that for the most part its up to ...
I'm building an iPhone application where I detach some threads to do long-running work in the background so as not to hang the UI. I understand that threads need NSAutoreleasePool instances for memory management. What I'm not sure about is if the threaded method calls another method - does that method also need an NSAutoreleasePool? Exa...
When using malloc and doing similar memory manipulation can I rely on sizeof( char ) being always 1? For example I need to allocate memory for N elements of type char. Is multiplying by sizeof( char ) necessary: char* buffer = malloc( N * sizeof( char ) ); or can I rely on sizeof( char ) always being 1 and just skip the multiplicatio...
What is the best way to tune a server application written in Java that uses a native C++ library? The environment is a 32-bit Windows machine with 4GB of RAM. The JDK is Sun 1.5.0_12. The Java process is given 1024MB of memory (-Xmx) at startup but I often see OutOfMemoryErrors due to lack of heap space. If the memory is increased to 1...
I am launching a java jar file which often requires more than the default 64MB max heap size. A 256MB heap size is sufficient for this app though. Is there anyway to specify (in the manifest maybe?) to always use a 256MB max heap size when launching the jar? (More specific details below, if needed.) This is a command-line app that ...
Callback* p = new Callback; func(p); If I want to delete the callback object, when and how to delete that? If it gets deleted early, then the callback may be failed. ...
I'd like to know how to find programmatically available memory in iPhone from Objective-C? ...
What are some of the technical differences between memory that is allocated with the new operator and memory that is allocated via a simple variable declaration, such as int var? Does c++ have any form of automatic memory management? In particular, I have a couple questions. First, since with dynamic memory you have to declare a pointer...
I have two classes, a class that handles db connectivity and an entity class. The db class has an instance method called GetEntityByID:(int)entity_id. This method does a simple select statement, and creates an Entity class instance using an init method. This works fine, however whoever calls GetEntityByID must remember to release it...
I've only used Java and Ruby for so long that I'm really not enjoying keeping track of my own memory again. It's not that I can't do it, I can. I just don't want to. Any special tricks, libraries, or anything else you've learned for dealing with memory in iApps, lay it on me here. ...
Windows API has a set of function for heap creation and handling: HeapCreate, HeapAlloc, HeapDestroy and etc. I wonder what is the use for another heap in a program? From fragmentation point of view, you will get external fragmentation where memory is not reused among heaps. So even if low-fragmentation heaps are used, stil there is a f...