Memory refers to the physical devices used to store programs or data on a temporary or permanent basis for use in a computer or other digital electronic device.

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63
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5answers
104k views

Stack and Heap memory in Java

As I understand, in Java, stack memory holds primitives and method invocations and heap memory is used to store objects. Suppose I have a class class A { int a ; String b; ...
30
votes
1answer
923 views

Performance of single-assignment ADT oriented code on modern CPUs

Working in immutable data with single assignments has the obvious effect of requiring more memory, one would presume, because you're constantly creating new values (though compilers under the covers ...
5
votes
2answers
922 views

Foreach loop and variable initialization

Is there a difference between these two versions of code? foreach (var thing in things) { int i = thing.number; // code using 'i' // pay no attention to the uselessness of 'i' } int ...
5
votes
6answers
2k views

Addressable memory unit

From Wikipedia: the term endian or endianness refers to the ordering of individually addressable sub-components within a longer data item as stored in external memory (or, sometimes, as ...
42
votes
6answers
15k views

Why is CPU cache memory so fast?

What makes CPU cache memory so much faster than main memory? I can see some benefit in a tiered cache system. It makes sense that a smaller cache is faster to search. But there must be more to it.
13
votes
2answers
918 views

How important it is to fix memory leaks?

I found by Valgring that some GTK+ programs leaks memory. How important it is to fix those leaks? I mean, often those programs works very well but on the other hand, one can never be sure if one wants ...
7
votes
3answers
4k views

Methods to share memory or state across JVMs?

This is long question I know. I have a few options for what I want. I don't want to know "this is obviously the best," but maybe any pros or cons I may be missing about the options, as well as any ...
25
votes
8answers
4k views

Is it possible to statically predict when to deallocate memory---from source code only?

Memory (and resource locks) are returned to the OS at deterministic points during a program's execution. The control flow of a program by itself is enough to know where, for sure, a given resource can ...
13
votes
11answers
2k views

Could it be more efficient for systems in general to do away with Stacks and just use Heap for memory management?

It seems to me that everything that can be done with a stack can be done with the heap, but not everything that can be done with the heap can be done with the stack. Is that correct? Then for ...
20
votes
3answers
2k views

Why are C string literals read-only?

What advantage(s) of string literals being read-only justify(-ies/-ied) the: Yet another way to shoot yourself in the foot char *foo = "bar"; foo[0] = 'd'; /* SEGFAULT */ Inability to elegantly ...
19
votes
4answers
5k views

Is it possible to read memory from another program by allocating all the empty space on a system?

Theoretically, if I were to build a program that allocated all the unused memory on a system, and continued to request more and more memory as other applications released memory that they no longer ...
3
votes
4answers
782 views

What factors should I consider when choosing names for identifiers?

What factors do I need to consider when choosing names for identifiers such as variables? I am concerned about space issues, i.e. extra memory consumption when choosing longer names. As an example, ...
2
votes
1answer
203 views

Why is checking weird bit errors important in garbage collectors?

Here's a rough translation of a tweet by @xharaken. "Space rays hit computers and mess up the bits in the memory" "hardware bugs mess up the bits in the memory" such things almost never happen, ...
3
votes
2answers
545 views

Purpose of Base Address?

What's the purpose of a base address in an executable? For example, in Microsoft Visual C++'s linker, you can set a base address, or use the default of 0x1000000. But with virtual memory, why would a ...
2
votes
4answers
319 views

How to initialize object which may be used in catch clause?

I've seen this sort of pattern in code before: //pseudo C# code var exInfo = null; //Line A try { var p = SomeProperty; //Line B exInfo = new ExceptionMessage("The property was " + p); ...