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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How many `malloc` calls is too many? If any?

I'm implementing a system in C, implemented partially as a library. The library does most of the memory management itself, with the application layer just having to call *_destroy functions on the ...
2
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4answers
258 views

Should I read a chapter about Memory management if now a days we mostly use ARC?

I'm reading a book on Objective C, and I was wondering about 2 things: Should I take the time currently to read a whole chapter on memory management? If you are doing a really good job on manual ...
6
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2answers
12k views

Java vs PHP Memory / CPU Consumption

I work in a PHP based company. There is a project where we want to create a backend service. Senior members here are going for PHP, even though it is slower than Java. Their only point of contention, ...
6
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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 ...
1
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3answers
202 views

Please help me understand the relationship between script file size and memory usage?

I am programming in PHP and I have an include file that I have to, well, include, as part of my script. The include file is 400 MB, and it contains an array of objects which are nothing more than ...
2
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6answers
284 views

Deterministic and controllable fully automated memory management

Fully automated memory management increases productivity and integrity greatly, but usual implementation (GC) has a critical problem. It's non-deterministic, and not controllable. This causes many ...
9
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1answer
493 views

Why is the main memory for object allocation called the 'heap'?

Has anybody got an idea why the area of main memory where objects are allocated is referred to as the heap. I can understand the rationale for that of the stack LIFO but would like to know what the ...
3
votes
2answers
491 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 ...
3
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5answers
733 views

Given that I voluntarily choose not to implement virtual memory in my kernel, how would the memory-management-unit work?

For my basic kernel I refuse to implement the dreaded confusion of virtual memory scheming, so I want only real memory addresses for everything. Some people have argued with me that since virtual ...
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5answers
1k views

Java memory management (thunks/lazyness)

If I want to create an infinite list of integers in Java like so: ArrayList<Integer> list = new ArrayList<Integer>(); for(int i = 0;;i++){ list.add(i); } I run out of memory. My ...
6
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5answers
5k views

Can multiple CPU's / cores access the same RAM simutaneously?

This is what I guess would happen: If two cores tried to access the same address in RAM, one would have to wait for the other to access the RAM. The second time that each core would try to access ...
7
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2answers
4k views

What are the pros and cons of Inter process communication done via sockets vs shared memory?

I understand that two of the many more options for inter process communication can be : Shared memory Sockets Actually I saw these two options being exposed by Intellij Idea for debugging a Java ...
2
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2answers
208 views

Possible to implement OOP without using extensive heap operations?

Is the concept of OOP intimately tied to allocating objects on the heap? Is it possible to write normal OOP without creating excessive objects on the heap?
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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 ...
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3answers
275 views

How flexible can hardware get? [closed]

This subject is long time in the making for me and it particularly took off when I was researching bootloaders for computers and consumer electronics, which, I will note, differ drastically. I've ...
7
votes
3answers
585 views

Why isn't DSM for unstructured memory done today?

Edit: Comments suggested, that DSM just faded out by being not used recently. What were the reasons for this, what are DSMs drawbacks? Literature lists many positive aspects like easy to port ...
0
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3answers
2k views

Instruction vs data cache usage

Say I've got a cache memory where instruction and data have different cache memories ("Harvard architecture"). Which cache, instruction or data, is used most often? I mean "most often" as in time, not ...
2
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2answers
169 views

Browser support for internal corporate tools

We are on the verge of a conversion. For years, our company supported only IE for its internal (intranet) home-built tools. Since a few of our users are still on XP, which means IE only goes up to ...
0
votes
1answer
607 views

Increase the size of a memory mapped file

I am maintaning a memory mapped file to store my tree like datastructure. When I'm updating the datastructure ,I got this problem. The file is limited on it's size and can't be too long or too small. ...
5
votes
3answers
933 views

Tension between the dependency inversion principle and avoiding “new” in C++?

I have seen a lot of advice that it is better to do Type object; than Type* object = new Type(); in C++ whenever possible—i.e., minimize your use of new. I understand the rational behind this and ...
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4answers
1k views

C simple arrays and pointers question

So here's the confusion, let's say I declare an array of characters char name[3] = "Sam"; and then I declare another array but this time using pointers char * name = "Sam"; What's the ...
5
votes
3answers
5k views

How would one go about reading memory from a process? Is it different by OS?

As an experienced web-developer, but a novice "low level" programmer, this stuff is sort of voodoo to me still. I'm curious about how one would even begin to go about finding a memory block, and then ...
2
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4answers
302 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); ...
3
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6answers
9k views

Serializing Data Structures in C [closed]

I've recently read three separate books on algorithms and data structures, tcp/ip socket programming, and programming with memory. The book about memory briefly discussed the topic of serializing data ...
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3answers
307 views

In what practical ways is it good to remember the memory/pointers model? [closed]

A variable refers to a value. A variable is also stored in a memory address. People say that it's good to have this memory model in mind. Is that true? What is some sample code that shows this as ...
3
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1answer
292 views

Concept of Address Space

I have searched the idea of address space that is The set of all legal addresses in memory for a given application. The address space represents the amount of memory available to a program. I am ...
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2answers
82 views

Evaluating mean and std as simulations are added

I have simulations that evaluate a certain value X. I run the simulations several times and save the value of X in a vector V. When all the runs have finished I evaluate the mean and standard ...
7
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1answer
4k views

Why the overhead when allocating objects/arrays in Java?

How many bytes an array occupies in Java? Assume It's a 64bit machine and also assume there are N elements in an array, so all these elements would take up 2*N, 4*N or 8*N bytes for different types of ...
13
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6answers
1k views

Term for 24-bits [closed]

Is there a term for a 24-bit (3-byte) integer? I know uncommon bit counts (such as a "nibble" or "nybble" for 4 bits) have names, and having 24-bits in both video and audio technology, for instance, ...
9
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4answers
3k views

Analyzing Memory Usage: Java vs C++ Negligible?

How does the memory usage of an integer object written in Java compare\contrast with the memory usage of a integer object written in C++? Is the difference negligible? No difference? A big difference? ...
0
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2answers
842 views

How are new[] and malloc implemented in Windows? [closed]

So when you call malloc or new [] from your C/C++ application, how does the CRT translate it into Windows API calls?
3
votes
4answers
989 views

strategies to keep tabs of memory leaks in non memory-managed languages

When it comes to non memory managed languages such as C, C++ or Fortran (my case), it becomes increasingly difficult to keep track of memory allocation/deallocation, especially when ownership must be ...
1
vote
1answer
540 views

GDI low on memory

I am fresh to Visual C++. While moving forward in the book "Programming Windows with MFC", I came across GDI (Graphics Device Interface) and use of paint brush. The book says a brush cannot be created ...
2
votes
2answers
951 views

Windows Physical Direct Memory Mapping

I'm a bit disappointed there is almost no discussion of this no matter where I look so I guess I'll have to ask. I'm writing a cross platform memory bench marking application which requires direct ...
0
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1answer
227 views

non-volatile virtual memory for C++ containers

Is there a virtual memory management process that would allow a program to use the standard container structures and classes, but retain these structures and their data when the program is not running ...
6
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5answers
482 views

On mobile is there a reason why processes are often short lived and must persist their state explicitly?

Most mobile platforms (such as Android, iOS, Windows phone 7 and I believe the new WinRT) can kill inactive application processes under memory pressure. To prevent this from affecting the user ...
2
votes
1answer
224 views

List structures in memory

Could anyone give an overview of how list structures which are composed of a head and a tail which references the rest of the list i.e linked list are represented in memory of the computer? Does the ...
3
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3answers
1k views

Can coding style cause or influence memory fragmentation?

As the title states, I'd like to know if coding style can cause or influence memory fragmentation in a native application, specifically one written using C++. If it does, I'd like to know how. An ...
2
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1answer
2k views

What metrics should be used to measure memory consumption of a program for performance test?

I am asked to provide performance statistics for a program, one of them being memory consumption. I noticed that in perfmon or in .NET API there is apparently many variable related to memory usage, ...
31
votes
4answers
6k views

Where are null values stored, or are they stored at all?

I want to learn about null values or null references. For example I have a class called Apple and I created an instance of it. Apple myApple = new Apple("yummy"); // The data is stored in memory ...
8
votes
3answers
13k views

How can I monitor the JVM memory in a proper way?

I'm thinking of how we do JVM memory monitor in a low overhead way in production environment even under busy hour. Suppose I have two tomcat app server in production, load balance set up behind them. ...
5
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4answers
692 views

Manual memory allocation and purity

Language like Haskell have concept of purity. In pure function, I can't mutate any state globally. Anyway Haskell fully abstracts memory management, so memory allocation is not a problem here. But if ...
17
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5answers
17k views

Why does IIS default to Recycling the Application Pool every 1740 minutes?

Why does IIS default to recycle the app pool after a given time? Is there some specific reason other than perhaps most web apps are not managing the memory prudently? Given that you are managing your ...
4
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3answers
143 views

Using “prevent execution of method” flags

First of all I want to point out my concern with some pseudocode (I think you'll understand better) Assume you have a global debug flag, or class variable named "debug", class a : var debug = ...
3
votes
4answers
751 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, ...
8
votes
5answers
4k views

Do threads use virtual memory or real memory?

I was trying to optimize my Linux server to handle 10,000 threads per process while it does just 382 right now. As per this article the following formula is used to find out total possible threads: ...
2
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1answer
802 views

Confused About Virtual Memory for All Processes

I hope this is the right place. This is a homework assignment for my Operating Systems course and I have to implement a working virtual memory system in C++ so programming is directly involved. I've ...
10
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3answers
2k views

Choose C++ or Java for applications requiring huge amounts of RAM? [closed]

I'm thinking of scientific applications that are mostly processor-bound and heavy on heap usage (at least several gigabytes). Any other time of the year I would happily go with C++, but in this case I ...
7
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3answers
3k views

Custom heap allocators

Most programs can be quite casual about heap allocation, even to the extent that functional programming languages prefer to allocate new objects than modify old ones, and let the garbage collector ...
2
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3answers
2k views

A good analogy for computer memory? [closed]

So, I'm a computer science major and I'm also a huge fan of the no-longer-on-TV show, Numb3rs. Now, whenever I talk with my friends they also ask me quite a few questions about programming and ...