• Announcements

    • khawk

      Download the Game Design and Indie Game Marketing Freebook   07/19/17

      GameDev.net and CRC Press have teamed up to bring a free ebook of content curated from top titles published by CRC Press. The freebook, Practices of Game Design & Indie Game Marketing, includes chapters from The Art of Game Design: A Book of Lenses, A Practical Guide to Indie Game Marketing, and An Architectural Approach to Level Design. The GameDev.net FreeBook is relevant to game designers, developers, and those interested in learning more about the challenges in game development. We know game development can be a tough discipline and business, so we picked several chapters from CRC Press titles that we thought would be of interest to you, the GameDev.net audience, in your journey to design, develop, and market your next game. The free ebook is available through CRC Press by clicking here. The Curated Books The Art of Game Design: A Book of Lenses, Second Edition, by Jesse Schell Presents 100+ sets of questions, or different lenses, for viewing a game’s design, encompassing diverse fields such as psychology, architecture, music, film, software engineering, theme park design, mathematics, anthropology, and more. Written by one of the world's top game designers, this book describes the deepest and most fundamental principles of game design, demonstrating how tactics used in board, card, and athletic games also work in video games. It provides practical instruction on creating world-class games that will be played again and again. View it here. A Practical Guide to Indie Game Marketing, by Joel Dreskin Marketing is an essential but too frequently overlooked or minimized component of the release plan for indie games. A Practical Guide to Indie Game Marketing provides you with the tools needed to build visibility and sell your indie games. With special focus on those developers with small budgets and limited staff and resources, this book is packed with tangible recommendations and techniques that you can put to use immediately. As a seasoned professional of the indie game arena, author Joel Dreskin gives you insight into practical, real-world experiences of marketing numerous successful games and also provides stories of the failures. View it here. An Architectural Approach to Level Design This is one of the first books to integrate architectural and spatial design theory with the field of level design. The book presents architectural techniques and theories for level designers to use in their own work. It connects architecture and level design in different ways that address the practical elements of how designers construct space and the experiential elements of how and why humans interact with this space. Throughout the text, readers learn skills for spatial layout, evoking emotion through gamespaces, and creating better levels through architectural theory. View it here. Learn more and download the ebook by clicking here. Did you know? GameDev.net and CRC Press also recently teamed up to bring GDNet+ Members up to a 20% discount on all CRC Press books. Learn more about this and other benefits here.
Sign in to follow this  
Followers 0
the dodger uk

memory and not using NEW ?

10 posts in this topic

just been going though my code and i create lots and lots of CModel by doing 

 

CModel temp = new CModel()

 

then putting it into a container

 

in the end i end up  doing this about 900 times and its slowing the loading down, 

is there a good way to preallocate it in one go then  point to it , 

if so is there any good tutorails i can use 

 

0

Share this post


Link to post
Share on other sites

You could write a memory manager for your program, which will preallocate memory and then manage it more efficiently for your needs than the virtual memory manager provided by your operating system. You should get some hits if you google that.

0

Share this post


Link to post
Share on other sites

The simplest example in C++ i can think of:

#include "CModel.h"

class NotSoGreatFactory {
protected:
	std::vector<CModel*> m_vPreAllocatedModels;
public:
	~NotSoGreatFactory {
		ClearReferences();
	}
	
	void ClearReferences() {
		for (int i = 0, size = int(m_vPreAllocatedModels.size(); i < size; ++i)
			delete m_vPreAllocatedModels[i];
		m_vPreAllocatedModels.clear();
	}
	
	CModel* GetModel() {
		if (m_vPreAllocatedModels.size() >= 1) {
			CModel* target = m_vPreAllocatedModels.pop_back();
			target->Reset();
			return target;
		} else return new CModel();
	}
	
	void ReturnModel(CModel* model) {
		m_vPreAllocatedModels.push_back(model);
	}
};

// And then in your code
NotSoGreatFactory modelFactory;
for (int i = 0; i < 100000; ++i) {
	CModel* tempModel = modelFactory.GetModel();
	// Do some stuff until temp model is no longer needed
	modelFactory.ReturnModel(tempModel);
}

 

In this scenario we only ever allocate one model.

Start with that, see how you can improve.

1

Share this post


Link to post
Share on other sites

Yes, it's called object pooling.  Here's the wikipedia entry for it.

 

What it basically does is to create all objects beforehand, and store them inside a special collection (the pool).  When you need one, you get an object from the pool, and use it.  After you are done, you return the object back to the pool.

 

This requires a small modification to your CModel class.  You need to include "enabled" and "disabled" states to your class.  When you return the object back to the pool, it "disables" that instance.  When you query it from the pool, it re-"enables" it back.

0

Share this post


Link to post
Share on other sites

just been going though my code and i create lots and lots of CModel by doing 

 

CModel temp = new CModel()

Is the slow part the memory allocation, or the code inside CModel's constructor?

I'm with Hodgman on this.

Even though there are better alternatives to what you're currently doing, 900 allocations won't stress a general-purpose allocator.

What is the constructor doing?

0

Share this post


Link to post
Share on other sites

just been going though my code and i create lots and lots of CModel by doing 

 

CModel temp = new CModel()

 

then putting it into a container

 

in the end i end up  doing this about 900 times and its slowing the loading down, 

is there a good way to preallocate it in one go then  point to it , 

if so is there any good tutorails i can use 

Doing a simple test, calling 900 new on a simple class, takes 45 microseconds. If you are doing this 900 times, and it is seen as slow from a human perspective, then we can say for sure that it is not the memory allocation that is the problem. That means that using a special allocation pool will not help you.

 

Either it is the constructor that is the problem, your measurements are wrong, or I don't understand the question.

0

Share this post


Link to post
Share on other sites

Since the OP seems to be doing this on a model class my first assumption would be that the slowdown is caused by file i/o rather than memory allocation.

 

Using a few larger archives rather than hundreds of small files can greatly speed this process up on conventional hdds.

 

The OP might also benefit by reserving space in the container (resizing a vector for example isn't extremely fast)

0

Share this post


Link to post
Share on other sites

A mempool (preallocation of space) is typically used when the objects are being deallocated and reallocated frequently.

 

How large is sizeof(CModel) and what is the ctor doing?

0

Share this post


Link to post
Share on other sites

Without measurements to guide your actions, you're not optimizing you're just randomly changing code in the hopes that it might have an effect.

 

Measure twice.  Refactor once.

0

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0