Click here to Skip to main content
15,843,031 members
Please Sign up or sign in to vote.
0.00/5 (No votes)
See more:
Hi,

How much memory can we allocate with the help of malloc function
( malloc(sizeof(?)); )?

What is the max number in place of '?' mark?

I want to allocate 1 GB memory at a time, is this possible?

How does it depend on the system?
Posted
Updated 25-Aug-10 2:23am
v5
Comments
Dalek Dave 25-Aug-10 6:01am    
Edited for Grammar and Syntax.
CPallini 25-Aug-10 6:26am    
Edited Dave's comment for grammar and syntax. :-D
Removed the OP ridiculous 'it is urgent' sentence.
Aescleal 25-Aug-10 7:24am    
Changed the tags to something more reasonable for the question

Hope this will help

Actually it depends on system.
 
Share this answer
 
Comments
patilvaibhavrao 25-Aug-10 6:10am    
how it is depend on system
Nyarost 25-Aug-10 6:11am    
Well I suppose there are different limits for Windows, Linux, BSD. Also it depends on system architecture: i386, amd64, ia64 and so on. Formula on Wikipedia says The maximum value is 2CHAR_BIT*sizeof(size_t) - 1, or the constant SIZE_MAX in the C99 standard. I assume you should check this constant.
4 bytes if you use an integer argument, 8 if you use a double.

Operator sizeof will return the size of the operand.

malloc(sizeof(675468)) => malloc(4), etc

Assuming 32 bit environment.
 
Share this answer
 
In addition to the other replies: if you have to allocate 1GB of memory, it is likely that you have so design issues. Why do you need to allocate that much memory at once ? What are you going to do with it ?
 
Share this answer
 

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)



CodeProject, 20 Bay Street, 11th Floor Toronto, Ontario, Canada M5J 2N8 +1 (416) 849-8900