malloc and new functions

[friendrangar]

Hello

Which function is faster , malloc or new ? why?

How much CPU utilisation will require for both and how to calculate CPU
utilisation for any function ?

 

[Axter]

Hello

Which function is faster , malloc or new ? why?

How much CPU utilisation will require for both and how to calculate CPU
utilisation for any function ?

You're comparing apples to oranges. malloc and new have different
functionallities.
malloc allocates memory.
Where as new allocates memory, and calls the object's constuctor.


---------------------------------------------------------------------------­­-------------

David Maisonave
http://axter.com


Author of policy smart pointers (http://axter.com/smartptr)
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[Sunil Varma]

Hello

Which function is faster , malloc or new ? why?

How much CPU utilisation will require for both and how to calculate CPU
utilisation for any function ?

new is an operator where as malloc() is a function.
Probably malloc() is faster, because it doesn't call the constructor,
where as new does.
Always use new to allocate memory dynamically.

I dont think there is a function that returns the CPU usage by a
funciton in C++.

But you can find out how much time a function took for execution.

int before = clock();
function(); // Your function here.
int after = clock();

now (after-before) gives you the time consumed by the function
function().

Regards
Sunil

 

[asterisc]

now (after-before) gives you the time consumed by the function

function().

The returned time is the time consumed by Operating System and the
function, not just by the function itself.
If you have many processes in memory, and a lot of threads, the time
obtained will be usefull.
You can run the test for milion times, then take the average value.