Managed C++/CLI

kclkl18 wrote:

What is the most efficient way of doing this?

gajatko wrote:

19 vs 37 msec

Mark Salsbery
Microsoft MVP - Visual C++

const int COUNT = 10000000;
myClass** objects = new myClass*[COUNT];

gajatko wrote:

I got 3582 native and 1612 with /clr

Mark Salsbery
Microsoft MVP - Visual C++

start = clock();
for (int i = 0; i < COUNT; i++) {
    objects[i] = new myClass();
    delete objects[i];
}
printf("Native with delete: %f\n", (double)(clock() - start) / CLOCKS_PER_SEC * 1000);

class myClass
{
};

int _tmain(int argc, _TCHAR* argv[])
{
	const int COUNT = 1000000;
	myClass** objects = new myClass*[COUNT];

	clock_t start1 = clock();
	for (int i = 0; i < COUNT; i++) 
	{
		objects[i] = new myClass();
		delete objects[i];
	}
	clock_t end1 = clock();

	clock_t start2 = clock();
	for (int i = 0; i < COUNT; i++){
		objects[i] = new myClass();
	}
	clock_t end2 = clock();
	clock_t start3 = clock();
	for (int i = 0; i < COUNT; i++){
		delete objects[i];
	}
	clock_t end3 = clock();

	printf("Loop with new/delete: %d\n\n", end1 - start1);
	printf("Loop with new: %d\n", end2 - start2);
	printf("Loop with delete: %d\n", end3 - start3);
	printf("Total of loop new and loop delete: %d\n", end3 - start2);

	printf("\n\nPress enter to end...");
	getchar();

	delete[] objects;

	return 0;
}

Mark Salsbery
Microsoft MVP - Visual C++

Mark Salsbery wrote:

Try this (and do NOT run in the debugger!)

gajatko wrote:

I get used to strange things happening with M$ implementation of Java VM*

Loop with new/delete: 174

Loop with new: 101
Loop with delete: 77
Total of loop new and loop delete: 178


Press enter to end...

Loop with new/delete: 306

Loop with new: 90
Loop with delete: 64
Total of loop new and loop delete: 154


Press enter to end...

Mark Salsbery wrote:

and compiler version?

Mark Salsbery wrote:

I'm not sure what you're expecting here.

Mark Salsbery wrote:

First, if you were running tests in the debugger, forgetaboutit.

Mark Salsbery wrote:

Second, comparing times for two sets of loops isn't going to work.

Mark Salsbery wrote:

the MSIL is better optimized

Mark Salsbery wrote:

Lastly, don't believe people that say managed code is slower

gajatko wrote:

Not sure what to expect, but definately not this

gajatko wrote:

Lucky and happy you.

gajatko wrote:

The problem is that if you believe something (God, Holy Grail, etc.) you likely believe people as well.

Mark Salsbery
Microsoft MVP - Visual C++

Mark Salsbery wrote:

Lastly, don't believe people that say managed code is slower

Rob Bryce wrote:

simply turn on the /clr switch on as many files as possible

Mark Salsbery
Microsoft MVP - Visual C++

Mark Salsbery wrote:

I certainly wouldn't do that. C++/CLI is meant to be a bridge from
native C++ to the managed .NET world. It should be used as that.
Use the #pragma managed/#pragma unmanaged macros to control what code gets
compiled managed and what stays native. Then you can keep your optimized or
performance critical code compiled native. This can be done at the function level!