Re: Do you use a garbage collector (java vs c++ difference in "new")

Razii <>
Thu, 10 Apr 2008 20:58:50 -0500
On Thu, 10 Apr 2008 21:43:45 -0400, Arne VajhHj <>

I can not imagine any C++ runtime that makes an operating system
call for each new.

The runtime allocates huge chunks from the OS and then manage
it internally.

Testing the keyword "new"

Time: 2125 ms (C++)
Time: 328 ms (java)

Explain that. What I am doing different in java than in c++? Code

--- c++--

#include <ctime>
#include <cstdlib>
#include <iostream>

using namespace std;

class Test {
    Test (int c) {count = c;}
    virtual ~Test() { }
    int count;

int main(int argc, char *argv[]) {
    clock_t start=clock();
       for (int i=0; i<=10000000; i++) {
    Test *test = new Test(i);
    if (i % 5000000 == 0)
        cout << test;
  clock_t endt=clock();
  std::cout <<"Time: " <<
     double(endt-start)/CLOCKS_PER_SEC * 1000 << " ms\n";

-- java ---

import java.util.*;

class Test {
    Test (int c) {count = c;}
    int count;

public static void main(String[] arg) {
    long start = System.currentTimeMillis();
        for (int i=0; i<=10000000; i++) {
    Test test = new Test(i);
    if (i % 5000000 == 0)
        System.out.println (test);
   long end = System.currentTimeMillis();
   System.out.println("Time: " + (end - start) + " ms");

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