Memory usage of strings (or any other objects) in .Net
- by ava
I wrote this little test program:
using System;
namespace GCMemTest
{
class Program
{
static void Main(string[] args)
{
System.GC.Collect();
System.Diagnostics.Process pmCurrentProcess = System.Diagnostics.Process.GetCurrentProcess();
long startBytes = pmCurrentProcess.PrivateMemorySize64;
double kbStart = (double)(startBytes) / 1024.0;
System.Console.WriteLine("Currently using " + kbStart + "KB.");
{
int size = 2000000;
string[] strings = new string[size];
for(int i = 0; i < size; i++)
{
strings[i] = "blabla" + i;
}
}
System.GC.Collect();
pmCurrentProcess = System.Diagnostics.Process.GetCurrentProcess();
long endBytes = pmCurrentProcess.PrivateMemorySize64;
double kbEnd = (double)(endBytes) / 1024.0;
System.Console.WriteLine("Currently using " + kbEnd + "KB.");
System.Console.WriteLine("Leaked " + (kbEnd - kbStart) + "KB.");
System.Console.ReadKey();
}
}
}
The output in Release build is:
Currently using 18800KB.
Currently using 118664KB.
Leaked 99864KB.
I assume that the GC.collect call will remove the allocated strings since they go out of scope, but it appears it does not. I do not understand nor can I find an explanation for it. Maybe anyone here?
Thanks,
Alex
