Re: string.<insertStaticMethodHere> performance in multithreaded envir

#1

dave.dolan <davedolan (AT) discussions (DOT) microsoft.com> wrote:

Quote:

The old saying goes something like, "Hey stupid, don't use static methods
when you're going to call that function a lot from multiple threads, if you
want to have any kind of good performance" at least I think that's how it
goes.

I don't know who says that.

Quote:

Anyway, I get the idea behind it, because it's locking the single instance
of code in the entire app domain for now and all the life of the app, and
everyone accessing it has to wait in line.

Only if there's synchronization involved. If there isn't (and usually
there needn't be) all the threads can run through the same method at
the same time. It's easy to verify this yourself:

using System;
using System.Threading;

public class Test
{
static void Main()
{
for (int i=0; i < 5; i++)
{
new Thread(new ThreadStart(Count)).Start();
}
}

static void Count()
{
for (int i=0; i < 10; i++)
{
Console.WriteLine (i);
Thread.Sleep(200);
}
}
}

If static methods had to queue all the requests up, you'd see
0
1
2
3
4
5
6
7
8
9

five times. Instead, you're more likely to see
0
0
0
0
0
1
1
1
1
1
2
2
2
2
2

(etc)

--
Jon Skeet - <skeet (AT) pobox (DOT) com>
http://www.pobox.com/~skeet Blog: http://www.msmvps.com/jon.skeet
If replying to the group, please do not mail me too

#2

Ok, thank you very much, I feel better after having read that!

I'm glad I asked instead of proceeding with my misinformation.

"Jon Skeet [C# MVP]" wrote:

Quote:

dave.dolan <davedolan (AT) discussions (DOT) microsoft.com> wrote:
The old saying goes something like, "Hey stupid, don't use static methods
when you're going to call that function a lot from multiple threads, if you
want to have any kind of good performance" at least I think that's how it
goes.

I don't know who says that.

Anyway, I get the idea behind it, because it's locking the single instance
of code in the entire app domain for now and all the life of the app, and
everyone accessing it has to wait in line.

Only if there's synchronization involved. If there isn't (and usually
there needn't be) all the threads can run through the same method at
the same time. It's easy to verify this yourself:

using System;
using System.Threading;

public class Test
{
static void Main()
{
for (int i=0; i < 5; i++)
{
new Thread(new ThreadStart(Count)).Start();
}
}

static void Count()
{
for (int i=0; i < 10; i++)
{
Console.WriteLine (i);
Thread.Sleep(200);
}
}
}

If static methods had to queue all the requests up, you'd see
0
1
2
3
4
5
6
7
8
9

five times. Instead, you're more likely to see
0
0
0
0
0
1
1
1
1
1
2
2
2
2
2

(etc)

--
Jon Skeet - <skeet (AT) pobox (DOT) com
http://www.pobox.com/~skeet Blog: http://www.msmvps.com/jon.skeet
If replying to the group, please do not mail me too

#3

dave.dolan <davedolan (AT) discussions (DOT) microsoft.com> wrote:

Quote:

Ok, thank you very much, I feel better after having read that!

I'm glad I asked instead of proceeding with my misinformation.

It's always good to check if something sounds dodgy

(Sorry if I wrote a bit harshly before - not sure what came over me.)

--
Jon Skeet - <skeet (AT) pobox (DOT) com>
http://www.pobox.com/~skeet Blog: http://www.msmvps.com/jon.skeet
If replying to the group, please do not mail me too

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Re: string.<insertStaticMethodHere> performance in multithreaded envir

Dotnet Framework (Performance) microsoft.public.dotnet.framework.performance

Re: string.<insertStaticMethodHere> performance in multithreaded envir - 04-18-2006 , 02:09 PM

Re: string.<insertStaticMethodHere> performance in multithreaded e - 04-18-2006 , 02:34 PM

Re: string.<insertStaticMethodHere> performance in multithreaded e - 04-18-2006 , 02:55 PM