[Mono-list] PFX still doesn't work correctly (in Mono 2.6.4)

[Yury Serdyuk]

Hi !

I have tried again a simple Parallel.For-program using Mono-2.6.4 now
(about old my attempt see 
http://lists.ximian.com/pipermail/mono-list/2009-December/044052.html).

But the program still works incorrectly: when needed to launch N 
threads, it launches N + 1 threads.

The code is:

> using System;
> using System.Threading;
>
> public class Test_PFX_For {
>  public static void Main ( String[] args ) {
>   int num_threads = Convert.ToInt32 ( args [ 0 ] );
>   Parallel.For ( 0, num_threads, i =>
>   {
>    long k = 0;
>    while ( true ){
>     k++;
>     k--;
>    }
>   });
>  }
> }

For example, starting the program as

> $ mono Test_PFX_For.exe 1

gives the workload

> top - 13:54:11 up 7 days,  1:00,  2 users,  load average: 0.44, 0.10, 0.03
> Tasks: 185 total,   2 running, 182 sleeping,   0 stopped,   1 zombie
> Cpu0  :  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  
> 0.0%si,  0.0%st
> Cpu1  :  0.0%us,  0.3%sy,  0.0%ni, 99.3%id,  0.3%wa,  0.0%hi,  
> 0.0%si,  0.0%st
> Cpu2  :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  
> 0.0%si,  0.0%st
> Cpu3  :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  
> 0.0%si,  0.0%st
> Cpu4  :  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  
> 0.0%si,  0.0%st
> Cpu5  :  0.0%us,  0.0%sy,  0.0%ni, 99.3%id,  0.0%wa,  0.0%hi,  
> 0.7%si,  0.0%st
> Cpu6  :  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  
> 0.0%si,  0.0%st
> Cpu7  :  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  
> 0.0%si,  0.0%st
> Mem:   8180840k total,  1957368k used,  6223472k free,   200808k buffers
> Swap:  2096472k total,        0k used,  2096472k free,  1518724k cached
>
>   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
> 28233 xxx   25   0 3457m 6644 3880 R 200.1  0.1   0:28.23 mono

Starting the program as

> $ mono Test_PFX_For.exe 2

gives

> top - 13:56:23 up 7 days,  1:03,  2 users,  load average: 2.19, 0.89, 0.33
> Tasks: 185 total,   2 running, 182 sleeping,   0 stopped,   1 zombie
> Cpu0  :  0.0%us,  0.3%sy,  0.0%ni, 93.0%id,  6.7%wa,  0.0%hi,  
> 0.0%si,  0.0%st
> Cpu1  :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  
> 0.0%si,  0.0%st
> Cpu2  :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  
> 0.0%si,  0.0%st
> Cpu3  :  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  
> 0.0%si,  0.0%st
> Cpu4  :  0.3%us,  0.3%sy,  0.0%ni, 99.3%id,  0.0%wa,  0.0%hi,  
> 0.0%si,  0.0%st
> Cpu5  :  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  
> 0.0%si,  0.0%st
> Cpu6  :  0.0%us,  0.3%sy,  0.0%ni, 99.7%id,  0.0%wa,  0.0%hi,  
> 0.0%si,  0.0%st
> Cpu7  :100.0%us,  0.0%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  
> 0.0%si,  0.0%st
> Mem:   8180840k total,  1956260k used,  6224580k free,   200808k buffers
> Swap:  2096472k total,        0k used,  2096472k free,  1518736k cached
>
>   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
> 28502 xxx   25   0 3457m 6556 3876 R 299.7  0.1   1:02.78 mono

and so on.

Thanks.

Yury.