Re: valid uses of shared

[Steven Schveighoffer]

On Sat, 09 Jun 2012 08:31:01 -0400, Mike Wey <mike-...@example.com> wrote:
On 06/09/2012 04:01 AM, mta`chrono wrote:
Would this be legal?

class A
{
      private static shared int counter; // shared across all instances

      this()
      {
           auto i = ++counter;
           pragma(msg, typeof(i)); // prints int
      }
}


Would it also be legal if the variable wasn't static?

No.

int opApply(int delegate(ref Pixels) dg)
{
     shared(int) progress;

     foreach ( row; taskPool.parallel(iota(extent.y, extent.y +  
extent.height)) )
     {
         int result = dg(Pixels(image, extent.x, row, extent.width, 1));

         if ( result )
              return result;

         if ( image.monitor !is null )
         {
             atomicOp!"+="(progress, 1);
             image.monitor()("ImageView/" ~ image.filename, progress,  
extent.height);
         }
     }
     return 0;
}

AFAIK, if you removed shared from progress, it would work.  I don't think  
std.parallel is as strict as std.concurrency (and for pretty good reason).

I think a better way to mark progress is to make it an atomic integer type  
(like Artur has developed).

-Steve