problem with parallel foreach

[Gerald Jansen via Digitalmars-d-learn]

On Tuesday, 12 May 2015 at 17:45:54 UTC, thedeemon wrote:
> On Tuesday, 12 May 2015 at 17:02:19 UTC, Gerald Jansen wrote:
>
>> About 3.5 million lines read by main(), 0.5 to 2 million lines 
>> read and 3.5 million lines written by runTraits (aka runJob).
>
> Each GC allocation in D is a locking operation (and disabling 
> GC doesn't help here at all), probably each writeln too, so 
> when multiple threads try to write millions of lines such issue 
> is easy to meet. I would look for a way to write those lines 
> without allocations and locking, and also reduce total number 
> of system calls by buffering data, doing less f.writef's.

Your advice is appreciated but quite disheartening. I was hoping 
for something (nearly) as easy to use as Python's parallel.Pool() 
map(), given that this is essentially an "embarassingly parallel" 
problem. Avoidance of GC allocation and  self-written buffered IO 
functions seems a bit much to ask of a newcomer to a language.