problem with parallel foreach

[thedeemon via Digitalmars-d-learn]

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.