Automatically-created threads (just want to understand)

[glathoud]

Hello,

after migrating a project from LDC 1.10.0 to 1.30.0, I now see 
(1) a significant speedup & less memory usage - many thanks for 
that - and (2) for each process (originally single-thread), up to 
1+N_CPU threads, which are active once in a while. These threads 
are automatically created, unless I am mistaken.

Just to understand: what are these threads for? Do they have 
anything to do with disk I/O? Something else?

Best regards,
Guillaume