Does dlang install some signal handlers by default

Question

I have infinite loop program written in D:

$ cat dprog.d 
import std.stdio;
import core.thread;

void main()
{
  while(1){
    Thread.sleep(dur!("seconds")(1));
  };
}

When I build and run this program on Linux (Ubuntu), kill -10 $PID has no effect on it. And indeed, it does catch a bunch of signals by default:

$ cat /proc/$PID/status | grep SigCgt
SigCgt: 0000000180000a00

Signal 10 is a SIGUSR1 signal, for which the default action is process termination (consult man 7 signal).

Equivalent program, written in C terminates on kill -10 $PID and its cat /proc/$PID/status | grep SigCgt is SigCgt: 0000000000000000.

Equivalent program, written in Rust also terminates on kill -10 $PID, however its cat /proc/$PID/status | grep SigCgt is SigCgt: 0000000180000440.

My question is: does D (Rust) compiler register default signal handlers? If yes, why? Also, is this documented somewhere?

Answer 1

The docs for core.thread.thread_setGCSignals tell us that, on Posix systems, SIGUSR1 and SIGUSR2 are used for the runtime to control suspending and resuming threads for GC purposes.

This function allows you to change which signals are used, in case there are different signals you don't need.