Directory.GetFiles Method example is a bit less basic, but can trigger given the right signal environment.
The Mono log profiler (in mono-complete package and other spots) signals enough. I’m using its syntax:
$ mono --profile=log:help some.exe
...
sample[-real][=FREQ] enable/disable statistical sampling of threads
FREQ in Hz, 100 by default
the -real variant uses wall clock time instead of process time
mono --profile=log:sample=1000 Microsoft.GetFiles.exe /mnt/emptyfiles fails on Linux Mint 19.3 with kernel 5.4.0-62-generic, but works on Manjaro Linux with kernel 5.9.16-1-MANJARO, and works on openSUSE Tumbleweed with kernel 5.10.9-1-default. I’d guess the reason is they have a kernel patch:
[PATCH] cifs: allow syscalls to be restarted in __smb_send_rqst()
Let me the kernel decide to whether or not restart the syscalls when
there is a signal pending in __smb_send_rqst() by returing
-ERESTARTSYS. If it can’t, it will return -EINTR anyway.
I wasn’t (and still am not) sure how general a fix this is, but for whatever reason the getdents/getdents64 system calls underneath the readdir that I think mono is using are doing better. Some distro kernels may eventually catch up. The two distros I picked for their test are rolling releases known to stay quite current.
Linux 5.10-rc7 shows it going into Linus’ kernel candidate Dec 6, 2020.
Linux 5.9.14 shows it going into that kernel.org kernel on Dec 11, 2020.
For additional testing, I also used a C program to send signals, with directory readers written in C and go.
I’m not sure what go has internally, but in the C program I used SA_RESTART in sigaction, so in patch’s context, I tell the kernel to restart, and then the patch allows linux-cifs to ask the kernel, so it does restart.
Both of these programs failed on the older Linux Mint system, and worked on the two leading-edge ones.
Ubuntu 20.10 with kernel 5.8.0-41-generic fails. This might be a Jan 18, 2021 kernel, but I don’t know how hard Ubuntu works to keep their kernel up to date with the latest kernel patches. SUSE documents nicely.