C++ threads

[denraskovalov_sof]

Am I right, that thread usage is disabled for C++?

I tried:
int clone_flags = CLONE_VM | CLONE_FS | CLONE_FILES;
pid_t pid1 = clone(threadFunc, stack1 + 123456, clone_flags, (int*)0);

clone returned -1. Does it mean, that threads are disabled?

I suppose that possibility of thread creation is intresting for compare solutions by time.

[nneonneo]

I think that the privileges on the judge system are locked down, so socket creation and stuff like that is denied.

[noix]

clone returned -1. Does it mean, that threads are disabled?

In C++ (and most other languages) there is a 1 process, 1 thread limit.
You have only 1 processor at your diposal and I don't see why would anyone need threads.