Tell me please how to solve this problem.

Solve what problem?

Your code does nothing useful, so it is impossible to say how to improve it.

As for how long it takes to run, your figures seem about right to me.

Running over 1000 threads all thrashing a single domain with HEAD requests looks like a DoS attack to me? Even if the domain your using for testing is your own, who are you practicing for?

And if the point of your code is to see how many simultaneous thread you can run before you bog down your system then: Congratulations! You succeeded.

If you have a real problem to solve, that doesn't sound like a DoS or another of blatent misuse, then by all means describe that problem and you might get some further help.