Simple code snippet hanging forever:

#include <csignal>
#include <mutex>
#include <print>
#include <iostream>

void *routine(void *arg) {
    pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, nullptr);
    pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, nullptr);

    std::istream &input = std::cin;
    int value;
    std::cout << "Reading" << std::endl;
    input >> value;
    std::cout << "Reading done" << std::endl;
    return nullptr;
}

int main() {
    pthread_t th;
    pthread_create(&th, nullptr, routine, nullptr);

    usleep(1000000);
    std::cout << "Cancelling thread" << std::endl;
    pthread_cancel(th);
    std::cout << "Cancelled" << std::endl;
    pthread_join(th, nullptr);
    std::cout << "Joined" << std::endl;
}

with output

Reading
Cancelling thread
Cancelled

routine is trying to read value from standard input and I’d like to cancel it.

MacOS, G++ or Clang
I would expect routine thread to be cancelled when pthread_cancel is called but it is not