tf::Executor executor;

tf::Taskflow taskflow("cancel");

// We create a taskflow graph of 1000 tasks each of 1 second.

// Ideally, the taskflow completes in 1000/P seconds, where P

// is the number of workers.

for(int i=0; i<1000; i++) {

taskflow.emplace([](){

std::this_thread::sleep_for(std::chrono::seconds(1));

});

}

// submit the taskflow

auto beg = std::chrono::steady_clock::now();

tf::Future fu = executor.run(taskflow);

// submit a cancel request to cancel all 1000 tasks.

fu.cancel();

// wait until the cancellation finishes

fu.get();

auto end = std::chrono::steady_clock::now();

// the duration should be much less than 1000 seconds

std::cout << "taskflow completes in "

<< std::chrono::duration_cast<std::chrono::milliseconds>(end-beg).count()

<< " milliseconds\n";

return 0;