A thread, sometimes called an execution context or a lightweight process, is a single sequential flow of control within a program. You use threads to isolate tasks. Each thread is a sequential flow of control within the same program. Each thread runs independently from the others, but at the same time.
We want to run a certain function a specified number of times per second. A class should be given such a function and some parameters, like the maximum number of threads, the number of active threads per second and a total duration.
import threading, time class Fire: def soldier(self, soldier_nr): while (1): self.work_lock.acquire() if (self.still_working): self.write_lock.acquire() self.nr_active_soldiers += 1 self.write_lock.release() start_time_counter = self.time_counter self.function.__call__(self.arguments) end_time_counter = self.time_counter self.write_lock.acquire() self.nr_active_soldiers -= 1 self.statistics.append((soldier_nr, start_time_counter, end_time_counter)) self.write_lock.release() else: break; def __init__(self, function, arguments, nr_threads, per_second, duration): self.function = function self.arguments = arguments self.nr_threads = nr_threads self.per_second = per_second self.duration = duration self.work_lock = threading.Semaphore(0) self.write_lock = threading.Semaphore(1) self.still_working = 1 self.nr_active_soldiers = 0 self.time_counter = 0 self.statistics =  def fire(self): print 'Start' for i in range(self.nr_threads): thread1 = threading.Thread(target=self.soldier, args=(i, )) thread1.start() for second in range(self.duration): for i in range(self.per_second): self.work_lock.release() self.write_lock.acquire() if (len(self.statistics) > 0): (soldier_nr, start_time_counter, end_time_counter) = self.statistics[-1] delta_time = end_time_counter - start_time_counter else: delta_time = -1 print 'Active', self.nr_active_soldiers, 'Time', delta_time self.write_lock.release() time.sleep(1) self.time_counter += 1 self.still_working = 0 for i in range(self.nr_threads): self.work_lock.release() time.sleep(5) output_file = open('output.txt', 'wb') for statistic in self.statistics: output_file.write(str(statistic) + 'n') output_file.close() print 'End' if (__name__ == '__main__'): def waste_time(arguments): time.sleep(2.5) nr_threads = 20 per_second = 3 duration = 15 firing_squad = Fire(waste_time, None, nr_threads, per_second, duration) firing_squad.fire()