#test_no_GIL.py
import threading
import time


def is_prime(n):
    """一个简单的质数判断函数"""
    if n <= 1:
        return False
    if n <= 3:
        return True
    if n % 2 == 0 or n % 3 == 0:
        return False
    i = 5
    while i * i <= n:
        if n % i == 0 or n % (i + 2) == 0:
            return False
        i += 6
    return True


def cpu_task(start, end, results, index):
    """CPU 密集型任务：计算指定范围内的质数个数"""
    count = 0
    for num in range(start, end):
        if is_prime(num):
            count += 1
    results[index] = count


def run_cpu_test(num_threads=4):
    """运行 CPU 密集型测试"""
    total_numbers = 1000000
    chunk_size = total_numbers // num_threads
    ranges = [(i * chunk_size, (i + 1) * chunk_size) for i in range(num_threads)]
    # 确保最后一个范围包含到 total_numbers
    ranges[-1] = (ranges[-1][0], total_numbers)

    threads = []
    results = [0] * num_threads
    start_time = time.time()

    for i in range(num_threads):
        thread = threading.Thread(
            target=cpu_task, args=(ranges[i][0], ranges[i][1], results, i)
        )
        threads.append(thread)
        thread.start()

    for thread in threads:
        thread.join()

    end_time = time.time()
    total_primes = sum(results)
    print(
        f"CPU密集型测试 - 线程数: {num_threads}, 总质数: {total_primes}, 耗时: {end_time - start_time:.2f} 秒"
    )


if __name__ == "__main__":
    print("--- CPU 密集型测试 ---")
    # 单线程测试
    run_cpu_test(num_threads=1)
    # 多线程测试 (例如 4 个线程)
    run_cpu_test(num_threads=4)