多线程多进程常用调用 [代码笔记]

import multiprocessing
import time
import threading
# 定义全局变量Queue
g_queue = multiprocessing.Queue()

def init_queue():
    print("init g_queue start")
    while not g_queue.empty():
        g_queue.get()
    for _index in range(10):
        g_queue.put(_index)
    print("init g_queue end")
    return

# 定义一个IO密集型任务：利用time.sleep()
def task_io(task_id):
    print("IOTask[%s] start" % task_id)
    while not g_queue.empty():
        time.sleep(1)
        try:
            data = g_queue.get(block=True, timeout=1)
            print("IOTask[%s] get data: %s" % (task_id, data))
        except Exception as excep:
            print("IOTask[%s] error: %s" % (task_id, str(excep)))
    print("IOTask[%s] end" % task_id)
    return

g_search_list = list(range(10000))
# 定义一个计算密集型任务：利用一些复杂加减乘除、列表查找等
def task_cpu(task_id):
    print("CPUTask[%s] start" % task_id)
    while not g_queue.empty():
        count = 0
        for i in range(10000):
            count += pow(3*2, 3*2) if i in g_search_list else 0
        try:
            data = g_queue.get(block=True, timeout=1)
            print("CPUTask[%s] get data: %s" % (task_id, data))
        except Exception as excep:
            print("CPUTask[%s] error: %s" % (task_id, str(excep)))
    print("CPUTask[%s] end" % task_id)
    return task_id

if __name__ == '__main__':
    print("cpu count:", multiprocessing.cpu_count(), "\n")

    print("========== 直接执行IO密集型任务 ==========")
    init_queue()
    time_0 = time.time()
    task_io(0)
    print("结束：", time.time() - time_0, "\n")

    print("========== 多线程执行IO密集型任务 ==========")
    init_queue()
    time_0 = time.time()
    thread_list = [threading.Thread(target=task_io, args=(i,)) for i in range(5)]
    for t in thread_list:
        t.start()
    for t in thread_list:
        if t.is_alive():
            t.join()
    print("结束：", time.time() - time_0, "\n")

    print("========== 多进程执行IO密集型任务 ==========")
    init_queue()
    time_0 = time.time()
    process_list = [multiprocessing.Process(target=task_io, args=(i,)) for i in range(multiprocessing.cpu_count())]
    for p in process_list:
        p.start()
    for p in process_list:
        if p.is_alive():
            p.join()
    print("结束：", time.time() - time_0, "\n")

    print("========== 直接执行CPU密集型任务 ==========")
    init_queue()
    time_0 = time.time()
    task_cpu(0)
    print("结束：", time.time() - time_0, "\n")

    print("========== 多线程执行CPU密集型任务 ==========")
    init_queue()
    time_0 = time.time()
    thread_list = [threading.Thread(target=task_cpu, args=(i,)) for i in range(5)]
    for t in thread_list:
        t.start()
    for t in thread_list:
        if t.is_alive():
            t.join()
    print("结束：", time.time() - time_0, "\n")

    print("========== 多进程执行cpu密集型任务 ==========")
    init_queue()
    time_0 = time.time()
    process_list = [multiprocessing.Process(target=task_cpu, args=(i,)) for i in range(multiprocessing.cpu_count())]
    for p in process_list:
        p.start()
    for p in process_list:
        if p.is_alive():
            p.join()
    print("结束：", time.time() - time_0, "\n")

运行结果：

cpu count: 8

========== 直接执行IO密集型任务 ==========
init g_queue start
init g_queue end
IOTask[0] start
IOTask[0] get data: 0
IOTask[0] get data: 1
IOTask[0] get data: 2
IOTask[0] get data: 3
IOTask[0] get data: 4
IOTask[0] get data: 5
IOTask[0] get data: 6
IOTask[0] get data: 7
IOTask[0] get data: 8
IOTask[0] get data: 9
IOTask[0] end
结束： 10.029563665390015

========== 多线程执行IO密集型任务 ==========
init g_queue start
init g_queue end
IOTask[0] start
IOTask[1] start
IOTask[2] start
IOTask[3] start
IOTask[4] start
IOTask[0] get data: 0
IOTask[2] get data: 1
IOTask[1] get data: 2
IOTask[3] get data: 3
IOTask[4] get data: 4
IOTask[0] get data: 5
IOTask[1] get data: 6
IOTask[2] get data: 7
IOTask[3] get data: 8
IOTask[4] get data: 9
IOTask[4] end
IOTask[0] error:
IOTask[1] error:
IOTask[3] error:
IOTask[2] error:
IOTask[1] end
IOTask[3] end
IOTask[2] end
IOTask[0] end
结束： 4.022611856460571

========== 多进程执行IO密集型任务 ==========
init g_queue start
init g_queue end
IOTask[2] start
IOTask[2] end
IOTask[3] start
IOTask[0] start
IOTask[3] end
IOTask[0] end
IOTask[7] start
IOTask[6] start
IOTask[7] end
IOTask[4] start
IOTask[6] end
IOTask[1] start
IOTask[4] end
IOTask[5] start
IOTask[1] end
IOTask[5] end
结束： 1.000349521636963

========== 直接执行CPU密集型任务 ==========
init g_queue start
init g_queue end
CPUTask[0] start
CPUTask[0] get data: 0
CPUTask[0] get data: 1
CPUTask[0] get data: 2
CPUTask[0] get data: 3
CPUTask[0] get data: 4
CPUTask[0] get data: 5
CPUTask[0] get data: 6
CPUTask[0] get data: 7
CPUTask[0] get data: 8
CPUTask[0] get data: 9
CPUTask[0] end
结束： 8.74844479560852

========== 多线程执行CPU密集型任务 ==========
init g_queue start
init g_queue end
CPUTask[0] start
CPUTask[1] start
CPUTask[2] start
CPUTask[3] start
CPUTask[4] start
CPUTask[2] get data: 0
CPUTask[0] get data: 1
CPUTask[1] get data: 2
CPUTask[3] get data: 3
CPUTask[4] get data: 4
CPUTask[2] get data: 5
CPUTask[1] get data: 6
CPUTask[0] get data: 7
CPUTask[4] get data: 8
CPUTask[3] get data: 9
CPUTask[3] end
CPUTask[2] error:
CPUTask[2] end
CPUTask[0] error:
CPUTask[0] end
CPUTask[1] error:
CPUTask[1] end
CPUTask[4] error:
CPUTask[4] end
结束： 25.572978973388672

========== 多进程执行cpu密集型任务 ==========
init g_queue start
init g_queue end
CPUTask[5] start
CPUTask[5] end
CPUTask[0] start
CPUTask[0] end
CPUTask[3] start
CPUTask[3] end
CPUTask[1] start
CPUTask[1] end
CPUTask[4] start
CPUTask[4] end
CPUTask[6] start
CPUTask[6] end
CPUTask[7] start
CPUTask[7] end
CPUTask[2] start
CPUTask[2] end
结束： 0.5453381538391113