Process pool in python's process

• Create a process pool
• Specifying the number of process pools means that there are at most the specified number of columns in the process pool.

pool = multiprocessing.Pool(3)

• Use synchronization to execute tasks. Processes in the process pool need to wait for other processes to complete before executing the specified task.

pool.apply(copy_work)

• Asynchronous execution, the processes in the process pool are executed together and will not wait for the execution of other processes

pool.apply_async(copy_work)

Tip: The main process will not wait for the process pool to complete the task execution before the program exits

Tip: The process pool no longer receives other tasks that need to be executed

pool.close()

• Wait for the process pool to complete the task execution before the program exits

pool.join()

queue in the process pool

queue = multiprocessing.Manager().Queue()

# 创建进程池
pool = multiprocessing.Pool(2)
# 让进程池执行写入数据的任务
# pool.apply(write_data, (queue,))
# # 让进程池执行读取数据的任务
# pool.apply(read_data, (queue,))

result = pool.apply_async(write_data, (queue,))

Wait for the asynchronous task execution to complete before the code continues to execute

2. Solution 2

result.wait()

1. Use time delay

# time.sleep(1.1)

pool.apply_async(read_data, (queue,))