Question

我正在编写一个程序来创建两个新进程，并且必须等待它们完成才能继续。如何启动这两个进程并让程序等待两个进程退出？考虑伪代码：

我目前有：

create_process("program1.exe").wait()
create_process("program2.exe").wait()

这很棒，因为program2可以与program1一起运行。

create_process("program1.exe")
create_process("program2.exe").wait()

这可能是错误的，因为program1可能需要比program2更长的时间。

我对一般解决方案感兴趣，我敢打赌，为了解决这个问题，我发明了算法或设计模式。但是要为问题添加上下文，我正在编写一个调用pgsql2shp.exe两次的Python脚本，将两个表从数据库导出到本地计算机，然后预先形成一个交集。此脚本使用Python 2.7编写，并使用subprocess.popen

Answer 1

使用线程怎么样？如果你启动几个线程，每个线程可以独立运行，你可以在完成后加入线程。

尝试使用以下代码:(此代码经过大量注释，以便您可以按照这些内容进行操作）

# Import threading
import threading

# Create a handler class.
# Each instance will run in it's own independent thread
class ThreadedHandler (threading.Thread):

    # This method is called when you call threadInstance.start()
    def run(self):

        # Run your sub process and wait for it
        # How you run your process is up to you
        create_process(self.programName).wait()

# Create a new thread object
thread1 = ThreadedHandler()

# Set your program name so that when the thread is started
# the correct process is run
thread1.programName = 'program1.exe'

# Start the thread
thread1.start()

# Again, create a new thread object for the 2nd program
thread2 = ThreadedHandler()

# Set the program name
thread2.programName = 'program2.exe'

# Start the thread
thread2.start()

# At this point, each program is running independently in separate threads
# Each thread will wait for their respective sub process to complete

# Here, we join both threads. (Wait for both threads to complete)
thread1.join()
thread2.join()

# When we get here, both of our programs are finished and they both ran in parallel

等待两个子流程完成但不一定等待第一个

1 个答案: