如何中断由 SCons 管理的长任务? [英] How do I interrupt a long task managed by SCons?

问题描述

我正在使用 SCons 来管理执行长时间计算的 Python 函数 long_task().如果我直接从脚本调用 long_task() ，那么我可以用 Ctrl-C 中断它.但是，如果 SCons 正在运行 long_task() 并且我按下 Ctrl-C，那么 long_task() 将继续运行直到它完成，并且 then SCons 显示构建中断./构建因错误而终止".在这种情况下，有没有办法让 Ctrl-C 立即停止 long_task()?

I'm using SCons to manage a Python function long_task() that carries out a long calculation. If I call long_task() directly from a script, then I can interrupt it with Ctrl-C. However, if SCons is running long_task() and I press Ctrl-C, then long_task() continues to run until it completes, and then SCons says "Build interrupted. / building terminated because of errors". Is there a way to make Ctrl-C stop long_task() immediately in this situation?

如果我在 long_task() 中使用信号处理程序来处理 SIGINT，那么它会按照我的意愿运行，但我宁愿不必在几个这样长的任务中的每一个中都这样做.如果我按 Ctrl-\，则 longtask() 和 SCons 都会立即退出，但这似乎相当激烈.

If I use a signal handler in long_task() to handle SIGINT then it behaves as I want, but I'd rather not have to do this in each of several such long tasks. If I press Ctrl-\ then both longtask() and SCons exit immediately, but this seems rather drastic.

我在 Ubuntu 18.04 下使用 SCons 3.0.1 和 Python 3.6.5.

I'm using SCons 3.0.1 and Python 3.6.5 under Ubuntu 18.04.

这是一个最小的 SConstruct 文件:

Here's a minimal SConstruct file:

#!/usr/bin/env python3

import time

def long_task(target, source, env):
    print('Starting long task')
    # Mimic a complex calculation
    for i in range(100):
        time.sleep(0.1)
    print('Finishing long task')

TestBuilder = Builder(action = long_task)

env = Environment(BUILDERS = {'TestBuild': TestBuilder})

env.TestBuild('dummy', [])

推荐答案

我强烈建议您不要将长时间运行的 Python 逻辑作为构建器中的一个操作来运行.而是通过 shell 作为独立的 Python 程序运行它.这也简化了在此类程序中设置时间限制的过程，因此它不会永远运行..

I highly encourage you to not run long running python logic as an action in a builder. Instead run it via shell as a free standing python program. This also simplifies building a time limit into such program so it doesn't run forever..

在 SCons 中运行长时间运行的 python 逻辑将限制并行构建.

Running long running python logic inside SCons will limit parallel builds.

基本上不要这样做..

(顺便说一句.我是 SCons 项目联合经理)

(BTW. I'm the SCons Project Co-Manager)

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