Question

虽然我遇到了python定时器的问题，但我发现当使用＆＃34; reloader = True＆＃34;运行bottle.py时，所有定时器函数都会快速连续运行两次。

我尝试了几种不同的调用定时器的方法，结果在所有实例中都是相同的（双击）。

示例代码：

 #!/usr/bin/env python

 from threading import Timer
 from bottle import *

# Short timer
def short_time():
        t = Timer(1, short_time)
        t.daemon = True
        t.start()
        print "Short Time..."

# Long timer
def long_time():
        t = Timer(5, long_time)
        t.daemon = True
        t.start()
        print "Long Time..."

# The App
app = Bottle()

@app.route('/status')
def default():
        return "OK"

#Run the app -----
if __name__ == '__main__':

    # Start the short timer.  
    short_time()

    # Start the long timer.  
    long_time()

    # Run the app
    # This interferes with the timers
    run(app, host='0.0.0.0', port=8002, reloader=True) 

    #This one works as expected
    #run(app, host='0.0.0.0', port=8002) #This works fine

启用了重新加载器的输出：

Short Time...
Short Time...
Short Time...
Short Time...
Short Time...
Short Time...
Short Time...
Short Time...
Long Time...
Short Time...
Long Time...
Short Time...
Short Time...
Short Time...

预期输出（没有重新加载器）：

Short Time...
Short Time...
Short Time...
Short Time...
Long Time...
Short Time...
Short Time...
Short Time...
Short Time...
Short Time...
Long Time...
Short Time...
Short Time...

有关如何使用重新加载器，但防止计时器问题的任何想法？

Answer 1

设置reloader=True后，瓶子流程re-runs the script as a child process：

if reloader and not os.environ.get('BOTTLE_CHILD'):
    import subprocess
    lockfile = None
    try:
        fd, lockfile = tempfile.mkstemp(prefix='bottle.', suffix='.lock')
        os.close(fd)  # We only need this file to exist. We never write to it
        while os.path.exists(lockfile):
            args = [sys.executable] + sys.argv
            environ = os.environ.copy()
            environ['BOTTLE_CHILD'] = 'true'
            environ['BOTTLE_LOCKFILE'] = lockfile
            p = subprocess.Popen(args, env=environ)

然后每隔interval秒（默认为1）重新启动。

在启动瓶子服务器时以及每次再次启动子进程时，都会运行在脚本顶级运行的任何内容。

因此，父和子进程都是独立运行的计时器。子进程中的长计时器永远不会被执行，因为该进程在5秒启动之前被终止，但是短计时器可能只是设法在父进程杀死子进程再次启动之前触发。

您可以通过测试BOTTLE_CHILD环境变量来检测您是否在子进程中：

import os if os.environ.get('BOTTLE_CHILD'): # in the child process, do something special perhaps? # this will be executed *each time the child is restarted* else: # in the parent process, which restarts the child process

当reloader = True时，Python计时器函数使用bottle.py运行两次

1 个答案: