PROSAGA码农传奇-调度引擎-如何限制函数运行的时间（添加超时）？

<div class =“post-text”itemprop =“text”>
  
    目前可能首选的选项之一就是使用Pythons
  
  <BLOCKQUOTE>
    
      多处理（特别是它的
      的
        proc.join（timeoutTime）
      </强>
       方法 ）
    
  </BLOCKQUOTE>
  
    模块（见
    <a href="https://docs.python.org/3.3/library/multiprocessing.html" rel="nofollow noreferrer">
      教程
    </A>
     ）
  
  
    只需复制/粘贴下面的代码示例并运行它。你是追求的吗？
  
   <pre>
 <code>
 def beBusyFor(noOfSeconds):
 import time
 print(" beBusyFor() message: going to rest for", noOfSeconds, "seconds")
 time.sleep(noOfSeconds)
 print(" beBusyFor() message: was resting", noOfSeconds, "seconds, now AWAKE")

import multiprocessing

noOfSecondsBusy = 5; timeoutTime  = 3
print("--- noOfSecondsBusy = 5; timeoutTime  = 3 ---")
proc = multiprocessing.Process(target=beBusyFor, args=(noOfSecondsBusy, ))
print("Start beBusyFor()")
proc.start()
print("beBusyFor() is running")
proc.join(timeoutTime)
if proc.is_alive():
    print(timeoutTime, "seconds passed, beBusyFor() still running, terminate()" )
    proc.terminate()
else:
    print("OK, beBusyFor() has finished its work in time.")
#:if

print()

noOfSecondsBusy = 2; timeoutTime  = 3
print("--- noOfSecondsBusy = 2; timeoutTime  = 3 ---")
proc = multiprocessing.Process(target=beBusyFor, args=(noOfSecondsBusy, ))
print("Start beBusyFor()")
proc.start()
print("beBusyFor() started")
proc.join(timeoutTime)
if proc.is_alive():
    print(timeoutTime, "seconds passed, beBusyFor() still running, terminate()" )
    proc.terminate()
else:
    print("OK, beBusyFor() has finished its work in time.")
#:if

</code>
 </pre>
  
    它输出：
  
   <pre>
 <code>
 --- noOfSecondsBusy = 5; timeoutTime = 3 ---
Start beBusyFor()
beBusyFor() is running
 beBusyFor() message: going to rest for 5 seconds
3 seconds passed, beBusyFor() still running, terminate()

--- noOfSecondsBusy = 2; timeoutTime  = 3 ---
Start beBusyFor()
beBusyFor() started
    beBusyFor() message: going to rest for 2 seconds
    beBusyFor() message: was resting 2 seconds, now AWAKE
OK, beBusyFor() has finished its work in time.

</code>
 </pre>
  
    另一个我知道的选择是使用a
  
  <BLOCKQUOTE>
    
      的
        装饰功能
      </强>
       和
      的
        信号模块
      </强>
    
  </BLOCKQUOTE>
  
    结帐
    <a href="http://www.saltycrane.com/blog/2010/04/using-python-timeout-decorator-uploading-s3/" rel="nofollow noreferrer">
      具有代码来源的网页
    </A>
     我在这里提供（只需要一个小调整就可以在Python 3.6上运行）：
  
   <pre>
 <code>
 import signal

class TimeoutError(Exception):
    def __init__(self, value = "Timed Out"):
        self.value = value
    def __str__(self):
        return repr(self.value)

def timeout(seconds_before_timeout):
    def decorate(f):
        def handler(signum, frame):
            raise TimeoutError()
        def new_f(*args, **kwargs):
            old = signal.signal(signal.SIGALRM, handler)
            signal.alarm(seconds_before_timeout)
            try:
                result = f(*args, **kwargs)
            finally:
                signal.signal(signal.SIGALRM, old)
            signal.alarm(0)
            return result
        # new_f.func_name = f.func_name
        new_f.__name__ = f.__name__
        return new_f
    return decorate

# Try it out:

import time

@timeout(5)
def mytest():
    print( "mytest() message:  Started" )
    for i in range(1,10):
        time.sleep(1)
        print( "mytest() message:  %d seconds have passed" % i )

try:
    mytest()
except TimeoutError as e:
    print("stopped executing mytest() because it", e)

print("continuing script execution past call of mytest()")

</code>
 </pre>
  
    上面的代码输出：
  
   <pre>
 <code>
 mytest() message: Started
mytest() message: 1 seconds have passed
mytest() message: 2 seconds have passed
mytest() message: 3 seconds have passed
mytest() message: 4 seconds have passed
stopped executing mytest() because it 'Timed Out'
continuing script execution past call of mytest()

</code>
 </pre>
</DIV>