中断主调用线程如果子线程抛出异常
问题描述:
我正在使用threading.Thread和t.start()与可调参数列表来执行长时间运行的多线程处理。我的主线程被阻塞,直到所有线程完成。但是,如果其中一个可调参数抛出异常并终止其他线程,我希望t.start()立即返回。中断主调用线程如果子线程抛出异常
使用t.join()检查执行的线程是否提供了有关因异常导致的失败的信息。
这里是代码:
import json
import requests
class ThreadServices:
def __init__(self):
self.obj = ""
def execute_services(self, arg1, arg2):
try:
result = call_some_process(arg1, arg2) #some method
#save results somewhere
except Exception, e:
# raise exception
print e
def invoke_services(self, stubs):
"""
Thread Spanning Function
"""
try:
p1 = "" #some value
p2 = "" #some value
# Call service 1
t1 = threading.Thread(target=self.execute_services, args=(a, b,)
# Start thread
t1.start()
# Block till thread completes execution
t1.join()
thread_pool = list()
for stub in stubs:
# Start parallel execution of threads
t = threading.Thread(target=self.execute_services,
args=(p1, p2))
t.start()
thread_pool.append(t)
for thread in thread_pool:
# Block till all the threads complete execution: Wait for all
the parallel tasks to complete
thread.join()
# Start another process thread
t2 = threading.Thread(target=self.execute_services,
args=(p1, p2)
t2.start()
# Block till this thread completes execution
t2.join()
requests.post(url, data= json.dumps({status_code=200}))
except Exception, e:
print e
requests.post(url, data= json.dumps({status_code=500}))
# Don't return anything as this function is invoked as a thread from
# main calling function
class Service(ThreadServices):
"""
Service Class
"""
def main_thread(self, request, context):
"""
Main Thread:Invokes Task Execution Sequence in ThreadedService
:param request:
:param context:
:return:
"""
try:
main_thread = threading.Thread(target=self.invoke_services,
args=(request,))
main_thread.start()
return True
except Exception, e:
return False
当我打电话服务()main_thread(请求,上下文)并有一些例外执行T1,我需要得到它在main_thread提出并返回false。我怎样才能实现这个结构。谢谢!!
答
首先,你太复杂了。我会这样做:
from thread import start_new_thread as thread
from time import sleep
class Task:
"""One thread per task.
This you should do with subclassing threading.Thread().
This is just conceptual example.
"""
def __init__ (self, func, args=(), kwargs={}):
self.func = func
self.args = args
self.kwargs = kwargs
self.error = None
self.done = 0
self.result = None
def _run (self):
self.done = 0
self.error = None
self.result = None
# So this is what you should do in subclassed Thread():
try: self.result = self.func(*self.args, **self.kwargs)
except Exception, e:
self.error = e
self.done = 1
def start (self):
thread(self._run,())
def wait (self, retrexc=1):
"""Used in place of threading.Thread.join(), but it returns the result of the function self.func() and manages errors.."""
while not self.done: sleep(0.001)
if self.error:
if retrexc: return self.error
raise self.error
return self.result
# And this is how you should use your pool:
def do_something (tasknr):
print tasknr-20
if tasknr%7==0: raise Exception, "Dummy exception!"
return tasknr**120/82.0
pool = []
for task in xrange(20, 50):
t = Task(do_something, (task,))
pool.append(t)
# And only then wait for each one:
results = []
for task in pool:
results.append(task.wait())
print results
这样你可以使task.wait()引发错误。该线程已经停止。所以你所要做的就是在完成后从池中或整个池中删除它们的引用。你甚至可以:
results = []
for task in pool:
try: results.append(task.wait(0))
except Exception, e:
print task.args, "Error:", str(e)
print results
现在,没有严格的(我的意思是任务()类)的使用,因为它需要很多的东西加入到用于实际。
只需子类threading.Thread()并通过重写run()和join()或添加新的函数(如wait())来实现类似的概念。
谢谢@Dalen。这种方法至少对我有用。一些解决方法,它启动。 – Zeus