decorator and signal handler

[stalex]

Hi all,

I wrote the following code since I want to try using a decorator to
install signal handler:

## The test.py script
############### ##
import os
import time
import signal

def sigHandler(sid) :
def handler(f):
signal.signal(s id, f)
return f
return handler

class Test(object):
@sigHandler(sig nal.SIGTERM)
def _sigHandler(sel f, signalId, currentFrame):
print "Received:" , signalId

if __name__ == "__main__":
print "pid:", os.getpid()

t = Test()
time.sleep(300)

# From terminal, say A
############### #####
$ python test.py
pid: 1234

# From terminal, say B
############### ####
$ kill -TERM 1234

After issuing the kill command from terminal B, the process of test.py
from terminal A is terminated.
Python print out some exception message as following:
Traceback (most recent call last):
File "a.py", line 22, in <module>
time.sleep(300)
TypeError: _sigHandler() takes exactly 3 arguments (2 given)

At a guess, I think the decorator I defined did not pass the 'self' as
the first argument to _sigHandler() method, did it? And I have no idea
of how to write a correct one. Any suggestion?

[Michele Simionato]

On Sep 5, 11:39 am, stalex <shao...@gmail. comwrote:

Hi all,

I wrote the following code since I want to try using a decorator to
install signal handler:

I do have a decorator for exactly that purpose in my code. Here it is:

def on(sig):
'''
A factory of decorators for signal handlers. An example of usage
is

@on(signal.SIGT ERM)
def termination(fra me):
print 'sent SIGTERM'
raise SystemExit

Code calling termination.sig nal() will send a SIGTERM signal to
the
main thread, which in turns will call the termination handler,
which
will print a message and raise SystemExit.
'''
def handler_decorat or(handler):
'Install the handler and add a .signal function attribute to
it'
signal.signal(s ig, lambda signum, frame : handler(frame))
handler.signal = lambda : os.kill(os.getp id(), sig)
return handler
return handler_decorat or

Michele Simionato