try/finally in threads

George Sakkis

I posted this on the Pyro list but I'm not sure if it's related
specifically to Pyro. The "finally" clause below is not executed when
f() runs on on a (daemon) thread and the program exits. DAEMON here is
a global Pyro.code.Daemon instance.

def f():
try: DAEMON.requestLoop()
finally:
# nothing is printed if f() runs in a thread
print "i am here!!"
DAEMON.shutdown()
print "i am over!!"

Is "finally" not guaranteed to be executed in a non-main thread or is
there something else going on ?

George

Jul 3 '07 #1

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Diez B. Roggisch

George Sakkis wrote:

I posted this on the Pyro list but I'm not sure if it's related
specifically to Pyro. The "finally" clause below is not executed when
f() runs on on a (daemon) thread and the program exits. DAEMON here is
a global Pyro.code.Daemon instance.

def f():
try: DAEMON.requestLoop()
finally:
# nothing is printed if f() runs in a thread
print "i am here!!"
DAEMON.shutdown()
print "i am over!!"

Is "finally" not guaranteed to be executed in a non-main thread or is
there something else going on ?

Well, that's pretty much the idea behind daemon threads - that they are
terminated immediately. If it were otherwise, a little endless-loop in that
finally-statement of yours would cause the program termination to hang
endlessly.

Diez

Jul 3 '07 #2

George Sakkis

On Jul 3, 5:05 am, "Diez B. Roggisch" <d...@nospam.web.dewrote:

George Sakkis wrote:
I posted this on the Pyro list but I'm not sure if it's related
specifically to Pyro. The "finally" clause below is not executed when
f() runs on on a (daemon) thread and the program exits. DAEMON here is
a global Pyro.code.Daemon instance.

def f():
try: DAEMON.requestLoop()
finally:
# nothing is printed if f() runs in a thread
print "i am here!!"
DAEMON.shutdown()
print "i am over!!"

Is "finally" not guaranteed to be executed in a non-main thread or is
there something else going on ?

Well, that's pretty much the idea behind daemon threads - that they are
terminated immediately. If it were otherwise, a little endless-loop in that
finally-statement of yours would cause the program termination to hang
endlessly.

Thanks, that makes sense; if the thread is non-daemon, it enters the
finally block as expected.

George

Jul 3 '07 #3

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