[PEAK] Stopping PEAK application on SIGINT

Discussion:

Alexey Smishlayev

2015-09-29 12:06:03 UTC

Good day everyone!
I would like my PEAK application to stop on ^C or SIGINT. Currently, in
that case I get an output something like

29.09.2015 14:56:48.179 [DEBUG] Connect.twisted Unexpected error in

main loop.

29.09.2015 14:56:48.190 [ERROR] Connect.twisted Traceback (most
29.09.2015 14:56:48.190 [ERROR] File

"/Users/alexey/xtech2/tester/build/lib/ank/BBS/CommandBase.py", line 38,
in run

29.09.2015 14:56:48.190 [ERROR] self.mainLoop.run()
29.09.2015 14:56:48.190 [ERROR] File

"/Library/Python/2.7/site-packages/peak/running/scheduler.py", line 78,
in run

29.09.2015 14:56:48.190 [ERROR] return

self.eventLoop.runUntil(self.exitCode,True,idle=self.sleep)[0]

29.09.2015 14:56:48.190 [ERROR] File

"/Library/Python/2.7/site-packages/peak/events/twisted_support.py", line
186, in runUntil

29.09.2015 14:56:48.190 [ERROR] self.reactor.run(False)
29.09.2015 14:56:48.190 [ERROR] File

"/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/twisted/internet/base.py",
line 1192, in run

29.09.2015 14:56:48.190 [ERROR] self.mainLoop()
29.09.2015 14:56:48.190 [ERROR] --- <exception caught here> ---
29.09.2015 14:56:48.190 [ERROR] File

"/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/twisted/internet/base.py",
line 1204, in mainLoop

29.09.2015 14:56:48.190 [ERROR] self.doIteration(t)
29.09.2015 14:56:48.190 [ERROR] File

"/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/twisted/internet/selectreactor.py",
line 105, in doSelect

29.09.2015 14:56:48.190 [ERROR] [], timeout)

in the log file. In CommandBase.py attribute self.mainloop is defined as

from peak.api import binding
from peak.running import commands, interfaces
mainLoop = binding.Obtain(interfaces.IMainLoop)
...

If I set "peak.running.mainLoop.stopOnSignals" in my project's .ini file
to anything else except empty tuple, on the application's startup I get
the following error (I tried "stopOnSignals = ('SIGINT',)")

File "../ank/BBS/Assembler.py", line 370, in run
_exitCode = _root.run()
File "/Library/Python/2.7/site-packages/peak/running/commands.py",

line 229, in run

return self._run() or 0
File "/Library/Python/2.7/site-packages/peak/running/commands.py",

line 509, in _run

return self.invoke()
File

"/Users/alexey/xtech2/tester/build/lib/ank/BBS/CommandBase.py", line 38,
in run

self.mainLoop.run()
File "/Library/Python/2.7/site-packages/peak/running/scheduler.py",

line 66, in run

handler = self.eventLoop.signals(*self.stopOnSignals)
File "_once.pyx", line 112, in _once.BaseDescriptor.__get__
File "_once.pyx", line 100, in _once.__get__
File

"/Library/Python/2.7/site-packages/peak/binding/components.py", line
682, in delegate

return getattr(getattr(s,delegateAttr),a)
File "_once.pyx", line 112, in _once.BaseDescriptor.__get__
File "_once.pyx", line 100, in _once.__get__
File

"/Library/Python/2.7/site-packages/peak/binding/components.py", line
682, in delegate

return getattr(getattr(s,delegateAttr),a)
File "_once.pyx", line 88, in _once.BaseDescriptor.__get__
AttributeError: ('Recursive attempt to compute attribute', 'signals')

How do I do everything correctly?

Best regards,
Alexey Smishlayev

PJ Eby

2015-09-29 21:27:27 UTC

Permalink

Which event loop are you using? Twisted, the PEAK default, or
something else? The issue here appears to be that the eventLoop
property of the MainLoop instance lacks a `signals()` method -- which
would seem to mean it doesn't fully implement IEventLoop or is the
wrong type of object to start with.

Post by Alexey Smishlayev
Good day everyone!
I would like my PEAK application to stop on ^C or SIGINT. Currently, in that
case I get an output something like

29.09.2015 14:56:48.179 [DEBUG] Connect.twisted Unexpected error in main
loop.
29.09.2015 14:56:48.190 [ERROR] Connect.twisted Traceback (most recent
29.09.2015 14:56:48.190 [ERROR] File
"/Users/alexey/xtech2/tester/build/lib/ank/BBS/CommandBase.py", line 38, in
run
29.09.2015 14:56:48.190 [ERROR] self.mainLoop.run()
29.09.2015 14:56:48.190 [ERROR] File
"/Library/Python/2.7/site-packages/peak/running/scheduler.py", line 78, in
run
29.09.2015 14:56:48.190 [ERROR] return
self.eventLoop.runUntil(self.exitCode,True,idle=self.sleep)[0]
29.09.2015 14:56:48.190 [ERROR] File
"/Library/Python/2.7/site-packages/peak/events/twisted_support.py", line
186, in runUntil
29.09.2015 14:56:48.190 [ERROR] self.reactor.run(False)
29.09.2015 14:56:48.190 [ERROR] File
"/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/twisted/internet/base.py",
line 1192, in run
29.09.2015 14:56:48.190 [ERROR] self.mainLoop()
29.09.2015 14:56:48.190 [ERROR] --- <exception caught here> ---
29.09.2015 14:56:48.190 [ERROR] File
"/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/twisted/internet/base.py",
line 1204, in mainLoop
29.09.2015 14:56:48.190 [ERROR] self.doIteration(t)
29.09.2015 14:56:48.190 [ERROR] File
"/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/twisted/internet/selectreactor.py",
line 105, in doSelect
29.09.2015 14:56:48.190 [ERROR] [], timeout)

in the log file. In CommandBase.py attribute self.mainloop is defined as

from peak.api import binding
from peak.running import commands, interfaces
mainLoop = binding.Obtain(interfaces.IMainLoop)
...

If I set "peak.running.mainLoop.stopOnSignals" in my project's .ini file to
anything else except empty tuple, on the application's startup I get the
following error (I tried "stopOnSignals = ('SIGINT',)")

File "../ank/BBS/Assembler.py", line 370, in run
_exitCode = _root.run()
File "/Library/Python/2.7/site-packages/peak/running/commands.py", line
229, in run
return self._run() or 0
File "/Library/Python/2.7/site-packages/peak/running/commands.py", line
509, in _run
return self.invoke()
File "/Users/alexey/xtech2/tester/build/lib/ank/BBS/CommandBase.py",
line 38, in run
self.mainLoop.run()
File "/Library/Python/2.7/site-packages/peak/running/scheduler.py", line
66, in run
handler = self.eventLoop.signals(*self.stopOnSignals)
File "_once.pyx", line 112, in _once.BaseDescriptor.__get__
File "_once.pyx", line 100, in _once.__get__
File "/Library/Python/2.7/site-packages/peak/binding/components.py",
line 682, in delegate
return getattr(getattr(s,delegateAttr),a)
File "_once.pyx", line 112, in _once.BaseDescriptor.__get__
File "_once.pyx", line 100, in _once.__get__
File "/Library/Python/2.7/site-packages/peak/binding/components.py",
line 682, in delegate
return getattr(getattr(s,delegateAttr),a)
File "_once.pyx", line 88, in _once.BaseDescriptor.__get__
AttributeError: ('Recursive attempt to compute attribute', 'signals')

How do I do everything correctly?
Best regards,
Alexey Smishlayev
_______________________________________________
PEAK mailing list
http://www.eby-sarna.com/mailman/listinfo/peak

Alexey Smishlayev

2015-09-29 21:56:00 UTC

Permalink

Hello, Phillip!

I use binding.Obtain() on "peak.running.interfaces.IMainLoop", which
seem to be instantiating as "peak.running.scheduler.MainLoop" and the
"peak.events.interfaces.IEventLoop" is bound to
"peak.events.twisted_support.EventLoop". Did not go that far, looked at
the PEAK default event loop and couldn't figure out what's wrong
(without investgating links in the project's .ini file).

Does that mean I cannot use stopOnSignals with the Twisted event loop?
Do I have to implement that method? I believe, it's used because Twisted
handles TCP communications for us.

Best regards,
Alexey Smishlayev

Post by PJ Eby
Which event loop are you using? Twisted, the PEAK default, or
something else? The issue here appears to be that the eventLoop
property of the MainLoop instance lacks a `signals()` method -- which
would seem to mean it doesn't fully implement IEventLoop or is the
wrong type of object to start with.

Post by Alexey Smishlayev
Good day everyone!
I would like my PEAK application to stop on ^C or SIGINT. Currently, in that
case I get an output something like

in the log file. In CommandBase.py attribute self.mainloop is defined as

from peak.api import binding
from peak.running import commands, interfaces
mainLoop = binding.Obtain(interfaces.IMainLoop)
...

If I set "peak.running.mainLoop.stopOnSignals" in my project's .ini file to
anything else except empty tuple, on the application's startup I get the
following error (I tried "stopOnSignals = ('SIGINT',)")

How do I do everything correctly?
Best regards,
Alexey Smishlayev
_______________________________________________
PEAK mailing list
http://www.eby-sarna.com/mailman/listinfo/peak

PJ Eby

2015-09-29 23:12:45 UTC

Permalink

The failure is in trying to retrieve the `signals()` method from the
ISignalSource, which should be the io_events.SignalSource singleton.
What I don't understand is why it's recursing on the attempt to
retrieve the signals attribute. Specifically, it seems as though this
should only be able to happen if trying to load the 'sigsrc' attribute
results in an attempt to load the 'signals' attribute. I would
suggest stepping through with the debugger from line 66 of
scheduler.py and see if you can tell what's happening there.

Post by Alexey Smishlayev
Hello, Phillip!
I use binding.Obtain() on "peak.running.interfaces.IMainLoop", which seem to
be instantiating as "peak.running.scheduler.MainLoop" and the
"peak.events.interfaces.IEventLoop" is bound to
"peak.events.twisted_support.EventLoop". Did not go that far, looked at the
PEAK default event loop and couldn't figure out what's wrong (without
investgating links in the project's .ini file).
Does that mean I cannot use stopOnSignals with the Twisted event loop? Do I
have to implement that method? I believe, it's used because Twisted handles
TCP communications for us.
Best regards,
Alexey Smishlayev
Which event loop are you using? Twisted, the PEAK default, or
something else? The issue here appears to be that the eventLoop
property of the MainLoop instance lacks a `signals()` method -- which
would seem to mean it doesn't fully implement IEventLoop or is the
wrong type of object to start with.
Good day everyone!
I would like my PEAK application to stop on ^C or SIGINT. Currently, in that
case I get an output something like
29.09.2015 14:56:48.179 [DEBUG] Connect.twisted Unexpected error in main
loop.
29.09.2015 14:56:48.190 [ERROR] Connect.twisted Traceback (most recent
29.09.2015 14:56:48.190 [ERROR] File
"/Users/alexey/xtech2/tester/build/lib/ank/BBS/CommandBase.py", line 38, in
run
29.09.2015 14:56:48.190 [ERROR] self.mainLoop.run()
29.09.2015 14:56:48.190 [ERROR] File
"/Library/Python/2.7/site-packages/peak/running/scheduler.py", line 78, in
run
29.09.2015 14:56:48.190 [ERROR] return
self.eventLoop.runUntil(self.exitCode,True,idle=self.sleep)[0]
29.09.2015 14:56:48.190 [ERROR] File
"/Library/Python/2.7/site-packages/peak/events/twisted_support.py", line
186, in runUntil
29.09.2015 14:56:48.190 [ERROR] self.reactor.run(False)
29.09.2015 14:56:48.190 [ERROR] File
"/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/twisted/internet/base.py",
line 1192, in run
29.09.2015 14:56:48.190 [ERROR] self.mainLoop()
29.09.2015 14:56:48.190 [ERROR] --- <exception caught here> ---
29.09.2015 14:56:48.190 [ERROR] File
"/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/twisted/internet/base.py",
line 1204, in mainLoop
29.09.2015 14:56:48.190 [ERROR] self.doIteration(t)
29.09.2015 14:56:48.190 [ERROR] File
"/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/twisted/internet/selectreactor.py",
line 105, in doSelect
29.09.2015 14:56:48.190 [ERROR] [], timeout)
in the log file. In CommandBase.py attribute self.mainloop is defined as
from peak.api import binding
from peak.running import commands, interfaces
mainLoop = binding.Obtain(interfaces.IMainLoop)
...
If I set "peak.running.mainLoop.stopOnSignals" in my project's .ini file to
anything else except empty tuple, on the application's startup I get the
following error (I tried "stopOnSignals = ('SIGINT',)")
File "../ank/BBS/Assembler.py", line 370, in run
_exitCode = _root.run()
File "/Library/Python/2.7/site-packages/peak/running/commands.py", line
229, in run
return self._run() or 0
File "/Library/Python/2.7/site-packages/peak/running/commands.py", line
509, in _run
return self.invoke()
File "/Users/alexey/xtech2/tester/build/lib/ank/BBS/CommandBase.py",
line 38, in run
self.mainLoop.run()
File "/Library/Python/2.7/site-packages/peak/running/scheduler.py", line
66, in run
handler = self.eventLoop.signals(*self.stopOnSignals)
File "_once.pyx", line 112, in _once.BaseDescriptor.__get__
File "_once.pyx", line 100, in _once.__get__
File "/Library/Python/2.7/site-packages/peak/binding/components.py",
line 682, in delegate
return getattr(getattr(s,delegateAttr),a)
File "_once.pyx", line 112, in _once.BaseDescriptor.__get__
File "_once.pyx", line 100, in _once.__get__
File "/Library/Python/2.7/site-packages/peak/binding/components.py",
line 682, in delegate
return getattr(getattr(s,delegateAttr),a)
File "_once.pyx", line 88, in _once.BaseDescriptor.__get__
AttributeError: ('Recursive attempt to compute attribute', 'signals')
How do I do everything correctly?
Best regards,
Alexey Smishlayev
_______________________________________________
PEAK mailing list
http://www.eby-sarna.com/mailman/listinfo/peak
_______________________________________________
PEAK mailing list
http://www.eby-sarna.com/mailman/listinfo/peak

Alexey Smishlayev

2015-10-02 10:51:54 UTC

Permalink

Hello!

I tried using pdb today, to some degree of success. Turns out that
eventLoop.sigsrc attribute gets an instance of
"peak.events.twisted_support.Selector". eventLoop.signals attribute is
"binding.Delegate('sigsrc')", so it gets resolved to
"peak.events.twisted_support.Selector.signals", which is
"binding.Delegate('sigsrc')" - that's where recursion appears.

I've gathered some evidence using pdb:
/Library/Python/2.7/site-packages/peak/config/config_components.py(398)lookup()
-> for value in iterValues(component, configKey):
(Pdb) component
<peak.config.config_components.ServiceArea object at 0x108ba3390>
(Pdb) configKey
config.MultiKey(<class 'peak.binding.interfaces.IComponentFactory'>,
<class 'peak.events.interfaces.ISignalSource'>)
(Pdb) [x for x in iterValues(component, configKey)]
[<class 'peak.events.twisted_support.Selector'>, <class
'peak.events.io_events.SignalEvents'>]

--
/Library/Python/2.7/site-packages/peak/config/config_components.py(384)iterValues()
-> value = gcd(forObj, configKey)
(Pdb) forObj
<peak.config.config_components.ServiceArea object at 0x108ba3390>
(Pdb) configKey
config.MultiKey(<class 'peak.binding.interfaces.IComponentFactory'>,
<class 'peak.events.interfaces.ISignalSource'>)
(Pdb) gcd
<bound method ServiceArea._getConfigData of
<peak.config.config_components.ServiceArea object at 0x108ba3390>>
(Pdb) gcd(forObj, configKey)
<class 'peak.events.twisted_support.Selector'>

--
/Library/Python/2.7/site-packages/peak/config/config_components.py(593)_getConfigData()
-> value = rule.get()(self, configKey, forObj)
(Pdb) rule.get()
<function f at 0x1094bfcf8>
(Pdb) rule.get()(self, configKey, forObj)
<class 'peak.events.twisted_support.Selector'>

Unfortunately, my efforts stop here. I have no idea where from this
function f appeared in configuration rules, but it creates Selector
instance, which messes up the lookup.
From peak.ini: " peak.events.interfaces.ISignalSource =
io_events.SignalEvents"
I tried grepping "ISignalSource" in my project's directory, but this
gives no results.

Regards,
Alexey

Post by PJ Eby
The failure is in trying to retrieve the `signals()` method from the
ISignalSource, which should be the io_events.SignalSource singleton.
What I don't understand is why it's recursing on the attempt to
retrieve the signals attribute. Specifically, it seems as though this
should only be able to happen if trying to load the 'sigsrc' attribute
results in an attempt to load the 'signals' attribute. I would
suggest stepping through with the debugger from line 66 of
scheduler.py and see if you can tell what's happening there.

PJ Eby

2015-10-02 23:07:25 UTC

Permalink

The issue is that ISelector is a subclass of ISignalSource, and so
another Selector is created instead of the SignalSource singleton. I
don't really have a good way to fix this right now, but as a
workaround you could monkeypatch to set Selector.sigsrc to
io_events.SignalEvents and see how that works. (In truth, I think the
real problem may be that PEAK's signals support was never tested in
conjunction with Twisted, and IIRC, the signals support was only
half-baked to begin with when most work on PEAK ceased 10-11 years
ago.)

Post by Alexey Smishlayev
Hello!
I tried using pdb today, to some degree of success. Turns out that
eventLoop.sigsrc attribute gets an instance of
"peak.events.twisted_support.Selector". eventLoop.signals attribute is
"binding.Delegate('sigsrc')", so it gets resolved to
"peak.events.twisted_support.Selector.signals", which is
"binding.Delegate('sigsrc')" - that's where recursion appears.

Post by Alexey Smishlayev
/Library/Python/2.7/site-packages/peak/config/config_components.py(398)lookup()

(Pdb) component
<peak.config.config_components.ServiceArea object at 0x108ba3390>
(Pdb) configKey
config.MultiKey(<class 'peak.binding.interfaces.IComponentFactory'>, <class
'peak.events.interfaces.ISignalSource'>)
(Pdb) [x for x in iterValues(component, configKey)]
[<class 'peak.events.twisted_support.Selector'>, <class
'peak.events.io_events.SignalEvents'>]
--

Post by Alexey Smishlayev
/Library/Python/2.7/site-packages/peak/config/config_components.py(384)iterValues()

-> value = gcd(forObj, configKey)
(Pdb) forObj
<peak.config.config_components.ServiceArea object at 0x108ba3390>
(Pdb) configKey
config.MultiKey(<class 'peak.binding.interfaces.IComponentFactory'>, <class
'peak.events.interfaces.ISignalSource'>)
(Pdb) gcd
<bound method ServiceArea._getConfigData of
<peak.config.config_components.ServiceArea object at 0x108ba3390>>
(Pdb) gcd(forObj, configKey)
<class 'peak.events.twisted_support.Selector'>
--

Post by Alexey Smishlayev
/Library/Python/2.7/site-packages/peak/config/config_components.py(593)_getConfigData()

-> value = rule.get()(self, configKey, forObj)
(Pdb) rule.get()
<function f at 0x1094bfcf8>
(Pdb) rule.get()(self, configKey, forObj)
<class 'peak.events.twisted_support.Selector'>
Unfortunately, my efforts stop here. I have no idea where from this function
f appeared in configuration rules, but it creates Selector instance, which
messes up the lookup.
From peak.ini: " peak.events.interfaces.ISignalSource =
io_events.SignalEvents"
I tried grepping "ISignalSource" in my project's directory, but this gives
no results.
Regards,
Alexey
The failure is in trying to retrieve the `signals()` method from the
ISignalSource, which should be the io_events.SignalSource singleton.
What I don't understand is why it's recursing on the attempt to
retrieve the signals attribute. Specifically, it seems as though this
should only be able to happen if trying to load the 'sigsrc' attribute
results in an attempt to load the 'signals' attribute. I would
suggest stepping through with the debugger from line 66 of
scheduler.py and see if you can tell what's happening there.
Hello, Phillip!
I use binding.Obtain() on "peak.running.interfaces.IMainLoop", which seem to
be instantiating as "peak.running.scheduler.MainLoop" and the
"peak.events.interfaces.IEventLoop" is bound to
"peak.events.twisted_support.EventLoop". Did not go that far, looked at the
PEAK default event loop and couldn't figure out what's wrong (without
investgating links in the project's .ini file).
Does that mean I cannot use stopOnSignals with the Twisted event loop? Do I
have to implement that method? I believe, it's used because Twisted handles
TCP communications for us.
Best regards,
Alexey Smishlayev
Which event loop are you using? Twisted, the PEAK default, or
something else? The issue here appears to be that the eventLoop
property of the MainLoop instance lacks a `signals()` method -- which
would seem to mean it doesn't fully implement IEventLoop or is the
wrong type of object to start with.
Good day everyone!
I would like my PEAK application to stop on ^C or SIGINT. Currently, in that
case I get an output something like
29.09.2015 14:56:48.179 [DEBUG] Connect.twisted Unexpected error in main
loop.
29.09.2015 14:56:48.190 [ERROR] Connect.twisted Traceback (most recent
29.09.2015 14:56:48.190 [ERROR] File
"/Users/alexey/xtech2/tester/build/lib/ank/BBS/CommandBase.py", line 38, in
run
29.09.2015 14:56:48.190 [ERROR] self.mainLoop.run()
29.09.2015 14:56:48.190 [ERROR] File
"/Library/Python/2.7/site-packages/peak/running/scheduler.py", line 78, in
run
29.09.2015 14:56:48.190 [ERROR] return
self.eventLoop.runUntil(self.exitCode,True,idle=self.sleep)[0]
29.09.2015 14:56:48.190 [ERROR] File
"/Library/Python/2.7/site-packages/peak/events/twisted_support.py", line
186, in runUntil
29.09.2015 14:56:48.190 [ERROR] self.reactor.run(False)
29.09.2015 14:56:48.190 [ERROR] File
"/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/twisted/internet/base.py",
line 1192, in run
29.09.2015 14:56:48.190 [ERROR] self.mainLoop()
29.09.2015 14:56:48.190 [ERROR] --- <exception caught here> ---
29.09.2015 14:56:48.190 [ERROR] File
"/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/twisted/internet/base.py",
line 1204, in mainLoop
29.09.2015 14:56:48.190 [ERROR] self.doIteration(t)
29.09.2015 14:56:48.190 [ERROR] File
"/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/twisted/internet/selectreactor.py",
line 105, in doSelect
29.09.2015 14:56:48.190 [ERROR] [], timeout)
in the log file. In CommandBase.py attribute self.mainloop is defined as
from peak.api import binding
from peak.running import commands, interfaces
mainLoop = binding.Obtain(interfaces.IMainLoop)
...
If I set "peak.running.mainLoop.stopOnSignals" in my project's .ini file to
anything else except empty tuple, on the application's startup I get the
following error (I tried "stopOnSignals = ('SIGINT',)")
File "../ank/BBS/Assembler.py", line 370, in run
_exitCode = _root.run()
File "/Library/Python/2.7/site-packages/peak/running/commands.py", line
229, in run
return self._run() or 0
File "/Library/Python/2.7/site-packages/peak/running/commands.py", line
509, in _run
return self.invoke()
File "/Users/alexey/xtech2/tester/build/lib/ank/BBS/CommandBase.py",
line 38, in run
self.mainLoop.run()
File "/Library/Python/2.7/site-packages/peak/running/scheduler.py", line
66, in run
handler = self.eventLoop.signals(*self.stopOnSignals)
File "_once.pyx", line 112, in _once.BaseDescriptor.__get__
File "_once.pyx", line 100, in _once.__get__
File "/Library/Python/2.7/site-packages/peak/binding/components.py",
line 682, in delegate
return getattr(getattr(s,delegateAttr),a)
File "_once.pyx", line 112, in _once.BaseDescriptor.__get__
File "_once.pyx", line 100, in _once.__get__
File "/Library/Python/2.7/site-packages/peak/binding/components.py",
line 682, in delegate
return getattr(getattr(s,delegateAttr),a)
File "_once.pyx", line 88, in _once.BaseDescriptor.__get__
AttributeError: ('Recursive attempt to compute attribute', 'signals')
How do I do everything correctly?
Best regards,
Alexey Smishlayev
_______________________________________________
PEAK mailing list
http://www.eby-sarna.com/mailman/listinfo/peak
_______________________________________________
PEAK mailing list
http://www.eby-sarna.com/mailman/listinfo/peak
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Alexey Smishlayev

2015-10-07 10:09:43 UTC

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Hello!

The application runs successfully with my patch applied and it even
reacts gracefully to the ^C, so you could say that the desired behavior
is achieved. I've done it with the following patch:

def _patchSelector(self):
from peak.events.io_events import Selector
from peak.events.io_events import SignalEvents
Selector.sigsrc = binding.Make(SignalEvents, attrName="sigsrc")
_patchSelector = binding.Make(_patchSelector, uponAssembly=True)

I guess, I'll leave it for now, but it is not a kind of code I would
like my colleagues to inherit. If you would provide some directions, I
will consider fixing and testing PEAK signaling with Twisted support and
contributing it to your project.

Regards,
Alexey

Post by PJ Eby
The issue is that ISelector is a subclass of ISignalSource, and so
another Selector is created instead of the SignalSource singleton. I
don't really have a good way to fix this right now, but as a
workaround you could monkeypatch to set Selector.sigsrc to
io_events.SignalEvents and see how that works. (In truth, I think the
real problem may be that PEAK's signals support was never tested in
conjunction with Twisted, and IIRC, the signals support was only
half-baked to begin with when most work on PEAK ceased 10-11 years
ago.)

Post by Alexey Smishlayev
/Library/Python/2.7/site-packages/peak/config/config_components.py(398)lookup()

Post by Alexey Smishlayev
/Library/Python/2.7/site-packages/peak/config/config_components.py(384)iterValues()

Post by Alexey Smishlayev
/Library/Python/2.7/site-packages/peak/config/config_components.py(593)_getConfigData()