Bug#575293: [Pkg-freevo-maint] Bug#575293: python-kaa-base: integration with twisted does not work anymore
hi, thanks a lot for the detailed analysis On Wed, Mar 24, 2010 at 09:14:20PM +0100, Mickael Royer wrote: More information : The problem does not appear in version 0.6.0-2 and is due to this diff : diff -ru kaa/process.py kaa--new/process.py [...] yes, this was added in the hope of supporting architectures with different libc When we import kaa, this code is called and ctypes.util.find_library call popen function which force kaa notifier init. do you mean that the call os.popen in line 55 in /usr/lib/python2.5/ctypes/util.py triggers an initialization of kaa notifier ? how does this happen? can it be avoided? a. -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Bug#575293: [Pkg-freevo-maint] Bug#575293: python-kaa-base: integration with twisted does not work anymore
Hi, do you mean that the call os.popen in line 55 in /usr/lib/python2.5/ctypes/util.py triggers an initialization of kaa notifier ? how does this happen? It happens like that : 1. import kaa 2. in kaa/__init__.py line 39 from async import ... 3. in kaa/async.py line 977 import main 4. in kaa/main.py line 30 from process import supervisor 5. in kaa/process.py line 182 supervisor = _Supervisor 6. in kaa/process.py line 64 in constructor of _Supervisor : signal.signal(signal.SIGCHLD, self._sigchld_handler) So kaa check SIGHDL (signal sent to a process when a child process terminates). Just after that (in the same function, line 79) we call ctypes.util.find_library which call popen. When popen finished, SIGHDL is raised, so self._sigchld_handler is called and the notifier is initialized. can it be avoided? The solution I see is to load libc library with ctypes just before start to handle SIGHDL signal. I try quickly and it seems to work well. Cheers Mickaël On Thu, Mar 25, 2010 at 9:44 AM, A Mennucc deb...@tonelli.sns.it wrote: hi, thanks a lot for the detailed analysis On Wed, Mar 24, 2010 at 09:14:20PM +0100, Mickael Royer wrote: More information : The problem does not appear in version 0.6.0-2 and is due to this diff : diff -ru kaa/process.py kaa--new/process.py [...] yes, this was added in the hope of supporting architectures with different libc When we import kaa, this code is called and ctypes.util.find_library call popen function which force kaa notifier init. do you mean that the call os.popen in line 55 in /usr/lib/python2.5/ctypes/util.py triggers an initialization of kaa notifier ? how does this happen? can it be avoided? a. -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Bug#575293: [Pkg-freevo-maint] Bug#575293: python-kaa-base: integration with twisted does not work anymore
It happens like that :
1. import kaa
2. in kaa/__init__.py line 39 from async import ...
3. in kaa/async.py line 977 import main
4. in kaa/main.py line 30 from process import supervisor
5. in kaa/process.py line 182 supervisor = _Supervisor
6. in kaa/process.py line 64 in constructor of _Supervisor :
signal.signal(signal.SIGCHLD, self._sigchld_handler)
From tonight's investigations, I could get the following backtrace
which is where the timer is started and thus the notifier is said to
be already started.
--
import kaa
File /usr/lib/python2.5/site-packages/kaa/__init__.py, line 39, in module
from async import TimeoutException, InProgress, InProgressCallback, \
File /usr/lib/python2.5/site-packages/kaa/async.py, line 977, in module
import main
File /usr/lib/python2.5/site-packages/kaa/main.py, line 50, in module
from process import supervisor
File /usr/lib/python2.5/site-packages/kaa/process.py, line 182, in module
supervisor = _Supervisor()
File /usr/lib/python2.5/site-packages/kaa/process.py, line 79, in __init__
libc=ctypes.util.find_library('c')
File /usr/lib/python2.5/ctypes/util.py, line 164, in find_library
return _findSoname_ldconfig(name) or _get_soname(_findLib_gcc(name))
File /usr/lib/python2.5/ctypes/util.py, line 158, in _findSoname_ldconfig
os.popen('LANG=C /sbin/ldconfig -p 2/dev/null').read())
File /usr/lib/python2.5/site-packages/kaa/timer.py, line 96, in newfunc
t.start(interval)
--
Now, this is in the @timed decorator from kaa.timer and using a dirty
print statement, I could get the only decorated function name which is
_sigchld_handler . This signal is triggered, because the ldconfig
child process terminates.
Knowing this, a working fix, as said, is as simple as delaying the
signal setting, as shown by the attached patch, which works.
Cheers,
Alex
diff -Nru kaa-base-0.6.0/src/process.py kaa-base-0.6.0.new//src/process.py
--- kaa-base-0.6.0/src/process.py 2010-03-25 23:04:04.0 +0100
+++ kaa-base-0.6.0.new//src/process.py 2010-03-25 23:15:37.0 +0100
@@ -61,7 +61,6 @@
def __init__(self):
self.processes = {}
-signal.signal(signal.SIGCHLD, self._sigchld_handler)
# Set SA_RESTART bit for the signal, which restarts any interrupted
# system calls -- however, select (at least on Linux) is NOT restarted
# for reasons described at:
@@ -72,11 +71,15 @@
v = sys.version_info
if v[0] = 3 or (v[0] == 2 and v[1] = 6):
# Python 2.6+
+signal.signal(signal.SIGCHLD, self._sigchld_handler)
signal.siginterrupt(signal.SIGCHLD, False)
elif v[0] == 2 and v[1] == 5:
# Python 2.5
import ctypes, ctypes.util
libc=ctypes.util.find_library('c')
+# ctypes.util.find_library() involves a child process, so the
+# hanler should be set after the call.
+signal.signal(signal.SIGCHLD, self._sigchld_handler)
ctypes.CDLL(libc).siginterrupt(signal.SIGCHLD, 0)
else:
# Python 2.4- is not supported.
Bug#575293: python-kaa-base: integration with twisted does not work anymore
Package: python-kaa-base
Version: 0.6.0-4
Severity: normal
Hi,
Using the following snippet, from the documentation[1], integration with
twisted does not work anymore. Maybe this is related to the new twisted
version 10.
--
# get reactor
from twisted.internet import reactor
import kaa
kaa.main.select_notifier('twisted')
# add callbacks to Twisted or kaa
# see test/kaa_in_twisted.py in the kaa.base package
# run Twisted mainloop
reactor.run()
--
The following exception is raised :
$ python kaa_twisted.py
Traceback (most recent call last):
File kaa_twisted.py, line 5, in module
kaa.main.select_notifier('twisted')
File /usr/lib/python2.5/site-packages/kaa/main.py, line 89, in
select_notifier
return nf_thread.init(module, **options)
File /usr/lib/python2.5/site-packages/kaa/nf_thread.py, line 147, in init
notifier.init( 'generic', force_internal=True, **options )
File /usr/lib/python2.5/site-packages/kaa/nf_wrapper.py, line 164, in init
raise RuntimeError('notifier already initialized')
RuntimeError: notifier already initialized
Please note that the test supplied in kaa-base (test/kaa_in_twisted.py )
also fails.
Feel free to ask for more info.
Thanks,
Alex
[1]
http://doc.freevo.org/api/kaa/base/core/mainloop.html#integration-with-other-frameworks
-- System Information:
Debian Release: squeeze/sid
APT prefers unstable
APT policy: (500, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Kernel: Linux 2.6.32-4-amd64 (SMP w/2 CPU cores)
Locale: LANG=fr_FR.UTF-8, LC_CTYPE=fr_FR.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Versions of packages python-kaa-base depends on:
ii libc62.10.2-6Embedded GNU C Library: Shared lib
ii libglib2.0-0 2.22.4-1The GLib library of C routines
ii python 2.5.4-9 An interactive high-level object-o
ii python-central 0.6.14+nmu2 register and build utility for Pyt
ii python-sqlite1.0.1-7+b1 python interface to SQLite 2
python-kaa-base recommends no packages.
python-kaa-base suggests no packages.
-- no debconf information
--
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Bug#575293: python-kaa-base: integration with twisted does not work anymore
More information :
The problem does not appear in version 0.6.0-2 and is due to this diff :
diff -ru kaa/process.py kaa--new/process.py
--- kaa/process.py 2010-03-24 20:44:55.080934884 +0100
+++ kaa--new/process.py 2010-03-24 17:57:34.0 +0100
@@ -75,10 +75,8 @@
signal.siginterrupt(signal.SIGCHLD, False)
elif v[0] == 2 and v[1] == 5:
# Python 2.5
-import ctypes
-libc=libc.so.6
-if not os.path.exists('/lib/'+libc): #ia64
-libc=libc.so.6.1
+import ctypes, ctypes.util
+libc=ctypes.util.find_library('c')
ctypes.CDLL(libc).siginterrupt(signal.SIGCHLD, 0)
else:
# Python 2.4- is not supported.
When we import kaa, this code is called and ctypes.util.find_library
call popen function which force kaa notifier init.
So when we try to select a notifier after the import, an exception is
raised because kaa notifier is already initialized.
Thanks
Mickaël
On Wed, Mar 24, 2010 at 8:01 PM, Alexandre Rossi
alexandre.ro...@gmail.com wrote:
Package: python-kaa-base
Version: 0.6.0-4
Severity: normal
Hi,
Using the following snippet, from the documentation[1], integration with
twisted does not work anymore. Maybe this is related to the new twisted
version 10.
--
# get reactor
from twisted.internet import reactor
import kaa
kaa.main.select_notifier('twisted')
# add callbacks to Twisted or kaa
# see test/kaa_in_twisted.py in the kaa.base package
# run Twisted mainloop
reactor.run()
--
The following exception is raised :
$ python kaa_twisted.py
Traceback (most recent call last):
File kaa_twisted.py, line 5, in module
kaa.main.select_notifier('twisted')
File /usr/lib/python2.5/site-packages/kaa/main.py, line 89, in
select_notifier
return nf_thread.init(module, **options)
File /usr/lib/python2.5/site-packages/kaa/nf_thread.py, line 147, in init
notifier.init( 'generic', force_internal=True, **options )
File /usr/lib/python2.5/site-packages/kaa/nf_wrapper.py, line 164, in init
raise RuntimeError('notifier already initialized')
RuntimeError: notifier already initialized
Please note that the test supplied in kaa-base (test/kaa_in_twisted.py )
also fails.
Feel free to ask for more info.
Thanks,
Alex
[1]
http://doc.freevo.org/api/kaa/base/core/mainloop.html#integration-with-other-frameworks
-- System Information:
Debian Release: squeeze/sid
APT prefers unstable
APT policy: (500, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Kernel: Linux 2.6.32-4-amd64 (SMP w/2 CPU cores)
Locale: LANG=fr_FR.UTF-8, LC_CTYPE=fr_FR.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Versions of packages python-kaa-base depends on:
ii libc6 2.10.2-6 Embedded GNU C Library: Shared
lib
ii libglib2.0-0 2.22.4-1 The GLib library of C routines
ii python 2.5.4-9 An interactive high-level
object-o
ii python-central 0.6.14+nmu2 register and build utility for
Pyt
ii python-sqlite 1.0.1-7+b1 python interface to SQLite 2
python-kaa-base recommends no packages.
python-kaa-base suggests no packages.
-- no debconf information
--
To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org
with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
