> 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 23:04:04.000000000 +0100
+++ kaa-base-0.6.0.new//src/process.py 2010-03-25 23:15:37.000000000 +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.
