I have an application using gevent 0.13.8 + psycopg2 2.5.1 which
segfaults when an attempt is made to 'green' psycopg using a slight
variant of Daniele Varrazzo's code provided by Denis Bilenko
here.
A snippet from my code:
if __name__ == '__main__':
from gevent import monkey
from gevent.pywsgi import WSGIServer
from psycopg_green import make_psycopg_green
monkey.patch_all()
#make_psycopg_green() # uncommenting this line -> segfault
...
app = WebApp(get_session_factory())
WSGIServer(('', 8000), app, log=None).serve_forever()
The segfault occurs in pyscopg2 C code. When the
make_psycopg_green() call is commented out, no
segfault occurs and operation is as expected, though of course
psycopg2 calls are synchronous.
The failure only occurs when I am invoking multiple web requests
from concurrent clients, which cause multiple greenlets to be
spawned to run long-running jobs which invoke psycopg2 through the
SQLAlchemy ORM.
Stack trace from core dump using gdb (in case it's
any use):
Core was generated by `python gwebapp.py'.
Program terminated with signal 11, Segmentation fault.
Core was generated by `python gwebapp.py'.
Program terminated with signal 11, Segmentation fault.
#0 0x00000000004606a9 in PyDict_SetItem ()
(gdb) where
#0 0x00000000004606a9 in PyDict_SetItem ()
#1 0x0000000000461a48 in PyDict_SetItemString ()
#2 0x00007fc172da98ba in psyco_error_reduce (self=0x25fb1b8)
at psycopg/error_type.c:166
#3 0x000000000041ad4a in PyObject_Call ()
#4 0x00000000004b5ed6 in PyEval_CallObjectWithKeywords ()
#5 0x000000000047c457 in ?? ()
#6 0x000000000041ad4a in PyObject_Call ()
#7 0x0000000000526f8e in ?? ()
#8 0x00000000005291d6 in ?? ()
#9 0x00000000005276c3 in ?? ()
#10 0x00000000005270f3 in ?? ()
#11 0x00000000005291d6 in ?? ()
#12 0x00000000005276c3 in ?? ()
#13 0x00000000005277c4 in ?? ()
#14 0x00000000005288d3 in ?? ()
#15 0x00000000005289a5 in ?? ()
#16 0x00000000004b66b9 in PyEval_EvalFrameEx ()
#17 0x00000000004b6f57 in PyEval_EvalFrameEx ()
#18 0x00000000004b6f57 in PyEval_EvalFrameEx ()
#19 0x00000000004bcdbd in PyEval_EvalCodeEx ()
#20 0x000000000044914f in ?? ()
#21 0x000000000041ad4a in PyObject_Call ()
#22 0x000000000043092e in ?? ()
#23 0x000000000041ad4a in PyObject_Call ()
#24 0x00000000004b6d7e in PyEval_EvalFrameEx ()
#25 0x00000000004b6f57 in PyEval_EvalFrameEx ()
#26 0x00000000004b6f57 in PyEval_EvalFrameEx ()
#27 0x00000000004b6f57 in PyEval_EvalFrameEx ()
#28 0x00000000004bcdbd in PyEval_EvalCodeEx ()
#29 0x0000000000449308 in ?? ()
#30 0x000000000041ad4a in PyObject_Call ()
#31 0x00000000004b8498 in PyEval_EvalFrameEx ()
#32 0x00000000004bcdbd in PyEval_EvalCodeEx ()
#33 0x0000000000449308 in ?? ()
#34 0x000000000041ad4a in PyObject_Call ()
#35 0x00000000004b8498 in PyEval_EvalFrameEx ()
#36 0x00000000004bcdbd in PyEval_EvalCodeEx ()
#37 0x00000000004b6c34 in PyEval_EvalFrameEx ()
#38 0x00000000004bd3ee in PyEval_EvalCodeEx ()
#39 0x0000000000449308 in ?? ()
#40 0x000000000041ad4a in PyObject_Call ()
#41 0x00000000004b8498 in PyEval_EvalFrameEx ()
#42 0x00000000004bd3ee in PyEval_EvalCodeEx ()
#43 0x0000000000449308 in ?? ()
#44 0x000000000041ad4a in PyObject_Call ()
#45 0x00000000004b8498 in PyEval_EvalFrameEx ()
#46 0x00000000004bcdbd in PyEval_EvalCodeEx ()
#47 0x00000000004b6c34 in PyEval_EvalFrameEx ()
#48 0x00000000004bcdbd in PyEval_EvalCodeEx ()
#49 0x00000000004b6c34 in PyEval_EvalFrameEx ()
#50 0x00000000004bcdbd in PyEval_EvalCodeEx ()
#51 0x000000000044914f in ?? ()
#52 0x000000000041ad4a in PyObject_Call ()
#53 0x000000000043092e in ?? ()
#54 0x000000000041ad4a in PyObject_Call ()
#55 0x0000000000480716 in ?? ()
#56 0x000000000041ad4a in PyObject_Call ()
#57 0x00000000004b6d7e in PyEval_EvalFrameEx ()
#58 0x00000000004b6f57 in PyEval_EvalFrameEx ()
#59 0x00000000004b6f57 in PyEval_EvalFrameEx ()
#60 0x00000000004b6f57 in PyEval_EvalFrameEx ()
#61 0x00000000004b6f57 in PyEval_EvalFrameEx ()
#62 0x00000000004bcdbd in PyEval_EvalCodeEx ()
#63 0x0000000000449308 in ?? ()
#64 0x000000000041ad4a in PyObject_Call ()
#65 0x00000000004b8498 in PyEval_EvalFrameEx ()
#66 0x00000000004bcdbd in PyEval_EvalCodeEx ()
#67 0x0000000000449308 in ?? ()
#68 0x000000000041ad4a in PyObject_Call ()
#69 0x000000000043092e in ?? ()
#70 0x000000000041ad4a in PyObject_Call ()
#71 0x00000000004b5ed6 in PyEval_CallObjectWithKeywords ()
#72 0x00007fc17329ea56 in g_initialstub (mark=<optimized out>)
at greenlet.c:804
#73 0x00007fc17329e398 in g_switch (target=0x1875f50, args=0x7fc175e66050,
kwargs=0x3741130) at greenlet.c:576
#74 0x00007fc17329ef26 in green_switch (self=<optimized out>,
args=<optimized out>, kwargs=<optimized out>) at greenlet.c:1092
#75 0x000000000041ad4a in PyObject_Call ()
#76 0x00007fc17390b3f3 in __pyx_f_6gevent_4core___simple_handler (
__pyx_v_fd=<optimized out>, __pyx_v_evtype=<optimized out>,
__pyx_v_arg=0x3eb1488) at gevent/core.c:5130
#77 0x00007fc1736b8d3c in event_base_loop () from /usr/lib/libevent-2.0.so.5
#78 0x00007fc1738fe105 in __pyx_pf_6gevent_4core_2dispatch (
__pyx_self=<optimized out>) at gevent/core.c:6083
#79 __pyx_pw_6gevent_4core_3dispatch (__pyx_self=<optimized out>,
unused=<optimized out>) at gevent/core.c:6036
#80 0x00000000004b7281 in PyEval_EvalFrameEx ()
#81 0x00000000004bcdbd in PyEval_EvalCodeEx ()
#82 0x000000000044914f in ?? ()
#83 0x000000000041ad4a in PyObject_Call ()
#84 0x000000000043092e in ?? ()
#85 0x000000000041ad4a in PyObject_Call ()
#86 0x00000000004b5ed6 in PyEval_CallObjectWithKeywords ()
#87 0x00007fc17329ea56 in g_initialstub (mark=<optimized out>)
at greenlet.c:804
#88 0x00007fc17329e398 in g_switch (target=0x25f7050, args=0x7fc175e66050,
kwargs=0x0) at greenlet.c:576
#89 0x00007fc17329ef26 in green_switch (self=<optimized out>,
args=<optimized out>, kwargs=<optimized out>) at greenlet.c:1092
#90 0x000000000041ad4a in PyObject_Call ()
#91 0x00000000004b5ed6 in PyEval_CallObjectWithKeywords ()
#92 0x00000000004399a7 in ?? ()
#93 0x000000000041ad4a in PyObject_Call ()
#94 0x00000000004b6d7e in PyEval_EvalFrameEx ()
#95 0x00000000004b6f57 in PyEval_EvalFrameEx ()
#96 0x00000000004bcdbd in PyEval_EvalCodeEx ()
#97 0x00000000004b6c34 in PyEval_EvalFrameEx ()
#98 0x00000000004bcdbd in PyEval_EvalCodeEx ()
#99 0x00000000004b6c34 in PyEval_EvalFrameEx ()
#100 0x00000000004bcdbd in PyEval_EvalCodeEx ()
#101 0x00000000004bd892 in PyEval_EvalCode ()
#102 0x00000000004dcd82 in ?? ()
#103 0x00000000004dd974 in PyRun_FileExFlags ()
tagged:rel-2.2.1
tagged:os-linux
tagged:gevent
Daniele Varrazzo
Vinay Sajip