Re: How can I catch segmentation fault in python?
Just checked what is valgrind, sounds promising. Let me try that. Thanks a lot, Justin. On Nov 17, 9:47 am, Wolfgang Rohdewald wrote: > On Mittwoch 17 November 2010, Wolfgang Rohdewald wrote: > > > On Mittwoch 17 November 2010, justin wrote: > > > But the problem is that the code is not mine, and it takes > > > over a day for me to get the point where the segmentation > > > fault occurred. Plus, it seems that the point is not > > > deterministic > > > > Still, I think I should at least try to figure out exactly > > > at which point the segmentation fault occurs, and think > > > where to go from there according to your kind advice. > > > try valgrind > > hit the send button too fast... > > even if the segmentation fault only happens after a long time > valgrind might find problems much sooner, and fixing them > might remove the segmentation fault. > > -- > Wolfgang -- http://mail.python.org/mailman/listinfo/python-list
Re: How can I catch segmentation fault in python?
On Mittwoch 17 November 2010, Wolfgang Rohdewald wrote: > On Mittwoch 17 November 2010, justin wrote: > > But the problem is that the code is not mine, and it takes > > over a day for me to get the point where the segmentation > > fault occurred. Plus, it seems that the point is not > > deterministic > > > > Still, I think I should at least try to figure out exactly > > at which point the segmentation fault occurs, and think > > where to go from there according to your kind advice. > > try valgrind hit the send button too fast... even if the segmentation fault only happens after a long time valgrind might find problems much sooner, and fixing them might remove the segmentation fault. -- Wolfgang -- http://mail.python.org/mailman/listinfo/python-list
Re: How can I catch segmentation fault in python?
On Mittwoch 17 November 2010, justin wrote: > But the problem is that the code is not mine, and it takes > over a day for me to get the point where the segmentation > fault occurred. Plus, it seems that the point is not > deterministic > > Still, I think I should at least try to figure out exactly at > which point the segmentation fault occurs, and think where to > go from there according to your kind advice. try valgrind -- mit freundlichen Grüssen with my best greetings Wolfgang Rohdewald dipl. Informatik Ing. ETH Rohdewald Systemberatung Karauschenstieg 4 D 21640 Horneburg Tel.: 04163 826 819 Fax: 04163 826 828 Internet: http://www.rohdewald.de -- http://mail.python.org/mailman/listinfo/python-list
Re: How can I catch segmentation fault in python?
On Nov 17, 1:06 am, John Nagle wrote: > On 11/16/2010 10:15 PM, swapnil wrote: > > > > > > > On Nov 17, 10:26 am, justin wrote: > >> Hi all, > > >> I am calling a program written in C inside Python using ctypes, > >> and it seems that sometimes the program in C crashes while it's being > >> used in Python. > >> Even under the circumstances, I want to get the Python program going > >> by handling the segmentation fault. > > >> I've already searched the Internet, but couldn't get the right answer > >> to catch them. > >> Could any of you please let me know how to deal with this and catch > >> the segmentation fault in Python? > > >> Thanks, > >> Justin. > > > Segmentation fault isn't exactly an exception that you can catch. It > > usually means something has gone horribly wrong, like dereferencing > > invalid pointer, trying to access memory out of process's range. Since > > if you run out of memory Python simply raises MemoryError exception, > > which you can catch. So that is not the case for segmentation fault. > > Either fix the program so it doesn't crash,or run the offending > module and the C code in a subprocess. > > John Nagle Thanks guys for this fast replies, Turns out that it is a fact that segmentation fault is not what I can deal with in programming level. But the problem is that the code is not mine, and it takes over a day for me to get the point where the segmentation fault occurred. Plus, it seems that the point is not deterministic Still, I think I should at least try to figure out exactly at which point the segmentation fault occurs, and think where to go from there according to your kind advice. Again many thanks, Justin. -- http://mail.python.org/mailman/listinfo/python-list
Re: How can I catch segmentation fault in python?
On 11/16/2010 10:15 PM, swapnil wrote: On Nov 17, 10:26 am, justin wrote: Hi all, I am calling a program written in C inside Python using ctypes, and it seems that sometimes the program in C crashes while it's being used in Python. Even under the circumstances, I want to get the Python program going by handling the segmentation fault. I've already searched the Internet, but couldn't get the right answer to catch them. Could any of you please let me know how to deal with this and catch the segmentation fault in Python? Thanks, Justin. Segmentation fault isn't exactly an exception that you can catch. It usually means something has gone horribly wrong, like dereferencing invalid pointer, trying to access memory out of process's range. Since if you run out of memory Python simply raises MemoryError exception, which you can catch. So that is not the case for segmentation fault. Either fix the program so it doesn't crash,or run the offending module and the C code in a subprocess. John Nagle -- http://mail.python.org/mailman/listinfo/python-list
Re: How can I catch segmentation fault in python?
On Tue, Nov 16, 2010 at 9:26 PM, justin wrote: > Hi all, > > I am calling a program written in C inside Python using ctypes, > and it seems that sometimes the program in C crashes while it's being > used in Python. > Even under the circumstances, I want to get the Python program going > by handling the segmentation fault. > > I've already searched the Internet, but couldn't get the right answer > to catch them. > Could any of you please let me know how to deal with this and catch > the segmentation fault in Python? You can't "catch" it. It's not a mere Exception, it's a fatal error that effectively crashes the interpreter itself. At best, you could perhaps use the `multiprocessing` or `subprocess` modules to segregate the part of your program that uses ctypes and then try and recover when you detect that the subprocess has crashed. Instead, if possible, fix the C program and/or ensure that there's not an error in your ctypes interfacing code. Cheers, Chris -- http://blog.rebertia.com -- http://mail.python.org/mailman/listinfo/python-list
Re: How can I catch segmentation fault in python?
On Nov 17, 10:26 am, justin wrote: > Hi all, > > I am calling a program written in C inside Python using ctypes, > and it seems that sometimes the program in C crashes while it's being > used in Python. > Even under the circumstances, I want to get the Python program going > by handling the segmentation fault. > > I've already searched the Internet, but couldn't get the right answer > to catch them. > Could any of you please let me know how to deal with this and catch > the segmentation fault in Python? > > Thanks, > Justin. Segmentation fault isn't exactly an exception that you can catch. It usually means something has gone horribly wrong, like dereferencing invalid pointer, trying to access memory out of process's range. Since if you run out of memory Python simply raises MemoryError exception, which you can catch. So that is not the case for segmentation fault. -- http://mail.python.org/mailman/listinfo/python-list
How can I catch segmentation fault in python?
Hi all, I am calling a program written in C inside Python using ctypes, and it seems that sometimes the program in C crashes while it's being used in Python. Even under the circumstances, I want to get the Python program going by handling the segmentation fault. I've already searched the Internet, but couldn't get the right answer to catch them. Could any of you please let me know how to deal with this and catch the segmentation fault in Python? Thanks, Justin. -- http://mail.python.org/mailman/listinfo/python-list
