classification
Title: kevent does not accept KQ_NOTE_EXIT (and other (f)flags)
Type: behavior Stage: patch review
Components: Extension Modules Versions: Python 3.3, Python 3.2, Python 3.1, Python 2.7
process
Status: open Resolution:
Dependencies: Superseder:
Assigned To: Nosy List: DragonSA, ned.deily, ronaldoussoren
Priority: normal Keywords:

Created on 2011-05-01 18:26 by DragonSA, last changed 2011-05-01 18:50 by pitrou.

Files
File name Uploaded Description Edit
patch-Modules-selectmodule.c DragonSA, 2011-05-01 18:26
Messages (1)
msg134918 - (view) Author: David Naylor (DragonSA) Date: 2011-05-01 18:26
kevent does not accept all legitimate parameters, such as KQ_NOTE_EXIT.  

For example:
>> from select import *
>> kevent(0, KQ_FILTER_PROC, KQ_EV_ADD | KQ_EV_ENABLE, KQ_NOTE_EXIT)
OverflowError: signed integer is greater than maximum

While the following C code compiles (under -Wall -pedantic) without error, or warning:
"""
#include <sys/types.h>
#include <sys/event.h>
#include <sys/time.h>

int main(int argc, char **argv) {

  struct kevent ke;

  EV_SET(&ke, 0, EVFILT_PROC, EV_ADD | EV_ENABLE, NOTE_EXIT, 0, 0);

  return (0);

}
"""

Looking at the Modules/selectmodule.c file it is clear that the fields "flags" and "fflags" are defined as T_USHORT and T_UINT however the flags passed to PyArg_ParseTupleAndKeywords are 'h' and 'i' respectively (implying signed numbers).  

A workaround exists where values X > (2**31 - 1) are passed as (X - 2**32).  Also the attached patch fixes the error.
History
Date User Action Args
2011-05-01 18:50:22pitrousetnosy: + ronaldoussoren, ned.deily
stage: patch review

versions: - Python 2.6, Python 2.5, Python 3.4
2011-05-01 18:26:33DragonSAcreate