setjmp in Cython
Found this nice little demo of how to use setjmp in Cython through Google Code:
cdef extern from "setjmp.h":
struct __jump_buf_tag:
pass
ctypedef __jump_buf_tag jmp_buf
int setjmp(jmp_buf __env)
From http://sage.math.washington.edu/home/dfdeshom/sage/devel/sage-darcs.tar.gz