[Python-Dev] KeyboardInterrupt on Windows

[Neal Norwitz]

On Fri, May 30, 2003 at 04:35:53PM -0400, Guido van Rossum wrote:
> I received this problem report (Kurt is the IDLEFORK developer).  Does
> anybody know what could be the matter here?  What changed recently???

>        while 1: pass
> 
> doesn't respond to a KeyboardInterrupt on Python2.3b1 on either
> WinXP or W2K.

Could this be from the optimization Raymond did:

>>> def f():
...  while 1: pass


>>> dis.dis(f)
  2           0 SETUP_LOOP              12 (to 15)
              3 JUMP_FORWARD             4 (to 10)
              6 JUMP_IF_FALSE            4 (to 13)
              9 POP_TOP
        >>   10 JUMP_ABSOLUTE           10
        >>   13 POP_TOP
             14 POP_BLOCK
        >>   15 LOAD_CONST               0 (None)
             18 RETURN_VALUE

3 jumps to 10, 10 jumps to itself unless I'm reading this wrong.

See Python/compile.c::optimize_code (starting around line 339)

Neal