Hopefully complete python ctypes module

• Previous message: Neal Becker: "python ctypes interface to blcr?"

1 question:
Not sure whether to the GIL should be released during the call or not.
I'm not using any multi-threading, so I think it doesn't matter?

from __future__ import with_statement
from ctypes import *
from errno import *
import os

def die (msg):
    abort (msg)
    
class cr_checkpoint_args_t (Structure):
    _fields_ = [("cr_version", c_int),
                ("cr_scope", c_int),
                ("cr_target", c_int),
                ("cr_fd", c_int),
                ("cr_signal", c_int),
                ("cr_timeout", c_int),
                ("cr_flags", c_int)]
    
libcr = CDLL ('/usr/lib64/libcr.so.0')

cr_args = cr_checkpoint_args_t()
cr_args.cr_version = 1
CR_SCOPE_PROC = 1

libcr.cri_initialize_checkpoint_args_t (byref(cr_args))
cr_args.cr_scope = CR_SCOPE_PROC
cr_args.cr_target = 0
cr_args.cr_signal = 0
cr_args.cr_timeout = 0
cr_args.cr_flags = 0

_id = libcr.cr_init()

assert (_id >= 0)


def request_checkpoint (cr_args, cr_handle):
     assert (isinstance (cr_args, cr_checkpoint_args_t))
     assert (isinstance (cr_handle, c_ulong))  # c long
     err = libcr.cr_request_checkpoint (byref(cr_args), byref (cr_handle))
     return err, cr_handle
 
cr_handle = c_ulong()
with open ("checkpoint", 'w') as cp_file:
    cr_args.cr_fd = cp_file.fileno()

    err,cr_handle = request_checkpoint (cr_args, cr_handle)

    err = -1
    while (err < 0):
        err = libcr.cr_poll_checkpoint (byref(cr_handle), POINTER(c_int)())
        print "err:", os.strerror(err)
        if (err < 0):
            if (errno == EINVAL):
                break                   # restarted
            elif (errno == EINTR):
                continue
            else:
                die ("cr_poll_checkpoint")
        elif (err == 0):
            die ("cr_poll_checkpoint returned unexpected 0")

• Previous message: Neal Becker: "python ctypes interface to blcr?"