SailfishOS libaudioresource<->python bridge

from ctypes import *
import time

a = cdll.LoadLibrary("/usr/lib/libaudioresource.so.1")
StatCB = CFUNCTYPE(None, c_void_p, c_bool, c_void_p)
init = a.audioresource_init
init.argtypes = [c_int, StatCB, c_void_p]
init.restype = c_void_p

CALLBACK = None
AUDIO_RESOURCE_MEDIA = 2

inited = False
is_acquired = False
resource = None

def _callback(resource, acquired, data):
    global is_acquired
    CALLBACK(acquired)
    if acquired:
        is_acquired = True

callbackref = StatCB(_callback)


def acquire(callback=None):
    global CALLBACK
    global resource
    global inited
    if not inited:
        if not callable(callback):
            raise TypeError(str(type(callback)) + " is not callable")
        CALLBACK = callback
        resource = init (AUDIO_RESOURCE_MEDIA, callbackref, None)
        inited = True
    a.audioresource_acquire(resource)
    while not is_acquired:
        a.g_main_context_iteration(None, False)
        time.sleep(0.01)

def release():
    a.audioresource_release(resource)
    is_acquired = False
    while is_acquired:
        a.g_main_context_iteration(None, False)
        time.sleep(0.01)

def free():
    if is_acquired:
        release()
    a.audioresource_free(resource)