global scheduled, scheduler, wrapper_ref

scheduled = []
from ctypes import pythonapi, cast, c_char_p, c_void_p, CFUNCTYPE

HOOKFUNC = CFUNCTYPE(c_char_p, c_void_p, c_void_p, c_char_p)

PyOS_InputHookFunctionPointer = c_void_p.in_dll(pythonapi, "PyOS_InputHook")

def scheduler(*a, **k):
    # *no effect : pthread_sigmask( SIG_BLOCK, [SIGWINCH,SIGINT])
    # *no effect :    oldmask = pthread_sigmask(signal.SIG_BLOCK, [SIGWINCH,SIGINT])
    global scheduled
    # prevent reenter
    lq = len(scheduled)
    while lq:
        fn, a = scheduled.pop(0)
        fn(a)
        lq -= 1
    # *no effect : pthread_sigmask( SIG_UNBLOCK, [SIGWINCH,SIGINT] )
    # *no effect : pthread_sigmask( SIG_UNBLOCK, oldmask )

wrapper_ref = HOOKFUNC(scheduler)
PyOS_InputHookFunctionPointer.value = cast(wrapper_ref, c_void_p).value


def schedule(fn, a):
    global scheduled
    if scheduled is None:
        init()
    scheduled.append((fn, a))


import os,time

os.system(f'( sleep 1 && for x in {{a..z}}; do kill -28 {os.getpid()}; done) &')

def loop_hook(arg):
    time.sleep(.016)
    schedule(loop_hook,1)

schedule(loop_hook,1)