import ctypes
import timeit

from typing import Callable

# to run this compiled with mypyc
# first do:
#   $ mypyc bench_callback_v2.py
# then do:
#   $ python -m "import bench_callback_v2"

# to run this vanilla, just use:
#   $ python bench_callback_v2.py

proto = ctypes.CFUNCTYPE(ctypes.c_int, ctypes.c_int, ctypes.c_int, ctypes.c_int, ctypes.c_int)

def f(a: int, b: int, c: int, d:int ) -> int:
    return 0

_f: Callable[[int, int, int, int], int] = proto(f)

c_source = """
#include <stdint.h>

void bench(int (*f2)(int, int, int, int)) {
    uint32_t i;
    for(i = 0; i < 0x4fffff; ++i) {
        f2(1,2,3,4);
    }
}
"""

import subprocess

subprocess.run(["cc", "-shared", "-fpic", "-o", "libtest.so", "-x", "c", "-"], input=c_source.encode("utf-8"))

libtest = ctypes.CDLL("./libtest.so")

bench_proto = ctypes.CFUNCTYPE(None, proto)
bench = bench_proto(("bench", libtest))

print(timeit.timeit(stmt='bench(_f)', number=1, globals=dict(bench=bench, _f=_f)))