Python ctypes FFI

ctypes.py

import ctypes
import threading
import time

def py_loop(i, j):
    s = 0
    for i in range(i, j):
        if (i % 3 == 0):
            s += 1
    return s

# Compile library
# gcc -fPIC -shared -o clibrary.so clibrary.c

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

# clibrary.display(b"Sid", 18)

# func = clibrary.display

"""
File clibrary.c

#include <stdio.h>

char* display(char* str, int age) {
  printf("My Name is %s and my Age is %d\n", str, age);

  return "Completed";
}

int loop(int from, int to)
{
  int i;
  int s = 0;
 
  for (i = from; i < to; i++)
    if (i % 3 == 0)
      s += i;

  return s;
}
"""

# func.argtypes = [ctypes.c_char_p, ctypes.c_int]
# func.restype = ctypes.c_char_p

# func(b"Sid", 18)

c_loop = clibrary.loop
c_loop.argtypes = [ctypes.c_int, ctypes.c_int]
c_loop.restype = ctypes.c_int
end = 1 * 10**9
fmt = lambda t: f"{t:.2f}"

tic = time.perf_counter()
py_loop(0, end)
py_loop(0, end)
py_loop(0, end)
py_loop(0, end)
print(f"Sequential runtime py_loop {fmt(time.perf_counter() - tic)} Seconds")

tic = time.perf_counter()
t1 = threading.Thread(target=py_loop, args=[0, end])
t2 = threading.Thread(target=py_loop, args=[0, end])
t3 = threading.Thread(target=py_loop, args=[0, end])
t4 = threading.Thread(target=py_loop, args=[0, end])
t1.start()
t2.start()
t3.start()
t4.start()
t1.join()
t2.join()
t3.join()
t4.join()
print(f"Parallet runtime py_loop {fmt(time.perf_counter() - tic)} Seconds")

tic = time.perf_counter()
c_loop(0, end)
c_loop(0, end)
c_loop(0, end)
c_loop(0, end)
print(f"Sequential runtime c_loop {fmt(time.perf_counter() - tic)} Seconds")

tic = time.perf_counter()
t1 = threading.Thread(target=c_loop, args=[0, end])
t2 = threading.Thread(target=c_loop, args=[0, end])
t3 = threading.Thread(target=c_loop, args=[0, end])
t4 = threading.Thread(target=c_loop, args=[0, end])
t1.start()
t2.start()
t3.start()
t4.start()
t1.join()
t2.join()
t3.join()
t4.join()
print(f"Parallet runtime c_loop {fmt(time.perf_counter() - tic)} Seconds")

Answers

Sequential runtime py_loop 207.47 Seconds
Parallet runtime py_loop 191.43 Seconds
Sequential runtime c_loop 6.93 Seconds
Parallet runtime c_loop 1.89 Seconds