{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "import sys\n",
    "from array import array\n",
    "import numpy as np\n",
    "from timeit import timeit\n",
    "from multiprocessing import shared_memory"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "def console(*msg):\n",
    "    print(*msg)\n",
    "    sys.stdout.flush()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [],
   "source": [
    "def test(size):\n",
    "    data = [1 for i in range(size)]\n",
    "    \n",
    "    dataA = array('I', [1 for i in range(size)])\n",
    "    byteSize = 4 * size\n",
    "    shmA1 = shared_memory.SharedMemory(create=True, name=f\"dataA{size}\", size=byteSize)\n",
    "    bufA1 = shmA1.buf\n",
    "    bufA1[0:byteSize] = array(\"I\", data).tobytes()\n",
    "    dataA1 = bufA1.cast(\"I\")\n",
    "    \n",
    "    shmA2 = shared_memory.SharedMemory(name=f\"dataA{size}\")\n",
    "    bufA2 = shmA2.buf\n",
    "    dataA2 = bufA2.cast('I')\n",
    "    \n",
    "    dataN = np.array([1 for i in range(size)])\n",
    "    byteSize = dataN.nbytes\n",
    "    shmN1 = shared_memory.SharedMemory(create=True, name=f\"dataN{size}\", size=byteSize)\n",
    "    bufN1 = shmN1.buf\n",
    "    dataN1 = np.ndarray(dataN.shape, dtype=dataN.dtype, buffer=bufN1)\n",
    "    dataN1[:] = dataN[:]\n",
    "    \n",
    "    shmN2 = shared_memory.SharedMemory(name=f\"dataN{size}\")\n",
    "    bufN2 = shmN2.buf\n",
    "    dataN2 = np.ndarray(dataN.shape, dtype=dataN.dtype, buffer=bufN2)\n",
    "    \n",
    "    half = size // 2\n",
    "    \n",
    "    dataA1[half] = 1000\n",
    "    dataN1[half] = 1000\n",
    "\n",
    "    console(f\"{dataA1[half]} == {dataA2[half]} ? {dataA1[half] == dataA2[half]}\")\n",
    "    console(f\"{dataN1[half]} == {dataN2[half]} ? {dataN1[half] == dataN2[half]}\")\n",
    "\n",
    "    \n",
    "    console(f'''list   : {timeit(\"max(data)\",   globals=locals(), number=1):>.3e}''')\n",
    "    console(f'''array  : {timeit(\"max(dataA)\",  globals=locals(), number=1):>.3e}''')\n",
    "    console(f'''array1 : {timeit(\"max(dataA1)\", globals=locals(), number=1):>.3e}''')\n",
    "    console(f'''array2 : {timeit(\"max(dataA2)\", globals=locals(), number=1):>.3e}''')\n",
    "    console(f'''numpy1 : {timeit(\"max(dataN1)\", globals=locals(), number=1):>.3e}''')\n",
    "    console(f'''numpy2 : {timeit(\"max(dataN2)\", globals=locals(), number=1):>.3e}''')\n",
    "\n",
    "\n",
    "    dataA1.release()\n",
    "    dataA2.release()\n",
    "    bufA1.release()\n",
    "    shmA1.close()\n",
    "    shmA2.close()\n",
    "    shmA1.unlink()\n",
    "    bufN1.release()\n",
    "    bufN2.release()\n",
    "    shmN1.close()\n",
    "    shmN2.close()\n",
    "    shmN1.unlink()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1000 == 1000 ? True\n",
      "1000 == 1000 ? True\n",
      "list   : 1.505e-02\n",
      "array  : 1.789e-02\n",
      "array1 : 2.230e-02\n",
      "array2 : 2.371e-02\n",
      "numpy1 : 1.044e-01\n",
      "numpy2 : 1.078e-01\n"
     ]
    }
   ],
   "source": [
    "test(1000000)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
 ],
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