asyncio_exercises.ipynb

{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [],
   "source": [
    "import asyncio\n",
    "import time"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# If the method is a coroutine"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 41,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "<_GatheringFuture pending>"
      ]
     },
     "execution_count": 41,
     "metadata": {},
     "output_type": "execute_result"
    },
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "start hoge...\n",
      "start foo...\n",
      "...end hoge\n",
      "...end foo\n"
     ]
    }
   ],
   "source": [
    "async def hoge():\n",
    "    print('start hoge...')\n",
    "    await asyncio.sleep(1)\n",
    "    print('...end hoge')\n",
    "\n",
    "async def foo():\n",
    "    print('start foo...')\n",
    "    await asyncio.sleep(1)\n",
    "    print('...end foo')\n",
    "\n",
    "asyncio.gather(hoge(), foo())"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# sync with Task"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 45,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "start foo...\n",
      "start hoge...\n",
      "...end foo\n",
      "...end hoge\n"
     ]
    }
   ],
   "source": [
    "async def hoge():\n",
    "    print('start hoge...')\n",
    "    await asyncio.sleep(1)\n",
    "    print('...end hoge')\n",
    "\n",
    "def foo():\n",
    "    print('start foo...')\n",
    "    time.sleep(1)\n",
    "    print('...end foo')\n",
    "\n",
    "loop = asyncio.get_event_loop()\n",
    "hoge_task = asyncio.Task(hoge())\n",
    "await loop.run_in_executor(None, foo)  # simply calling foo() won't work (???)\n",
    "await hoge_task"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# If the library supports futures"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 39,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "start hoge...\n",
      "start foo...\n",
      "...end hoge\n",
      "...end foo\n",
      "hoge result\n"
     ]
    }
   ],
   "source": [
    "def hoge():  # returns future\n",
    "    def execute():\n",
    "        print('start hoge...')\n",
    "        time.sleep(1)\n",
    "        print('...end hoge')\n",
    "        return('hoge result')\n",
    "    loop = asyncio.get_event_loop()\n",
    "    return loop.run_in_executor(None, execute)\n",
    "\n",
    "def foo():\n",
    "    print('start foo...')\n",
    "    time.sleep(1)\n",
    "    print('...end foo')\n",
    "\n",
    "\n",
    "hoge_future = hoge()\n",
    "foo()  # blocks\n",
    "hoge_result = await hoge_future\n",
    "print(hoge_result)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# If the method is simply blocking"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 43,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "start hoge...\n",
      "start foo...\n",
      "...end hoge\n",
      "...end foo\n"
     ]
    }
   ],
   "source": [
    "def hoge():\n",
    "    print('start hoge...')\n",
    "    time.sleep(1)\n",
    "    print('...end hoge')\n",
    "\n",
    "def foo():\n",
    "    print('start foo...')\n",
    "    time.sleep(1)\n",
    "    print('...end foo')\n",
    "    \n",
    "loop = asyncio.get_event_loop()\n",
    "hoge_task = loop.run_in_executor(None, hoge)\n",
    "foo()  # blocks\n",
    "await hoge_task"
   ]
  }
 ],
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