Parallel Computing

 

 

  

mhadaily

What will be explored

Web Workers
Web Assembly
Service Worker
Parallel Computing VS Concurrency

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Worklets

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What will be explored

Web Workers
Web Assembly
Service Worker
Parallel Computing VS Concurrency

mhadaily

Worklets

PRACTICAL

<ME />

import HelloWorld from "@/components/HelloWorld.component";
export default {
  name: "whoAmI",
  data: {
      me: {
        name: "Majid Hajian",
        location: "Oslo, Norway",
        description: ```
        	Passionate Software engineer, 
	        Community Leader, Author and international Speaker
         ```,
        main: "Web, Javascripter, Flutter/Dart, IoT",
        homepage: "https://www.majidhajian.com",
        socials: {
          twitter: "https://www.twitter.com/mhadaily",
          github: "https://www.github.com/mhadaily"
        },
        books: {
          "Progressive Web App with Angular": {
             version: "1.0.0", 
             publishedBy: "Apress", 
             foundOn: "www.pwawithangular.com",
          }
        },
        author: {
          packtpub: "PWA development, 7 hours video course",
          Udemy: "PWA development, 7 hours video course"
        }
        founder: "Softiware As (www.Softiware.com)"
        devDependencies: {
          tea: "green", mac: "10.14+",
        },
        engines: {
          VueJsOslo: "Orginizer", MobileEraConference: "Orginizer",
          ngVikingsConference: "Orginizer", 
          MobileMeetupOslo:"Co-Orginizer",AngularOslo: "Co-Orginizer",
          FlutterDartOslo: "Co-Orginizer",Framsia: "Co-Orginizer",          
        }};} 
     };

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Find me on the internet by

Parallel Computing

Concurrency

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Thread is not equal to CPU core

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Javascript code

mouse event

other event

other event

Event queue

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Javascript code

mouse event

Some other event

other event

Web Workers

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Spwan another instance of the JS Engine

Runs in worker thread

No shared state

Communicate vis msg

Have their own event(msg) queue

No access to dom & window obj

Javascript code

msg

msg

mouse event

other event

some other  event

Browser Event Queue

Web Worker Message Queue

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Javascript code

msg

msg

mouse event

other event

some other  event

Browser Event Queue

Web Worker Message Queue

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Concurrency

Task Parallelism?

Javascript code

msg

msg

mouse event

other event

some other  event

Browser Event Queue

Web Worker Message Queue

Parallel

Core 2

Core 1

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Use cases

  • Data and web page caching
  • Image manipulation and encoding (base64 conversion)
  • Canvas drawing and image filtering
  • Network polling and web sockets
  • Background I/O operations
  • Video/Audio buffering and analysis
  • Virtual DOM diffing
  • Local database (indexedDB) operations
  • Computationally intensive data operations

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postMessage

Main Thread

Worker Thread

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// Main
const worker = new Worker("./worker.js");
let counter = 0;
setInterval(() => {
  counter = counter + 1;
  worker.postMessage({ action: "power2", payload: counter });
}, 3000);

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// Worker
self.onmessage = message => {
  const { data } = message;
  switch (data.action) {
    case "power2":
      const number = data.payload;
      const power2 = number * number;
      self.postMessage({ command: "power2", payload: power2 });
      break;
  }
};

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// Main
const worker = new Worker("./worker.js");
let counter = 0;
setInterval(() => {
  counter = counter + 1;
  worker.postMessage({ action: "power2", payload: counter });
}, 1000);

worker.onmessage = message => {
  const { data } = message;
  switch (data.command) {
    case "power2":
      const power2 = data.value;
      console.log("power2: ", power2);
      break;
  }
};

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Main Thread

Worker Thread

function  power2(){}

w.power2(5);

const w = new Worker();

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// Main 
import * as Comlink from "https://unpkg.com/comlink@alpha/dist/esm/comlink.mjs";
// import * as Comlink from "../../../dist/esm/comlink.mjs";

async function init() {
  const worker = new Worker("./worker.js");
  const service = Comlink.proxy(worker);
  const power2 = await service.power2(2);
  console.log(power2);
  const increment = await service.increment(2);
  console.log(increment);
}

init();

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// Worker
importScripts("https://unpkg.com/comlink@alpha/dist/umd/comlink.js");
// importScripts("../../../dist/umd/comlink.js");

const service = {
  power2: value => value * value,
  increment: (value) => value * 1
};

Comlink.expose(service);

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// all imports 
class UsersWrapper extends Component {
    worker;
    workerService;
  
    constructor(props) {
        super(props);
        this.state = {
            users: [],
        };
    }
    componentDidMount() {
        this.worker = new Worker('./worker.js');
      
        this.workerService = Comlink.wrap(worker);
      
        // Assumption is we have a list of 3000 users! 
        fetchUsers().then(users => {
            this.setState({ users });
        })
    }
    async sortAscending() {
        const sortedUsers = await this.workerService.sort(this.state.users);
		this.setState({ users: sortedUsers });
        return;
    }
   componentDidMount(){
     this.worker.terminate();
   }
   render() {
      return this.state.users.slice(0,20).map((user, index) => (<User key={user.id}>);
   }
}

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// WORKER 
// all importScripts();

const service = {
  sortDesc(users){},
  sortAsc(users) {
        for (let i = 0; i < users.length-1; i++) {
            for (let j = i+1; j < users.length; j++) {
                if (users[i].commentCount > users[j].commentCount) {
                    const t = users[i];
                    users[i] = users[j];
                    users[j] = t;
                }
            }
        }
  }
};

Comlink.expose(service);

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Web Assembly

Different languages

 

and

 

 run in browsers.

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how about Javascript / web developer?

AssemblyScript compiles a strict subset of TypeScript to WebAssembly 

npm init
npm install assemblyscript/assemblyscript
npx asinit .


/*
  ./assembly
  Directory holding the AssemblyScript sources being compiled to WebAssembly.

  ./assembly/tsconfig.json
  TypeScript configuration inheriting recommended AssemblyScript settings.

  ./assembly/index.ts
  Exemplary entry file being compiled to WebAssembly to get you started.

  ./build
  Build artifact directory where compiled WebAssembly files are stored.

  ./build/.gitignore
  Git configuration that excludes compiled binaries from source control.

  ./index.js
  Main file loading the WebAssembly module and exporting its exports.

  ./package.json
  Package info containing the necessary commands to compile to WebAssembly.
*/

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// The entry file of your WebAssembly module.
export function power2(a: i32): i32 {
  return a + a;
}

// no optimization, no memoization
export function fibonacci(num: i32): i32 {
  if (num <= 1) return 1;

  return fibonacci(num - 1) + fibonacci(num - 2);
}

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var int8: i8 = <i8>0; // 8-bit signed integer [-128 to 127]
var uint8: u8 = <u8>0; // 8-bit unsigned integer [0 to 255]
var int16: i16 = <i16>0; // 16-bit signed integer [-32,768 to 32,767]
var uint16: u16 = <u16>0; // 16-bit unsigned integer [0 to 65,535]
var int32: i32 = <i32>0; // 32-bit signed integer [-2,147,483,648 to 2,147,483,647]
var uint32: u32 = <u32>0; // 32-bit unsigned integer [0 to 4,294,967,295]
var int64: i64 = <i64>; // 64-bit signed integer [-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807]
var uint64: i64 = <u64>0; // 64-bit unsigned integer [0 to 18,446,744,073,709,551,615]
var float32: f32 = <f32>0.0; // 32-bit float [32 bit float range]
var float64: f64 = <f64>0.0; // 64-bit float [64 bit float range]
var pointer: usize = <usize>0; // a 32/64-bit pointer to a location in memory

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import "allocator/tlsf";

let ptr = memory.allocate(64);

// do something with ptr ...
// 
// ... once you are done, make sure you free it again. 
memory.free(ptr);

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npm run asbuild


/**
Created: ./build/optimized.wasm
Created: ./build/optimized.wasm.map
Created: ./build/optimized.wat
Created: ./build/untouched.wasm
Created: ./build/untouched.wasm.map
Created: ./build/untouched.wat
 * /

// untouched.wasm is good for debugging
// optimized.wasm can be used in production
// wat is the text representation of the genrated .wasm 

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// all other imports 
import { instantiateStreaming, ASUtil } from "assemblyscript/lib/loader";

// no optimization, no memoization
function fibonacci(num) {
  if (num <= 1) return 1;

  return fibonacci(num - 1) + fibonacci(num - 2);
}


class FibWrapper extends Component {
    imports = {};
	wasmService;

  async componentDidMount() {
    this.wasmService = await instantiateStreaming(fetch('/optimized.wasm'), this.imports);
  }

  async factorialwasm() {
    const result = await this.wasmService.fibonacci(9999);
    this.setState({ number: result });
    return;
  }

  factorialJS() {
    const result = fibonacci(9999);
    this.setState({ number: result });
    return;
  }
   render() {
      return <Fib />;
   }
}

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Always measure and do the right things

 

 9999-th Fibonacci number

WebAssembly: 0.051025390625ms

Javascript: 0.384765625msms

 

WebAssembly was about 7 times faster for the first run

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Worklets

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A lightweight version of WebWorkers

Access to low-level parts of rendering pipleline

Run Javascript and WebAssembly

graphic rendering or audio processing

High performance

 Worklets Types

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Paint

Animation

Layout

Audio

CSS Paint API

 

(also known as “CSS Custom Paint” or “Houdini’s paint worklet”)

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// checkerboard.js
class CheckerboardPainter {
    paint(ctx, geom, properties) {
      // Use `ctx` as if it was a normal canvas
      const colors = ['black', 'white'];
      const size = 32;
      for(let y = 0; y < geom.height/size; y++) {
        for(let x = 0; x < geom.width/size; x++) {
          const color = colors[(x + y) % colors.length];
          ctx.beginPath();
          ctx.fillStyle = color;
          ctx.rect(x * size, y * size, size, size);
          ctx.fill();
        }
      }
    }
  }

// Register our class under a specific name
registerPaint('checkerboard', CheckerboardPainter);

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<!-- index.html -->
<!doctype html>
<style>
  textarea {
    background-image: paint(checkerboard);
  }
</style>
<textarea></textarea>
<script>
  if (typeof CSS === 'undefined' || !('paintWorklet' in CSS)) {
    return;
  } else {
	  CSS.paintWorklet.addModule('checkerboard.js');
  }
</script>

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Service Worker

All Frameworks

Brain of 

Service Worker in-depth:

https://vimeo.com/273475511

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A type of Web Worker

Essentially a Javascript File

Runs different Thread & Background

Intercepts network requests

Caching, delivering push msgs

// Register a Service Worker

// index.html

if ('serviceWorker' in navigator) {
  navigator.serviceWorker.register('/sw.js')
  .then( (reg) => console.log(reg))
  .catch((error) => 
  console.log('Registration failed with ' + error)
  );
}

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Why is it interesting?

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Why is it interesting?

because you can do many things on the fly!

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// all imports and workaround by Kenneth Christiansen
// webp_wasm.wasm

self.addEventListener('fetch', async event => {
  if (event.request.method != 'GET') return;
  if (!event.request.url.endsWith(".webp")) return;

  event.respondWith(async function() {
    try {
      const response = await fetch(event.request);
      const buffer = await response.arrayBuffer();

      const WebPDecoder = await fetchWebPDecoderWithWorkarounds();
      const decoder = new WebPDecoder(buffer);
      const blob = await decoder.decodeToBMP();

      return new Response(blob, { headers: { "content-type": "image/bmp", "status": 200 } });
    } catch(err) {
      console.error(err);
    }

    return fetch(event.request);
  }());
});

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Summary

What we have learned

 

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Web Workers (comlink)
Web Assembly (AssemblyScript)
Service Worker
Worklets (CSS paint API)
Boost User experince

Majid Hajian

mhadaily

Slides and link to source code

bit.ly/parallel-computing-in-react

majid[at]softiware[dot]com

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