The document discusses using worker threads in Node.js to parallelize work. It provides an example of splitting a workload across multiple workers to check if numbers are prime in parallel. The code shows how to spawn workers, send data to workers, listen for messages from workers, and handle errors.

1. WORKERS E A NOVA
API DE THREADS DO
NODE
@CAIQUEMITSUOKA
@ BRAZILJS ON THE
ROAD BH - 27/10/18

2. CAIQUE MITSUOKA
1ª VEZ EM BH
SOROCABA - SP
@ SÃO PAULO - SP
SOFTWARE DEVELOPER
@ PLATAFORMATEC
RUBY, ELIXIR E JS
SEGUE LÁ
@CAIQUEMITSUOKA

3. VAGAS!

4. API NÃO ESTÁ PRONTA
ISSO É UM SHOWCASE
A TALK NÃO TEM CONCLUSÃO
(E NEM ERA PARA TER)
BE
REAL

45. I/O

47. THREADS

65. NOW THE CODE

66. EXPERIMENTAL!

67. const { Worker } =
require('worker_threads')

68. const workerPath =
require('path')
.resolve('work.js')

69. const splitWork = (number) => {
...
}

70. const spawnWorkers = (number) => {
...

71. const spawnWorkers = (number) => {
splitWorker(number).map(
...

72. const spawnWorkers = (number) => {
splitWorker(number).map(
(segment) => {
...

73. const spawnWorkers = (number) => {
splitWorker(number).map(
(segment) => {
const worker = new Worker(
workerPath,{
...

74. const spawnWorkers = (number) => {
splitWorker(number).map(
(segment) => {
const worker = new Worker(
workerPath,{
workerData: segment
}
)
...

75. ...
worker.on(
'message',
(result) =>
console.log(
'[DONE]',
result)
)
...

76. ...
worker.on(
'error',
(result) =>
console.log(
'[ERROR]',
result)
)
...

77. ...
worker.on(
'exit',
(code) => {
if(code !== 0) {
throw new Error()
}
}
...

78. WORKER CODE

79. const { workerData, parentPort }=
require('worker_threads')

80. const isPrime = (number) => {
...
}

81. let result = []

82. console.log('[START]')

83. workerData.forEach(
(data) => {
if (isPrime(data)) {
result.push(data)
}
}
)

84. parentPort.postMessage(
result.reduce((a,b) => {
return a + b
})
)

85. console.log('[END]')

86. USE CASE

87. MOST LIBS

88. FLW

89. #ELENAO