WoZ

#include <arpa/inet.h>
#include <net/if.h>
#include <ifaddrs.h>
#include <netdb.h>
#include <stdio.h>

int main(int argc, char* argv[], char* envp[]) {
    struct ifaddrs *ifa=NULL,*ifEntry=NULL;
    void *addPtr = NULL;
    int rc = 0;

WoZ

#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <arpa/inet.h>

int main(int argc, char *argv[])
{
    struct addrinfo hints, *res, *p;

WoZ

const {EventEmitter} = require('events');

const ee = new EventEmitter();

function waitForMessage() {
  return new Promise(resolve => {
    ee.once('message', msg => {
      console.log('waitForMessage. Message is received', msg);
      resolve();
      console.log('waitForMessage. Ooops, resolve will run in microtask. not immediately');

WoZ

const cluster = require('cluster');

async function waitForMessage(child) {
  return new Promise(resolve => {
    child.once('message', msg => {
      console.log('Master. waitForMessage. Message is received', msg);
      return resolve();
    });
  });
}

WoZ

setTimeout(() => { process.exit(); }, 200);

function f() {
    try {
        return new Promise((resolve, reject) => {
            throw new Error('Error: Threw right in the executor');
        });
    } catch (err) {
        console.log('Error caught in f()', err);
    }

WoZ

const {EventEmitter} = require('events');

const ee = new EventEmitter();

function log(...args) {
    console.log(Date.now() / 1000, ...args);
}

function blockingOperation() {
    log('-- Blocking operation has started');

WoZ

Usage: node strace_log_analyzer.js strace.log /tmp

This scripts parses input file that must contain strace log from a single thread. Then script calculates:

• execution time of read/write syscall for each file descriptor and summarize execution time for each 1 sec period,
• calulates amount of read/write syscalls for each file descriptor

strace log must be collcted with -t -T -f options.

WoZ

const url = process.argv[2];
const concurrency = process.argv[3] === undefined ? 1 : parseInt(process.argv[3]);
const requestInterval = process.argv[4] === undefined ? 10000 : parseInt(process.argv[4]);

if (url === undefined || isNaN(concurrency) || isNaN(requestInterval)) {
    console.log('Usage: node keepalive_test.js http://google.com/ 10 10000');
    console.log('Where: 2nd - URL');
    console.log('       3rd - amount of concurrent connections (default is 1)');
    console.log('       4rd - interval between sequential requests');
    process.exit();

WoZ

const url = process.argv[2];
const concurrency = process.argv[3] === undefined ? 1 : parseInt(process.argv[3]);
const requestInterval = process.argv[4] === undefined ? 10000 : parseInt(process.argv[4]);

if (url === undefined || isNaN(concurrency) || isNaN(requestInterval)) {
    console.log('Usage: node no_keepalive_test.js http://google.com/ 10 10000');
    console.log('Where: 2nd - URL');
    console.log('       3rd - amount of concurrent connections (default is 1)');
    console.log('       4rd - interval between sequential requests');
    process.exit();

WoZ

const readline = require('readline');
const fs = require('fs');

const argv = process.argv.slice(2);
if (argv.length !== 1) {
    console.error('Invalid list of arguments');
    process.exit(1);
}

const filename = argv[0];