For https://github.com/lovell/sharp/issues/21

test_sharp_async.js

var exec = require('child_process').exec
var async = require('async');
var sharp = require('sharp');

sharp.cache(0);

var tasks = 0;

console.log('RSS: ' + process.memoryUsage().rss);

async.whilst(
  function() {
    return tasks < 10000;
  },
  function(callback) {
    sharp('input.jpg').resize(300, 200).toFile('output.jpg', function(err) {
      tasks++;
      callback(err);
    });
  },
  function(err) {
    if (err) {
      throw err;
    }
    console.log('RSS: ' + process.memoryUsage().rss);
    exec('cat /proc/pagetypeinfo', function (err, stdout, stderr) {
      console.log(stdout);
    });
  }
);