Timers are fired even if the descriptors are ready for read

a.js

var fs = require('fs');

var readCount = 0;

var read_stream = fs.createReadStream('/dev/zero', {encoding: 'ascii'});
read_stream.on("data", function(data) {
        console.log("Read " + (readCount++) + " times");
});
setInterval(function(){
  console.log("Timer: " + (new Date()).valueOf() % 10000);
}, 100);


/*

$ node a.js | grep Timer
Timer: 6536
Timer: 6637
Timer: 6738
Timer: 6837
Timer: 6940
Timer: 7038
Timer: 7138
Timer: 7237
Timer: 7337
Timer: 7437
Timer: 7539
Timer: 7640
Timer: 7738
Timer: 7838
Timer: 7937

*/