Function call

node/lib/util.js:834–839

(a, b, c)

  var callbackCalled = false;

  function call(a, b, c) {
    if (cb && !callbackCalled) {
      cb(a, b, c);
      callbackCalled = true;
    }
  }

  readStream.addListener('data', function(chunk) {
    if (writeStream.write(chunk) === false) readStream.pause();