Implementing timeouts for node.js callbacks

Question

This is a typical situation in node.js:

asyncFunction(arguments, callback);

When asynFunction completes, callback

Answer 1

I'm not familiar with any libraries that do this, but it's not hard to wire up yourself.

// Setup the timeout handler
var timeoutProtect = setTimeout(function() {

  // Clear the local timer variable, indicating the timeout has been triggered.
  timeoutProtect = null;

  // Execute the callback with an error argument.
  callback({error:'async timed out'});

}, 5000);

// Call the async function
asyncFunction(arguments, function() {

  // Proceed only if the timeout handler has not yet fired.
  if (timeoutProtect) {

    // Clear the scheduled timeout handler
    clearTimeout(timeoutProtect);

    // Run the real callback.
    callback();
  }
});