temporal

Non-blocking, temporal task sequencing. temporal does NOT use setTimeout or setInterval, however there is a cost for using "recursive" setImmediate to create an extremely fast, async execution loop. CPU usage is expected to peak when using temporal, because the internal ticker needs to execute as fast as possible and as many times per second as possible. It's this speed that allows temporal to review the internal schedule for tasks to execute more than once per millisecond, which is needed to create preferential execution cycles for hardware programming.

temporal is for writing timing sensitive programs that are expected to be the primary process running on a given system, where the power source itself is tuned to accommodate that program specifically. Concrete examples include:

walking robots (autonomous and remote control bipeds, quadrupeds or hexapods)
driving robots (autonomous and remote control rovers)
flying robots (autonomous and remote control single and multi-rotor helicopter)
water based robots (underwater rovs, surface boat-likes)

temporal allows for sub-millisecond task scheduling through us of the resolution method.

temporal is not good for sparse task scheduling.

Presentations

Getting Started

npm install temporal

Examples

var temporal = require("temporal");

temporal.on("idle", function() {
  console.log("Temporal is idle");  
});

// Wait 500 milliseconds, execute a task
temporal.delay(500, function() {

  console.log("500ms later...");

});

// Loop every n milliseconds, executing a task each time
temporal.loop(500, function() {

  console.log("Every 500ms...");

  // |this| is a reference to the temporal instance
  // use it to cancel the loop by calling:
  //
  this.stop();

  // The number of times this loop has been executed:
  this.called; // number

  // The first argument to the callback is the same as |this|
});

// Queue a sequence of tasks: delay, delay
// Each delay time is added to the prior delay times.
temporal.queue([
  {
    delay: 500,
    task: function() {
      // Executes 500ms after temporal.queue(...) is called
    }
  },
  {
    delay: 500,
    task: function() {
      // Executes 1000ms after temporal.queue(...) is called

      // The last "delay" task will emit an "ended" event
    }
  }
]);

// Queue a sequence of tasks: delay then loop
// Each delay time is added to the prior delay times.
temporal.queue([
  {
    delay: 500,
    task: function() {
      // Executes 500ms after temporal.queue(...) is called
    }
  },
  {
    loop: 100,
    task: function() {
      // Executes 600ms after temporal.queue(...) is called

      // Executes every 100ms thereafter.
    }
  }
]);

var temporal = require("temporal");

temporal.on("idle", function() {
  console.log("Temporal is idle");  
});

// Set temporal resolution to 0.1ms
temporal.resolution(0.1);

// Wait 0.7 milliseconds, execute a task
temporal.delay(0.7, function() {

  console.log("0.7ms later...");

});

Contributing

In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint and test your code using grunt.

License

See LICENSE file.

rwaldron / temporal

readme