gate-executor/README.md

A work queue that can be gated, stopping to wait for sub-queues to complete.

# gate-executor

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#### A work queue that can be gated, stopping to wait for sub-queues to complete.

[Annotated Source](http://senecajs.github.io/gate-executor/gate-executor.html)

A work execution queue that provides gating. Work items submitted to
the queue are called in order, and execute concurrently. However, if
the queue is *gated*, then a sub-queue is created, and work items
added to the sub-queue must complete first.

Gating operates to any depth, allowing you to form a tree-structured
queue that must complete breadth-first.

The queue also handles timeouts, so that failing work items do not
block processing. Timeouts use a shared `setInterval`, so are nice and
efficient.

Used by the [Seneca](http://senecajs.org/) microservice framework to
implement plugin initialisation.

# Usage


```js
var GateExecutor = require('gate-executor')

var ge = GateExecutor()

ge.add({
  fn: function first (done) {
    console.log('first')
    done()
  }
})

// create a gate
var subge = ge.gate()

ge.add({
  fn: function second (done) {
    console.log('second')
    done()
  }
})

// this needs to complete before 'second' can run
subge.add({
  fn: function second (done) {
    console.log('third')
    done()
  }
})

ge.start(function () {
  console.log('done')
  done()
})

// prints:
//   first
//   third
//   second
//   done
```

For detailed information, and API descriptions, see the
[Annotated Source](http://senecajs.github.io/gate-executor/doc/gate-executor.html)

# Support

If you're using this module, feel free to contact me on twitter if you
have any questions! :) [@rjrodger](http://twitter.com/rjrodger)

# Testing

```js
npm test
```

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