“use strict”; var firstLineError; try {throw new Error(); } catch (e) {firstLineError = e;} var schedule = require(“./schedule”); var Queue = require(“./queue”);

function Async() {

this._customScheduler = false;
this._isTickUsed = false;
this._lateQueue = new Queue(16);
this._normalQueue = new Queue(16);
this._haveDrainedQueues = false;
var self = this;
this.drainQueues = function () {
    self._drainQueues();
};
this._schedule = schedule;

}

Async.prototype.setScheduler = function(fn) {

var prev = this._schedule;
this._schedule = fn;
this._customScheduler = true;
return prev;

};

Async.prototype.hasCustomScheduler = function() {

return this._customScheduler;

};

Async.prototype.haveItemsQueued = function () {

return this._isTickUsed || this._haveDrainedQueues;

};

Async.prototype.fatalError = function(e, isNode) {

if (isNode) {
    process.stderr.write("Fatal " + (e instanceof Error ? e.stack : e) +
        "\n");
    process.exit(2);
} else {
    this.throwLater(e);
}

};

Async.prototype.throwLater = function(fn, arg) {

if (arguments.length === 1) {
    arg = fn;
    fn = function () { throw arg; };
}
if (typeof setTimeout !== "undefined") {
    setTimeout(function() {
        fn(arg);
    }, 0);
} else try {
    this._schedule(function() {
        fn(arg);
    });
} catch (e) {
    throw new Error("No async scheduler available\u000a\u000a    See http://goo.gl/MqrFmX\u000a");
}

};

function AsyncInvokeLater(fn, receiver, arg) {

this._lateQueue.push(fn, receiver, arg);
this._queueTick();

}

function AsyncInvoke(fn, receiver, arg) {

this._normalQueue.push(fn, receiver, arg);
this._queueTick();

}

function AsyncSettlePromises(promise) {

this._normalQueue._pushOne(promise);
this._queueTick();

}

Async.prototype.invokeLater = AsyncInvokeLater; Async.prototype.invoke = AsyncInvoke; Async.prototype.settlePromises = AsyncSettlePromises;

function _drainQueue(queue) {

while (queue.length() > 0) {
    _drainQueueStep(queue);
}

}

function _drainQueueStep(queue) {

var fn = queue.shift();
if (typeof fn !== "function") {
    fn._settlePromises();
} else {
    var receiver = queue.shift();
    var arg = queue.shift();
    fn.call(receiver, arg);
}

}

Async.prototype._drainQueues = function () {

_drainQueue(this._normalQueue);
this._reset();
this._haveDrainedQueues = true;
_drainQueue(this._lateQueue);

};

Async.prototype._queueTick = function () {

if (!this._isTickUsed) {
    this._isTickUsed = true;
    this._schedule(this.drainQueues);
}

};

Async.prototype._reset = function () {

this._isTickUsed = false;

};

module.exports = Async; module.exports.firstLineError = firstLineError;