-
Notifications
You must be signed in to change notification settings - Fork 215
/
next-tick.js
117 lines (103 loc) · 4 KB
/
next-tick.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
/* <copyright>
Copyright (c) 2012, Motorola Mobility LLC.
All Rights Reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
* Neither the name of Motorola Mobility LLC nor the names of its
contributors may be used to endorse or promote products derived from this
software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
</copyright> */
/*global bootstrap,setImmediate */
/**
Provides [nextTick]{@link nextTick}
@see nextTick
@module montage/core/next-tick
*/
/**
Executes a function as soon as possible in a future event. The task
is not cancelable.
@function module:montage/core/next-tick#nextTick
@param {Function} task a function to call in a future turn of the event loop
*/
(function (definition) {
if (typeof bootstrap !== "undefined") {
bootstrap("core/next-tick", definition);
} else if (typeof require !== "undefined") {
definition(require, exports, module);
} else {
definition({}, {}, {});
}
})(function (require, exports, module) {
var nextTick;
// Node implementation:
if (typeof process !== "undefined") {
nextTick = process.nextTick;
// Browser implementation: based on MessageChannel, setImmediate, or setTimeout
} else {
// queue of tasks implemented as a singly linked list with a head node
var head = {}, tail = head;
// whether a task is pending is represented by the existence of head.next
nextTick = function (task) {
var alreadyPending = head.next;
tail = tail.next = {task: task};
if (!alreadyPending) {
// setImmediate,
// postMessage, or
// setTimeout:
request(flush, 0);
}
};
var flush = function () {
try {
// unroll all pending events
while (head.next) {
head = head.next;
// guarantee consistent queue state
// before task, because it may throw
head.task(); // may throw
}
} finally {
// if a task throws an exception and
// there are more pending tasks, dispatch
// another event
if (head.next) {
// setImmediate,
// postMessage, or
// setTimeout:
request(flush, 0);
}
}
};
var request; // must always be called like request(flush, 0);
// in order of desirability:
if (typeof setImmediate !== "undefined") {
request = setImmediate;
} else if (typeof MessageChannel !== "undefined") {
// http://www.nonblocking.io/2011/06/windownexttick.html
var channel = new MessageChannel();
channel.port1.onmessage = flush;
request = function (flush, zero) {
channel.port2.postMessage(0);
};
} else {
request = setTimeout;
}
}
exports.nextTick = nextTick;
});