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Diffstat (limited to 'node_modules/montage-user/core/next-tick.js')
-rw-r--r-- | node_modules/montage-user/core/next-tick.js | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/node_modules/montage-user/core/next-tick.js b/node_modules/montage-user/core/next-tick.js new file mode 100644 index 00000000..0c3e209a --- /dev/null +++ b/node_modules/montage-user/core/next-tick.js | |||
@@ -0,0 +1,91 @@ | |||
1 | /* <copyright> | ||
2 | This file contains proprietary software owned by Motorola Mobility, Inc.<br/> | ||
3 | No rights, expressed or implied, whatsoever to this software are provided by Motorola Mobility, Inc. hereunder.<br/> | ||
4 | (c) Copyright 2011 Motorola Mobility, Inc. All Rights Reserved. | ||
5 | </copyright> */ | ||
6 | |||
7 | /** | ||
8 | Defines [nextTick()]{#link nextTick} | ||
9 | @see nextTick | ||
10 | @module montage/core/next-tick | ||
11 | */ | ||
12 | |||
13 | /** | ||
14 | @function | ||
15 | @name nextTick | ||
16 | */ | ||
17 | |||
18 | (function (definition) { | ||
19 | if (typeof bootstrap !== "undefined") { | ||
20 | bootstrap("core/next-tick", definition); | ||
21 | } else if (typeof require !== "undefined") { | ||
22 | definition(require, exports, module); | ||
23 | } else { | ||
24 | definition({}, {}, {}); | ||
25 | } | ||
26 | })(function (require, exports, module) { | ||
27 | |||
28 | var nextTick; | ||
29 | // Node implementation: | ||
30 | if (typeof process !== "undefined") { | ||
31 | nextTick = process.nextTick; | ||
32 | // Browser implementation: based on MessageChannel, setImmediate, or setTimeout | ||
33 | } else { | ||
34 | |||
35 | // queue of tasks implemented as a singly linked list with a head node | ||
36 | var head = {}, tail = head; | ||
37 | // whether a task is pending is represented by the existence of head.next | ||
38 | |||
39 | nextTick = function (task) { | ||
40 | var alreadyPending = head.next; | ||
41 | tail = tail.next = {task: task}; | ||
42 | if (!alreadyPending) { | ||
43 | // setImmediate, | ||
44 | // postMessage, or | ||
45 | // setTimeout: | ||
46 | request(flush, 0); | ||
47 | } | ||
48 | } | ||
49 | |||
50 | var flush = function () { | ||
51 | try { | ||
52 | // unroll all pending events | ||
53 | while (head.next) { | ||
54 | head = head.next; | ||
55 | // guarantee consistent queue state | ||
56 | // before task, because it may throw | ||
57 | head.task(); // may throw | ||
58 | } | ||
59 | } finally { | ||
60 | // if a task throws an exception and | ||
61 | // there are more pending tasks, dispatch | ||
62 | // another event | ||
63 | if (head.next) { | ||
64 | // setImmediate, | ||
65 | // postMessage, or | ||
66 | // setTimeout: | ||
67 | request(flush, 0); | ||
68 | } | ||
69 | } | ||
70 | }; | ||
71 | |||
72 | var request; // must always be called like request(flush, 0); | ||
73 | // in order of desirability: | ||
74 | if (typeof setImmediate !== "undefined") { | ||
75 | request = setImmediate; | ||
76 | } else if (typeof MessageChannel !== "undefined") { | ||
77 | // http://www.nonblocking.io/2011/06/windownexttick.html | ||
78 | var channel = new MessageChannel(); | ||
79 | channel.port1.onmessage = flush; | ||
80 | request = function (flush, zero) { | ||
81 | channel.port2.postMessage(0); | ||
82 | }; | ||
83 | } else { | ||
84 | request = setTimeout; | ||
85 | } | ||
86 | |||
87 | } | ||
88 | |||
89 | exports.nextTick = nextTick; | ||
90 | |||
91 | }); | ||