diff options
| author | ruki <waruqi@gmail.com> | 2018-11-08 00:38:48 +0800 |
|---|---|---|
| committer | ruki <waruqi@gmail.com> | 2018-11-07 21:53:09 +0800 |
| commit | 26105034da4fcce7ac883c899d781f016559310d (patch) | |
| tree | c459a5dc4e3aa0972d9919033ece511ce76dd129 /node_modules/webpack/lib/util/Semaphore.js | |
| parent | 2c77f00f1a7ecb6c8192f9c16d3b2001b254a107 (diff) | |
| download | xmake-docs-26105034da4fcce7ac883c899d781f016559310d.tar.gz xmake-docs-26105034da4fcce7ac883c899d781f016559310d.zip | |
switch to vuepress
Diffstat (limited to 'node_modules/webpack/lib/util/Semaphore.js')
| -rw-r--r-- | node_modules/webpack/lib/util/Semaphore.js | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/node_modules/webpack/lib/util/Semaphore.js b/node_modules/webpack/lib/util/Semaphore.js new file mode 100644 index 00000000..d6c87665 --- /dev/null +++ b/node_modules/webpack/lib/util/Semaphore.js @@ -0,0 +1,53 @@ +/* + MIT License http://www.opensource.org/licenses/mit-license.php + Author Tobias Koppers @sokra +*/ +"use strict"; + +class Semaphore { + /** + * Creates an instance of Semaphore. + * + * @param {number} available the amount available number of "tasks" + * in the Semaphore + */ + constructor(available) { + this.available = available; + /** @type {(function(): void)[]} */ + this.waiters = []; + /** @private */ + this._continue = this._continue.bind(this); + } + + /** + * @param {function(): void} callback function block to capture and run + * @returns {void} + */ + acquire(callback) { + if (this.available > 0) { + this.available--; + callback(); + } else { + this.waiters.push(callback); + } + } + + release() { + this.available++; + if (this.waiters.length > 0) { + process.nextTick(this._continue); + } + } + + _continue() { + if (this.available > 0) { + if (this.waiters.length > 0) { + this.available--; + const callback = this.waiters.pop(); + callback(); + } + } + } +} + +module.exports = Semaphore; |
