更新

TongjiUniApp/node_modules/licia/Semaphore.js

@@ -0,0 +1,28 @@
+var Class = require('./Class');
+var Queue = require('./Queue');
+exports = Class({
+    initialize: function Semaphore() {
+        var counter =
+            arguments.length > 0 && arguments[0] !== undefined
+                ? arguments[0]
+                : 1;
+        this._counter = counter;
+        this._tasks = new Queue();
+    },
+    wait: function(fn) {
+        if (this._counter > 0) {
+            this._counter--;
+            return fn();
+        }
+        this._tasks.enqueue(fn);
+    },
+    signal: function() {
+        var task = this._tasks.dequeue();
+        if (task) {
+            return task();
+        }
+        this._counter++;
+    }
+});
+
+module.exports = exports;