parallel.js

src/parallel.js

@@ -0,0 +1,52 @@
+// Параллельные вычисления
+
+const WAIT_CHECK_TIME = 10;
+
+function parallel(promises, callback) {
+    const result = [];
+    
+    let done = 0;
+    const setResult = (i, res) => {
+        done++;
+        result[i] = res;
+    }
+    for (let i in promises) {
+        const promise = promises[i];
+        const res = promise((res) => setResult(i, res));
+        if (res) {
+            setResult(i, res);
+        }
+    }
+    
+    // if all sync
+    if (done === promises.length) {
+        callback(result);
+        return;
+    }
+    
+    // if at least one is async
+    const waitInterval = setInterval(() => {
+        if (done === promises.length) {
+            clearInterval(waitInterval);
+            callback(result);   
+        }
+    }, WAIT_CHECK_TIME);
+}
+
+parallel([
+	function (resolve) {
+		setTimeout(function () {
+			resolve(10);
+		}, 50);
+	},
+	function () {
+		return 5;
+	},
+	function (resolve) {
+		setTimeout(function () {
+			resolve(0);
+		}, 10)
+	}
+], function (results) {
+	console.log(results); // [10, 5, 0]
+});