Create 1114-print-in-order.cpp

Author: everthis

1114-print-in-order.cpp

@@ -0,0 +1,33 @@
+class Foo {
+public:
+    int count = 0;
+    mutex mtx;
+    condition_variable cv;
+    Foo() {
+        count = 1;
+    }
+
+    void first(function<void()> printFirst) {
+        unique_lock<mutex> lck(mtx);
+        // printFirst() outputs "first". Do not change or remove this line.
+        printFirst();
+        count = 2;
+        cv.notify_all();
+    }
+
+    void second(function<void()> printSecond) {
+        unique_lock<mutex> lck(mtx);
+        cv.wait(lck, [this]() { return count == 2;});
+        // printSecond() outputs "second". Do not change or remove this line.
+        printSecond();
+        count = 3;
+        cv.notify_all();
+    }
+
+    void third(function<void()> printThird) {
+        unique_lock<mutex> lck(mtx);
+        cv.wait(lck, [this]() { return count == 3;});
+        // printThird() outputs "third". Do not change or remove this line.
+        printThird();
+    }
+};