removed unused methods(BeginPlay, Tick) and added rider plugin

Plugins/Developer/RiderLink/Source/RD/thirdparty/countdownlatch/countdownlatch.cpp

@@ -0,0 +1,34 @@
+#include <chrono>
+#include "countdownlatch.hpp"
+
+clatch::countdownlatch::countdownlatch(uint32_t count) {
+   this->count = count; 
+}
+
+void clatch::countdownlatch::await(uint64_t nanosecs) {
+    std::unique_lock<std::mutex> lck(lock);
+    if (0 == count){
+        return;
+    }
+    if (nanosecs > 0) {
+       cv.wait_for(lck, std::chrono::nanoseconds(nanosecs));
+    } else {
+       cv.wait(lck);
+    }
+}
+
+uint32_t clatch::countdownlatch::get_count() {
+    std::unique_lock<std::mutex> lck(lock);
+    return count;
+}
+
+void clatch::countdownlatch::count_down() {
+    std::unique_lock<std::mutex> lck(lock);
+    if (0 == count) {
+        return;
+    } 
+    --count;
+    if (0 == count) {
+        cv.notify_all();
+    }
+}