Add more checks and warnings for cork buffer misuse

src/Loop.h

@@ -22,6 +22,7 @@
 
 #include "LoopData.h"
 #include <libusockets.h>
+#include <iostream>
 
 namespace uWS {
 struct Loop {
@@ -56,6 +57,12 @@ private:
         for (auto &p : loopData->postHandlers) {
             p.second((Loop *) loop);
         }
+
+        /* After every event loop iteration, we must not hold the cork buffer */
+        if (loopData->corkedSocket) {
+            std::cerr << "Error: Cork buffer must not be held across event loop iterations!" << std::endl;
+            std::terminate();
+        }
     }
 
     Loop() = delete;