Add new fuzz target for async responses

fuzzing/AsyncEpollHelloWorld.cpp

@@ -0,0 +1,60 @@
+/* We rely on wrapped syscalls */
+#include "libEpollFuzzer/epoll_fuzzer.h"
+
+#include "App.h"
+
+/* We keep this one for teardown later on */
+struct us_listen_socket_t *listen_socket;
+
+/* This test is run by libEpollFuzzer */
+void test() {
+
+    {
+        /* Keep in mind that uWS::SSLApp({options}) is the same as uWS::App() when compiled without SSL support.
+        * You may swap to using uWS:App() if you don't need SSL */
+        auto app = uWS::App({
+            /* There are example certificates in uWebSockets.js repo */
+            .key_file_name = "../misc/key.pem",
+            .cert_file_name = "../misc/cert.pem",
+            .passphrase = "1234"
+        }).get("/*", [](auto *res, auto *req) {
+            bool *aborted = new bool;
+            *aborted = false;
+            res->onAborted([aborted]() {
+                *aborted = true;
+            });
+
+            uWS::Loop::get()->defer([res, aborted]() {
+                if (!*aborted) {
+                    res->cork([res, aborted]() {
+                        // Todo: also test upgrade to websocket here
+                        res->end("Hello async!");
+                    });
+                }
+                delete aborted;
+            });
+        }).listen(9001, [](auto *listenSocket) {
+            listen_socket = listenSocket;
+        });
+
+        app.run();
+    }
+    uWS::Loop::get()->free();
+}
+
+/* Thus function should shutdown the event-loop and let the test fall through */
+void teardown() {
+	/* If we are called twice there's a bug (it potentially could if
+	 * all open sockets cannot be error-closed in one epoll_wait call).
+	 * But we only allow 1k FDs and we have a buffer of 1024 from epoll_wait */
+	if (!listen_socket) {
+		exit(-1);
+	}
+
+	/* We might have open sockets still, and these will be error-closed by epoll_wait */
+	// us_socket_context_close - close all open sockets created with this socket context
+    if (listen_socket) {
+        us_listen_socket_close(0, listen_socket);
+        listen_socket = NULL;
+    }
+}