diff -uprN a/http.c b/http.c
--- a/http.c	2020-07-05 20:02:46.000000000 +0800
+++ b/http.c	2021-09-28 13:56:14.045159153 +0800
@@ -3975,6 +3975,14 @@ evhttp_set_bevcb(struct evhttp *http,
 	http->bevcbarg = cbarg;
 }
 
+void
+evhttp_set_newreqcb(struct evhttp *http,
+    int (*cb)(struct evhttp_request *, void *), void *cbarg)
+{
+	http->newreqcb = cb;
+	http->newreqcbarg = cbarg;
+}
+
 /*
  * Request related functions
  */
@@ -4036,6 +4044,8 @@ evhttp_request_free(struct evhttp_reques
 		req->flags |= EVHTTP_REQ_NEEDS_FREE;
 		return;
 	}
+	if (req->on_free_cb)
+		(*req->on_free_cb)(req, req->on_free_cb_arg);
 
 	if (req->remote_host != NULL)
 		mm_free(req->remote_host);
@@ -4116,6 +4126,15 @@ evhttp_request_set_on_complete_cb(struct
 	req->on_complete_cb_arg = cb_arg;
 }
 
+void
+evhttp_request_set_on_free_cb(struct evhttp_request *req,
+    void (*cb)(struct evhttp_request *, void *), void *cb_arg)
+{
+	req->on_free_cb = cb;
+	req->on_free_cb_arg = cb_arg;
+}
+
+
 /*
  * Allows for inspection of the request URI
  */
@@ -4307,10 +4326,15 @@ evhttp_associate_new_request_with_connec
 	 */
 	req->userdone = 1;
 
-	TAILQ_INSERT_TAIL(&evcon->requests, req, next);
-
 	req->kind = EVHTTP_REQUEST;
 
+	if (http->newreqcb && http->newreqcb(req, http->newreqcbarg) == -1) {
+		evhttp_request_free(req);
+		return (-1);
+	}
+
+	TAILQ_INSERT_TAIL(&evcon->requests, req, next);
+
 
 	evhttp_start_read_(evcon);
 
diff -uprN a/http-internal.h b/http-internal.h
--- a/http-internal.h	2020-07-05 20:02:46.000000000 +0800
+++ b/http-internal.h	2021-09-28 13:56:13.925151028 +0800
@@ -167,6 +167,8 @@ struct evhttp {
 	void *gencbarg;
 	struct bufferevent* (*bevcb)(struct event_base *, void *);
 	void *bevcbarg;
+	int (*newreqcb)(struct evhttp_request *req, void *);
+	void *newreqcbarg;
 
 	struct event_base *base;
 };
diff -uprN a/include/event2/http.h b/include/event2/http.h
--- a/include/event2/http.h	2020-07-05 20:02:46.000000000 +0800
+++ b/include/event2/http.h	2021-09-28 13:56:13.928151231 +0800
@@ -299,6 +299,20 @@ void evhttp_set_bevcb(struct evhttp *htt
     struct bufferevent *(*cb)(struct event_base *, void *), void *arg);
 
 /**
+   Set a callback which allows the user to note or throttle incoming requests.
+   The requests are not populated with HTTP level information. They
+   are just associated to a connection.
+   If the callback returns -1, the associated connection is terminated
+   and the request is closed.
+   @param http the evhttp server object for which to set the callback
+   @param cb the callback to invoke for incoming connections
+   @param arg an context argument for the callback
+ */
+EVENT2_EXPORT_SYMBOL
+void evhttp_set_newreqcb(struct evhttp *http,
+    int (*cb)(struct evhttp_request*, void *), void *arg);
+
+/**
    Adds a virtual host to the http server.
 
    A virtual host is a newly initialized evhttp object that has request
@@ -624,6 +638,20 @@ EVENT2_EXPORT_SYMBOL
 void evhttp_request_set_on_complete_cb(struct evhttp_request *req,
     void (*cb)(struct evhttp_request *, void *), void *cb_arg);
 
+/**
+ * Set a callback to be called on request free.
+ *
+ * The callback function will be called just before the evhttp_request object
+ * is destroyed.
+ *
+ * @param req a request object
+ * @param cb callback function that will be called before request free
+ * @param cb_arg an additional context argument for the callback
+ */
+EVENT2_EXPORT_SYMBOL
+void evhttp_request_set_on_free_cb(struct evhttp_request *req,
+    void (*cb)(struct evhttp_request *, void *), void *cb_arg);
+
 /** Frees the request object and removes associated events. */
 EVENT2_EXPORT_SYMBOL
 void evhttp_request_free(struct evhttp_request *req);
diff -uprN a/include/event2/http_struct.h b/include/event2/http_struct.h
--- a/include/event2/http_struct.h	2020-07-05 20:02:46.000000000 +0800
+++ b/include/event2/http_struct.h	2021-09-28 13:56:13.928151231 +0800
@@ -142,6 +142,12 @@ struct {
 	 */
 	void (*on_complete_cb)(struct evhttp_request *, void *);
 	void *on_complete_cb_arg;
+
+	/*
+	 * Free callback - called just before the request is freed.
+	 */
+	void (*on_free_cb)(struct evhttp_request *, void *);
+	void *on_free_cb_arg;
 };
 
 #ifdef __cplusplus
diff -uprN a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt	2020-07-05 20:02:46.000000000 +0800
+++ b/CMakeLists.txt	2022-01-10 13:29:32.912883436 +0800
@@ -200,6 +200,6 @@ endif()
 if (("${CMAKE_C_COMPILER_ID}" STREQUAL "GNU") OR (${CLANG}))
     set(GNUC 1)
 endif()
-if (("${CMAKE_C_COMPILER_ID}" STREQUAL "MSVC") OR (${CLANG}))
+if (("${CMAKE_C_COMPILER_ID}" STREQUAL "MSVC") OR ("${CMAKE_C_SIMULATE_ID}" STREQUAL "MSVC"))
     set(MSVC 1)
 endif()