From 660bdbf785a32024f0694915fa043968a0afb573 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20Barbosa?= <joao.paulo.barbosa@gmail.com>
Date: Sat, 3 Aug 2019 02:52:53 +0100
Subject: [PATCH] http: Release server before waiting for event base loop exit

---
 src/httpserver.cpp | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/src/httpserver.cpp b/src/httpserver.cpp
index f49f2b3f37b..5c1bbc87fcf 100644
--- a/src/httpserver.cpp
+++ b/src/httpserver.cpp
@@ -486,15 +486,18 @@ void StopHTTPServer()
             return g_requests.empty();
         });
     }
+    if (eventHTTP) {
+        // Schedule a callback to call evhttp_free in the event base thread, so
+        // that evhttp_free does not need to be called again after the handling
+        // of unfinished request connections that follows.
+        event_base_once(eventBase, -1, EV_TIMEOUT, [](evutil_socket_t, short, void*) {
+            evhttp_free(eventHTTP);
+            eventHTTP = nullptr;
+        }, nullptr, nullptr);
+    }
     if (eventBase) {
         LogPrint(BCLog::HTTP, "Waiting for HTTP event thread to exit\n");
         if (g_thread_http.joinable()) g_thread_http.join();
-    }
-    if (eventHTTP) {
-        evhttp_free(eventHTTP);
-        eventHTTP = nullptr;
-    }
-    if (eventBase) {
         event_base_free(eventBase);
         eventBase = nullptr;
     }