From 68f23f57d77bc172ed39ecdd4d2d5cd5e13cf483 Mon Sep 17 00:00:00 2001 From: stickies-v Date: Fri, 29 Sep 2023 15:24:14 +0100 Subject: [PATCH] http: bugfix: track closed connection It is possible that the client disconnects before the request is handled. In those cases, evhttp_request_set_on_complete_cb is never called, which means that on shutdown the server we'll keep waiting endlessly. By adding evhttp_connection_set_closecb, libevent automatically cleans up those dead connections at latest when we shutdown, and depending on the libevent version already at the moment of remote client disconnect. In both cases, the bug is fixed. --- src/httpserver.cpp | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/src/httpserver.cpp b/src/httpserver.cpp index 995c446b58..069511563c 100644 --- a/src/httpserver.cpp +++ b/src/httpserver.cpp @@ -262,19 +262,22 @@ std::string RequestMethodString(HTTPRequest::RequestMethod m) /** HTTP request callback */ static void http_request_cb(struct evhttp_request* req, void* arg) { + evhttp_connection* conn{evhttp_request_get_connection(req)}; // Track active requests { g_requests.AddRequest(req); evhttp_request_set_on_complete_cb(req, [](struct evhttp_request* req, void*) { g_requests.RemoveRequest(req); }, nullptr); + evhttp_connection_set_closecb(conn, [](evhttp_connection* conn, void* arg) { + g_requests.RemoveConnection(conn); + }, nullptr); } // Disable reading to work around a libevent bug, fixed in 2.1.9 // See https://github.com/libevent/libevent/commit/5ff8eb26371c4dc56f384b2de35bea2d87814779 // and https://github.com/bitcoin/bitcoin/pull/11593. if (event_get_version_number() >= 0x02010600 && event_get_version_number() < 0x02010900) { - evhttp_connection* conn = evhttp_request_get_connection(req); if (conn) { bufferevent* bev = evhttp_connection_get_bufferevent(conn); if (bev) {