Method startDetectClientClose

src/httpserver.cpp:565–590

}

void HTTPRequest::startDetectClientClose() {
    LogPrint("http-poll", "start detect http connection close\n");
    // will need to call evhttp_send_reply_end to clean this up
    auto conn = evhttp_request_get_connection(req);

    // evhttp_connection_set_closecb does not reliably detect client connection close unless we write to it.
    //
    // This problem is supposedly resolved in 2.1.8. See: https://github.com/libevent/libevent/issues/78
    //
    // But we should just write to the socket to test liveness. This is useful for long-poll RPC calls to see
    // if they should terminate the request early.
    //
    // More weirdness: if process received SIGTERM, the http event loop (in HTTPThread) returns prematurely with 1.
    // In which case evhttp_send_reply_end doesn't seem to get called, and evhttp_connection_set_closecb is
    // not called. BUT when the event base is freed, this callback IS called, and HTTPRequest is already freed.
    //
    // So, waitClientClose and startDetectClientClose should just not do anything if RPC is shutting down.
    evhttp_connection_set_closecb(conn, [](struct evhttp_connection *conn, void *data) {
        LogPrint("http-poll", "http connection close detected\n");

        if (IsRPCRunning()) {
            auto req = (HTTPRequest*) data;
            req->setConnClosed();
        }
    }, (void *) this);
}

void HTTPRequest::setConnClosed() {
    std::lock_guard<std::mutex> lock(cs);