为什么信号连接会使套接字客户端对象失效?

Why does signal connection invalidate the SocketClient object?

本文关键字:客户端 对象 失效 套接字 信号 连接 为什么      更新时间:2023-10-16

我正在尝试通过 giomm 与 Gio 的 SocketClient 类建立 TCP/TLS 连接。

一切都很好,直到我用sigc::ptr_fun ()连接到SocketClient::event_signal ()信号。

下面是演示该问题的精简示例代码:

#include <giomm/error.h>
#include <giomm/init.h>
#include <giomm/networkaddress.h>
#include <giomm/socketclient.h>
#include <glibmm/main.h>
#include <iostream>
void socket_client_event (Gio::SocketClientEvent event,
const Glib::RefPtr<Gio::SocketConnectable> &connectable,
const Glib::RefPtr<Gio::IOStream> &connection) {
}
int main () {
auto loop = Glib::MainLoop::create ();
Gio::init ();
auto network_address = Gio::NetworkAddress::create ("www.example.org", 437);
auto socket_client = Gio::SocketClient::create ();
socket_client->set_tls (true);
socket_client->signal_event ().connect (sigc::ptr_fun (&socket_client_event));
Glib::RefPtr<Gio::SocketConnection> socket_connection;
try {
socket_connection = socket_client->connect (network_address);
}
catch (const Gio::TlsError &e) {
std::cerr << e.what (). c_str () << std::endl;
return 1;
}
catch (const Gio::Error &e) {
std::cerr << e.what (). c_str () << std::endl;
return 1;
}
loop->run ();
}

当调用connect ()方法时,我得到以下控制台输出:

(process:9046): GLib-GIO-CRITICAL **: g_socket_connection_connect: assertion 'G_IS_SOCKET_CONNECTION (connection)' failed
(process:9046): GLib-GObject-CRITICAL **: g_object_unref: assertion 'G_IS_OBJECT (object)' failed
(process:9046): GLib-GObject-CRITICAL **: g_object_get_qdata: assertion 'G_IS_OBJECT (object)' failed
(process:9046): GLib-GObject-CRITICAL **: g_object_get_qdata: assertion 'G_IS_OBJECT (object)' failed

然后分割错误使程序死亡。

我已经打开了 G_DEBUG=all 并在第一个错误处停止,但根据回溯,这是connect ()方法中的某个地方。

奇怪的是,注释掉连接信号处理程序的源代码行可以解决问题。

那么我在这里连接信号时做错了什么?为什么套接字客户端连接后无效?

在 glibmm 或 gio 中的引用计数中似乎存在错误。

如果我在问题消失时手动引用对象:

void socket_client_event (Gio::SocketClientEvent event,
const Glib::RefPtr<Gio::SocketConnectable> &connectable,
const Glib::RefPtr<Gio::IOStream> &connection) {
// Workaround for reference counting problems
if (connectable) {
connectable->reference ();
}
if (connection) {
connection->reference ();
}
}