Pushing live data on HTTP connections -> handling closed connection on client side

[Juggler-5]

Hello. Using http logger from your tutorial, the Q is - what is the way to understand that connection is closed at client`s side, when we simply close browser window? Is it possible to modify below function to handle disconnectein event?

static void broadcast_message(struct mg_mgr *mgr, const char *message) {
struct mg_connection *c;
for (c = mgr->conns; c != NULL; c = c->next) {
if (c->data[0] == 'L') mg_http_printf_chunk(c, "%s", message);
}
}

[scaprile]

When a connection is closed, either from your handler or from the other end, that handler will receive a CLOSE event, then the connection will be removed from the connection list.

The piece of code you wrote (presumably part of the example code that could have been referred with a simple permalink, to avoid assumptions and etc), apparently parsing all connections, apparently looking for some tag put by the example, will put data in a buffer and that may or may not be sent depending on when the connection is closed.
And I fail to see what it has to do with what I seem to understand as "your problem", which honestly I don't get, either.

[Juggler-5]

When old connection is closed by browser, and new one opened in new browser window (eventually those are different connections) I want to refresh data related to this "new" connection, not using data for "old" one. If I can see that "old" connection is aborted externally I can do it, otherwise I feed "old" data to new connection. In other words I just whant to catch browser closure events as easy as possible.

[scaprile]

There is no "old connection". There is no "aborted externally".
HTTP runs over TCP

When a connection is closed, either from your handler or from the other end, that handler will receive a CLOSE event, then the connection will be removed from the connection list.

If a TCP connection is closed, your event handler will receive an MG_EV_CLOSE event. Whatever you need to happen when a connection is closed, you handle by catching that event. After that, that very connection will be removed from the Mongoose connection list.
If a TCP connection is not closed, it remains in the Mongoose connection list, as expected.
If you don't receive an MG_EV_CLOSE event, then the connection is not being closed.
As long as the TCP connection is not closed, it is a valid connection; we have no idea what the user is doing or not doing.
If your browser sends some HTTP request, you can catch it and parse it when getting an MG_EV_HTTP_MSG event. If it does not, then there's nothing you can do.

• Please sniff your network (using Wireshark, for example) and observe the traffic.
• If, after your network inspection, you find an actual issue, feel free to open an issue, fill the issue template, and provide us with pertinent information (including useful network capture files; no snapshots, please attach capture files) in order to reproduce and fix the issue. We don't inspect your code for errors, please attach the minimum piece of code that can reproduce the issue. If you post code, please correctly format it so Github shows it as code.

[scaprile]

If you want connection 2 to not get whatever connection 1 did, then remove that when connection 1 is closed.
If you want simultaneous connections and don't want something to leak, use different tags, or write your own code. An example is an example is an example, we are here teaching how to do something; we're not providing a production-ready multi-user streamer.