mongoose/examples/timers/main.c
2022-04-12 14:14:55 +01:00

51 lines
1.9 KiB
C

// Copyright (c) 2020 Cesanta Software Limited
// All rights reserved
//
// Example Websocket server with timers. This is a simple Websocket echo
// server, which sends a message to all connected clients periodically,
// using timer API.
//
// 1. Start this server, type `make`
// 2. Open https://www.websocket.org/echo.html in your browser
// 3. In the "Location" text field, type ws://127.0.0.1:8000/websocket
// 4. See "hi" messages appearing periodically
#include "mongoose.h"
static const char *s_listen_on = "http://localhost:8000";
// This RESTful server implements the following endpoints:
static void fn(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
if (ev == MG_EV_HTTP_MSG) {
struct mg_http_message *hm = (struct mg_http_message *) ev_data;
mg_ws_upgrade(c, hm, NULL);
c->label[0] = 'W'; // Set some unique mark on a connection
} else if (ev == MG_EV_WS_MSG) {
// Got websocket frame. Received data is wm->data. Echo it back!
struct mg_ws_message *wm = (struct mg_ws_message *) ev_data;
mg_ws_send(c, wm->data.ptr, wm->data.len, WEBSOCKET_OP_TEXT);
mg_iobuf_del(&c->recv, 0, c->recv.len);
}
(void) fn_data;
}
static void timer_fn(void *arg) {
struct mg_mgr *mgr = (struct mg_mgr *) arg;
// Broadcast "hi" message to all connected websocket clients.
// Traverse over all connections
for (struct mg_connection *c = mgr->conns; c != NULL; c = c->next) {
// Send only to marked connections
if (c->label[0] == 'W') mg_ws_send(c, "hi", 2, WEBSOCKET_OP_TEXT);
}
}
int main(void) {
struct mg_mgr mgr; // Event manager
mg_mgr_init(&mgr); // Initialise event manager
mg_timer_add(&mgr, 300, MG_TIMER_REPEAT, timer_fn, &mgr); // Init timer
mg_http_listen(&mgr, s_listen_on, fn, NULL); // Create HTTP listener
for (;;) mg_mgr_poll(&mgr, 1000); // Infinite event loop
mg_mgr_free(&mgr); // Free manager resources
return 0;
}