Add timer example

examples/timers/Makefile

@@ -0,0 +1,10 @@
+PROG ?= example
+
+all: $(PROG)
+	$(DEBUGGER) ./$(PROG) $(ARGS)
+
+$(PROG): main.c
+	$(CC) ../../mongoose.c -I../.. -W -Wall -DMG_ENABLE_LINES=1 -DMG_ENABLE_DIRECTORY_LISTING=1 $(CFLAGS) -o $(PROG) main.c
+
+clean:
+	rm -rf $(PROG) *.o *.dSYM *.gcov *.gcno *.gcda *.obj *.exe *.ilk *.pdb

examples/timers/main.c

@@ -0,0 +1,54 @@
+// 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);
+  } 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_delete(&c->recv, c->recv.len);
+  }
+  (void) fn_data;
+}
+
+static void timer_fn(void *arg) {
+  struct mg_mgr *mgr = (struct mg_mgr *) arg;
+  struct mg_connection *c;
+  // Broadcast "hi" message to all connected websocket clients.
+  // Traverse over all connections
+  for (c = mgr->conns; c != NULL; c = c->next) {
+    // Send only to accepted websocket connections
+    if (c->is_accepted && c->is_websocket) {
+      mg_ws_send(c, "hi", 2, WEBSOCKET_OP_TEXT);
+    }
+  }
+}
+
+int main(void) {
+  struct mg_mgr mgr;                            // Event manager
+  struct mg_timer t1;                           // Timer
+  mg_mgr_init(&mgr);                            // Initialise event manager
+  mg_timer_init(&t1, 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_timer_free(&t1);                           // Free timer resources
+  mg_mgr_free(&mgr);                            // Free manager resources
+  return 0;
+}