Handler for websocket connection (Step 3/?)

Add an interface to register handler for websocket connections.
See enhancement #30 and question #101

examples/embedded_c/embedded_c.c

@@ -121,7 +121,8 @@ int WebSocketStartHandler(struct mg_connection *conn, void *cbdata)
 
 
 #ifdef USE_WEBSOCKET
-static struct mg_connection * ws_client;
+#define MAX_WS_CLIENTS 1024
+static struct mg_connection * ws_clients[MAX_WS_CLIENTS];
 static unsigned long cnt;
 
 int WebSocketConnectHandler(const struct mg_connection * conn, void *cbdata)
@@ -134,13 +135,19 @@ int WebSocketConnectHandler(const struct mg_connection * conn, void *cbdata)
 void WebSocketReadyHandler(const struct mg_connection * conn, void *cbdata)
 {
     struct mg_context *ctx = mg_get_context((struct mg_connection *) /* TODO: check const_casts */ conn);
+    int i;
 
     const char * text = "Hello from the websocket ready handler";
     /* TODO: check "const struct mg_connection *" vs "struct mg_connection *" everywhere */
     mg_websocket_write((struct mg_connection *)conn, WEBSOCKET_OPCODE_TEXT, text, strlen(text));
     fprintf(stdout, "Client added to the set of webserver connections\r\n\r\n");
     mg_lock_context(ctx);
-    ws_client = conn;
+    for (i=0; i<MAX_WS_CLIENTS; i++) {
+        if (ws_clients[i] == NULL) {
+            ws_clients[i] = conn;
+            break;
+        }
+    }
     mg_unlock_context(ctx);
 }
 
@@ -156,9 +163,15 @@ int WebsocketDataHandler(const struct mg_connection * conn, int bits, char * dat
 void WebSocketCloseHandler(const struct mg_connection * conn, void *cbdata)
 {
     struct mg_context *ctx = mg_get_context((struct mg_connection *) /* TODO: check const_casts */ conn);
+    int i;
 
     mg_lock_context(ctx);
-    ws_client = NULL;
+    for (i=0; i<MAX_WS_CLIENTS; i++) {
+        if (ws_clients[i] == conn) {
+            ws_clients[i] = NULL;
+            break;
+        }
+    }
     mg_unlock_context(ctx);
     fprintf(stdout, "Client droped from the set of webserver connections\r\n\r\n");
 }
@@ -166,11 +179,15 @@ void WebSocketCloseHandler(const struct mg_connection * conn, void *cbdata)
 void InformWebsockets(struct mg_context *ctx)
 {
     char text[32];
+    int i;
+
+    sprintf(text, "%lu", ++cnt);
 
     mg_lock_context(ctx);
-    if (ws_client) {
-        sprintf(text, "%lu", ++cnt);
-        mg_websocket_write(ws_client, WEBSOCKET_OPCODE_TEXT, text, strlen(text));
+    for (i=0; i<MAX_WS_CLIENTS; i++) {
+        if (ws_clients[i] != NULL) {
+            mg_websocket_write(ws_clients[i], WEBSOCKET_OPCODE_TEXT, text, strlen(text));
+        }
     }
     mg_unlock_context(ctx);
 }