fix crashing on receive signal

Segmentation fault can happen when we attempting to emit signals from within the static method.

In other words, from the callback, we need to invoke some non-static method of WebSocket which would emit the needed signal

src/binance_websocket.cpp

@@ -21,13 +21,13 @@ static struct lws_context *context;
 static map<lws*, CB> handles;
 static lws_sorted_usec_list_t _sul;
 static atomic<int> lws_service_cancelled(0);
-static void connect_client(lws_sorted_usec_list_t *sul);
+void connect_client(lws_sorted_usec_list_t *sul);
 
 /*
  * This "contains" the endpoint connection proprty and has
  * the connection bound to it
  */
-static struct endpoint_connection {
+struct endpoint_connection {
 	lws_sorted_usec_list_t	sul; /* schedule connection retry */
 	struct lws		*wsi;	     /* related wsi if any */
 	uint16_t		retry_count; /* count of consequetive retries */
@@ -39,18 +39,18 @@ static struct endpoint_connection {
 /*
  * The retry and backoff policy we want to use for our client connections
  */
-static const uint32_t backoff_ms[] = { 1000, 1000*2, 1000*3, 1000*4, 1000*5};
+const uint32_t backoff_ms[] = { 1000, 1000*2, 1000*3, 1000*4, 1000*5};
 
 /*
  * This struct sets the policy for delays between retries,
  * and for how long a connection may be 'idle'
  * before it first tries to ping / pong on it to confirm it's up,
  * or drops the connection if still idle.
  */
-static const lws_retry_bo_t retry = {
+const lws_retry_bo_t retry = {
 	.retry_ms_table			= backoff_ms,
 	.retry_ms_table_count		= LWS_ARRAY_SIZE(backoff_ms),
-	.conceal_count			= LWS_ARRAY_SIZE(backoff_ms)*2,
+	.conceal_count			= LWS_ARRAY_SIZE(backoff_ms),
 	.secs_since_valid_ping		= 30, /* force PINGs after secs idle */
 	.secs_since_valid_hangup	= 60, /* hangup after secs idle */
 	.jitter_percent			= 15,
@@ -73,7 +73,7 @@ static const lws_retry_bo_t retry = {
  * permessage-deflate reduces the data size before the tls layer, for >100mps
  * reducing the colesced records to ~1.2KB.
  */
-static const struct lws_extension extensions[] = {
+const struct lws_extension extensions[] = {
 	{
 		"permessage-deflate",
 		lws_extension_callback_pm_deflate,
@@ -84,7 +84,7 @@ static const struct lws_extension extensions[] = {
 	{ NULL, NULL, NULL /* terminator */ }
 };
 
-static int event_cb(lws *wsi, enum lws_callback_reasons reason, void *user, void *in, size_t len)
+int event_cb(lws *wsi, enum lws_callback_reasons reason, void *user, void *in, size_t len)
 {
 	struct endpoint_connection *endpoint_prop = (struct endpoint_connection *)user;
 
@@ -168,8 +168,8 @@ static int event_cb(lws *wsi, enum lws_callback_reasons reason, void *user, void
 				handles.erase(wsi);
 			lws_cancel_service(lws_get_context(wsi));
 			lwsl_err("%s: connection attempts exhausted\n", __func__);
-			atomic_store(&lws_service_cancelled, 0);
-			return 0;
+			atomic_store(&lws_service_cancelled, 1);
+			return -1;
 		}
 	}catch (exception &e)
 	{
@@ -181,7 +181,7 @@ static int event_cb(lws *wsi, enum lws_callback_reasons reason, void *user, void
 	return 0;
 }
 
-static const lws_protocols protocols[] =
+const lws_protocols protocols[] =
 	{
 		{
 			.name = "binance-websocket-api",
@@ -193,7 +193,7 @@ static const lws_protocols protocols[] =
 		{ NULL, NULL, 0, 0 } /* end */
 	};
 
-static void
+void
 sigint_handler(int sig)
 {
 	Logger::write_log("<binance::Websocket::sigint_handler> Interactive attention signal : %d\n", sig);
@@ -203,7 +203,7 @@ sigint_handler(int sig)
 /*
  * Scheduled sul callback that starts the connection attempt
  */
-static void connect_client(lws_sorted_usec_list_t *sul)
+void connect_client(lws_sorted_usec_list_t *sul)
 {
 	struct endpoint_connection *endpoint_prop = lws_container_of(&_sul, struct endpoint_connection, sul);
 	struct lws_client_connect_info ccinfo;