Add client reference from moment we receive a message

src/stratifier.c

@@ -3126,24 +3126,18 @@ static void suggest_diff(stratum_instance_t *client, const char *method, json_t
 	stratum_send_diff(sdata, client);
 }
 
-static void parse_method(sdata_t *sdata, const int64_t client_id, json_t *id_val,
-			 json_t *method_val, json_t *params_val, char *address)
+/* Enter with client holding ref count */
+static void parse_method(sdata_t *sdata, stratum_instance_t *client, const int64_t client_id,
+			 json_t *id_val, json_t *method_val, json_t *params_val, char *address)
 {
-	stratum_instance_t *client;
 	const char *method;
 	char buf[256];
 
-	client = ref_instance_by_id(sdata, client_id);
-	if (unlikely(!client)) {
-		LOGINFO("Failed to find client id %ld in hashtable!", client_id);
-		return;
-	}
-
 	if (unlikely(client->reject == 2)) {
 		LOGINFO("Dropping client %"PRId64" tagged for lazy invalidation", client_id);
-		snprintf(buf, 255, "dropclient=%ld", client->id);
+		snprintf(buf, 255, "dropclient=%ld", client_id);
 		send_proc(client->ckp->connector, buf);
-		goto out;
+		return;
 	}
 
 	/* Random broken clients send something not an integer as the id so we copy
@@ -3155,7 +3149,7 @@ static void parse_method(sdata_t *sdata, const int64_t client_id, json_t *id_val
 		/* Shouldn't happen, sanity check */
 		if (unlikely(!result_val)) {
 			LOGWARNING("parse_subscribe returned NULL result_val");
-			goto out;
+			return;
 		}
 		val = json_object();
 		json_object_set_new_nocheck(val, "result", result_val);
@@ -3164,10 +3158,11 @@ static void parse_method(sdata_t *sdata, const int64_t client_id, json_t *id_val
 		stratum_add_send(sdata, val, client_id);
 		if (likely(client->subscribed))
 			update_client(sdata, client, client_id);
-		goto out;
+		return;
 	}
 
 	if (unlikely(cmdmatch(method, "mining.passthrough"))) {
+		LOGNOTICE("Adding passthrough client %ld", client_id);
 		/* We need to inform the connector process that this client
 		 * is a passthrough and to manage its messages accordingly.
 		 * Remove this instance since the client id may well be
@@ -3178,17 +3173,16 @@ static void parse_method(sdata_t *sdata, const int64_t client_id, json_t *id_val
 		__add_dead(sdata, client);
 		ck_wunlock(&sdata->instance_lock);
 
-		LOGNOTICE("Adding passthrough client %ld", client->id);
-		snprintf(buf, 255, "passthrough=%ld", client->id);
+		snprintf(buf, 255, "passthrough=%ld", client_id);
 		send_proc(client->ckp->connector, buf);
-		goto out;
+		return;
 	}
 
 	if (cmdmatch(method, "mining.auth") && client->subscribed) {
 		json_params_t *jp = create_json_params(client_id, method_val, params_val, id_val, address);
 
 		ckmsgq_add(sdata->sauthq, jp);
-		goto out;
+		return;
 	}
 
 	/* We should only accept authorised requests from here on */
@@ -3196,22 +3190,22 @@ static void parse_method(sdata_t *sdata, const int64_t client_id, json_t *id_val
 		/* Dropping unauthorised clients here also allows the
 		 * stratifier process to restart since it will have lost all
 		 * the stratum instance data. Clients will just reconnect. */
-		LOGINFO("Dropping unauthorised client %ld", client->id);
-		snprintf(buf, 255, "dropclient=%ld", client->id);
+		LOGINFO("Dropping unauthorised client %ld", client_id);
+		snprintf(buf, 255, "dropclient=%ld", client_id);
 		send_proc(client->ckp->connector, buf);
-		goto out;
+		return;
 	}
 
 	if (cmdmatch(method, "mining.submit")) {
 		json_params_t *jp = create_json_params(client_id, method_val, params_val, id_val, address);
 
 		ckmsgq_add(sdata->sshareq, jp);
-		goto out;
+		return;
 	}
 
 	if (cmdmatch(method, "mining.suggest")) {
 		suggest_diff(client, method, params_val);
-		goto out;
+		return;
 	}
 
 	/* Covers both get_transactions and get_txnhashes */
@@ -3219,14 +3213,15 @@ static void parse_method(sdata_t *sdata, const int64_t client_id, json_t *id_val
 		json_params_t *jp = create_json_params(client_id, method_val, params_val, id_val, address);
 
 		ckmsgq_add(sdata->stxnq, jp);
-		goto out;
+		return;
 	}
 	/* Unhandled message here */
-out:
-	dec_instance_ref(sdata, client);
+	LOGINFO("Unhandled client %ld method %s", client_id, method);
+	return;
 }
 
-static void parse_instance_msg(sdata_t *sdata, smsg_t *msg)
+/* Entered with client holding ref count */
+static void parse_instance_msg(sdata_t *sdata, smsg_t *msg, stratum_instance_t *client)
 {
 	json_t *val = msg->json_msg, *id_val, *method, *params;
 	int64_t client_id = msg->client_id;
@@ -3257,7 +3252,7 @@ static void parse_instance_msg(sdata_t *sdata, smsg_t *msg)
 		send_json_err(sdata, client_id, id_val, "-1:params not found");
 		goto out;
 	}
-	parse_method(sdata, client_id, id_val, method, params, msg->address);
+	parse_method(sdata, client, client_id, id_val, method, params, msg->address);
 out:
 	json_decref(val);
 	free(msg);
@@ -3266,6 +3261,7 @@ out:
 static void srecv_process(ckpool_t *ckp, char *buf)
 {
 	sdata_t *sdata = ckp->data;
+	stratum_instance_t *client;
 	smsg_t *msg;
 	json_t *val;
 	int server;
@@ -3310,12 +3306,15 @@ static void srecv_process(ckpool_t *ckp, char *buf)
 
 	/* Parse the message here */
 	ck_wlock(&sdata->instance_lock);
-	/* client_id instance doesn't exist yet, create one */
-	if (!__instance_by_id(sdata, msg->client_id))
-		__stratum_add_instance(ckp, msg->client_id, server);
+	client = __instance_by_id(sdata, msg->client_id);
+	/* If client_id instance doesn't exist yet, create one */
+	if (unlikely(!client))
+		client = __stratum_add_instance(ckp, msg->client_id, server);
+	__inc_instance_ref(client);
 	ck_wunlock(&sdata->instance_lock);
 
-	parse_instance_msg(sdata, msg);
+	parse_instance_msg(sdata, msg, client);
+	dec_instance_ref(sdata, client);
 out:
 	free(buf);
 }