diff --git a/include/villas/node.h b/include/villas/node.h
index 09ca1a429..cce336a90 100644
--- a/include/villas/node.h
+++ b/include/villas/node.h
@@ -154,7 +154,7 @@ char * node_name_long(struct node *n);
  */
 int node_reverse(struct node *n);
 
-int node_read(struct node *n, struct sample *smps[], unsigned cnt);
+int node_read(struct node *n, struct sample *smps[], int *cnt);
 
 int node_write(struct node *n, struct sample *smps[], unsigned cnt);
 
diff --git a/include/villas/node_type.h b/include/villas/node_type.h
index b9026b1d3..5d716aea4 100644
--- a/include/villas/node_type.h
+++ b/include/villas/node_type.h
@@ -136,7 +136,7 @@ struct node_type {
 	 * @param cnt	The number of messages which should be received.
 	 * @return	The number of messages actually received.
 	 */
-	int (*read)(struct node *n, struct sample *smps[], unsigned cnt);
+	int (*read)(struct node *n, struct sample *smps[], int *cnt);
 
 	/** Send multiple messages in a single datagram / packet.
 	 *
diff --git a/include/villas/nodes/amqp.h b/include/villas/nodes/amqp.h
index b343190c1..42e379946 100644
--- a/include/villas/nodes/amqp.h
+++ b/include/villas/nodes/amqp.h
@@ -80,7 +80,7 @@ int amqp_start(struct node *n);
 int amqp_stop(struct node *n);
 
 /** @see node_type::read */
-int amqp_read(struct node *n, struct sample *smps[], unsigned cnt);
+int amqp_read(struct node *n, struct sample *smps[], int *cnt);
 
 /** @see node_type::write */
 int amqp_write(struct node *n, struct sample *smps[], unsigned cnt);
diff --git a/include/villas/nodes/file.h b/include/villas/nodes/file.h
index 498afb0a4..4ccf2bcb2 100644
--- a/include/villas/nodes/file.h
+++ b/include/villas/nodes/file.h
@@ -83,7 +83,7 @@ int file_start(struct node *n);
 int file_stop(struct node *n);
 
 /** @see node_type::read */
-int file_read(struct node *n, struct sample *smps[], unsigned cnt);
+int file_read(struct node *n, struct sample *smps[], int *cnt);
 
 /** @see node_type::write */
 int file_write(struct node *n, struct sample *smps[], unsigned cnt);
diff --git a/include/villas/nodes/infiniband.h b/include/villas/nodes/infiniband.h
index cf2cb286d..6452fa661 100644
--- a/include/villas/nodes/infiniband.h
+++ b/include/villas/nodes/infiniband.h
@@ -112,31 +112,31 @@ struct infiniband {
 };
 
 /** @see node_type::reverse */
-int infiniband_reverse(struct node *n);
+int ib_reverse(struct node *n);
 
 /** @see node_type::print */
-char * infiniband_print(struct node *n);
+char * ib_print(struct node *n);
 
 /** @see node_type::parse */
-int infiniband_parse(struct node *n, json_t *cfg);
+int ib_parse(struct node *n, json_t *cfg);
 
 /** @see node_type::open */
-int infiniband_start(struct node *n);
+int ib_start(struct node *n);
 
 /** @see node_type::destroy */
-int infiniband_destroy(struct node *n);
+int ib_destroy(struct node *n);
 
 /** @see node_type::close */
-int infiniband_stop(struct node *n);
+int ib_stop(struct node *n);
 
 /** @see node_type::init */
-int infiniband_init(struct super_node *n);
+int ib_init(struct super_node *n);
 
 /** @see node_type::deinit */
-int infiniband_deinit();
+int ib_deinit();
 
 /** @see node_type::read */
-int infiniband_read(struct node *n, struct sample *smps[], unsigned cnt);
+int ib_read(struct node *n, struct sample *smps[], int *cnt);
 
 /** @see node_type::write */
 int infiniband_write(struct node *n, struct sample *smps[], unsigned cnt);
diff --git a/include/villas/nodes/loopback.h b/include/villas/nodes/loopback.h
index 4cff73eb6..2c6556eb8 100644
--- a/include/villas/nodes/loopback.h
+++ b/include/villas/nodes/loopback.h
@@ -63,7 +63,7 @@ int loopback_open(struct node *n);
 int loopback_close(struct node *n);
 
 /** @see node_type::read */
-int loopback_read(struct node *n, struct sample *smps[], unsigned cnt);
+int loopback_read(struct node *n, struct sample *smps[], int *cnt);
 
 /** @see node_type::write */
 int loopback_write(struct node *n, struct sample *smps[], unsigned cnt);
diff --git a/include/villas/nodes/mqtt.h b/include/villas/nodes/mqtt.h
index 40713c8b2..d2f7061a2 100644
--- a/include/villas/nodes/mqtt.h
+++ b/include/villas/nodes/mqtt.h
@@ -95,7 +95,7 @@ int mqtt_init();
 int mqtt_deinit();
 
 /** @see node_type::read */
-int mqtt_read(struct node *n, struct sample *smps[], unsigned cnt);
+int mqtt_read(struct node *n, struct sample *smps[], int *cnt);
 
 /** @see node_type::write */
 int mqtt_write(struct node *n, struct sample *smps[], unsigned cnt);
diff --git a/include/villas/nodes/nanomsg.h b/include/villas/nodes/nanomsg.h
index 11b5d2a3e..715d21122 100644
--- a/include/villas/nodes/nanomsg.h
+++ b/include/villas/nodes/nanomsg.h
@@ -71,7 +71,7 @@ int nanomsg_start(struct node *n);
 int nanomsg_stop(struct node *n);
 
 /** @see node_type::read */
-int nanomsg_read(struct node *n, struct sample *smps[], unsigned cnt);
+int nanomsg_read(struct node *n, struct sample *smps[], int *cnt);
 
 /** @see node_type::write */
 int nanomsg_write(struct node *n, struct sample *smps[], unsigned cnt);
diff --git a/include/villas/nodes/ngsi.h b/include/villas/nodes/ngsi.h
index 6160907a5..c43f813e3 100644
--- a/include/villas/nodes/ngsi.h
+++ b/include/villas/nodes/ngsi.h
@@ -93,7 +93,7 @@ int ngsi_start(struct node *n);
 int ngsi_stop(struct node *n);
 
 /** @see node_type::read */
-int ngsi_read(struct node *n, struct sample *smps[], unsigned cnt);
+int ngsi_read(struct node *n, struct sample *smps[], int *cnt);
 
 /** @see node_type::write */
 int ngsi_write(struct node *n, struct sample *smps[], unsigned cnt);
diff --git a/include/villas/nodes/shmem.h b/include/villas/nodes/shmem.h
index 0426645ce..a37374111 100644
--- a/include/villas/nodes/shmem.h
+++ b/include/villas/nodes/shmem.h
@@ -64,7 +64,7 @@ int shmem_start(struct node *n);
 int shmem_stop(struct node *n);
 
 /** @see node_type::read */
-int shmem_read(struct node *n, struct sample *smps[], unsigned cnt);
+int shmem_read(struct node *n, struct sample *smps[], int *cnt);
 
 /** @see node_type::write */
 int shmem_write(struct node *n, struct sample *smps[], unsigned cnt);
diff --git a/include/villas/nodes/signal_generator.h b/include/villas/nodes/signal_generator.h
index 18d0c0b48..a43156af4 100644
--- a/include/villas/nodes/signal_generator.h
+++ b/include/villas/nodes/signal_generator.h
@@ -89,7 +89,7 @@ int signal_generator_start(struct node *n);
 int signal_generator_stop(struct node *n);
 
 /** @see node_type::read */
-int signal_generator_read(struct node *n, struct sample *smps[], unsigned cnt);
+int signal_generator_read(struct node *n, struct sample *smps[], int *cnt);
 
 enum signal_generator_type signal_generator_lookup_type(const char *type);
 
diff --git a/include/villas/nodes/socket.h b/include/villas/nodes/socket.h
index ad2ed1372..cc80c6216 100644
--- a/include/villas/nodes/socket.h
+++ b/include/villas/nodes/socket.h
@@ -122,7 +122,7 @@ int socket_stop(struct node *n);
 int socket_write(struct node *n, struct sample *smps[], unsigned cnt);
 
 /** @see node_type::read */
-int socket_read(struct node *n, struct sample *smps[], unsigned cnt);
+int socket_read(struct node *n, struct sample *smps[], int *cnt);
 
 /** @see node_type::parse */
 int socket_parse(struct node *n, json_t *cfg);
diff --git a/include/villas/nodes/stats.h b/include/villas/nodes/stats.h
index 89a161656..eea8ca746 100644
--- a/include/villas/nodes/stats.h
+++ b/include/villas/nodes/stats.h
@@ -67,7 +67,7 @@ int stats_node_start(struct node *n);
 int stats_node_stop(struct node *n);
 
 /** @see node_type::read */
-int stats_node_read(struct node *n, struct sample *smps[], unsigned cnt);
+int stats_node_read(struct node *n, struct sample *smps[], int *cnt);
 
 #ifdef __cplusplus
 }
diff --git a/include/villas/nodes/test_rtt.h b/include/villas/nodes/test_rtt.h
index 20f204410..b65f92030 100644
--- a/include/villas/nodes/test_rtt.h
+++ b/include/villas/nodes/test_rtt.h
@@ -79,7 +79,7 @@ int test_rtt_start(struct node *n);
 int test_rtt_stop(struct node *n);
 
 /** @see node_type::read */
-int test_rtt_read(struct node *n, struct sample *smps[], unsigned cnt);
+int test_rtt_read(struct node *n, struct sample *smps[], int *cnt);
 
 /** @see node_type::write */
 int test_rtt_write(struct node *n, struct sample *smps[], unsigned cnt);
diff --git a/include/villas/nodes/websocket.h b/include/villas/nodes/websocket.h
index 0e5097a17..6d6c15ad7 100644
--- a/include/villas/nodes/websocket.h
+++ b/include/villas/nodes/websocket.h
@@ -112,7 +112,7 @@ int websocket_stop(struct node *n);
 int websocket_destroy(struct node *n);
 
 /** @see node_type::read */
-int websocket_read(struct node *n, struct sample *smps[], unsigned cnt);
+int websocket_read(struct node *n, struct sample *smps[], int *cnt);
 
 /** @see node_type::write */
 int websocket_write(struct node *n, struct sample *smps[], unsigned cnt);
diff --git a/include/villas/nodes/zeromq.h b/include/villas/nodes/zeromq.h
index 4f31de46e..997388b45 100644
--- a/include/villas/nodes/zeromq.h
+++ b/include/villas/nodes/zeromq.h
@@ -102,7 +102,7 @@ int zeromq_start(struct node *n);
 int zeromq_stop(struct node *n);
 
 /** @see node_type::read */
-int zeromq_read(struct node *n, struct sample *smps[], unsigned cnt);
+int zeromq_read(struct node *n, struct sample *smps[], int *cnt);
 
 /** @see node_type::write */
 int zeromq_write(struct node *n, struct sample *smps[], unsigned cnt);
diff --git a/include/villas/stats.h b/include/villas/stats.h
index ac440a5f5..8f628ff10 100644
--- a/include/villas/stats.h
+++ b/include/villas/stats.h
@@ -72,7 +72,7 @@ int stats_destroy(struct stats *s);
 
 void stats_update(struct stats *s, enum stats_id id, double val);
 
-void stats_collect(struct stats *s, struct sample *smps[], size_t cnt);
+void stats_collect(struct stats *s, struct sample *smps[], size_t *cnt);
 
 int stats_commit(struct stats *s);
 
diff --git a/lib/node.c b/lib/node.c
index c7d93b84b..660a6ed34 100644
--- a/lib/node.c
+++ b/lib/node.c
@@ -408,7 +408,7 @@ int node_destroy(struct node *n)
 	return 0;
 }
 
-int node_read(struct node *n, struct sample *smps[], unsigned cnt)
+int node_read(struct node *n, struct sample *smps[], int *cnt)
 {
 	int readd, nread = 0;
 
@@ -416,9 +416,10 @@ int node_read(struct node *n, struct sample *smps[], unsigned cnt)
 		return -1;
 
 	/* Send in parts if vector not supported */
-	if (n->_vt->vectorize > 0 && n->_vt->vectorize < cnt) {
-		while (cnt - nread > 0) {
-			readd = n->_vt->read(n, &smps[nread], MIN(cnt - nread, n->_vt->vectorize));
+	if (n->_vt->vectorize > 0 && n->_vt->vectorize < *cnt) {
+		int cnt_vec_min = MIN(*cnt - nread, n->_vt->vectorize);
+		while (*cnt - nread > 0) {
+			readd = n->_vt->read(n, &smps[nread], &cnt_vec_min);
 			if (readd < 0)
 				return readd;
 
diff --git a/lib/nodes/amqp.c b/lib/nodes/amqp.c
index 2e9472c2a..13ae172ac 100644
--- a/lib/nodes/amqp.c
+++ b/lib/nodes/amqp.c
@@ -301,7 +301,7 @@ int amqp_stop(struct node *n)
 	return 0;
 }
 
-int amqp_read(struct node *n, struct sample *smps[], unsigned cnt)
+int amqp_read(struct node *n, struct sample *smps[], int *cnt)
 {
 	int ret;
 	struct amqp *a = n->_vd;
@@ -312,7 +312,7 @@ int amqp_read(struct node *n, struct sample *smps[], unsigned cnt)
 	if (rep.reply_type != AMQP_RESPONSE_NORMAL)
 		return -1;
 
-	ret = io_sscan(&a->io, env.message.body.bytes, env.message.body.len, NULL, smps, cnt);
+	ret = io_sscan(&a->io, env.message.body.bytes, env.message.body.len, NULL, smps, *cnt);
 
 	amqp_destroy_envelope(&env);
 
diff --git a/lib/nodes/cbuilder.c b/lib/nodes/cbuilder.c
index bf0ecaf2e..acd58874b 100644
--- a/lib/nodes/cbuilder.c
+++ b/lib/nodes/cbuilder.c
@@ -94,7 +94,7 @@ int cbuilder_stop(struct node *n)
 	return 0;
 }
 
-int cbuilder_read(struct node *n, struct sample *smps[], unsigned cnt)
+int cbuilder_read(struct node *n, struct sample *smps[], int *cnt)
 {
 	struct cbuilder *cb = (struct cbuilder *) n->_vd;
 	struct sample *smp = smps[0];
diff --git a/lib/nodes/file.c b/lib/nodes/file.c
index 674c0bd0b..a9dcbe67d 100644
--- a/lib/nodes/file.c
+++ b/lib/nodes/file.c
@@ -278,15 +278,15 @@ int file_destroy(struct node *n)
 	return 0;
 }
 
-int file_read(struct node *n, struct sample *smps[], unsigned cnt)
+int file_read(struct node *n, struct sample *smps[], int *cnt)
 {
 	struct file *f = (struct file *) n->_vd;
 	int ret;
 	uint64_t steps;
 
-	assert(cnt == 1);
+	assert(*cnt == 1);
 
-retry:	ret = io_scan(&f->io, smps, cnt);
+retry:	ret = io_scan(&f->io, smps, *cnt);
 	if (ret <= 0) {
 		if (io_eof(&f->io)) {
 			switch (f->eof) {
@@ -322,7 +322,7 @@ retry:	ret = io_scan(&f->io, smps, cnt);
 
 	/* We dont wait in FILE_EPOCH_ORIGINAL mode */
 	if (f->epoch_mode == FILE_EPOCH_ORIGINAL)
-		return cnt;
+		return *cnt;
 
 	if (f->rate) {
 		steps = task_wait(&f->task);
@@ -342,7 +342,7 @@ retry:	ret = io_scan(&f->io, smps, cnt);
 	else if (steps != 1)
 		warn("Missed steps: %" PRIu64, steps - 1);
 
-	return cnt;
+	return *cnt;
 }
 
 int file_write(struct node *n, struct sample *smps[], unsigned cnt)
diff --git a/lib/nodes/infiniband.c b/lib/nodes/infiniband.c
index 5b103b71e..1549642aa 100644
--- a/lib/nodes/infiniband.c
+++ b/lib/nodes/infiniband.c
@@ -730,12 +730,12 @@ int ib_deinit()
 	return 0;
 }
 
-int ib_read(struct node *n, struct sample *smps[], unsigned cnt)
+int ib_read(struct node *n, struct sample *smps[], int *cnt)
 {
 	struct infiniband *ib = (struct infiniband *) n->_vd;
 	struct ibv_wc wc[n->in.vectorize];
-	struct ibv_recv_wr wr[cnt], *bad_wr = NULL;
-    	struct ibv_sge sge[cnt];
+	struct ibv_recv_wr wr[*cnt], *bad_wr = NULL;
+    	struct ibv_sge sge[*cnt];
 	struct ibv_mr *mr;
 	int ret = 0;
 
@@ -743,11 +743,11 @@ int ib_read(struct node *n, struct sample *smps[], unsigned cnt)
 
 	if (n->state == STATE_CONNECTED) {
 
-		if (ib->conn.available_recv_wrs < ib->qp_init.cap.max_recv_wr && cnt==n->in.vectorize)	{
+		if (ib->conn.available_recv_wrs < ib->qp_init.cap.max_recv_wr && *cnt)	{
 			// Get Memory Region
 			mr = memory_ib_get_mr(smps[0]);
 
-			for (int i = 0; i < cnt; i++) {
+			for (int i = 0; i < *cnt; i++) {
 				// Increase refcnt of sample
 				sample_get(smps[i]);
 
@@ -764,7 +764,7 @@ int ib_read(struct node *n, struct sample *smps[], unsigned cnt)
 
 				ib->conn.available_recv_wrs++;
 
-				if (ib->conn.available_recv_wrs == ib->qp_init.cap.max_recv_wr || i==(cnt-1)) {
+				if (ib->conn.available_recv_wrs == ib->qp_init.cap.max_recv_wr || i==(*cnt-1)) {
 					debug(LOG_IB | 10, "Prepared %i new receive Work Requests", (i+1));
 
 					wr[i].next = NULL;
diff --git a/lib/nodes/loopback.c b/lib/nodes/loopback.c
index 62b11519c..2ab769d19 100644
--- a/lib/nodes/loopback.c
+++ b/lib/nodes/loopback.c
@@ -69,14 +69,14 @@ int loopback_close(struct node *n)
 	return queue_signalled_destroy(&l->queue);
 }
 
-int loopback_read(struct node *n, struct sample *smps[], unsigned cnt)
+int loopback_read(struct node *n, struct sample *smps[], int *cnt)
 {
 	int avail;
 
 	struct loopback *l = (struct loopback *) n->_vd;
-	struct sample *cpys[cnt];
+	struct sample *cpys[*cnt];
 
-	avail = queue_signalled_pull_many(&l->queue, (void **) cpys, cnt);
+	avail = queue_signalled_pull_many(&l->queue, (void **) cpys, *cnt);
 
 	for (int i = 0; i < avail; i++) {
 		sample_copy(smps[i], cpys[i]);
diff --git a/lib/nodes/mqtt.c b/lib/nodes/mqtt.c
index 893d10d8d..ee0230d31 100644
--- a/lib/nodes/mqtt.c
+++ b/lib/nodes/mqtt.c
@@ -358,13 +358,13 @@ int mqtt_deinit()
 	return 0;
 }
 
-int mqtt_read(struct node *n, struct sample *smps[], unsigned cnt)
+int mqtt_read(struct node *n, struct sample *smps[], int *cnt)
 {
 	int pulled;
 	struct mqtt *m = (struct mqtt *) n->_vd;
-	struct sample *smpt[cnt];
+	struct sample *smpt[*cnt];
 
-	pulled = queue_signalled_pull_many(&m->queue, (void **) smpt, cnt);
+	pulled = queue_signalled_pull_many(&m->queue, (void **) smpt, *cnt);
 
 	sample_copy_many(smps, smpt, pulled);
 	sample_put_many(smpt, pulled);
diff --git a/lib/nodes/nanomsg.c b/lib/nodes/nanomsg.c
index 432734803..f6f397d40 100644
--- a/lib/nodes/nanomsg.c
+++ b/lib/nodes/nanomsg.c
@@ -228,7 +228,7 @@ int nanomsg_deinit()
 	return 0;
 }
 
-int nanomsg_read(struct node *n, struct sample *smps[], unsigned cnt)
+int nanomsg_read(struct node *n, struct sample *smps[], int *cnt)
 {
 	struct nanomsg *m = (struct nanomsg *) n->_vd;
 	int bytes;
@@ -239,7 +239,7 @@ int nanomsg_read(struct node *n, struct sample *smps[], unsigned cnt)
 	if (bytes < 0)
 		return -1;
 
-	return io_sscan(&m->io, data, bytes, NULL, smps, cnt);
+	return io_sscan(&m->io, data, bytes, NULL, smps, *cnt);
 }
 
 int nanomsg_write(struct node *n, struct sample *smps[], unsigned cnt)
diff --git a/lib/nodes/ngsi.c b/lib/nodes/ngsi.c
index 8e5618e43..36a61cee6 100644
--- a/lib/nodes/ngsi.c
+++ b/lib/nodes/ngsi.c
@@ -533,7 +533,7 @@ int ngsi_stop(struct node *n)
 	return ret;
 }
 
-int ngsi_read(struct node *n, struct sample *smps[], unsigned cnt)
+int ngsi_read(struct node *n, struct sample *smps[], int *cnt)
 {
 	struct ngsi *i = (struct ngsi *) n->_vd;
 	int ret;
@@ -548,7 +548,7 @@ int ngsi_read(struct node *n, struct sample *smps[], unsigned cnt)
 	if (ret)
 		goto out;
 
-	ret = ngsi_parse_entity(rentity, i, smps, cnt);
+	ret = ngsi_parse_entity(rentity, i, smps, *cnt);
 	if (ret)
 		goto out2;
 
diff --git a/lib/nodes/shmem.c b/lib/nodes/shmem.c
index 177b548be..0461ab7ab 100644
--- a/lib/nodes/shmem.c
+++ b/lib/nodes/shmem.c
@@ -110,14 +110,14 @@ int shmem_stop(struct node *n)
 	return shmem_int_close(&shm->intf);
 }
 
-int shmem_read(struct node *n, struct sample *smps[], unsigned cnt)
+int shmem_read(struct node *n, struct sample *smps[], int *cnt)
 {
 	struct shmem *shm = (struct shmem *) n->_vd;
 	int recv;
-	struct sample *shared_smps[cnt];
+	struct sample *shared_smps[*cnt];
 
 	do {
-		recv = shmem_int_read(&shm->intf, shared_smps, cnt);
+		recv = shmem_int_read(&shm->intf, shared_smps, *cnt);
 	} while (recv == 0);
 
 	if (recv < 0) {
diff --git a/lib/nodes/signal_generator.c b/lib/nodes/signal_generator.c
index 13a26dba6..8d038b7de 100644
--- a/lib/nodes/signal_generator.c
+++ b/lib/nodes/signal_generator.c
@@ -212,7 +212,7 @@ int signal_generator_stop(struct node *n)
 	return 0;
 }
 
-int signal_generator_read(struct node *n, struct sample *smps[], unsigned cnt)
+int signal_generator_read(struct node *n, struct sample *smps[], int *cnt)
 {
 	struct signal_generator *s = (struct signal_generator *) n->_vd;
 	struct sample *t = smps[0];
@@ -220,7 +220,7 @@ int signal_generator_read(struct node *n, struct sample *smps[], unsigned cnt)
 	struct timespec ts;
 	int steps;
 
-	assert(cnt == 1);
+	assert(*cnt == 1);
 
 	/* Throttle output if desired */
 	if (s->rt) {
diff --git a/lib/nodes/socket.c b/lib/nodes/socket.c
index 61c7fa2a1..2b853a662 100644
--- a/lib/nodes/socket.c
+++ b/lib/nodes/socket.c
@@ -336,7 +336,7 @@ int socket_destroy(struct node *n)
 	return 0;
 }
 
-int socket_read(struct node *n, struct sample *smps[], unsigned cnt)
+int socket_read(struct node *n, struct sample *smps[], int *cnt)
 {
 	int ret;
 	struct socket *s = (struct socket *) n->_vd;
@@ -391,7 +391,7 @@ int socket_read(struct node *n, struct sample *smps[], unsigned cnt)
 		goto out;
 	}
 
-	ret = io_sscan(&s->io, ptr, bytes, &rbytes, smps, cnt);
+	ret = io_sscan(&s->io, ptr, bytes, &rbytes, smps, *cnt);
 
 	if (ret < 0 || bytes != rbytes)
 		warn("Received invalid packet from node: %s ret=%d, bytes=%zu, rbytes=%zu", node_name(n), ret, bytes, rbytes);
diff --git a/lib/nodes/stats.c b/lib/nodes/stats.c
index 4a5e0abd9..146e6fbf5 100644
--- a/lib/nodes/stats.c
+++ b/lib/nodes/stats.c
@@ -119,12 +119,12 @@ int stats_node_destroy(struct node *n)
 	return 0;
 }
 
-int stats_node_read(struct node *n, struct sample *smps[], unsigned cnt)
+int stats_node_read(struct node *n, struct sample *smps[], int *cnt)
 {
 	struct stats_node *sn = (struct stats_node *) n->_vd;
 	struct stats *s = sn->node->stats;
 
-	if (!cnt)
+	if (!*cnt)
 		return 0;
 
 	if (!sn->node->stats)
diff --git a/lib/nodes/test_rtt.c b/lib/nodes/test_rtt.c
index 2de5d887f..a48229ce1 100644
--- a/lib/nodes/test_rtt.c
+++ b/lib/nodes/test_rtt.c
@@ -277,7 +277,7 @@ int test_rtt_stop(struct node *n)
 	return 0;
 }
 
-int test_rtt_read(struct node *n, struct sample *smps[], unsigned cnt)
+int test_rtt_read(struct node *n, struct sample *smps[], int *cnt)
 {
 	int i, ret, values;
 	uint64_t steps;
@@ -320,7 +320,7 @@ int test_rtt_read(struct node *n, struct sample *smps[], unsigned cnt)
 	struct timespec now = time_now();
 
 	/* Prepare samples */
-	for (i = 0; i < cnt; i++) {
+	for (i = 0; i < *cnt; i++) {
 		values = c->values;
 		if (smps[i]->capacity < values) {
 			values = smps[i]->capacity;
diff --git a/lib/nodes/websocket.c b/lib/nodes/websocket.c
index a81b8b2e8..29d996ce5 100644
--- a/lib/nodes/websocket.c
+++ b/lib/nodes/websocket.c
@@ -467,14 +467,14 @@ int websocket_destroy(struct node *n)
 	return 0;
 }
 
-int websocket_read(struct node *n, struct sample *smps[], unsigned cnt)
+int websocket_read(struct node *n, struct sample *smps[], int *cnt)
 {
 	int avail;
 
 	struct websocket *w = (struct websocket *) n->_vd;
-	struct sample *cpys[cnt];
+	struct sample *cpys[*cnt];
 
-	avail = queue_signalled_pull_many(&w->queue, (void **) cpys, cnt);
+	avail = queue_signalled_pull_many(&w->queue, (void **) cpys, *cnt);
 	if (avail < 0)
 		return avail;
 
diff --git a/lib/nodes/zeromq.c b/lib/nodes/zeromq.c
index 930e45bf9..db8176c46 100644
--- a/lib/nodes/zeromq.c
+++ b/lib/nodes/zeromq.c
@@ -419,7 +419,7 @@ int zeromq_destroy(struct node *n)
 	return 0;
 }
 
-int zeromq_read(struct node *n, struct sample *smps[], unsigned cnt)
+int zeromq_read(struct node *n, struct sample *smps[], int *cnt)
 {
 	int recv, ret;
 	struct zeromq *z = (struct zeromq *) n->_vd;
@@ -446,7 +446,7 @@ int zeromq_read(struct node *n, struct sample *smps[], unsigned cnt)
 	if (ret < 0)
 		return ret;
 
-	recv = io_sscan(&z->io, zmq_msg_data(&m), zmq_msg_size(&m), NULL, smps, cnt);
+	recv = io_sscan(&z->io, zmq_msg_data(&m), zmq_msg_size(&m), NULL, smps, *cnt);
 
 	ret = zmq_msg_close(&m);
 	if (ret)
diff --git a/lib/path.c b/lib/path.c
index 48048d7e8..5fe35879f 100644
--- a/lib/path.c
+++ b/lib/path.c
@@ -84,7 +84,7 @@ static void path_source_read(struct path_source *ps, struct path *p, int i)
 		warn("Pool underrun for path source %s", node_name(ps->node));
 
 	/* Read ready samples and store them to blocks pointed by smps[] */
-	recv = node_read(ps->node, read_smps, ready);
+	recv = node_read(ps->node, read_smps, &ready);
 	if (recv == 0)
 		goto out2;
 	else if (recv < 0)
diff --git a/src/villas-pipe.cpp b/src/villas-pipe.cpp
index 0133454e2..82669d01d 100644
--- a/src/villas-pipe.cpp
+++ b/src/villas-pipe.cpp
@@ -210,7 +210,7 @@ static void * recv_loop(void *ctx)
 		else if (ready < node->in.vectorize)
 			warn("Receive pool underrun");
 
-		recv = node_read(node, smps, ready);
+		recv = node_read(node, smps, &ready);
 		if (recv < 0)
 			warn("Failed to receive samples from node %s: reason=%d", node_name(node), recv);
 
@@ -239,7 +239,7 @@ int main(int argc, char *argv[])
 
 	sendd.enabled = true;
 	sendd.limit = -1;
-	
+
 	recvv.enabled = true;
 	recvv.limit = -1;
 
diff --git a/src/villas-signal.cpp b/src/villas-signal.cpp
index 2330d83e3..3e3a05ffb 100644
--- a/src/villas-signal.cpp
+++ b/src/villas-signal.cpp
@@ -170,8 +170,9 @@ int main(int argc, char *argv[])
 	for (;;) {
 		t = sample_alloc(&q);
 
-		node_read(&n, &t, 1);
-		io_print(&io, &t, 1);
+		int one = 1;
+		node_read(&n, &t, &one);
+		io_print(&io, &t, one);
 
 		sample_put(t);
 	}
diff --git a/src/villas-test-rtt.cpp b/src/villas-test-rtt.cpp
index c591c853e..513bafef3 100644
--- a/src/villas-test-rtt.cpp
+++ b/src/villas-test-rtt.cpp
@@ -166,8 +166,9 @@ void test_rtt() {
 	while (running && (count < 0 || count--)) {
 		clock_gettime(CLOCK_ID, &send);
 
-		node_write(node, &smp_send, 1); /* Ping */
-		node_read(node,  &smp_recv, 1); /* Pong */
+		int one = 1;
+		node_write(node, &smp_send, one); /* Ping */
+		node_read(node,  &smp_recv, &one); /* Pong */
 
 		clock_gettime(CLOCK_ID, &recv);