diff --git a/config.h b/config.h
index b425ce9c2..3f9b62cca 100644
--- a/config.h
+++ b/config.h
@@ -10,8 +10,7 @@
  *   Unauthorized copying of this file, via any medium is strictly prohibited. 
  *********************************************************************************/
 
-#ifndef _CONFIG_H_
-#define _CONFIG_H_
+#pragma once
 
 #ifndef _GIT_REV
   #define _GIT_REV		"nogit"
@@ -70,5 +69,3 @@ struct settings {
 	int debug;		/**< Debug log level */
 	double stats;		/**< Interval for path statistics. Set to 0 to disable themo disable them. */
 };
-
-#endif /* _CONFIG_H_ */
diff --git a/include/villas/advio.h b/include/villas/advio.h
index 99897873a..b4ab47bcc 100644
--- a/include/villas/advio.h
+++ b/include/villas/advio.h
@@ -2,8 +2,7 @@
  *
  */
 
-#ifndef _ADVIO_H_
-#define _ADVIO_H_
+#pragma once
 
 #include <stdio.h>
 
@@ -40,6 +39,4 @@ int afflush(AFILE *file);
 #define afeof(af)		feof(af->file)
 
 size_t afread(void *restrict ptr, size_t size, size_t nitems, AFILE *restrict stream);
-size_t afwrite(const void *restrict ptr, size_t size, size_t nitems, AFILE *restrict stream);
-
-#endif /* _ADVIO_H_ */
\ No newline at end of file
+size_t afwrite(const void *restrict ptr, size_t size, size_t nitems, AFILE *restrict stream);
\ No newline at end of file
diff --git a/include/villas/cfg.h b/include/villas/cfg.h
index 9d8dcea75..2065d6d95 100644
--- a/include/villas/cfg.h
+++ b/include/villas/cfg.h
@@ -11,8 +11,7 @@
  *   Unauthorized copying of this file, via any medium is strictly prohibited. 
  *********************************************************************************/
 
-#ifndef _CFG_H_
-#define _CFG_H_
+#pragma once
 
 #include <libconfig.h>
 
@@ -106,6 +105,4 @@ int cfg_parse_hook(config_setting_t *cfg, struct list *list);
  * @retval 0 Success. Everything went well.
  * @retval <0 Error. Something went wrong.
  */
-int cfg_parse_node(config_setting_t *cfg, struct list *nodes, struct settings *set);
-
-#endif /* _CFG_H_ */
+int cfg_parse_node(config_setting_t *cfg, struct list *nodes, struct cfg *set);
\ No newline at end of file
diff --git a/include/villas/hist.h b/include/villas/hist.h
index 72b232a21..fefd3a728 100644
--- a/include/villas/hist.h
+++ b/include/villas/hist.h
@@ -7,8 +7,7 @@
  *   Unauthorized copying of this file, via any medium is strictly prohibited. 
  *********************************************************************************/
 
-#ifndef _HIST_H_
-#define _HIST_H_
+#pragma once
 
 #include <stdio.h>
 
@@ -75,6 +74,4 @@ void hist_plot(struct hist *h);
 char * hist_dump(struct hist *h);
 
 /** Prints Matlab struct containing all infos to file. */
-void hist_matlab(struct hist *h, FILE *f);
-
-#endif /* _HIST_H_ */
+void hist_matlab(struct hist *h, FILE *f);
\ No newline at end of file
diff --git a/include/villas/kernel/if.h b/include/villas/kernel/if.h
index 6099b0280..8317270d7 100644
--- a/include/villas/kernel/if.h
+++ b/include/villas/kernel/if.h
@@ -10,8 +10,7 @@
  *   Unauthorized copying of this file, via any medium is strictly prohibited. 
  *********************************************************************************/
 
-#ifndef _KERNEL_IF_H_
-#define _KERNEL_IF_H_
+#pragma once
 
 #include <sys/types.h>
 #include <sys/socket.h>
@@ -104,6 +103,4 @@ int if_get_irqs(struct interface *i);
  * @retval 0 Success. Everything went well.
  * @retval <0 Error. Something went wrong.
  */
-int if_set_affinity(struct interface *i, int affinity);
-
-#endif /* _KERNEL_IF_H_ */
+int if_set_affinity(struct interface *i, int affinity);
\ No newline at end of file
diff --git a/include/villas/kernel/kernel.h b/include/villas/kernel/kernel.h
index 86d99406d..b8bf1351d 100644
--- a/include/villas/kernel/kernel.h
+++ b/include/villas/kernel/kernel.h
@@ -7,8 +7,7 @@
  *   Unauthorized copying of this file, via any medium is strictly prohibited.
  *********************************************************************************/
 
-#ifndef _KERNEL_KERNEL_H_
-#define _KERNEL_KERNEL_H_
+#pragma once
 
 #include <stdint.h>
 
@@ -67,6 +66,4 @@ int kernel_module_set_param(const char *module, const char *param, const char *v
 int kernel_get_cacheline_size();
 
 /** Set SMP affinity of IRQ */
-int kernel_irq_setaffinity(unsigned irq, uintmax_t new, uintmax_t *old);
-
-#endif /* _KERNEL_KERNEL_H_ */
+int kernel_irq_setaffinity(unsigned irq, uintmax_t new, uintmax_t *old);
\ No newline at end of file
diff --git a/include/villas/kernel/nl.h b/include/villas/kernel/nl.h
index 1e7593626..4a3e32f4a 100644
--- a/include/villas/kernel/nl.h
+++ b/include/villas/kernel/nl.h
@@ -7,8 +7,7 @@
  *   Unauthorized copying of this file, via any medium is strictly prohibited. 
  *********************************************************************************/
 
-#ifndef _KERNEL_NL_H_
-#define _KERNEL_NL_H_
+#pragma once
 
 #include <netlink/netlink.h>
 #include <netlink/route/route.h>
@@ -25,6 +24,4 @@ int nl_get_egress(struct nl_addr *addr);
 struct nl_sock * nl_init();
 
 /** Close and free global netlink socket. */
-void nl_shutdown();
-
-#endif /* _KERNEL_NL_H_ */
\ No newline at end of file
+void nl_shutdown();
\ No newline at end of file
diff --git a/include/villas/kernel/pci.h b/include/villas/kernel/pci.h
index acb0bab39..ae4e6417a 100644
--- a/include/villas/kernel/pci.h
+++ b/include/villas/kernel/pci.h
@@ -7,8 +7,7 @@
  *   Unauthorized copying of this file, via any medium is strictly prohibited.
  **********************************************************************************/
 
-#ifndef _KERNEL_PCI_H_
-#define _KERNEL_PCI_H_
+#pragma once
 
 #include "list.h"
 
@@ -62,6 +61,4 @@ struct pci_dev * pci_lookup_device(struct pci *p, struct pci_dev *filter);
 int pci_attach_driver(struct pci_dev *d, const char *driver);
 
 /** Return the IOMMU group of this PCI device or -1 if the device is not in a group. */
-int pci_get_iommu_group(struct pci_dev *d);
-
-#endif /* _KERNEL_PCI_H_ */
\ No newline at end of file
+int pci_get_iommu_group(struct pci_dev *d);
\ No newline at end of file
diff --git a/include/villas/kernel/rt.h b/include/villas/kernel/rt.h
index dc6d0ae77..c4b5cd2bf 100644
--- a/include/villas/kernel/rt.h
+++ b/include/villas/kernel/rt.h
@@ -7,9 +7,7 @@
  *   Unauthorized copying of this file, via any medium is strictly prohibited. 
  *********************************************************************************/
 
-#ifndef _KERNEL_RT_H_
-#define _KERNEL_RT_H_
+#pragma once
 
 int rt_init(int affinity, int priority);
 
-#endif /* _KERNEL_RT_H_ */
\ No newline at end of file
diff --git a/include/villas/kernel/tc.h b/include/villas/kernel/tc.h
index 147e7dc80..48fdc67af 100644
--- a/include/villas/kernel/tc.h
+++ b/include/villas/kernel/tc.h
@@ -12,8 +12,7 @@
  *   Unauthorized copying of this file, via any medium is strictly prohibited. 
  *********************************************************************************/
 
-#ifndef _KERNEL_TC_H_
-#define _KERNEL_TC_H_
+#pragma once
 
 #include <stdint.h>
 
@@ -82,6 +81,4 @@ int tc_netem(struct interface *i, struct rtnl_qdisc **qd, tc_hdl_t handle, tc_hd
  * @retval 0 Success. Everything went well.
  * @retval <0 Error. Something went wrong.
 */
-int tc_mark(struct interface *i, struct rtnl_cls **cls, tc_hdl_t flowid, uint32_t mark);
-
-#endif /* _TC_H_ */
+int tc_mark(struct interface *i, struct rtnl_cls **cls, tc_hdl_t flowid, uint32_t mark);
\ No newline at end of file
diff --git a/include/villas/kernel/vfio.h b/include/villas/kernel/vfio.h
index 928f518cb..b03a5c4a4 100644
--- a/include/villas/kernel/vfio.h
+++ b/include/villas/kernel/vfio.h
@@ -7,8 +7,7 @@
  *   Unauthorized copying of this file, via any medium is strictly prohibited.
  *********************************************************************************/
 
-#ifndef _KERNEL_VFIO_H_
-#define _KERNEL_VFIO_H_
+#pragma once
 
 #include <stdbool.h>
 #include <sys/mman.h>
@@ -108,6 +107,4 @@ int vfio_map_dma(struct vfio_container *c, struct dma_mem *mem);
 int vfio_unmap_dma(struct vfio_container *c, struct dma_mem *mem);
 
 /** munmap() a region which has been mapped by vfio_map_region() */
-int vfio_unmap_region(struct vfio_dev *d, int idx);
-
-#endif /* _KERNEL_VFIO_H_ */
+int vfio_unmap_region(struct vfio_dev *d, int idx);
\ No newline at end of file
diff --git a/include/villas/list.h b/include/villas/list.h
index 4487ad10c..2e3e5ec6c 100644
--- a/include/villas/list.h
+++ b/include/villas/list.h
@@ -13,8 +13,7 @@
  *   Unauthorized copying of this file, via any medium is strictly prohibited. 
  *********************************************************************************/
 
-#ifndef _LIST_H_
-#define _LIST_H_
+#pragma once
 
 #include <stdbool.h>
 #include <pthread.h>
@@ -97,6 +96,4 @@ int list_count(struct list *l, cmp_cb_t cmp, void *ctx);
 int list_contains(struct list *l, void *p);
 
 /** Sort the list using the quicksort algorithm of libc */
-void list_sort(struct list *l, cmp_cb_t cmp);
-
-#endif /* _LIST_H_ */
+void list_sort(struct list *l, cmp_cb_t cmp);
\ No newline at end of file
diff --git a/include/villas/log.h b/include/villas/log.h
index dbd7bda46..1fa7ead85 100644
--- a/include/villas/log.h
+++ b/include/villas/log.h
@@ -7,8 +7,7 @@
  *   Unauthorized copying of this file, via any medium is strictly prohibited. 
  *********************************************************************************/
  
-#ifndef _LOG_H_
-#define _LOG_H_
+#pragma once
 
 #include <stdarg.h>
 #include <libconfig.h>
@@ -121,7 +120,4 @@ void serror(const char *fmt, ...)
 
 /** Print configuration error and exit. */
 void cerror(config_setting_t *cfg, const char *fmt, ...)
-	__attribute__ ((format(printf, 2, 3)));
-
-#endif /* _LOG_H_ */
-
+	__attribute__ ((format(printf, 2, 3)));
\ No newline at end of file
diff --git a/include/villas/memory.h b/include/villas/memory.h
index f6e3064f5..4890b490a 100644
--- a/include/villas/memory.h
+++ b/include/villas/memory.h
@@ -10,8 +10,7 @@
 #include <stddef.h>
 #include <stdint.h>
 
-#ifndef _MEMORY_H_
-#define _MEMORY_H_
+#pragma once
 
 #define HUGEPAGESIZE	(1 << 21)
 
@@ -56,6 +55,4 @@ void * memory_alloc_aligned(const struct memtype *m, size_t len, size_t alignmen
 int memory_free(const struct memtype *m, void *ptr, size_t len);
 
 extern const struct memtype memtype_heap;
-extern const struct memtype memtype_hugepage;
-
-#endif /* _MEMORY_H_ */
\ No newline at end of file
+extern const struct memtype memtype_hugepage;
\ No newline at end of file
diff --git a/include/villas/msg.h b/include/villas/msg.h
index 2fb032f8c..7916e8c28 100644
--- a/include/villas/msg.h
+++ b/include/villas/msg.h
@@ -7,8 +7,7 @@
  *   Unauthorized copying of this file, via any medium is strictly prohibited. 
  *********************************************************************************/
 
-#ifndef _MSG_H_
-#define _MSG_H_
+#pragma once
 
 #include <stdio.h>
 
@@ -37,6 +36,4 @@ void msg_hdr_swap(struct msg *m);
  * @retval 0 The message header is valid.
  * @retval <0 The message header is invalid.
  */
-int msg_verify(struct msg *m);
-
-#endif /* _MSG_H_ */
+int msg_verify(struct msg *m);
\ No newline at end of file
diff --git a/include/villas/msg_format.h b/include/villas/msg_format.h
index 5e9e2bccc..5d1be6e8d 100644
--- a/include/villas/msg_format.h
+++ b/include/villas/msg_format.h
@@ -7,8 +7,7 @@
  *   Unauthorized copying of this file, via any medium is strictly prohibited. 
  *********************************************************************************/
 
-#ifndef _MSG_FORMAT_H_
-#define _MSG_FORMAT_H_
+#pragma once
 
 #include <stdint.h>
 
@@ -95,6 +94,4 @@ struct msg
 		float    f;	/**< Floating point values (note msg::endian) */
 		uint32_t i;	/**< Integer values (note msg::endian) */
 	} data[];
-} __attribute__((packed));
-
-#endif /* _MSG_FORMAT_H_ */
+} __attribute__((packed));
\ No newline at end of file
diff --git a/include/villas/node.h b/include/villas/node.h
index f237f6866..af24a35cb 100644
--- a/include/villas/node.h
+++ b/include/villas/node.h
@@ -10,8 +10,7 @@
  * @{
  *********************************************************************************/
 
-#ifndef _NODE_H_
-#define _NODE_H_
+#pragma once
 
 #include <sys/socket.h>
 #include <netinet/in.h>
@@ -250,4 +249,4 @@ int node_read(struct node *n, struct sample *smps[], unsigned cnt);
 
 int node_write(struct node *n, struct sample *smps[], unsigned cnt);
 
-#endif /** _NODE_H_ @} */
+/** @} */
diff --git a/include/villas/nodes/cbuilder.h b/include/villas/nodes/cbuilder.h
index c2364e018..817b52362 100644
--- a/include/villas/nodes/cbuilder.h
+++ b/include/villas/nodes/cbuilder.h
@@ -12,8 +12,7 @@
  * @{
  *********************************************************************************/
  
-#ifndef _NODES_CBUILDER_H_
-#define _NODES_CBUILDER_H_
+#pragma once
 
 #include <pthread.h>
 
@@ -52,4 +51,4 @@ struct cbuilder {
 	pthread_cond_t cv;
 };
 
-#endif /** _NODES_CBUILDER_H_ @} */
\ No newline at end of file
+/** @} */
\ No newline at end of file
diff --git a/include/villas/nodes/file.h b/include/villas/nodes/file.h
index 70e0e5e7b..64febba1b 100644
--- a/include/villas/nodes/file.h
+++ b/include/villas/nodes/file.h
@@ -15,8 +15,7 @@
  *********************************************************************************/
 
 
-#ifndef _NODES_FILE_H_
-#define _NODES_FILE_H_
+#pragma once
 
 #include "node.h"
 
@@ -73,4 +72,4 @@ int file_read(struct node *n, struct sample *smps[], unsigned cnt);
 /** @see node_vtable::write */
 int file_write(struct node *n, struct sample *smps[], unsigned cnt);
 
-#endif /** _NODES_FILE_H_ @} */
+/** @} */
diff --git a/include/villas/nodes/fpga.h b/include/villas/nodes/fpga.h
index 752d0b57c..5685f654d 100644
--- a/include/villas/nodes/fpga.h
+++ b/include/villas/nodes/fpga.h
@@ -14,44 +14,22 @@
  * @{
  *********************************************************************************/
 
-#ifndef _NODES_FPGA_H_
-#define _NODES_FPGA_H_
+#pragma once
 
 #include "kernel/vfio.h"
 #include "kernel/pci.h"
 
-#include "fpga/dma.h"
-#include "fpga/ip.h"
-#include "fpga/intc.h"
+#include "fpga/ips/dma.h"
 
 #include "node.h"
 #include "list.h"
 
+/* Forward declarations */
+struct fpga_ip;
+
+/** The node type */
 struct fpga {
-	struct pci_dev filter;		/**< Filter for PCI device. */
-	struct vfio_dev vd;		/**< VFIO device handle. */
-
-	int do_reset;			/**< Reset VILLASfpga during startup? */
-	int affinity;			/**< Affinity for MSI interrupts */
-
-	struct list ips;		/**< List of IP components on FPGA. */
-
-	char *map;			/**< PCI BAR0 mapping for register access */
-
-	size_t maplen;
-	size_t dmalen;
-
-	/* Some IP cores are special and referenced here */
-	struct ip *intc;
-	struct ip *reset;
-	struct ip *sw;
-	
-	config_setting_t *cfg;
-};
-
-struct fpga_dm {
-	struct ip *ip;
-	const char *ip_name;
+	struct fpga_ip *ip;
 
 	int use_irqs;
 
@@ -61,8 +39,6 @@ struct fpga_dm {
 		FPGA_DM_DMA,
 		FPGA_DM_FIFO
 	} type;
-
-	struct fpga *card;
 };
 
 /** @see node_vtable::init */
@@ -75,7 +51,7 @@ int fpga_deinit();
 int fpga_parse(struct node *n, config_setting_t *cfg);
 
 /** Parse the 'fpga' section in the configuration file */
-int fpga_parse_card(struct fpga *v, int argc, char * argv[], config_setting_t *cfg);
+int fpga_parse_cards(config_setting_t *cfg);
 
 /** @see node_vtable::print */
 char * fpga_print(struct node *n);
@@ -101,4 +77,4 @@ int fpga_reset(struct fpga *f);
 /** Dump some details about the fpga card */
 void fpga_dump(struct fpga *f);
 
-#endif /** _NODES_FPGA_H_ @} */
+/** @} */
diff --git a/include/villas/nodes/ngsi.h b/include/villas/nodes/ngsi.h
index f40b5a257..9a184e690 100644
--- a/include/villas/nodes/ngsi.h
+++ b/include/villas/nodes/ngsi.h
@@ -18,8 +18,7 @@
  * @{
  **********************************************************************************/
 
-#ifndef _NODES_NGSI_H_
-#define _NODES_NGSI_H_
+#pragma once
 
 #include <curl/curl.h>
 #include <jansson.h>
@@ -81,4 +80,4 @@ int ngsi_read(struct node *n, struct sample *smps[], unsigned cnt);
 /** @see node_vtable::write */
 int ngsi_write(struct node *n, struct sample *smps[], unsigned cnt);
 
-#endif /** _NODES_NGSI_H_ @} */
\ No newline at end of file
+/** @} */
\ No newline at end of file
diff --git a/include/villas/nodes/opal.h b/include/villas/nodes/opal.h
index dd3a5b704..5f2db6aea 100644
--- a/include/villas/nodes/opal.h
+++ b/include/villas/nodes/opal.h
@@ -14,8 +14,7 @@
  * @{
  **********************************************************************************/
 
-#ifndef _NODES_OPAL_H_
-#define _NODES_OPAL_H_
+#pragma once
 
 #include <pthread.h>
 
@@ -73,4 +72,4 @@ int opal_read(struct node *n, struct sample *smps[], unsigned cnt);
 /** @see node_vtable::write */
 int opal_write(struct node *n, struct sample *smps[], unsigned cnt);
 
-#endif /** _NODES_OPAL_H_ @} */
+/** @} */
\ No newline at end of file
diff --git a/include/villas/nodes/socket.h b/include/villas/nodes/socket.h
index 00a80d7b9..948301b0c 100644
--- a/include/villas/nodes/socket.h
+++ b/include/villas/nodes/socket.h
@@ -14,8 +14,7 @@
  * @{
  *********************************************************************************/
 
-#ifndef _NODES_SOCKET_H_
-#define _NODES_SOCKET_H_
+#pragma once
 
 #include <sys/socket.h>
 #include <linux/if_packet.h>
@@ -109,4 +108,4 @@ char * socket_print_addr(struct sockaddr *saddr);
  */
 int socket_parse_addr(const char *str, struct sockaddr *sa, enum socket_layer layer, int flags);
 
-#endif /** _NODES_SOCKET_H_ @} */
+/** @} */
\ No newline at end of file
diff --git a/include/villas/nodes/websocket.h b/include/villas/nodes/websocket.h
index a0bacdcc2..4017230c3 100644
--- a/include/villas/nodes/websocket.h
+++ b/include/villas/nodes/websocket.h
@@ -15,9 +15,7 @@
  * @{
  *********************************************************************************/
 
-
-#ifndef _NODES_WEBSOCKET_H_
-#define _NODES_WEBSOCKET_H_
+#pragma once
 
 #include "node.h"
 #include "pool.h"
@@ -63,6 +61,8 @@ struct websocket_connection {
 	qptr_t received;
 };
 
+int websocket_protocol_cb(struct lws *wsi, enum lws_callback_reasons reason, void *user, void *in, size_t len);
+
 /** @see node_vtable::init */
 int websocket_init(int argc, char * argv[], config_setting_t *cfg);
 
@@ -84,4 +84,4 @@ int websocket_read(struct node *n, struct sample *smps[], unsigned cnt);
 /** @see node_vtable::write */
 int websocket_write(struct node *n, struct sample *smps[], unsigned cnt);
 
-#endif /** _NODES_WEBSOCKET_H_ @} */
\ No newline at end of file
+/** @} */
\ No newline at end of file
diff --git a/include/villas/path.h b/include/villas/path.h
index fb01e5d23..e09109a3e 100644
--- a/include/villas/path.h
+++ b/include/villas/path.h
@@ -12,8 +12,7 @@
  * @{
  *********************************************************************************/
 
-#ifndef _PATH_H_
-#define _PATH_H_
+#pragma once
 
 #include <pthread.h>
 #include <libconfig.h>
@@ -130,4 +129,4 @@ const char * path_name(struct path *p);
 /** Check if node is used as source or destination of a path. */
 int path_uses_node(struct path *p, struct node *n);
 
-#endif /** _PATH_H_ @} */
+/** @} */
\ No newline at end of file
diff --git a/include/villas/plugin.h b/include/villas/plugin.h
index 8c1c5a681..c67fe5b51 100644
--- a/include/villas/plugin.h
+++ b/include/villas/plugin.h
@@ -7,8 +7,7 @@
  *   Unauthorized copying of this file, via any medium is strictly prohibited.
  *********************************************************************************/
 
-#ifndef _PLUGIN_H_
-#define _PLUGIN_H_
+#pragma once
 
 #include "hooks.h"
 #include "api.h"
@@ -67,5 +66,3 @@ int plugin_load(struct plugin *p);
 int plugin_unload(struct plugin *p);
 
 int plugin_destroy(struct plugin *p);
-
-#endif /* _PLUGIN_H_ */
\ No newline at end of file
diff --git a/include/villas/pool.h b/include/villas/pool.h
index 49f2f1c9a..a36e292db 100644
--- a/include/villas/pool.h
+++ b/include/villas/pool.h
@@ -9,8 +9,7 @@
  *   Unauthorized copying of this file, via any medium is strictly prohibited.
  */
 
-#ifndef _POOL_H_
-#define _POOL_H_
+#pragma once
 
 #include <sys/types.h>
 
@@ -61,6 +60,4 @@ INLINE void * pool_get(struct pool *p)
 INLINE int pool_put(struct pool *p, void *buf)
 {
 	return queue_push(&p->queue, buf);
-}
-
-#endif /* _POOL_H_ */
\ No newline at end of file
+}
\ No newline at end of file
diff --git a/include/villas/queue.h b/include/villas/queue.h
index 40baf1f17..654ee4a49 100644
--- a/include/villas/queue.h
+++ b/include/villas/queue.h
@@ -31,9 +31,6 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef _MPMC_QUEUE_H_
-#define _MPMC_QUEUE_H_
-
 #include <stdint.h>
 #include <stdatomic.h>
 
@@ -82,6 +79,4 @@ int queue_pull(struct queue *q, void **ptr);
 
 int queue_push_many(struct queue *q, void *ptr[], size_t cnt);
 
-int queue_pull_many(struct queue *q, void *ptr[], size_t cnt);
-
-#endif /* _MPMC_QUEUE_H_ */
\ No newline at end of file
+int queue_pull_many(struct queue *q, void *ptr[], size_t cnt);
\ No newline at end of file
diff --git a/include/villas/sample.h b/include/villas/sample.h
index ec58f8bd8..d3a349c22 100644
--- a/include/villas/sample.h
+++ b/include/villas/sample.h
@@ -7,8 +7,7 @@
  *   Unauthorized copying of this file, via any medium is strictly prohibited.
  */
 
-#ifndef _SAMPLE_H_
-#define _SAMPLE_H_
+#pragma once
 
 #include <stdlib.h>
 #include <stdio.h>
@@ -109,6 +108,4 @@ int sample_fprint(FILE *f, struct sample *s, int flags);
  * @retval 0 Success. Everything went well.
  * @retval <0 Error. Something went wrong.
  */
-int sample_fscan(FILE *f, struct sample *s, int *flags);
-
-#endif /* _SAMPLE_H_ */
\ No newline at end of file
+int sample_fscan(FILE *f, struct sample *s, int *flags);
\ No newline at end of file
diff --git a/include/villas/timing.h b/include/villas/timing.h
index 20b2e6baf..1d00de4e7 100644
--- a/include/villas/timing.h
+++ b/include/villas/timing.h
@@ -7,8 +7,7 @@
  *   Unauthorized copying of this file, via any medium is strictly prohibited. 
  *********************************************************************************/
 
-#ifndef _TIME_H_
-#define _TIME_H_
+#pragma once
 
 #include <stdio.h>
 #include <stdint.h>
@@ -52,6 +51,4 @@ double time_delta(struct timespec *start, struct timespec *end);
 double time_to_double(struct timespec *ts);
 
 /** Convert double containing seconds after 1970 to timespec. */
-struct timespec time_from_double(double secs);
-
-#endif /* _TIMING_H_ */
\ No newline at end of file
+struct timespec time_from_double(double secs);
\ No newline at end of file
diff --git a/include/villas/utils.h b/include/villas/utils.h
index c1e7328a8..ee5b5c43c 100644
--- a/include/villas/utils.h
+++ b/include/villas/utils.h
@@ -7,8 +7,7 @@
  *   Unauthorized copying of this file, via any medium is strictly prohibited. 
  *********************************************************************************/
 
-#ifndef _UTILS_H_
-#define _UTILS_H_
+#pragma once
 
 #include <stdlib.h>
 #include <stdint.h>
@@ -239,6 +238,4 @@ static inline int log2i(long long x) {
 }
 
 /** Sleep with rdtsc */
-void rdtsc_sleep(uint64_t nanosecs, uint64_t start);
-
-#endif /* _UTILS_H_ */
\ No newline at end of file
+void rdtsc_sleep(uint64_t nanosecs, uint64_t start);
\ No newline at end of file