From: Guus Sliepen <guus@meshlink.io>
Date: Thu, 11 Jun 2020 20:17:23 +0000 (+0200)
Subject: Add asserts() to all pthread related function calls.
X-Git-Url: http://git.meshlink.io/?p=meshlink;a=commitdiff_plain;h=6558e508cc80ec97ec9c5bbcf7df922e13ed5b2e

Add asserts() to all pthread related function calls.

We normally expect all pthread-related functions to succeed, so in all
places where we didn't already explicitly check the return value, assert()
that the functions return 0.
---

diff --git a/src/adns.c b/src/adns.c
index cb9611e1..08fd8123 100644
--- a/src/adns.c
+++ b/src/adns.c
@@ -107,7 +107,7 @@ void exit_adns(meshlink_handle_t *mesh) {
 		abort();
 	}
 
-	pthread_cond_signal(&mesh->adns_cond);
+	assert(pthread_cond_signal(&mesh->adns_cond) == 0);
 
 	pthread_join(mesh->adns_thread, NULL);
 	meshlink_queue_exit(&mesh->adns_queue);
@@ -128,7 +128,7 @@ void adns_queue(meshlink_handle_t *mesh, char *host, char *serv, adns_cb_t cb, v
 		abort();
 	}
 
-	pthread_cond_signal(&mesh->adns_cond);
+	assert(pthread_cond_signal(&mesh->adns_cond) == 0);
 }
 
 struct adns_blocking_info {
@@ -157,16 +157,16 @@ static void *adns_blocking_handler(void *data) {
 		info->ai = NULL;
 	}
 
-	pthread_mutex_lock(&info->mutex);
+	assert(pthread_mutex_lock(&info->mutex) == 0);
 
 	bool cleanup = info->done;
 
 	if(!info->done) {
 		info->done = true;
-		pthread_cond_signal(&info->cond);
+		assert(pthread_cond_signal(&info->cond) == 0);
 	}
 
-	pthread_mutex_unlock(&info->mutex);
+	assert(pthread_mutex_unlock(&info->mutex) == 0);
 
 	if(cleanup) {
 		free(info->host);
@@ -184,8 +184,8 @@ struct addrinfo *adns_blocking_request(meshlink_handle_t *mesh, char *host, char
 	info->host = host;
 	info->serv = serv;
 	info->socktype = socktype;
-	pthread_mutex_init(&info->mutex, NULL);
-	pthread_cond_init(&info->cond, NULL);
+	assert(pthread_mutex_init(&info->mutex, NULL) == 0);
+	assert(pthread_cond_init(&info->cond, NULL) == 0);
 
 	struct timespec deadline;
 	clock_gettime(CLOCK_REALTIME, &deadline);
@@ -199,11 +199,11 @@ struct addrinfo *adns_blocking_request(meshlink_handle_t *mesh, char *host, char
 		free(info);
 		return NULL;
 	} else {
-		pthread_detach(thread);
+		assert(pthread_detach(thread) == 0);
 	}
 
-	pthread_mutex_lock(&info->mutex);
-	pthread_cond_timedwait(&info->cond, &info->mutex, &deadline);
+	assert(pthread_mutex_lock(&info->mutex) == 0);
+	assert(pthread_cond_timedwait(&info->cond, &info->mutex, &deadline) == 0);
 
 	struct addrinfo *result = NULL;
 	bool cleanup = info->done;
@@ -215,7 +215,7 @@ struct addrinfo *adns_blocking_request(meshlink_handle_t *mesh, char *host, char
 		info->done = true;
 	}
 
-	pthread_mutex_unlock(&info->mutex);
+	assert(pthread_mutex_unlock(&info->mutex) == 0);
 
 	if(cleanup) {
 		free(info->host);
diff --git a/src/devtools.c b/src/devtools.c
index e172b071..e6ba5617 100644
--- a/src/devtools.c
+++ b/src/devtools.c
@@ -65,7 +65,7 @@ devtool_edge_t *devtool_get_all_edges(meshlink_handle_t *mesh, devtool_edge_t *e
 		return NULL;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	devtool_edge_t *result = NULL;
 	unsigned int result_size = 0;
@@ -113,7 +113,7 @@ devtool_edge_t *devtool_get_all_edges(meshlink_handle_t *mesh, devtool_edge_t *e
 		meshlink_errno = MESHLINK_ENOMEM;
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return result;
 }
@@ -135,7 +135,7 @@ bool devtool_export_json_all_edges_state(meshlink_handle_t *mesh, FILE *stream)
 
 	bool result = true;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	// export edges and nodes
 	size_t node_count = 0;
@@ -250,7 +250,7 @@ done:
 	free(nodes);
 	free(edges);
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return result;
 }
@@ -263,7 +263,7 @@ void devtool_get_node_status(meshlink_handle_t *mesh, meshlink_node_t *node, dev
 
 	node_t *internal = (node_t *)node;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	memcpy(&status->status, &internal->status, sizeof status->status);
 	memcpy(&status->address, &internal->address, sizeof status->address);
@@ -293,7 +293,7 @@ void devtool_get_node_status(meshlink_handle_t *mesh, meshlink_node_t *node, dev
 		status->udp_status = DEVTOOL_UDP_UNKNOWN;
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 meshlink_submesh_t **devtool_get_all_submeshes(meshlink_handle_t *mesh, meshlink_submesh_t **submeshes, size_t *nmemb) {
@@ -305,7 +305,7 @@ meshlink_submesh_t **devtool_get_all_submeshes(meshlink_handle_t *mesh, meshlink
 	meshlink_submesh_t **result;
 
 	//lock mesh->nodes
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	*nmemb = mesh->submeshes->count;
 	result = realloc(submeshes, *nmemb * sizeof(*submeshes));
@@ -322,7 +322,7 @@ meshlink_submesh_t **devtool_get_all_submeshes(meshlink_handle_t *mesh, meshlink
 		meshlink_errno = MESHLINK_ENOMEM;
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return result;
 }
diff --git a/src/discovery.c b/src/discovery.c
index d4790c43..3023444d 100644
--- a/src/discovery.c
+++ b/src/discovery.c
@@ -126,13 +126,13 @@ static void discovery_server_callback(CattaServer *server, CattaServerState stat
 	case CATTA_SERVER_RUNNING:
 		/* The serve has startup successfully and registered its host
 		 * name on the network, so it's time to create our services */
-		pthread_mutex_lock(&mesh->mutex);
+		assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 		if(!mesh->catta_group) {
 			discovery_create_services(mesh);
 		}
 
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 		break;
 
@@ -141,7 +141,7 @@ static void discovery_server_callback(CattaServer *server, CattaServerState stat
 		char hostname[17];
 		generate_rand_string(mesh, hostname, sizeof(hostname));
 
-		pthread_mutex_lock(&mesh->mutex);
+		assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 		assert(mesh->catta_server);
 		assert(mesh->catta_poll);
@@ -152,12 +152,12 @@ static void discovery_server_callback(CattaServer *server, CattaServerState stat
 			catta_simple_poll_quit(mesh->catta_poll);
 		}
 
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 	}
 	break;
 
 	case CATTA_SERVER_REGISTERING:
-		pthread_mutex_lock(&mesh->mutex);
+		assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 		/* Let's drop our registered services. When the server is back
 		 * in CATTA_SERVER_RUNNING state we will register them
@@ -167,12 +167,12 @@ static void discovery_server_callback(CattaServer *server, CattaServerState stat
 			mesh->catta_group = NULL;
 		}
 
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 		break;
 
 	case CATTA_SERVER_FAILURE:
-		pthread_mutex_lock(&mesh->mutex);
+		assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 		assert(mesh->catta_server);
 		assert(mesh->catta_poll);
@@ -180,7 +180,7 @@ static void discovery_server_callback(CattaServer *server, CattaServerState stat
 		/* Terminate on failure */
 		catta_simple_poll_quit(mesh->catta_poll);
 
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		break;
 
 	case CATTA_SERVER_INVALID:
@@ -215,7 +215,7 @@ static void discovery_resolve_callback(CattaSServiceResolver *resolver, CattaIfI
 		char *node_fp = (char *)catta_string_list_get_text(node_fp_li) + strlen(MESHLINK_MDNS_FINGERPRINT_KEY);
 
 		if(node_name[0] == '=' && node_fp[0] == '=') {
-			pthread_mutex_lock(&mesh->mutex);
+			assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 			node_name += 1;
 
@@ -273,7 +273,7 @@ static void discovery_resolve_callback(CattaSServiceResolver *resolver, CattaIfI
 				logger(mesh, MESHLINK_WARNING, "Node %s is not part of the mesh network.\n", node_name);
 			}
 
-			pthread_mutex_unlock(&mesh->mutex);
+			assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		}
 	}
 
@@ -288,22 +288,22 @@ static void discovery_browse_callback(CattaSServiceBrowser *browser, CattaIfInde
 	/* Called whenever a new services becomes available on the LAN or is removed from the LAN */
 	switch(event) {
 	case CATTA_BROWSER_FAILURE:
-		pthread_mutex_lock(&mesh->mutex);
+		assert(pthread_mutex_lock(&mesh->mutex) == 0);
 		catta_simple_poll_quit(mesh->catta_poll);
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		break;
 
 	case CATTA_BROWSER_NEW:
-		pthread_mutex_lock(&mesh->mutex);
+		assert(pthread_mutex_lock(&mesh->mutex) == 0);
 		catta_s_service_resolver_new(mesh->catta_server, interface_, protocol, name, type, domain, CATTA_PROTO_UNSPEC, 0, discovery_resolve_callback, mesh);
 		handle_network_change(mesh, ++mesh->catta_interfaces);
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		break;
 
 	case CATTA_BROWSER_REMOVE:
-		pthread_mutex_lock(&mesh->mutex);
+		assert(pthread_mutex_lock(&mesh->mutex) == 0);
 		handle_network_change(mesh, --mesh->catta_interfaces);
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		break;
 
 	case CATTA_BROWSER_ALL_FOR_NOW:
@@ -343,7 +343,7 @@ static void *discovery_loop(void *userdata) {
 	meshlink_handle_t *mesh = userdata;
 	assert(mesh);
 
-	pthread_mutex_lock(&mesh->discovery_mutex);
+	assert(pthread_mutex_lock(&mesh->discovery_mutex) == 0);
 
 	// handle catta logs
 	catta_set_log_function(discovery_log_cb);
@@ -416,8 +416,8 @@ static void *discovery_loop(void *userdata) {
 
 fail:
 
-	pthread_cond_broadcast(&mesh->discovery_cond);
-	pthread_mutex_unlock(&mesh->discovery_mutex);
+	assert(pthread_cond_broadcast(&mesh->discovery_cond) == 0);
+	assert(pthread_mutex_unlock(&mesh->discovery_mutex) == 0);
 
 	if(status) {
 		catta_simple_poll_loop(mesh->catta_poll);
@@ -462,18 +462,18 @@ bool discovery_start(meshlink_handle_t *mesh) {
 	assert(!mesh->discovery_threadstarted);
 	assert(!mesh->catta_servicetype);
 
-	pthread_mutex_lock(&mesh->discovery_mutex);
+	assert(pthread_mutex_lock(&mesh->discovery_mutex) == 0);
 
 	// Start the discovery thread
 	if(pthread_create(&mesh->discovery_thread, NULL, discovery_loop, mesh) != 0) {
-		pthread_mutex_unlock(&mesh->discovery_mutex);
+		assert(pthread_mutex_unlock(&mesh->discovery_mutex) == 0);
 		logger(mesh, MESHLINK_ERROR, "Could not start discovery thread: %s\n", strerror(errno));
 		memset(&mesh->discovery_thread, 0, sizeof(mesh)->discovery_thread);
 		return false;
 	}
 
-	pthread_cond_wait(&mesh->discovery_cond, &mesh->discovery_mutex);
-	pthread_mutex_unlock(&mesh->discovery_mutex);
+	assert(pthread_cond_wait(&mesh->discovery_cond, &mesh->discovery_mutex) == 0);
+	assert(pthread_mutex_unlock(&mesh->discovery_mutex) == 0);
 
 	mesh->discovery_threadstarted = true;
 
@@ -492,7 +492,7 @@ void discovery_stop(meshlink_handle_t *mesh) {
 
 	// Wait for the discovery thread to finish
 	if(mesh->discovery_threadstarted == true) {
-		pthread_join(mesh->discovery_thread, NULL);
+		assert(pthread_join(mesh->discovery_thread, NULL) == 0);
 		mesh->discovery_threadstarted = false;
 	}
 
diff --git a/src/event.c b/src/event.c
index 39a7d18f..5e9763e2 100644
--- a/src/event.c
+++ b/src/event.c
@@ -311,7 +311,7 @@ bool event_loop_run(event_loop_t *loop, pthread_mutex_t *mutex) {
 		}
 
 		// release mesh mutex during select
-		pthread_mutex_unlock(mutex);
+		assert(pthread_mutex_unlock(mutex) == 0);
 
 #ifdef HAVE_PSELECT
 		int n = pselect(fds, &readable, &writable, NULL, &ts, NULL);
@@ -320,7 +320,7 @@ bool event_loop_run(event_loop_t *loop, pthread_mutex_t *mutex) {
 		int n = select(fds, &readable, &writable, NULL, (struct timeval *)&tv);
 #endif
 
-		pthread_mutex_lock(mutex);
+		assert(pthread_mutex_lock(mutex) == 0);
 
 		clock_gettime(EVENT_CLOCK, &loop->now);
 
diff --git a/src/meshlink.c b/src/meshlink.c
index 8ad72c15..92246694 100644
--- a/src/meshlink.c
+++ b/src/meshlink.c
@@ -154,7 +154,7 @@ static int socket_in_netns(int domain, int type, int protocol, int netns) {
 	pthread_t thr;
 
 	if(pthread_create(&thr, NULL, socket_in_netns_thread, &params) == 0) {
-		pthread_join(thr, NULL);
+		assert(pthread_join(thr, NULL) == 0);
 	}
 
 	return params.fd;
@@ -1213,7 +1213,7 @@ bool meshlink_encrypted_key_rotate(meshlink_handle_t *mesh, const void *new_key,
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	// Create hash for the new key
 	void *new_config_key;
@@ -1222,7 +1222,7 @@ bool meshlink_encrypted_key_rotate(meshlink_handle_t *mesh, const void *new_key,
 	if(!prf(new_key, new_keylen, "MeshLink configuration key", 26, new_config_key, CHACHA_POLY1305_KEYLEN)) {
 		logger(mesh, MESHLINK_ERROR, "Error creating new configuration key!\n");
 		meshlink_errno = MESHLINK_EINTERNAL;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
@@ -1231,7 +1231,7 @@ bool meshlink_encrypted_key_rotate(meshlink_handle_t *mesh, const void *new_key,
 	if(!config_copy(mesh, "current", mesh->config_key, "new", new_config_key)) {
 		logger(mesh, MESHLINK_ERROR, "Could not set up configuration in %s/old: %s\n", mesh->confbase, strerror(errno));
 		meshlink_errno = MESHLINK_ESTORAGE;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
@@ -1242,7 +1242,7 @@ bool meshlink_encrypted_key_rotate(meshlink_handle_t *mesh, const void *new_key,
 	if(!config_rename(mesh, "current", "old")) {
 		logger(mesh, MESHLINK_ERROR, "Cannot rename %s/current to %s/old\n", mesh->confbase, mesh->confbase);
 		meshlink_errno = MESHLINK_ESTORAGE;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
@@ -1253,7 +1253,7 @@ bool meshlink_encrypted_key_rotate(meshlink_handle_t *mesh, const void *new_key,
 	if(!config_rename(mesh, "new", "current")) {
 		logger(mesh, MESHLINK_ERROR, "Cannot rename %s/new to %s/current\n", mesh->confbase, mesh->confbase);
 		meshlink_errno = MESHLINK_ESTORAGE;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
@@ -1262,7 +1262,7 @@ bool meshlink_encrypted_key_rotate(meshlink_handle_t *mesh, const void *new_key,
 	// Cleanup the "old" confbase sub-directory
 
 	if(!config_destroy(mesh->confbase, "old")) {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
@@ -1271,7 +1271,7 @@ bool meshlink_encrypted_key_rotate(meshlink_handle_t *mesh, const void *new_key,
 	free(mesh->config_key);
 	mesh->config_key = new_config_key;
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return true;
 }
@@ -1458,14 +1458,14 @@ meshlink_handle_t *meshlink_open_ex(const meshlink_open_params_t *params) {
 
 	// initialize mutexes and conds
 	pthread_mutexattr_t attr;
-	pthread_mutexattr_init(&attr);
-	pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
-	pthread_mutex_init(&mesh->mutex, &attr);
+	assert(pthread_mutexattr_init(&attr) == 0);
+	assert(pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE) == 0);
+	assert(pthread_mutex_init(&mesh->mutex, &attr) == 0);
 
-	pthread_mutex_init(&mesh->discovery_mutex, NULL);
-	pthread_cond_init(&mesh->discovery_cond, NULL);
+	assert(pthread_mutex_init(&mesh->discovery_mutex, NULL) == 0);
+	assert(pthread_cond_init(&mesh->discovery_cond, NULL) == 0);
 
-	pthread_cond_init(&mesh->adns_cond, NULL);
+	assert(pthread_cond_init(&mesh->adns_cond, NULL) == 0);
 
 	mesh->threadstarted = false;
 	event_loop_init(&mesh->loop);
@@ -1565,11 +1565,11 @@ meshlink_submesh_t *meshlink_submesh_open(meshlink_handle_t  *mesh, const char *
 	}
 
 	//lock mesh->nodes
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	s = (meshlink_submesh_t *)create_submesh(mesh, submesh);
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return s;
 }
@@ -1581,12 +1581,12 @@ static void *meshlink_main_loop(void *arg) {
 #ifdef HAVE_SETNS
 
 		if(setns(mesh->netns, CLONE_NEWNET) != 0) {
-			pthread_cond_signal(&mesh->cond);
+			assert(pthread_cond_signal(&mesh->cond) == 0);
 			return NULL;
 		}
 
 #else
-		pthread_cond_signal(&mesh->cond);
+		assert(pthread_cond_signal(&mesh->cond) == 0);
 		return NULL;
 #endif // HAVE_SETNS
 	}
@@ -1599,14 +1599,14 @@ static void *meshlink_main_loop(void *arg) {
 
 #endif
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	logger(mesh, MESHLINK_DEBUG, "Starting main_loop...\n");
-	pthread_cond_broadcast(&mesh->cond);
+	assert(pthread_cond_broadcast(&mesh->cond) == 0);
 	main_loop(mesh);
 	logger(mesh, MESHLINK_DEBUG, "main_loop returned.\n");
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 #if HAVE_CATTA
 
@@ -1628,7 +1628,7 @@ bool meshlink_start(meshlink_handle_t *mesh) {
 
 	logger(mesh, MESHLINK_DEBUG, "meshlink_start called\n");
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	assert(mesh->self);
 	assert(mesh->private_key);
@@ -1637,7 +1637,7 @@ bool meshlink_start(meshlink_handle_t *mesh) {
 
 	if(mesh->threadstarted) {
 		logger(mesh, MESHLINK_DEBUG, "thread was already running\n");
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return true;
 	}
 
@@ -1653,7 +1653,7 @@ bool meshlink_start(meshlink_handle_t *mesh) {
 	if(!mesh->name) {
 		logger(mesh, MESHLINK_DEBUG, "No name given!\n");
 		meshlink_errno = MESHLINK_EINVAL;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
@@ -1666,25 +1666,25 @@ bool meshlink_start(meshlink_handle_t *mesh) {
 
 	// Ensure we have a decent amount of stack space. Musl's default of 80 kB is too small.
 	pthread_attr_t attr;
-	pthread_attr_init(&attr);
-	pthread_attr_setstacksize(&attr, 1024 * 1024);
+	assert(pthread_attr_init(&attr) == 0);
+	assert(pthread_attr_setstacksize(&attr, 1024 * 1024) == 0);
 
 	if(pthread_create(&mesh->thread, &attr, meshlink_main_loop, mesh) != 0) {
 		logger(mesh, MESHLINK_DEBUG, "Could not start thread: %s\n", strerror(errno));
 		memset(&mesh->thread, 0, sizeof(mesh)->thread);
 		meshlink_errno = MESHLINK_EINTERNAL;
 		event_loop_stop(&mesh->loop);
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
-	pthread_cond_wait(&mesh->cond, &mesh->mutex);
+	assert(pthread_cond_wait(&mesh->cond, &mesh->mutex) == 0);
 	mesh->threadstarted = true;
 
 	// Ensure we are considered reachable
 	graph(mesh);
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 	return true;
 }
 
@@ -1694,7 +1694,7 @@ void meshlink_stop(meshlink_handle_t *mesh) {
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	logger(mesh, MESHLINK_DEBUG, "meshlink_stop called\n");
 
 	// Shut down the main thread
@@ -1717,9 +1717,9 @@ void meshlink_stop(meshlink_handle_t *mesh) {
 
 	if(mesh->threadstarted) {
 		// Wait for the main thread to finish
-		pthread_mutex_unlock(&mesh->mutex);
-		pthread_join(mesh->thread, NULL);
-		pthread_mutex_lock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
+		assert(pthread_join(mesh->thread, NULL) == 0);
+		assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 		mesh->threadstarted = false;
 	}
@@ -1751,7 +1751,7 @@ void meshlink_stop(meshlink_handle_t *mesh) {
 		}
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_close(meshlink_handle_t *mesh) {
@@ -1764,7 +1764,7 @@ void meshlink_close(meshlink_handle_t *mesh) {
 	meshlink_stop(mesh);
 
 	// lock is not released after this
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	// Close and free all resources used.
 
@@ -1808,8 +1808,8 @@ void meshlink_close(meshlink_handle_t *mesh) {
 
 	main_config_unlock(mesh);
 
-	pthread_mutex_unlock(&mesh->mutex);
-	pthread_mutex_destroy(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
+	assert(pthread_mutex_destroy(&mesh->mutex) == 0);
 
 	memset(mesh, 0, sizeof(*mesh));
 
@@ -1885,9 +1885,9 @@ void meshlink_set_receive_cb(meshlink_handle_t *mesh, meshlink_receive_cb_t cb)
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	mesh->receive_cb = cb;
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_set_connection_try_cb(meshlink_handle_t *mesh, meshlink_connection_try_cb_t cb) {
@@ -1896,9 +1896,9 @@ void meshlink_set_connection_try_cb(meshlink_handle_t *mesh, meshlink_connection
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	mesh->connection_try_cb = cb;
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_set_node_status_cb(meshlink_handle_t *mesh, meshlink_node_status_cb_t cb) {
@@ -1907,9 +1907,9 @@ void meshlink_set_node_status_cb(meshlink_handle_t *mesh, meshlink_node_status_c
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	mesh->node_status_cb = cb;
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_set_node_pmtu_cb(meshlink_handle_t *mesh, meshlink_node_pmtu_cb_t cb) {
@@ -1918,9 +1918,9 @@ void meshlink_set_node_pmtu_cb(meshlink_handle_t *mesh, meshlink_node_pmtu_cb_t
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	mesh->node_pmtu_cb = cb;
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_set_node_duplicate_cb(meshlink_handle_t *mesh, meshlink_node_duplicate_cb_t cb) {
@@ -1929,17 +1929,17 @@ void meshlink_set_node_duplicate_cb(meshlink_handle_t *mesh, meshlink_node_dupli
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	mesh->node_duplicate_cb = cb;
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_set_log_cb(meshlink_handle_t *mesh, meshlink_log_level_t level, meshlink_log_cb_t cb) {
 	if(mesh) {
-		pthread_mutex_lock(&mesh->mutex);
+		assert(pthread_mutex_lock(&mesh->mutex) == 0);
 		mesh->log_cb = cb;
 		mesh->log_level = cb ? level : 0;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 	} else {
 		global_log_cb = cb;
 		global_log_level = cb ? level : 0;
@@ -1952,9 +1952,9 @@ void meshlink_set_error_cb(struct meshlink_handle *mesh, meshlink_error_cb_t cb)
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	mesh->error_cb = cb;
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 static bool prepare_packet(meshlink_handle_t *mesh, meshlink_node_t *destination, const void *data, size_t len, vpn_packet_t *packet) {
@@ -2072,19 +2072,19 @@ ssize_t meshlink_get_pmtu(meshlink_handle_t *mesh, meshlink_node_t *destination)
 		return -1;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	node_t *n = (node_t *)destination;
 
 	if(!n->status.reachable) {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return 0;
 
 	} else if(n->mtuprobes > 30 && n->minmtu) {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return n->minmtu;
 	} else {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return MTU;
 	}
 }
@@ -2095,13 +2095,13 @@ char *meshlink_get_fingerprint(meshlink_handle_t *mesh, meshlink_node_t *node) {
 		return NULL;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	node_t *n = (node_t *)node;
 
 	if(!node_read_public_key(mesh, n) || !n->ecdsa) {
 		meshlink_errno = MESHLINK_EINTERNAL;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
@@ -2111,7 +2111,7 @@ char *meshlink_get_fingerprint(meshlink_handle_t *mesh, meshlink_node_t *node) {
 		meshlink_errno = MESHLINK_EINTERNAL;
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 	return fingerprint;
 }
 
@@ -2132,9 +2132,9 @@ meshlink_node_t *meshlink_get_node(meshlink_handle_t *mesh, const char *name) {
 
 	node_t *n = NULL;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	n = lookup_node(mesh, (char *)name); // TODO: make lookup_node() use const
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	if(!n) {
 		meshlink_errno = MESHLINK_ENOENT;
@@ -2151,9 +2151,9 @@ meshlink_submesh_t *meshlink_get_submesh(meshlink_handle_t *mesh, const char *na
 
 	meshlink_submesh_t *submesh = NULL;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	submesh = (meshlink_submesh_t *)lookup_submesh(mesh, name);
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	if(!submesh) {
 		meshlink_errno = MESHLINK_ENOENT;
@@ -2171,7 +2171,7 @@ meshlink_node_t **meshlink_get_all_nodes(meshlink_handle_t *mesh, meshlink_node_
 	meshlink_node_t **result;
 
 	//lock mesh->nodes
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	*nmemb = mesh->nodes->count;
 	result = realloc(nodes, *nmemb * sizeof(*nodes));
@@ -2188,7 +2188,7 @@ meshlink_node_t **meshlink_get_all_nodes(meshlink_handle_t *mesh, meshlink_node_
 		meshlink_errno = MESHLINK_ENOMEM;
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return result;
 }
@@ -2196,7 +2196,7 @@ meshlink_node_t **meshlink_get_all_nodes(meshlink_handle_t *mesh, meshlink_node_
 static meshlink_node_t **meshlink_get_all_nodes_by_condition(meshlink_handle_t *mesh, const void *condition, meshlink_node_t **nodes, size_t *nmemb, search_node_by_condition_t search_node) {
 	meshlink_node_t **result;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	*nmemb = 0;
 
@@ -2208,7 +2208,7 @@ static meshlink_node_t **meshlink_get_all_nodes_by_condition(meshlink_handle_t *
 
 	if(*nmemb == 0) {
 		free(nodes);
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return NULL;
 	}
 
@@ -2228,7 +2228,7 @@ static meshlink_node_t **meshlink_get_all_nodes_by_condition(meshlink_handle_t *
 		meshlink_errno = MESHLINK_ENOMEM;
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return result;
 }
@@ -2313,11 +2313,11 @@ dev_class_t meshlink_get_node_dev_class(meshlink_handle_t *mesh, meshlink_node_t
 
 	dev_class_t devclass;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	devclass = ((node_t *)node)->devclass;
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return devclass;
 }
@@ -2346,7 +2346,7 @@ bool meshlink_get_node_reachability(struct meshlink_handle *mesh, struct meshlin
 	node_t *n = (node_t *)node;
 	bool reachable;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	reachable = n->status.reachable && !n->status.blacklisted;
 
 	if(last_reachable) {
@@ -2357,7 +2357,7 @@ bool meshlink_get_node_reachability(struct meshlink_handle *mesh, struct meshlin
 		*last_unreachable = n->last_unreachable;
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return reachable;
 }
@@ -2373,16 +2373,16 @@ bool meshlink_sign(meshlink_handle_t *mesh, const void *data, size_t len, void *
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	if(!ecdsa_sign(mesh->private_key, data, len, signature)) {
 		meshlink_errno = MESHLINK_EINTERNAL;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
 	*siglen = MESHLINK_SIGLEN;
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 	return true;
 }
 
@@ -2397,7 +2397,7 @@ bool meshlink_verify(meshlink_handle_t *mesh, meshlink_node_t *source, const voi
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	bool rval = false;
 
@@ -2410,12 +2410,12 @@ bool meshlink_verify(meshlink_handle_t *mesh, meshlink_node_t *source, const voi
 		rval = ecdsa_verify(((struct node_t *)source)->ecdsa, data, len, signature);
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 	return rval;
 }
 
 static bool refresh_invitation_key(meshlink_handle_t *mesh) {
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	size_t count = invitation_purge_old(mesh, time(NULL) - mesh->invitation_timeout);
 
@@ -2423,7 +2423,7 @@ static bool refresh_invitation_key(meshlink_handle_t *mesh) {
 		// TODO: Update invitation key if necessary?
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return mesh->invitation_key;
 }
@@ -2461,18 +2461,18 @@ bool meshlink_set_canonical_address(meshlink_handle_t *mesh, meshlink_node_t *no
 		canonical_address = xstrdup(address);
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	node_t *n = (node_t *)node;
 	free(n->canonical_address);
 	n->canonical_address = canonical_address;
 
 	if(!node_write_config(mesh, n)) {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return config_sync(mesh, "current");
 }
@@ -2503,14 +2503,14 @@ bool meshlink_add_invitation_address(struct meshlink_handle *mesh, const char *a
 		combo = xstrdup(address);
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	if(!mesh->invitation_addresses) {
 		mesh->invitation_addresses = list_alloc((list_action_t)free);
 	}
 
 	list_insert_tail(mesh->invitation_addresses, combo);
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return true;
 }
@@ -2521,14 +2521,14 @@ void meshlink_clear_invitation_addresses(struct meshlink_handle *mesh) {
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	if(mesh->invitation_addresses) {
 		list_delete_list(mesh->invitation_addresses);
 		mesh->invitation_addresses = NULL;
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 bool meshlink_add_address(meshlink_handle_t *mesh, const char *address) {
@@ -2566,9 +2566,9 @@ int meshlink_get_port(meshlink_handle_t *mesh) {
 
 	int port;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	port = atoi(mesh->myport);
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return port;
 }
@@ -2592,7 +2592,7 @@ bool meshlink_set_port(meshlink_handle_t *mesh, int port) {
 
 	bool rval = false;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	if(mesh->threadstarted) {
 		meshlink_errno = MESHLINK_EINVAL;
@@ -2633,7 +2633,7 @@ bool meshlink_set_port(meshlink_handle_t *mesh, int port) {
 	rval = config_sync(mesh, "current");
 
 done:
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return rval && meshlink_get_port(mesh) == port;
 }
@@ -2662,13 +2662,13 @@ char *meshlink_invite_ex(meshlink_handle_t *mesh, meshlink_submesh_t *submesh, c
 		s = (meshlink_submesh_t *)mesh->self->submesh;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	// Check validity of the new node's name
 	if(!check_id(name)) {
 		logger(mesh, MESHLINK_ERROR, "Invalid name for node.\n");
 		meshlink_errno = MESHLINK_EINVAL;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return NULL;
 	}
 
@@ -2676,7 +2676,7 @@ char *meshlink_invite_ex(meshlink_handle_t *mesh, meshlink_submesh_t *submesh, c
 	if(config_exists(mesh, "current", name)) {
 		logger(mesh, MESHLINK_ERROR, "A host config file for %s already exists!\n", name);
 		meshlink_errno = MESHLINK_EEXIST;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return NULL;
 	}
 
@@ -2684,7 +2684,7 @@ char *meshlink_invite_ex(meshlink_handle_t *mesh, meshlink_submesh_t *submesh, c
 	if(lookup_node(mesh, name)) {
 		logger(mesh, MESHLINK_ERROR, "A node with name %s is already known!\n", name);
 		meshlink_errno = MESHLINK_EEXIST;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return NULL;
 	}
 
@@ -2694,13 +2694,13 @@ char *meshlink_invite_ex(meshlink_handle_t *mesh, meshlink_submesh_t *submesh, c
 	if(!address) {
 		logger(mesh, MESHLINK_ERROR, "No Address known for ourselves!\n");
 		meshlink_errno = MESHLINK_ERESOLV;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return NULL;
 	}
 
 	if(!refresh_invitation_key(mesh)) {
 		meshlink_errno = MESHLINK_EINTERNAL;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return NULL;
 	}
 
@@ -2708,7 +2708,7 @@ char *meshlink_invite_ex(meshlink_handle_t *mesh, meshlink_submesh_t *submesh, c
 	if(mesh->self->status.dirty) {
 		if(!node_write_config(mesh, mesh->self)) {
 			logger(mesh, MESHLINK_ERROR, "Could not write our own host config file!\n");
-			pthread_mutex_unlock(&mesh->mutex);
+			assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 			return NULL;
 		}
 	}
@@ -2770,7 +2770,7 @@ char *meshlink_invite_ex(meshlink_handle_t *mesh, meshlink_submesh_t *submesh, c
 	if(!invitation_write(mesh, "current", cookiehash, &config, mesh->config_key)) {
 		logger(mesh, MESHLINK_DEBUG, "Could not create invitation file %s: %s\n", cookiehash, strerror(errno));
 		meshlink_errno = MESHLINK_ESTORAGE;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return NULL;
 	}
 
@@ -2779,7 +2779,7 @@ char *meshlink_invite_ex(meshlink_handle_t *mesh, meshlink_submesh_t *submesh, c
 	xasprintf(&url, "%s/%s%s", address, hash, cookie);
 	free(address);
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 	return url;
 }
 
@@ -2804,7 +2804,7 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 	//TODO: think of a better name for this variable, or of a different way to tokenize the invitation URL.
 	char copy[strlen(invitation) + 1];
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	//Before doing meshlink_join make sure we are not connected to another mesh
 	if(mesh->threadstarted) {
@@ -3022,7 +3022,7 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
 	ecdsa_free(key);
 	closesocket(state.sock);
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 	return true;
 
 invalid:
@@ -3037,7 +3037,7 @@ exit:
 		closesocket(state.sock);
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 	return false;
 }
 
@@ -3055,7 +3055,7 @@ char *meshlink_export(meshlink_handle_t *mesh) {
 	packmsg_add_str(&out, mesh->name);
 	packmsg_add_str(&out, CORE_MESH);
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	packmsg_add_int32(&out, mesh->self->devclass);
 	packmsg_add_bool(&out, mesh->self->status.blacklisted);
@@ -3089,7 +3089,7 @@ char *meshlink_export(meshlink_handle_t *mesh) {
 	packmsg_add_int64(&out, 0);
 	packmsg_add_int64(&out, 0);
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	if(!packmsg_output_ok(&out)) {
 		logger(mesh, MESHLINK_DEBUG, "Error creating export data\n");
@@ -3143,7 +3143,7 @@ bool meshlink_import(meshlink_handle_t *mesh, const char *data) {
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	while(count--) {
 		const void *data2;
@@ -3199,7 +3199,7 @@ bool meshlink_import(meshlink_handle_t *mesh, const char *data) {
 		node_add(mesh, n);
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	free(buf);
 
@@ -3267,14 +3267,14 @@ bool meshlink_blacklist(meshlink_handle_t *mesh, meshlink_node_t *node) {
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	if(!blacklist(mesh, (node_t *)node)) {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	logger(mesh, MESHLINK_DEBUG, "Blacklisted %s.\n", node->name);
 	return true;
@@ -3286,7 +3286,7 @@ bool meshlink_blacklist_by_name(meshlink_handle_t *mesh, const char *name) {
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	node_t *n = lookup_node(mesh, (char *)name);
 
@@ -3297,11 +3297,11 @@ bool meshlink_blacklist_by_name(meshlink_handle_t *mesh, const char *name) {
 	}
 
 	if(!blacklist(mesh, (node_t *)n)) {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	logger(mesh, MESHLINK_DEBUG, "Blacklisted %s.\n", name);
 	return true;
@@ -3335,14 +3335,14 @@ bool meshlink_whitelist(meshlink_handle_t *mesh, meshlink_node_t *node) {
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	if(!whitelist(mesh, (node_t *)node)) {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	logger(mesh, MESHLINK_DEBUG, "Whitelisted %s.\n", node->name);
 	return true;
@@ -3354,7 +3354,7 @@ bool meshlink_whitelist_by_name(meshlink_handle_t *mesh, const char *name) {
 		return false;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	node_t *n = lookup_node(mesh, (char *)name);
 
@@ -3365,11 +3365,11 @@ bool meshlink_whitelist_by_name(meshlink_handle_t *mesh, const char *name) {
 	}
 
 	if(!whitelist(mesh, (node_t *)n)) {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	logger(mesh, MESHLINK_DEBUG, "Whitelisted %s.\n", name);
 	return true;
@@ -3387,18 +3387,18 @@ bool meshlink_forget_node(meshlink_handle_t *mesh, meshlink_node_t *node) {
 
 	node_t *n = (node_t *)node;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	/* Check that the node is not reachable */
 	if(n->status.reachable || n->connection) {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		logger(mesh, MESHLINK_WARNING, "Could not forget %s: still reachable", n->name);
 		return false;
 	}
 
 	/* Check that we don't have any active UTCP connections */
 	if(n->utcp && utcp_is_active(n->utcp)) {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		logger(mesh, MESHLINK_WARNING, "Could not forget %s: active UTCP connections", n->name);
 		return false;
 	}
@@ -3406,7 +3406,7 @@ bool meshlink_forget_node(meshlink_handle_t *mesh, meshlink_node_t *node) {
 	/* Check that we have no active connections to this node */
 	for list_each(connection_t, c, mesh->connections) {
 		if(c->node == n) {
-			pthread_mutex_unlock(&mesh->mutex);
+			assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 			logger(mesh, MESHLINK_WARNING, "Could not forget %s: active connection", n->name);
 			return false;
 		}
@@ -3423,14 +3423,14 @@ bool meshlink_forget_node(meshlink_handle_t *mesh, meshlink_node_t *node) {
 
 	/* Delete the config file for this node */
 	if(!config_delete(mesh, "current", n->name)) {
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return false;
 	}
 
 	/* Delete the node struct and any remaining edges referencing this node */
 	node_del(mesh, n);
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return config_sync(mesh, "current");
 }
@@ -3444,7 +3444,7 @@ void meshlink_hint_address(meshlink_handle_t *mesh, meshlink_node_t *node, const
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	node_t *n = (node_t *)node;
 
@@ -3454,7 +3454,7 @@ void meshlink_hint_address(meshlink_handle_t *mesh, meshlink_node_t *node, const
 		}
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 	// @TODO do we want to fire off a connection attempt right away?
 }
 
@@ -3758,10 +3758,10 @@ void meshlink_set_channel_poll_cb(meshlink_handle_t *mesh, meshlink_channel_t *c
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	channel->poll_cb = cb;
 	utcp_set_poll_cb(channel->c, (cb || channel->aio_send) ? channel_poll : NULL);
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_set_channel_accept_cb(meshlink_handle_t *mesh, meshlink_channel_accept_cb_t cb) {
@@ -3770,7 +3770,7 @@ void meshlink_set_channel_accept_cb(meshlink_handle_t *mesh, meshlink_channel_ac
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	mesh->channel_accept_cb = cb;
 	mesh->receive_cb = channel_receive;
 
@@ -3782,7 +3782,7 @@ void meshlink_set_channel_accept_cb(meshlink_handle_t *mesh, meshlink_channel_ac
 		}
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_set_channel_sndbuf(meshlink_handle_t *mesh, meshlink_channel_t *channel, size_t size) {
@@ -3793,9 +3793,9 @@ void meshlink_set_channel_sndbuf(meshlink_handle_t *mesh, meshlink_channel_t *ch
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	utcp_set_sndbuf(channel->c, size);
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_set_channel_rcvbuf(meshlink_handle_t *mesh, meshlink_channel_t *channel, size_t size) {
@@ -3806,9 +3806,9 @@ void meshlink_set_channel_rcvbuf(meshlink_handle_t *mesh, meshlink_channel_t *ch
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	utcp_set_rcvbuf(channel->c, size);
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 meshlink_channel_t *meshlink_channel_open_ex(meshlink_handle_t *mesh, meshlink_node_t *node, uint16_t port, meshlink_channel_receive_cb_t cb, const void *data, size_t len, uint32_t flags) {
@@ -3821,7 +3821,7 @@ meshlink_channel_t *meshlink_channel_open_ex(meshlink_handle_t *mesh, meshlink_n
 		return NULL;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	node_t *n = (node_t *)node;
 
@@ -3833,7 +3833,7 @@ meshlink_channel_t *meshlink_channel_open_ex(meshlink_handle_t *mesh, meshlink_n
 
 		if(!n->utcp) {
 			meshlink_errno = errno == ENOMEM ? MESHLINK_ENOMEM : MESHLINK_EINTERNAL;
-			pthread_mutex_unlock(&mesh->mutex);
+			assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 			return NULL;
 		}
 	}
@@ -3841,7 +3841,7 @@ meshlink_channel_t *meshlink_channel_open_ex(meshlink_handle_t *mesh, meshlink_n
 	if(n->status.blacklisted) {
 		logger(mesh, MESHLINK_ERROR, "Cannot open a channel with blacklisted node\n");
 		meshlink_errno = MESHLINK_EBLACKLISTED;
-		pthread_mutex_unlock(&mesh->mutex);
+		assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 		return NULL;
 	}
 
@@ -3855,7 +3855,7 @@ meshlink_channel_t *meshlink_channel_open_ex(meshlink_handle_t *mesh, meshlink_n
 
 	channel->c = utcp_connect_ex(n->utcp, port, channel_recv, channel, flags);
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	if(!channel->c) {
 		meshlink_errno = errno == ENOMEM ? MESHLINK_ENOMEM : MESHLINK_EINTERNAL;
@@ -3876,9 +3876,9 @@ void meshlink_channel_shutdown(meshlink_handle_t *mesh, meshlink_channel_t *chan
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	utcp_shutdown(channel->c, direction);
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_channel_close(meshlink_handle_t *mesh, meshlink_channel_t *channel) {
@@ -3887,7 +3887,7 @@ void meshlink_channel_close(meshlink_handle_t *mesh, meshlink_channel_t *channel
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	if(channel->c) {
 		utcp_close(channel->c);
@@ -3902,7 +3902,7 @@ void meshlink_channel_close(meshlink_handle_t *mesh, meshlink_channel_t *channel
 		free(channel);
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 ssize_t meshlink_channel_send(meshlink_handle_t *mesh, meshlink_channel_t *channel, const void *data, size_t len) {
@@ -3927,7 +3927,7 @@ ssize_t meshlink_channel_send(meshlink_handle_t *mesh, meshlink_channel_t *chann
 
 	ssize_t retval;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	/* Disallow direct calls to utcp_send() while we still have AIO active. */
 	if(channel->aio_send) {
@@ -3936,7 +3936,7 @@ ssize_t meshlink_channel_send(meshlink_handle_t *mesh, meshlink_channel_t *chann
 		retval = utcp_send(channel->c, data, len);
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	if(retval < 0) {
 		meshlink_errno = MESHLINK_ENETWORK;
@@ -3962,7 +3962,7 @@ bool meshlink_channel_aio_send(meshlink_handle_t *mesh, meshlink_channel_t *chan
 	aio->cb.buffer = cb;
 	aio->priv = priv;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	/* Append the AIO buffer descriptor to the end of the chain */
 	meshlink_aio_buffer_t **p = &channel->aio_send;
@@ -3981,7 +3981,7 @@ bool meshlink_channel_aio_send(meshlink_handle_t *mesh, meshlink_channel_t *chan
 		channel_poll(channel->c, todo);
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return true;
 }
@@ -4003,7 +4003,7 @@ bool meshlink_channel_aio_fd_send(meshlink_handle_t *mesh, meshlink_channel_t *c
 	aio->cb.fd = cb;
 	aio->priv = priv;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	/* Append the AIO buffer descriptor to the end of the chain */
 	meshlink_aio_buffer_t **p = &channel->aio_send;
@@ -4022,7 +4022,7 @@ bool meshlink_channel_aio_fd_send(meshlink_handle_t *mesh, meshlink_channel_t *c
 		channel_poll(channel->c, left);
 	}
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return true;
 }
@@ -4044,7 +4044,7 @@ bool meshlink_channel_aio_receive(meshlink_handle_t *mesh, meshlink_channel_t *c
 	aio->cb.buffer = cb;
 	aio->priv = priv;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	/* Append the AIO buffer descriptor to the end of the chain */
 	meshlink_aio_buffer_t **p = &channel->aio_receive;
@@ -4055,7 +4055,7 @@ bool meshlink_channel_aio_receive(meshlink_handle_t *mesh, meshlink_channel_t *c
 
 	*p = aio;
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return true;
 }
@@ -4077,7 +4077,7 @@ bool meshlink_channel_aio_fd_receive(meshlink_handle_t *mesh, meshlink_channel_t
 	aio->cb.fd = cb;
 	aio->priv = priv;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	/* Append the AIO buffer descriptor to the end of the chain */
 	meshlink_aio_buffer_t **p = &channel->aio_receive;
@@ -4088,7 +4088,7 @@ bool meshlink_channel_aio_fd_receive(meshlink_handle_t *mesh, meshlink_channel_t
 
 	*p = aio;
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 
 	return true;
 }
@@ -4137,7 +4137,7 @@ void meshlink_set_node_channel_timeout(meshlink_handle_t *mesh, meshlink_node_t
 
 	node_t *n = (node_t *)node;
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	if(!n->utcp) {
 		n->utcp = utcp_init(channel_accept, channel_pre_accept, channel_send, n);
@@ -4147,7 +4147,7 @@ void meshlink_set_node_channel_timeout(meshlink_handle_t *mesh, meshlink_node_t
 
 	utcp_set_user_timeout(n->utcp, timeout);
 
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void update_node_status(meshlink_handle_t *mesh, node_t *n) {
@@ -4191,7 +4191,7 @@ void meshlink_enable_discovery(meshlink_handle_t *mesh, bool enable) {
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 
 	if(mesh->discovery == enable) {
 		goto end;
@@ -4208,7 +4208,7 @@ void meshlink_enable_discovery(meshlink_handle_t *mesh, bool enable) {
 	mesh->discovery = enable;
 
 end:
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 #else
 	(void)mesh;
 	(void)enable;
@@ -4227,10 +4227,10 @@ void meshlink_set_dev_class_timeouts(meshlink_handle_t *mesh, dev_class_t devcla
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	mesh->dev_class_traits[devclass].pinginterval = pinginterval;
 	mesh->dev_class_traits[devclass].pingtimeout = pingtimeout;
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_set_dev_class_fast_retry_period(meshlink_handle_t *mesh, dev_class_t devclass, int fast_retry_period) {
@@ -4244,9 +4244,9 @@ void meshlink_set_dev_class_fast_retry_period(meshlink_handle_t *mesh, dev_class
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	mesh->dev_class_traits[devclass].fast_retry_period = fast_retry_period;
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 extern void meshlink_set_inviter_commits_first(struct meshlink_handle *mesh, bool inviter_commits_first) {
@@ -4255,9 +4255,9 @@ extern void meshlink_set_inviter_commits_first(struct meshlink_handle *mesh, boo
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	mesh->inviter_commits_first = inviter_commits_first;
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_set_external_address_discovery_url(struct meshlink_handle *mesh, const char *url) {
@@ -4271,10 +4271,10 @@ void meshlink_set_external_address_discovery_url(struct meshlink_handle *mesh, c
 		return;
 	}
 
-	pthread_mutex_lock(&mesh->mutex);
+	assert(pthread_mutex_lock(&mesh->mutex) == 0);
 	free(mesh->external_address_url);
 	mesh->external_address_url = url ? xstrdup(url) : NULL;
-	pthread_mutex_unlock(&mesh->mutex);
+	assert(pthread_mutex_unlock(&mesh->mutex) == 0);
 }
 
 void meshlink_set_scheduling_granularity(struct meshlink_handle *mesh, long granularity) {
diff --git a/src/meshlink_queue.h b/src/meshlink_queue.h
index b6e63c67..cacda0ed 100644
--- a/src/meshlink_queue.h
+++ b/src/meshlink_queue.h
@@ -40,13 +40,13 @@ static inline void meshlink_queue_init(meshlink_queue_t *queue) {
 	queue->head = NULL;
 	queue->tail = NULL;
 	pthread_mutexattr_t attr;
-	pthread_mutexattr_init(&attr);
-	pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_DEFAULT);
-	pthread_mutex_init(&queue->mutex, &attr);
+	assert(pthread_mutexattr_init(&attr) == 0);
+	assert(pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_DEFAULT) == 0);
+	assert(pthread_mutex_init(&queue->mutex, &attr) == 0);
 }
 
 static inline void meshlink_queue_exit(meshlink_queue_t *queue) {
-	pthread_mutex_destroy(&queue->mutex);
+	assert(pthread_mutex_destroy(&queue->mutex) == 0);
 }
 
 static inline __attribute__((__warn_unused_result__)) bool meshlink_queue_push(meshlink_queue_t *queue, void *data) {
@@ -58,7 +58,7 @@ static inline __attribute__((__warn_unused_result__)) bool meshlink_queue_push(m
 
 	item->data = data;
 	item->next = NULL;
-	pthread_mutex_lock(&queue->mutex);
+	assert(pthread_mutex_lock(&queue->mutex) == 0);
 
 	if(!queue->tail) {
 		queue->head = queue->tail = item;
@@ -66,14 +66,14 @@ static inline __attribute__((__warn_unused_result__)) bool meshlink_queue_push(m
 		queue->tail = queue->tail->next = item;
 	}
 
-	pthread_mutex_unlock(&queue->mutex);
+	assert(pthread_mutex_unlock(&queue->mutex) == 0);
 	return true;
 }
 
 static inline __attribute__((__warn_unused_result__)) void *meshlink_queue_pop(meshlink_queue_t *queue) {
 	meshlink_queue_item_t *item;
 
-	pthread_mutex_lock(&queue->mutex);
+	assert(pthread_mutex_lock(&queue->mutex) == 0);
 
 	if((item = queue->head)) {
 		queue->head = item->next;
@@ -83,7 +83,7 @@ static inline __attribute__((__warn_unused_result__)) void *meshlink_queue_pop(m
 		}
 	}
 
-	pthread_mutex_unlock(&queue->mutex);
+	assert(pthread_mutex_unlock(&queue->mutex) == 0);
 
 	void *data = item ? item->data : NULL;
 	free(item);
@@ -93,10 +93,10 @@ static inline __attribute__((__warn_unused_result__)) void *meshlink_queue_pop(m
 static inline __attribute__((__warn_unused_result__)) void *meshlink_queue_pop_cond(meshlink_queue_t *queue, pthread_cond_t *cond) {
 	meshlink_queue_item_t *item;
 
-	pthread_mutex_lock(&queue->mutex);
+	assert(pthread_mutex_lock(&queue->mutex) == 0);
 
 	while(!queue->head) {
-		pthread_cond_wait(cond, &queue->mutex);
+		assert(pthread_cond_wait(cond, &queue->mutex) == 0);
 	}
 
 	item = queue->head;
@@ -106,7 +106,7 @@ static inline __attribute__((__warn_unused_result__)) void *meshlink_queue_pop_c
 		queue->tail = NULL;
 	}
 
-	pthread_mutex_unlock(&queue->mutex);
+	assert(pthread_mutex_unlock(&queue->mutex) == 0);
 
 	void *data = item->data;
 	free(item);