*: Change thread->func to return void instead of int

The int return value is never used.  Modify the code
base to just return a void instead.

Signed-off-by: Donald Sharp <sharpd@nvidia.com>

22 files changed, 124 insertions, 172 deletions

diff --git a/lib/agentx.c b/lib/agentx.c
index 5f865ca2b..821c573fb 100644
--- a/lib/agentx.c
+++ b/lib/agentx.c
@@ -46,7 +46,7 @@ static struct list *events = NULL;
 
 static void agentx_events_update(void);
 
-static int agentx_timeout(struct thread *t)
+static void agentx_timeout(struct thread *t)
 {
 	timeout_thr = NULL;
 
@@ -54,10 +54,9 @@ static int agentx_timeout(struct thread *t)
 	run_alarms();
 	netsnmp_check_outstanding_agent_requests();
 	agentx_events_update();
-	return 0;
 }
 
-static int agentx_read(struct thread *t)
+static void agentx_read(struct thread *t)
 {
 	fd_set fds;
 	int flags, new_flags = 0;
@@ -72,7 +71,7 @@ static int agentx_read(struct thread *t)
 	if (-1 == flags) {
 		flog_err(EC_LIB_SYSTEM_CALL, "Failed to get FD settings fcntl: %s(%d)",
 			 strerror(errno), errno);
-		return -1;
+		return;
 	}
 
 	if (flags & O_NONBLOCK)
@@ -101,7 +100,6 @@ static int agentx_read(struct thread *t)
 
 	netsnmp_check_outstanding_agent_requests();
 	agentx_events_update();
-	return 0;
 }
 
 static void agentx_events_update(void)
diff --git a/lib/bfd.c b/lib/bfd.c
index 7b711a9fb..29b8d85d8 100644
--- a/lib/bfd.c
+++ b/lib/bfd.c
@@ -461,14 +461,14 @@ static bool _bfd_sess_valid(const struct bfd_session_params *bsp)
 	return true;
 }
 
-static int _bfd_sess_send(struct thread *t)
+static void _bfd_sess_send(struct thread *t)
 {
 	struct bfd_session_params *bsp = THREAD_ARG(t);
 	int rv;
 
 	/* Validate configuration before trying to send bogus data. */
 	if (!_bfd_sess_valid(bsp))
-		return 0;
+		return;
 
 	if (bsp->lastev == BSE_INSTALL) {
 		bsp->args.command = bsp->installed ? ZEBRA_BFD_DEST_UPDATE
@@ -478,7 +478,7 @@ static int _bfd_sess_send(struct thread *t)
 
 	/* If not installed and asked for uninstall, do nothing. */
 	if (!bsp->installed && bsp->args.command == ZEBRA_BFD_DEST_DEREGISTER)
-		return 0;
+		return;
 
 	rv = zclient_bfd_command(bsglobal.zc, &bsp->args);
 	/* Command was sent successfully. */
@@ -504,8 +504,6 @@ static int _bfd_sess_send(struct thread *t)
 			bsp->lastev == BSE_INSTALL ? "installed"
 						   : "uninstalled");
 	}
-
-	return 0;
 }
 
 static void _bfd_sess_remove(struct bfd_session_params *bsp)
diff --git a/lib/frr_pthread.c b/lib/frr_pthread.c
index 898fe98aa..0f56fbac8 100644
--- a/lib/frr_pthread.c
+++ b/lib/frr_pthread.c
@@ -237,18 +237,16 @@ void frr_pthread_stop_all(void)
  */
 
 /* dummy task for sleeper pipe */
-static int fpt_dummy(struct thread *thread)
+static void fpt_dummy(struct thread *thread)
 {
-	return 0;
 }
 
 /* poison pill task to end event loop */
-static int fpt_finish(struct thread *thread)
+static void fpt_finish(struct thread *thread)
 {
 	struct frr_pthread *fpt = THREAD_ARG(thread);
 
 	atomic_store_explicit(&fpt->running, false, memory_order_relaxed);
-	return 0;
 }
 
 /* stop function, called from other threads to halt this one */
diff --git a/lib/frr_zmq.c b/lib/frr_zmq.c
index e572558de..db5c4c91a 100644
--- a/lib/frr_zmq.c
+++ b/lib/frr_zmq.c
@@ -56,7 +56,7 @@ void frrzmq_finish(void)
 	}
 }
 
-static int frrzmq_read_msg(struct thread *t)
+static void frrzmq_read_msg(struct thread *t)
 {
 	struct frrzmq_cb **cbp = THREAD_ARG(t);
 	struct frrzmq_cb *cb;
@@ -67,10 +67,10 @@ static int frrzmq_read_msg(struct thread *t)
 	size_t moresz;
 
 	if (!cbp)
-		return 1;
+		return;
 	cb = (*cbp);
 	if (!cb || !cb->zmqsock)
-		return 1;
+		return;
 
 	while (1) {
 		zmq_pollitem_t polli = {.socket = cb->zmqsock,
@@ -97,7 +97,7 @@ static int frrzmq_read_msg(struct thread *t)
 				if (cb->write.cancelled && !cb->write.thread)
 					XFREE(MTYPE_ZEROMQ_CB, *cbp);
 
-				return 0;
+				return;
 			}
 			continue;
 		}
@@ -129,7 +129,7 @@ static int frrzmq_read_msg(struct thread *t)
 				if (cb->write.cancelled && !cb->write.thread)
 					XFREE(MTYPE_ZEROMQ_CB, *cbp);
 
-				return 0;
+				return;
 			}
 
 			/* cb_part may have read additional parts of the
@@ -153,14 +153,13 @@ static int frrzmq_read_msg(struct thread *t)
 
 	thread_add_read(t->master, frrzmq_read_msg, cbp,
 			cb->fd, &cb->read.thread);
-	return 0;
+	return;
 
 out_err:
 	flog_err(EC_LIB_ZMQ, "ZeroMQ read error: %s(%d)", strerror(errno),
 		 errno);
 	if (cb->read.cb_error)
 		cb->read.cb_error(cb->read.arg, cb->zmqsock);
-	return 1;
 }
 
 int _frrzmq_thread_add_read(const struct xref_threadsched *xref,
@@ -215,7 +214,7 @@ int _frrzmq_thread_add_read(const struct xref_threadsched *xref,
 	return 0;
 }
 
-static int frrzmq_write_msg(struct thread *t)
+static void frrzmq_write_msg(struct thread *t)
 {
 	struct frrzmq_cb **cbp = THREAD_ARG(t);
 	struct frrzmq_cb *cb;
@@ -223,10 +222,10 @@ static int frrzmq_write_msg(struct thread *t)
 	int ret;
 
 	if (!cbp)
-		return 1;
+		return;
 	cb = (*cbp);
 	if (!cb || !cb->zmqsock)
-		return 1;
+		return;
 
 	while (1) {
 		zmq_pollitem_t polli = {.socket = cb->zmqsock,
@@ -252,7 +251,7 @@ static int frrzmq_write_msg(struct thread *t)
 				if (cb->read.cancelled && !cb->read.thread)
 					XFREE(MTYPE_ZEROMQ_CB, *cbp);
 
-				return 0;
+				return;
 			}
 			continue;
 		}
@@ -263,14 +262,13 @@ static int frrzmq_write_msg(struct thread *t)
 
 	thread_add_write(t->master, frrzmq_write_msg, cbp,
 			 cb->fd, &cb->write.thread);
-	return 0;
+	return;
 
 out_err:
 	flog_err(EC_LIB_ZMQ, "ZeroMQ write error: %s(%d)", strerror(errno),
 		 errno);
 	if (cb->write.cb_error)
 		cb->write.cb_error(cb->write.arg, cb->zmqsock);
-	return 1;
 }
 
 int _frrzmq_thread_add_write(const struct xref_threadsched *xref,
diff --git a/lib/libfrr.c b/lib/libfrr.c
index d5e326be4..10b3aad89 100644
--- a/lib/libfrr.c
+++ b/lib/libfrr.c
@@ -962,7 +962,7 @@ static void frr_daemonize(void)
  * to read the config in after thread execution starts, so that
  * we can match this behavior.
  */
-static int frr_config_read_in(struct thread *t)
+static void frr_config_read_in(struct thread *t)
 {
 	hook_call(frr_config_pre, master);
 
@@ -1000,8 +1000,6 @@ static int frr_config_read_in(struct thread *t)
 	}
 
 	hook_call(frr_config_post, master);
-
-	return 0;
 }
 
 void frr_config_fork(void)
@@ -1097,7 +1095,7 @@ static void frr_terminal_close(int isexit)
 
 static struct thread *daemon_ctl_thread = NULL;
 
-static int frr_daemon_ctl(struct thread *t)
+static void frr_daemon_ctl(struct thread *t)
 {
 	char buf[1];
 	ssize_t nr;
@@ -1106,7 +1104,7 @@ static int frr_daemon_ctl(struct thread *t)
 	if (nr < 0 && (errno == EINTR || errno == EAGAIN))
 		goto out;
 	if (nr <= 0)
-		return 0;
+		return;
 
 	switch (buf[0]) {
 	case 'S': /* SIGTSTP */
@@ -1131,7 +1129,6 @@ static int frr_daemon_ctl(struct thread *t)
 out:
 	thread_add_read(master, frr_daemon_ctl, NULL, daemon_ctl_sock,
 			&daemon_ctl_thread);
-	return 0;
 }
 
 void frr_detach(void)
diff --git a/lib/northbound_cli.c b/lib/northbound_cli.c
index 70c71b18c..1e25f6a1e 100644
--- a/lib/northbound_cli.c
+++ b/lib/northbound_cli.c
@@ -347,7 +347,7 @@ int nb_cli_confirmed_commit_rollback(struct vty *vty)
 	return ret;
 }
 
-static int nb_cli_confirmed_commit_timeout(struct thread *thread)
+static void nb_cli_confirmed_commit_timeout(struct thread *thread)
 {
 	struct vty *vty = THREAD_ARG(thread);
 
@@ -357,8 +357,6 @@ static int nb_cli_confirmed_commit_timeout(struct thread *thread)
 
 	nb_cli_confirmed_commit_rollback(vty);
 	nb_cli_confirmed_commit_clean(vty);
-
-	return 0;
 }
 
 static int nb_cli_commit(struct vty *vty, bool force,
diff --git a/lib/northbound_confd.c b/lib/northbound_confd.c
index e1c8983fc..27eaefd07 100644
--- a/lib/northbound_confd.c
+++ b/lib/northbound_confd.c
@@ -283,7 +283,7 @@ frr_confd_cdb_diff_iter(confd_hkeypath_t *kp, enum cdb_iter_op cdb_op,
 	return ITER_RECURSE;
 }
 
-static int frr_confd_cdb_read_cb_prepare(int fd, int *subp, int reslen)
+static void frr_confd_cdb_read_cb_prepare(int fd, int *subp, int reslen)
 {
 	struct nb_context context = {};
 	struct nb_config *candidate;
@@ -313,9 +313,9 @@ static int frr_confd_cdb_read_cb_prepare(int fd, int *subp, int reslen)
 			    0, "Couldn't apply configuration changes")
 		    != CONFD_OK) {
 			flog_err_confd("cdb_sub_abort_trans");
-			return -1;
+			return;
 		}
-		return 0;
+		return;
 	}
 
 	/*
@@ -346,25 +346,23 @@ static int frr_confd_cdb_read_cb_prepare(int fd, int *subp, int reslen)
 					errmsg)
 		    != CONFD_OK) {
 			flog_err_confd("cdb_sub_abort_trans");
-			return -1;
+			return;
 		}
 	} else {
 		/* Acknowledge the notification. */
 		if (cdb_sync_subscription_socket(fd, CDB_DONE_PRIORITY)
 		    != CONFD_OK) {
 			flog_err_confd("cdb_sync_subscription_socket");
-			return -1;
+			return;
 		}
 
 		/* No configuration changes. */
 		if (!transaction)
 			nb_config_free(candidate);
 	}
-
-	return 0;
 }
 
-static int frr_confd_cdb_read_cb_commit(int fd, int *subp, int reslen)
+static void frr_confd_cdb_read_cb_commit(int fd, int *subp, int reslen)
 {
 	/*
 	 * No need to process the configuration changes again as we're already
@@ -385,10 +383,8 @@ static int frr_confd_cdb_read_cb_commit(int fd, int *subp, int reslen)
 	/* Acknowledge the notification. */
 	if (cdb_sync_subscription_socket(fd, CDB_DONE_PRIORITY) != CONFD_OK) {
 		flog_err_confd("cdb_sync_subscription_socket");
-		return -1;
+		return;
 	}
-
-	return 0;
 }
 
 static int frr_confd_cdb_read_cb_abort(int fd, int *subp, int reslen)
@@ -417,7 +413,7 @@ static int frr_confd_cdb_read_cb_abort(int fd, int *subp, int reslen)
 	return 0;
 }
 
-static int frr_confd_cdb_read_cb(struct thread *thread)
+static void frr_confd_cdb_read_cb(struct thread *thread)
 {
 	int fd = THREAD_FD(thread);
 	enum cdb_sub_notification cdb_ev;
@@ -430,19 +426,22 @@ static int frr_confd_cdb_read_cb(struct thread *thread)
 	if (cdb_read_subscription_socket2(fd, &cdb_ev, &flags, &subp, &reslen)
 	    != CONFD_OK) {
 		flog_err_confd("cdb_read_subscription_socket2");
-		return -1;
+		return;
 	}
 
 	switch (cdb_ev) {
 	case CDB_SUB_PREPARE:
-		return frr_confd_cdb_read_cb_prepare(fd, subp, reslen);
+		frr_confd_cdb_read_cb_prepare(fd, subp, reslen);
+		break;
 	case CDB_SUB_COMMIT:
-		return frr_confd_cdb_read_cb_commit(fd, subp, reslen);
+		frr_confd_cdb_read_cb_commit(fd, subp, reslen);
+		break;
 	case CDB_SUB_ABORT:
-		return frr_confd_cdb_read_cb_abort(fd, subp, reslen);
+		frr_confd_cdb_read_cb_abort(fd, subp, reslen);
+		break;
 	default:
 		flog_err_confd("unknown CDB event");
-		return -1;
+		break;
 	}
 }
 
@@ -1186,7 +1185,7 @@ static int frr_confd_dp_read(struct confd_daemon_ctx *dctx, int fd)
 	return 0;
 }
 
-static int frr_confd_dp_ctl_read(struct thread *thread)
+static void frr_confd_dp_ctl_read(struct thread *thread)
 {
 	struct confd_daemon_ctx *dctx = THREAD_ARG(thread);
 	int fd = THREAD_FD(thread);
@@ -1194,11 +1193,9 @@ static int frr_confd_dp_ctl_read(struct thread *thread)
 	thread_add_read(master, frr_confd_dp_ctl_read, dctx, fd, &t_dp_ctl);
 
 	frr_confd_dp_read(dctx, fd);
-
-	return 0;
 }
 
-static int frr_confd_dp_worker_read(struct thread *thread)
+static void frr_confd_dp_worker_read(struct thread *thread)
 {
 	struct confd_daemon_ctx *dctx = THREAD_ARG(thread);
 	int fd = THREAD_FD(thread);
@@ -1206,8 +1203,6 @@ static int frr_confd_dp_worker_read(struct thread *thread)
 	thread_add_read(master, frr_confd_dp_worker_read, dctx, fd, &t_dp_worker);
 
 	frr_confd_dp_read(dctx, fd);
-
-	return 0;
 }
 
 static int frr_confd_subscribe_state(const struct lysc_node *snode, void *arg)
diff --git a/lib/northbound_grpc.cpp b/lib/northbound_grpc.cpp
index e227d0385..34bb1e498 100644
--- a/lib/northbound_grpc.cpp
+++ b/lib/northbound_grpc.cpp
@@ -206,7 +206,7 @@ template <typename Q, typename S> class NewRpcState : RpcStateBase
 	}
 
 
-	static int c_callback(struct thread *thread)
+	static void c_callback(struct thread *thread)
 	{
 		auto _tag = static_cast<NewRpcState<Q, S> *>(thread->arg);
 		/*
@@ -225,7 +225,7 @@ template <typename Q, typename S> class NewRpcState : RpcStateBase
 
 		pthread_cond_signal(&_tag->cond);
 		pthread_mutex_unlock(&_tag->cmux);
-		return 0;
+		return;
 	}
 	NewRpcState<Q, S> *orig;
 
@@ -1368,7 +1368,7 @@ static int frr_grpc_finish(void)
  * fork. This is done by scheduling this init function as an event task, since
  * the event loop doesn't run until after fork.
  */
-static int frr_grpc_module_very_late_init(struct thread *thread)
+static void frr_grpc_module_very_late_init(struct thread *thread)
 {
 	const char *args = THIS_MODULE->load_args;
 	uint port = GRPC_DEFAULT_PORT;
@@ -1386,11 +1386,10 @@ static int frr_grpc_module_very_late_init(struct thread *thread)
 	if (frr_grpc_init(port) < 0)
 		goto error;
 
-	return 0;
+	return;
 
 error:
 	flog_err(EC_LIB_GRPC_INIT, "failed to initialize the gRPC module");
-	return -1;
 }
 
 static int frr_grpc_module_late_init(struct thread_master *tm)
diff --git a/lib/northbound_sysrepo.c b/lib/northbound_sysrepo.c
index 86a159e50..0158d8ea0 100644
--- a/lib/northbound_sysrepo.c
+++ b/lib/northbound_sysrepo.c
@@ -41,7 +41,7 @@ static sr_session_ctx_t *session;
 static sr_conn_ctx_t *connection;
 static struct nb_transaction *transaction;
 
-static int frr_sr_read_cb(struct thread *thread);
+static void frr_sr_read_cb(struct thread *thread);
 static int frr_sr_finish(void);
 
 /* Convert FRR YANG data value to sysrepo YANG data value. */
@@ -526,7 +526,7 @@ static int frr_sr_notification_send(const char *xpath, struct list *arguments)
 	return NB_OK;
 }
 
-static int frr_sr_read_cb(struct thread *thread)
+static void frr_sr_read_cb(struct thread *thread)
 {
 	struct yang_module *module = THREAD_ARG(thread);
 	int fd = THREAD_FD(thread);
@@ -536,12 +536,10 @@ static int frr_sr_read_cb(struct thread *thread)
 	if (ret != SR_ERR_OK) {
 		flog_err(EC_LIB_LIBSYSREPO, "%s: sr_fd_event_process(): %s",
 			 __func__, sr_strerror(ret));
-		return -1;
+		return;
 	}
 
 	thread_add_read(master, frr_sr_read_cb, module, fd, &module->sr_thread);
-
-	return 0;
 }
 
 static void frr_sr_subscribe_config(struct yang_module *module)
diff --git a/lib/pullwr.c b/lib/pullwr.c
index 15563d247..5e836984b 100644
--- a/lib/pullwr.c
+++ b/lib/pullwr.c
@@ -51,7 +51,7 @@ struct pullwr {
 DEFINE_MTYPE_STATIC(LIB, PULLWR_HEAD, "pull-driven write controller");
 DEFINE_MTYPE_STATIC(LIB, PULLWR_BUF,  "pull-driven write buffer");
 
-static int pullwr_run(struct thread *t);
+static void pullwr_run(struct thread *t);
 
 struct pullwr *_pullwr_new(struct thread_master *tm, int fd,
 		void *arg,
@@ -189,7 +189,7 @@ void pullwr_write(struct pullwr *pullwr, const void *data, size_t len)
 	pullwr_bump(pullwr);
 }
 
-static int pullwr_run(struct thread *t)
+static void pullwr_run(struct thread *t)
 {
 	struct pullwr *pullwr = THREAD_ARG(t);
 	struct iovec iov[2];
@@ -222,7 +222,7 @@ static int pullwr_run(struct thread *t)
 			 * into idle, i.e. no calling thread_add_write()
 			 */
 			pullwr_resize(pullwr, 0);
-			return 0;
+			return;
 		}
 
 		niov = pullwr_iov(pullwr, iov);
@@ -233,12 +233,12 @@ static int pullwr_run(struct thread *t)
 			if (errno == EAGAIN || errno == EWOULDBLOCK)
 				break;
 			pullwr->err(pullwr->arg, pullwr, false);
-			return 0;
+			return;
 		}
 
 		if (nwr == 0) {
 			pullwr->err(pullwr->arg, pullwr, true);
-			return 0;
+			return;
 		}
 
 		pullwr->total_written += nwr;
@@ -258,7 +258,6 @@ static int pullwr_run(struct thread *t)
 	 */
 	if (!maxspun)
 		pullwr_resize(pullwr, 0);
-	return 0;
 }
 
 void pullwr_stats(struct pullwr *pullwr, uint64_t *total_written,
diff --git a/lib/resolver.c b/lib/resolver.c
index 29138bbc8..93fa84bbe 100644
--- a/lib/resolver.c
+++ b/lib/resolver.c
@@ -104,17 +104,15 @@ static void resolver_fd_drop_maybe(struct resolver_fd *resfd)
 
 static void resolver_update_timeouts(struct resolver_state *r);
 
-static int resolver_cb_timeout(struct thread *t)
+static void resolver_cb_timeout(struct thread *t)
 {
 	struct resolver_state *r = THREAD_ARG(t);
 
 	ares_process(r->channel, NULL, NULL);
 	resolver_update_timeouts(r);
-
-	return 0;
 }
 
-static int resolver_cb_socket_readable(struct thread *t)
+static void resolver_cb_socket_readable(struct thread *t)
 {
 	struct resolver_fd *resfd = THREAD_ARG(t);
 	struct resolver_state *r = resfd->state;
@@ -127,11 +125,9 @@ static int resolver_cb_socket_readable(struct thread *t)
 	 */
 	ares_process_fd(r->channel, resfd->fd, ARES_SOCKET_BAD);
 	resolver_update_timeouts(r);
-
-	return 0;
 }
 
-static int resolver_cb_socket_writable(struct thread *t)
+static void resolver_cb_socket_writable(struct thread *t)
 {
 	struct resolver_fd *resfd = THREAD_ARG(t);
 	struct resolver_state *r = resfd->state;
@@ -144,8 +140,6 @@ static int resolver_cb_socket_writable(struct thread *t)
 	 */
 	ares_process_fd(r->channel, ARES_SOCKET_BAD, resfd->fd);
 	resolver_update_timeouts(r);
-
-	return 0;
 }
 
 static void resolver_update_timeouts(struct resolver_state *r)
@@ -232,7 +226,7 @@ static void ares_address_cb(void *arg, int status, int timeouts,
 	callback(query, NULL, i, &addr[0]);
 }
 
-static int resolver_cb_literal(struct thread *t)
+static void resolver_cb_literal(struct thread *t)
 {
 	struct resolver_query *query = THREAD_ARG(t);
 	void (*callback)(struct resolver_query *, const char *, int,
@@ -242,7 +236,6 @@ static int resolver_cb_literal(struct thread *t)
 	query->callback = NULL;
 
 	callback(query, ARES_SUCCESS, 1, &query->literal_addr);
-	return 0;
 }
 
 void resolver_resolve(struct resolver_query *query, int af, vrf_id_t vrf_id,
diff --git a/lib/sigevent.c b/lib/sigevent.c
index 00bc31f51..0f20bc027 100644
--- a/lib/sigevent.c
+++ b/lib/sigevent.c
@@ -143,7 +143,7 @@ int frr_sigevent_process(void)
 
 #ifdef SIGEVENT_SCHEDULE_THREAD
 /* timer thread to check signals. shouldn't be needed */
-int frr_signal_timer(struct thread *t)
+void frr_signal_timer(struct thread *t)
 {
 	struct frr_sigevent_master_t *sigm;
 
@@ -151,7 +151,7 @@ int frr_signal_timer(struct thread *t)
 	sigm->t = NULL;
 	thread_add_timer(sigm->t->master, frr_signal_timer, &sigmaster,
 			 FRR_SIGNAL_TIMER_INTERVAL, &sigm->t);
-	return frr_sigevent_process();
+	frr_sigevent_process();
 }
 #endif /* SIGEVENT_SCHEDULE_THREAD */
 
diff --git a/lib/spf_backoff.c b/lib/spf_backoff.c
index a273e9346..117b7d3e8 100644
--- a/lib/spf_backoff.c
+++ b/lib/spf_backoff.c
@@ -117,17 +117,16 @@ void spf_backoff_free(struct spf_backoff *backoff)
 	XFREE(MTYPE_SPF_BACKOFF, backoff);
 }
 
-static int spf_backoff_timetolearn_elapsed(struct thread *thread)
+static void spf_backoff_timetolearn_elapsed(struct thread *thread)
 {
 	struct spf_backoff *backoff = THREAD_ARG(thread);
 
 	backoff->state = SPF_BACKOFF_LONG_WAIT;
 	backoff_debug("SPF Back-off(%s) TIMETOLEARN elapsed, move to state %s",
 		      backoff->name, spf_backoff_state2str(backoff->state));
-	return 0;
 }
 
-static int spf_backoff_holddown_elapsed(struct thread *thread)
+static void spf_backoff_holddown_elapsed(struct thread *thread)
 {
 	struct spf_backoff *backoff = THREAD_ARG(thread);
 
@@ -136,7 +135,6 @@ static int spf_backoff_holddown_elapsed(struct thread *thread)
 	backoff->state = SPF_BACKOFF_QUIET;
 	backoff_debug("SPF Back-off(%s) HOLDDOWN elapsed, move to state %s",
 		      backoff->name, spf_backoff_state2str(backoff->state));
-	return 0;
 }
 
 long spf_backoff_schedule(struct spf_backoff *backoff)
diff --git a/lib/systemd.c b/lib/systemd.c
index 2238dc9f3..1c9a6f122 100644
--- a/lib/systemd.c
+++ b/lib/systemd.c
@@ -80,14 +80,13 @@ void systemd_send_stopping(void)
 
 static struct thread_master *systemd_master = NULL;
 
-static int systemd_send_watchdog(struct thread *t)
+static void systemd_send_watchdog(struct thread *t)
 {
 	systemd_send_information("WATCHDOG=1");
 
 	assert(watchdog_msec > 0);
 	thread_add_timer_msec(systemd_master, systemd_send_watchdog, NULL,
 			      watchdog_msec, NULL);
-	return 1;
 }
 
 void systemd_send_started(struct thread_master *m)
diff --git a/lib/thread.c b/lib/thread.c
index ada7a9cc8..58b8e206f 100644
--- a/lib/thread.c
+++ b/lib/thread.c
@@ -773,7 +773,7 @@ char *thread_timer_to_hhmmss(char *buf, int buf_size,
 
 /* Get new thread.  */
 static struct thread *thread_get(struct thread_master *m, uint8_t type,
-				 int (*func)(struct thread *), void *arg,
+				 void (*func)(struct thread *), void *arg,
 				 const struct xref_threadsched *xref)
 {
 	struct thread *thread = thread_list_pop(&m->unuse);
@@ -930,7 +930,7 @@ done:
 /* Add new read thread. */
 void _thread_add_read_write(const struct xref_threadsched *xref,
 			    struct thread_master *m,
-			    int (*func)(struct thread *), void *arg, int fd,
+			    void (*func)(struct thread *), void *arg, int fd,
 			    struct thread **t_ptr)
 {
 	int dir = xref->thread_type;
@@ -1010,7 +1010,7 @@ void _thread_add_read_write(const struct xref_threadsched *xref,
 
 static void _thread_add_timer_timeval(const struct xref_threadsched *xref,
 				      struct thread_master *m,
-				      int (*func)(struct thread *), void *arg,
+				      void (*func)(struct thread *), void *arg,
 				      struct timeval *time_relative,
 				      struct thread **t_ptr)
 {
@@ -1057,7 +1057,7 @@ static void _thread_add_timer_timeval(const struct xref_threadsched *xref,
 
 /* Add timer event thread. */
 void _thread_add_timer(const struct xref_threadsched *xref,
-		       struct thread_master *m, int (*func)(struct thread *),
+		       struct thread_master *m, void (*func)(struct thread *),
 		       void *arg, long timer, struct thread **t_ptr)
 {
 	struct timeval trel;
@@ -1073,8 +1073,8 @@ void _thread_add_timer(const struct xref_threadsched *xref,
 /* Add timer event thread with "millisecond" resolution */
 void _thread_add_timer_msec(const struct xref_threadsched *xref,
 			    struct thread_master *m,
-			    int (*func)(struct thread *), void *arg, long timer,
-			    struct thread **t_ptr)
+			    void (*func)(struct thread *), void *arg,
+			    long timer, struct thread **t_ptr)
 {
 	struct timeval trel;
 
@@ -1088,15 +1088,16 @@ void _thread_add_timer_msec(const struct xref_threadsched *xref,
 
 /* Add timer event thread with "timeval" resolution */
 void _thread_add_timer_tv(const struct xref_threadsched *xref,
-			  struct thread_master *m, int (*func)(struct thread *),
-			  void *arg, struct timeval *tv, struct thread **t_ptr)
+			  struct thread_master *m,
+			  void (*func)(struct thread *), void *arg,
+			  struct timeval *tv, struct thread **t_ptr)
 {
 	_thread_add_timer_timeval(xref, m, func, arg, tv, t_ptr);
 }
 
 /* Add simple event thread. */
 void _thread_add_event(const struct xref_threadsched *xref,
-		       struct thread_master *m, int (*func)(struct thread *),
+		       struct thread_master *m, void (*func)(struct thread *),
 		       void *arg, int val, struct thread **t_ptr)
 {
 	struct thread *thread = NULL;
@@ -2008,7 +2009,7 @@ void thread_call(struct thread *thread)
 
 /* Execute thread */
 void _thread_execute(const struct xref_threadsched *xref,
-		     struct thread_master *m, int (*func)(struct thread *),
+		     struct thread_master *m, void (*func)(struct thread *),
 		     void *arg, int val)
 {
 	struct thread *thread;
diff --git a/lib/thread.h b/lib/thread.h
index 0c2a4ba86..a2049ae52 100644
--- a/lib/thread.h
+++ b/lib/thread.h
@@ -114,7 +114,7 @@ struct thread {
 	struct thread_timer_list_item timeritem;
 	struct thread **ref;	  /* external reference (if given) */
 	struct thread_master *master; /* pointer to the struct thread_master */
-	int (*func)(struct thread *); /* event function */
+	void (*func)(struct thread *); /* event function */
 	void *arg;		      /* event argument */
 	union {
 		int val;	      /* second argument of the event. */
@@ -134,7 +134,7 @@ struct thread {
 #endif
 
 struct cpu_thread_history {
-	int (*func)(struct thread *);
+	void (*func)(struct thread *);
 	atomic_size_t total_cpu_warn;
 	atomic_size_t total_wall_warn;
 	atomic_size_t total_starv_warn;
@@ -227,32 +227,32 @@ extern void thread_master_free_unused(struct thread_master *);
 
 extern void _thread_add_read_write(const struct xref_threadsched *xref,
 				   struct thread_master *master,
-				   int (*fn)(struct thread *), void *arg,
+				   void (*fn)(struct thread *), void *arg,
 				   int fd, struct thread **tref);
 
 extern void _thread_add_timer(const struct xref_threadsched *xref,
 			      struct thread_master *master,
-			      int (*fn)(struct thread *), void *arg, long t,
+			      void (*fn)(struct thread *), void *arg, long t,
 			      struct thread **tref);
 
 extern void _thread_add_timer_msec(const struct xref_threadsched *xref,
 				   struct thread_master *master,
-				   int (*fn)(struct thread *), void *arg,
+				   void (*fn)(struct thread *), void *arg,
 				   long t, struct thread **tref);
 
 extern void _thread_add_timer_tv(const struct xref_threadsched *xref,
 				 struct thread_master *master,
-				 int (*fn)(struct thread *), void *arg,
+				 void (*fn)(struct thread *), void *arg,
 				 struct timeval *tv, struct thread **tref);
 
 extern void _thread_add_event(const struct xref_threadsched *xref,
 			      struct thread_master *master,
-			      int (*fn)(struct thread *), void *arg, int val,
+			      void (*fn)(struct thread *), void *arg, int val,
 			      struct thread **tref);
 
 extern void _thread_execute(const struct xref_threadsched *xref,
 			    struct thread_master *master,
-			    int (*fn)(struct thread *), void *arg, int val);
+			    void (*fn)(struct thread *), void *arg, int val);
 
 extern void thread_cancel(struct thread **event);
 extern void thread_cancel_async(struct thread_master *, struct thread **,
diff --git a/lib/vty.c b/lib/vty.c
index 8eaf13619..a42b8c92b 100644
--- a/lib/vty.c
+++ b/lib/vty.c
@@ -1299,7 +1299,7 @@ static void vty_buffer_reset(struct vty *vty)
 }
 
 /* Read data via vty socket. */
-static int vty_read(struct thread *thread)
+static void vty_read(struct thread *thread)
 {
 	int i;
 	int nbytes;
@@ -1312,7 +1312,7 @@ static int vty_read(struct thread *thread)
 		if (nbytes < 0) {
 			if (ERRNO_IO_RETRY(errno)) {
 				vty_event(VTY_READ, vty);
-				return 0;
+				return;
 			}
 			vty->monitor = 0; /* disable monitoring to avoid
 					     infinite recursion */
@@ -1496,11 +1496,10 @@ static int vty_read(struct thread *thread)
 		vty_event(VTY_WRITE, vty);
 		vty_event(VTY_READ, vty);
 	}
-	return 0;
 }
 
 /* Flush buffer to the vty. */
-static int vty_flush(struct thread *thread)
+static void vty_flush(struct thread *thread)
 {
 	int erase;
 	buffer_status_t flushrc;
@@ -1532,7 +1531,7 @@ static int vty_flush(struct thread *thread)
 		buffer_reset(vty->lbuf);
 		buffer_reset(vty->obuf);
 		vty_close(vty);
-		return 0;
+		return;
 	case BUFFER_EMPTY:
 		if (vty->status == VTY_CLOSE)
 			vty_close(vty);
@@ -1549,8 +1548,6 @@ static int vty_flush(struct thread *thread)
 			vty_event(VTY_WRITE, vty);
 		break;
 	}
-
-	return 0;
 }
 
 /* Allocate new vty struct. */
@@ -1753,7 +1750,7 @@ struct vty *vty_stdio(void (*atclose)(int isexit))
 }
 
 /* Accept connection from the network. */
-static int vty_accept(struct thread *thread)
+static void vty_accept(struct thread *thread)
 {
 	struct vty_serv *vtyserv = THREAD_ARG(thread);
 	int vty_sock;
@@ -1774,7 +1771,7 @@ static int vty_accept(struct thread *thread)
 	if (vty_sock < 0) {
 		flog_err(EC_LIB_SOCKET, "can't accept vty socket : %s",
 			 safe_strerror(errno));
-		return -1;
+		return;
 	}
 	set_nonblocking(vty_sock);
 	set_cloexec(vty_sock);
@@ -1783,7 +1780,7 @@ static int vty_accept(struct thread *thread)
 		close(vty_sock);
 		zlog_info("Vty unable to convert prefix from sockunion %pSU",
 			  &su);
-		return -1;
+		return;
 	}
 
 	/* VTY's accesslist apply. */
@@ -1792,7 +1789,7 @@ static int vty_accept(struct thread *thread)
 		    && (access_list_apply(acl, &p) == FILTER_DENY)) {
 			zlog_info("Vty connection refused from %pSU", &su);
 			close(vty_sock);
-			return 0;
+			return;
 		}
 	}
 
@@ -1803,7 +1800,7 @@ static int vty_accept(struct thread *thread)
 		    && (access_list_apply(acl, &p) == FILTER_DENY)) {
 			zlog_info("Vty connection refused from %pSU", &su);
 			close(vty_sock);
-			return 0;
+			return;
 		}
 	}
 
@@ -1817,8 +1814,6 @@ static int vty_accept(struct thread *thread)
 	zlog_info("Vty connection from %pSU", &su);
 
 	vty_create(vty_sock, &su);
-
-	return 0;
 }
 
 static void vty_serv_sock_addrinfo(const char *hostname, unsigned short port)
@@ -1968,7 +1963,7 @@ static void vty_serv_un(const char *path)
 
 /* #define VTYSH_DEBUG 1 */
 
-static int vtysh_accept(struct thread *thread)
+static void vtysh_accept(struct thread *thread)
 {
 	struct vty_serv *vtyserv = THREAD_ARG(thread);
 	int accept_sock = vtyserv->sock;
@@ -1988,7 +1983,7 @@ static int vtysh_accept(struct thread *thread)
 	if (sock < 0) {
 		flog_err(EC_LIB_SOCKET, "can't accept vty socket : %s",
 			 safe_strerror(errno));
-		return -1;
+		return;
 	}
 
 	if (set_nonblocking(sock) < 0) {
@@ -1997,7 +1992,7 @@ static int vtysh_accept(struct thread *thread)
 			"vtysh_accept: could not set vty socket %d to non-blocking, %s, closing",
 			sock, safe_strerror(errno));
 		close(sock);
-		return -1;
+		return;
 	}
 	set_cloexec(sock);
 
@@ -2013,8 +2008,6 @@ static int vtysh_accept(struct thread *thread)
 	vtys_add_tail(vtysh_sessions, vty);
 
 	vty_event(VTYSH_READ, vty);
-
-	return 0;
 }
 
 static int vtysh_flush(struct vty *vty)
@@ -2038,7 +2031,7 @@ static int vtysh_flush(struct vty *vty)
 	return 0;
 }
 
-static int vtysh_read(struct thread *thread)
+static void vtysh_read(struct thread *thread)
 {
 	int ret;
 	int sock;
@@ -2055,7 +2048,7 @@ static int vtysh_read(struct thread *thread)
 		if (nbytes < 0) {
 			if (ERRNO_IO_RETRY(errno)) {
 				vty_event(VTYSH_READ, vty);
-				return 0;
+				return;
 			}
 			vty->monitor = 0; /* disable monitoring to avoid
 					     infinite recursion */
@@ -2070,7 +2063,7 @@ static int vtysh_read(struct thread *thread)
 #ifdef VTYSH_DEBUG
 		printf("close vtysh\n");
 #endif /* VTYSH_DEBUG */
-		return 0;
+		return;
 	}
 
 #ifdef VTYSH_DEBUG
@@ -2112,7 +2105,7 @@ static int vtysh_read(struct thread *thread)
 				if (!vty->t_write && (vtysh_flush(vty) < 0))
 					/* Try to flush results; exit if a write
 					 * error occurs. */
-					return 0;
+					return;
 			}
 		}
 	}
@@ -2121,16 +2114,13 @@ static int vtysh_read(struct thread *thread)
 		vty_close(vty);
 	else
 		vty_event(VTYSH_READ, vty);
-
-	return 0;
 }
 
-static int vtysh_write(struct thread *thread)
+static void vtysh_write(struct thread *thread)
 {
 	struct vty *vty = THREAD_ARG(thread);
 
 	vtysh_flush(vty);
-	return 0;
 }
 
 #endif /* VTYSH */
@@ -2221,7 +2211,7 @@ void vty_close(struct vty *vty)
 }
 
 /* When time out occur output message then close connection. */
-static int vty_timeout(struct thread *thread)
+static void vty_timeout(struct thread *thread)
 {
 	struct vty *vty;
 
@@ -2236,8 +2226,6 @@ static int vty_timeout(struct thread *thread)
 	/* Close connection. */
 	vty->status = VTY_CLOSE;
 	vty_close(vty);
-
-	return 0;
 }
 
 /* Read up configuration file from file_name. */
diff --git a/lib/wheel.c b/lib/wheel.c
index 1a0469b25..463410bea 100644
--- a/lib/wheel.c
+++ b/lib/wheel.c
@@ -29,9 +29,9 @@ DEFINE_MTYPE_STATIC(LIB, TIMER_WHEEL_LIST, "Timer Wheel Slot List");
 
 static int debug_timer_wheel = 0;
 
-static int wheel_timer_thread(struct thread *t);
+static void wheel_timer_thread(struct thread *t);
 
-static int wheel_timer_thread_helper(struct thread *t)
+static void wheel_timer_thread_helper(struct thread *t)
 {
 	struct listnode *node, *nextnode;
 	unsigned long long curr_slot;
@@ -63,19 +63,15 @@ static int wheel_timer_thread_helper(struct thread *t)
 	wheel->slots_to_skip = slots_to_skip;
 	thread_add_timer_msec(wheel->master, wheel_timer_thread, wheel,
 			      wheel->nexttime * slots_to_skip, &wheel->timer);
-
-	return 0;
 }
 
-static int wheel_timer_thread(struct thread *t)
+static void wheel_timer_thread(struct thread *t)
 {
 	struct timer_wheel *wheel;
 
 	wheel = THREAD_ARG(t);
 
 	thread_execute(wheel->master, wheel_timer_thread_helper, wheel, 0);
-
-	return 0;
 }
 
 struct timer_wheel *wheel_init(struct thread_master *master, int period,
diff --git a/lib/workqueue.c b/lib/workqueue.c
index 86afe4082..92869594d 100644
--- a/lib/workqueue.c
+++ b/lib/workqueue.c
@@ -238,7 +238,7 @@ void work_queue_unplug(struct work_queue *wq)
  * will reschedule itself if required,
  * otherwise work_queue_item_add
  */
-int work_queue_run(struct thread *thread)
+void work_queue_run(struct thread *thread)
 {
 	struct work_queue *wq;
 	struct work_queue_item *item, *titem;
@@ -388,6 +388,4 @@ stats:
 
 	} else if (wq->spec.completion_func)
 		wq->spec.completion_func(wq);
-
-	return 0;
 }
diff --git a/lib/workqueue.h b/lib/workqueue.h
index b076ed0d2..39202dcda 100644
--- a/lib/workqueue.h
+++ b/lib/workqueue.h
@@ -177,7 +177,7 @@ extern void work_queue_unplug(struct work_queue *wq);
 bool work_queue_is_scheduled(struct work_queue *);
 
 /* Helpers, exported for thread.c and command.c */
-extern int work_queue_run(struct thread *);
+extern void work_queue_run(struct thread *);
 
 extern void workqueue_cmd_init(void);
 
diff --git a/lib/zclient.c b/lib/zclient.c
index ab2dd0989..cfccb2166 100644
--- a/lib/zclient.c
+++ b/lib/zclient.c
@@ -263,20 +263,21 @@ static enum zclient_send_status zclient_failed(struct zclient *zclient)
 	return ZCLIENT_SEND_FAILURE;
 }
 
-static int zclient_flush_data(struct thread *thread)
+static void zclient_flush_data(struct thread *thread)
 {
 	struct zclient *zclient = THREAD_ARG(thread);
 
 	zclient->t_write = NULL;
 	if (zclient->sock < 0)
-		return -1;
+		return;
 	switch (buffer_flush_available(zclient->wb, zclient->sock)) {
 	case BUFFER_ERROR:
 		flog_err(
 			EC_LIB_ZAPI_SOCKET,
 			"%s: buffer_flush_available failed on zclient fd %d, closing",
 			__func__, zclient->sock);
-		return zclient_failed(zclient);
+		zclient_failed(zclient);
+		return;
 	case BUFFER_PENDING:
 		zclient->t_write = NULL;
 		thread_add_write(zclient->master, zclient_flush_data, zclient,
@@ -287,7 +288,6 @@ static int zclient_flush_data(struct thread *thread)
 			(*zclient->zebra_buffer_write_ready)();
 		break;
 	}
-	return 0;
 }
 
 /*
@@ -754,7 +754,7 @@ void zclient_init(struct zclient *zclient, int redist_default,
 
 /* This function is a wrapper function for calling zclient_start from
    timer or event thread. */
-static int zclient_connect(struct thread *t)
+static void zclient_connect(struct thread *t)
 {
 	struct zclient *zclient;
 
@@ -764,7 +764,7 @@ static int zclient_connect(struct thread *t)
 	if (zclient_debug)
 		zlog_debug("zclient_connect is called");
 
-	return zclient_start(zclient);
+	zclient_start(zclient);
 }
 
 enum zclient_send_status zclient_send_rnh(struct zclient *zclient, int command,
@@ -3864,7 +3864,7 @@ static zclient_handler *const lib_handlers[] = {
 };
 
 /* Zebra client message read function. */
-static int zclient_read(struct thread *thread)
+static void zclient_read(struct thread *thread)
 {
 	size_t already;
 	uint16_t length, command;
@@ -3888,11 +3888,12 @@ static int zclient_read(struct thread *thread)
 				zlog_debug(
 					"zclient connection closed socket [%d].",
 					zclient->sock);
-			return zclient_failed(zclient);
+			zclient_failed(zclient);
+			return;
 		}
 		if (nbyte != (ssize_t)(ZEBRA_HEADER_SIZE - already)) {
 			zclient_event(ZCLIENT_READ, zclient);
-			return 0;
+			return;
 		}
 		already = ZEBRA_HEADER_SIZE;
 	}
@@ -3912,14 +3913,16 @@ static int zclient_read(struct thread *thread)
 			EC_LIB_ZAPI_MISSMATCH,
 			"%s: socket %d version mismatch, marker %d, version %d",
 			__func__, zclient->sock, marker, version);
-		return zclient_failed(zclient);
+		zclient_failed(zclient);
+		return;
 	}
 
 	if (length < ZEBRA_HEADER_SIZE) {
 		flog_err(EC_LIB_ZAPI_MISSMATCH,
 			 "%s: socket %d message length %u is less than %d ",
 			 __func__, zclient->sock, length, ZEBRA_HEADER_SIZE);
-		return zclient_failed(zclient);
+		zclient_failed(zclient);
+		return;
 	}
 
 	/* Length check. */
@@ -3947,12 +3950,13 @@ static int zclient_read(struct thread *thread)
 				zlog_debug(
 					"zclient connection closed socket [%d].",
 					zclient->sock);
-			return zclient_failed(zclient);
+			zclient_failed(zclient);
+			return;
 		}
 		if (nbyte != (ssize_t)(length - already)) {
 			/* Try again later. */
 			zclient_event(ZCLIENT_READ, zclient);
-			return 0;
+			return;
 		}
 	}
 
@@ -3969,13 +3973,11 @@ static int zclient_read(struct thread *thread)
 
 	if (zclient->sock < 0)
 		/* Connection was closed during packet processing. */
-		return -1;
+		return;
 
 	/* Register read thread. */
 	stream_reset(zclient->ibuf);
 	zclient_event(ZCLIENT_READ, zclient);
-
-	return 0;
 }
 
 void zclient_redistribute(int command, struct zclient *zclient, afi_t afi,
diff --git a/lib/zlog_5424.c b/lib/zlog_5424.c
index 740d6bfba..9da7c55fc 100644
--- a/lib/zlog_5424.c
+++ b/lib/zlog_5424.c
@@ -799,7 +799,7 @@ static void zlog_5424_cycle(struct zlog_cfg_5424 *zcf, int fd)
 	rcu_free(MTYPE_LOG_5424, oldt, zt.rcu_head);
 }
 
-static int zlog_5424_reconnect(struct thread *t)
+static void zlog_5424_reconnect(struct thread *t)
 {
 	struct zlog_cfg_5424 *zcf = THREAD_ARG(t);
 	int fd = THREAD_FD(t);
@@ -812,7 +812,7 @@ static int zlog_5424_reconnect(struct thread *t)
 			/* logger is sending us something?!?! */
 			thread_add_read(t->master, zlog_5424_reconnect, zcf, fd,
 					&zcf->t_reconnect);
-			return 0;
+			return;
 		}
 
 		if (ret == 0)
@@ -832,7 +832,6 @@ static int zlog_5424_reconnect(struct thread *t)
 	frr_with_mutex (&zcf->cfg_mtx) {
 		zlog_5424_cycle(zcf, fd);
 	}
-	return 0;
 }
 
 static int zlog_5424_unix(struct sockaddr_un *suna, int sock_type)