FiWiTSF: single exit points in helpers and main

- follower_var_pop, kf1_update: one return each.

- stats_maybe_print, apply_correction: goto out.

- run_single: goto out on alloc failure; main: funnel to out.

Made-with: Cursor

tsf_sync_rt_starter.c

@@ -219,9 +219,11 @@ static void welford_add(struct follower_acc *acc, double x)
 
 static double follower_var_pop(const struct follower_acc *a)
 {
-	if (a->n == 0)
-		return 0.0;
-	return a->m2 / (double)a->n;
+	double v = 0.0;
+
+	if (a->n != 0)
+		v = a->m2 / (double)a->n;
+	return v;
 }
 
 static void acc_add_sample(struct follower_acc *acc, int64_t err, int64_t step,
@@ -279,18 +281,21 @@ static double kf1_update(struct kf1 *k, double z, double q, double r)
 {
 	double p_pred;
 	double Kgain;
+	double xf;
 
 	if (!k->inited) {
 		k->x = z;
 		k->P = r;
 		k->inited = 1;
-		return k->x;
-	}
+		xf = k->x;
+	} else {
 		p_pred = k->P + q;
 		Kgain = p_pred / (p_pred + r);
 		k->x += Kgain * (z - k->x);
 		k->P = (1.0 - Kgain) * p_pred;
-	return k->x;
+		xf = k->x;
+	}
+	return xf;
 }
 
 static void stats_maybe_print(const struct cli *cli, struct follower_acc *acc,
@@ -299,16 +304,16 @@ static void stats_maybe_print(const struct cli *cli, struct follower_acc *acc,
 	struct timespec now;
 
 	if (!cli->stats_interval_sec || !acc)
-		return;
+		goto out;
 	if (clock_gettime(CLOCK_MONOTONIC, &now) < 0)
-		return;
+		goto out;
 	if (last_mono->tv_sec == 0 && last_mono->tv_nsec == 0) {
 		*last_mono = now;
-		return;
+		goto out;
 	}
 	if ((unsigned long)(now.tv_sec - last_mono->tv_sec) <
 	    cli->stats_interval_sec)
-		return;
+		goto out;
 	if (mu)
 		pthread_mutex_lock(mu);
 	stats_print_and_reset(stderr, cli->follower_paths, cli->n_followers,
@@ -316,6 +321,8 @@ static void stats_maybe_print(const struct cli *cli, struct follower_acc *acc,
 	if (mu)
 		pthread_mutex_unlock(mu);
 	*last_mono = now;
+out:
+	return;
 }
 
 static void apply_correction(const struct cli *cli, uint64_t master,
@@ -332,7 +339,7 @@ static void apply_correction(const struct cli *cli, uint64_t master,
 
 	if (read_tsf_hex(slave_path, &slave) < 0) {
 		fprintf(stderr, "read follower TSF failed: %s\n", slave_path);
-		return;
+		goto out;
 	}
 	err = (int64_t)(master - slave);
 	if (cli->use_kalman && kf_states)
@@ -355,10 +362,12 @@ static void apply_correction(const struct cli *cli, uint64_t master,
 
 	if (write_tsf_decimal(slave_path, new_tsf) < 0) {
 		fprintf(stderr, "set follower TSF failed: %s\n", slave_path);
-		return;
+		goto out;
 	}
 	if (stats_all)
 		acc_add_sample(&stats_all[idx], err, step, stats_mu);
+out:
+	return;
 }
 
 /* ---------- single RT thread (default) ---------- */
@@ -760,15 +769,16 @@ static int run_single(const struct cli *cli)
 		stats = calloc(cli->n_followers, sizeof(struct follower_acc));
 		if (!stats) {
 			perror("calloc stats");
-			return 1;
+			ret = 1;
+			goto out;
 		}
 	}
 	if (cli->use_kalman) {
 		kf = calloc(cli->n_followers, sizeof(struct kf1));
 		if (!kf) {
 			perror("calloc kf");
-			free(stats);
-			return 1;
+			ret = 1;
+			goto out;
 		}
 	}
 	sctx.stats = stats;
@@ -786,6 +796,7 @@ static int run_single(const struct cli *cli)
 	}
 
 	pthread_attr_destroy(&attr);
+out:
 	free(kf);
 	free(stats);
 	return ret;
@@ -800,9 +811,12 @@ int main(int argc, char **argv)
 	pr = parse_cli(argc, argv, &cli);
 	if (pr < 0) {
 		ret = 1;
-	} else if (pr == 0) {
+		goto out;
+	}
+	if (pr == 0) {
 		ret = 0;
-	} else {
+		goto out;
+	}
 	if (mlockall(MCL_CURRENT | MCL_FUTURE) < 0)
 		perror("mlockall (ignore if unprivileged)");
 
@@ -813,8 +827,7 @@ int main(int argc, char **argv)
 		ret = run_parallel(&cli);
 	else
 		ret = run_single(&cli);
-	}
-
+out:
 	free(cli.follower_paths);
 	return ret;
 }