A simple app to get run times from a thread

Just a quick app to test and demonstrate how to get run times from a
specific thread on FreeBSD.

fast_cpu_time.cpp

@@ -0,0 +1,32 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Eilertsens Kodeknekkeri
+ * SPDX-FileCopyrightText: 2025 The FreeBSD Foundation
+ * SPDX-FileContributor: Harald Eilertsen <haraldei@anduin.net>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include "fast_cpu_time.hpp"
+#include "helpers.hpp"
+#include <cassert>
+
+namespace {
+	clockid_t get_thread_clock_id(pthread_t thread) {
+		clockid_t clock_id;
+
+		auto rc = pthread_getcpuclockid(thread, &clock_id);
+		assert(rc == 0);
+
+		return clock_id;
+	}
+}
+
+unsigned long fast_thread_cpu_time(pthread_t thread) {
+	auto clock_id = get_thread_clock_id(thread);
+
+	struct timespec time;
+	auto rc = clock_gettime(clock_id, &time);
+	assert(rc == 0);
+
+	return time.tv_sec * 1000000 + time.tv_nsec;
+}