kernel: Add k_thread_runtime_stats_is_enabled function

include/zephyr/kernel.h

@@ -6418,6 +6418,16 @@ int k_thread_runtime_stats_enable(k_tid_t thread);
  */
 int k_thread_runtime_stats_disable(k_tid_t thread);
 
+/**
+ * @brief Check if runtime statistics gathering is enabled for a thread
+ *
+ * This routine checks whether the specified thread has enabled runtime statistics.
+ *
+ * @param thread ID of thread
+ * @return true if usage statistics are enabled for the given thread, otherwise false
+ */
+bool k_thread_runtime_stats_is_enabled(k_tid_t thread);
+
 /**
  * @brief Enable gathering of system runtime statistics
  *

kernel/usage.c

@@ -272,6 +272,11 @@ int k_thread_runtime_stats_disable(k_tid_t  thread)
 
 	return 0;
 }
+
+bool k_thread_runtime_stats_is_enabled(k_tid_t thread)
+{
+	return thread->base.usage.track_usage;
+}
 #endif /* CONFIG_SCHED_THREAD_USAGE_ANALYSIS */
 
 #ifdef CONFIG_SCHED_THREAD_USAGE_ALL

lib/posix/options/Kconfig.timer

@@ -17,6 +17,8 @@ if POSIX_TIMERS
 
 config POSIX_THREAD_CPUTIME
 	bool "POSIX per-thread CPU-time clocks"
+	select THREAD_RUNTIME_STATS
+	select SCHED_THREAD_USAGE_ANALYSIS
 	help
 	  This enables CLOCK_THREAD_CPUTIME_ID.
 

lib/posix/options/clock.c

@@ -43,6 +43,23 @@ int z_impl___posix_clock_get_base(clockid_t clock_id, struct timespec *base)
 			*base = rt_clock_base;
 		}
 		break;
+#ifdef CONFIG_POSIX_THREAD_CPUTIME
+	case CLOCK_THREAD_CPUTIME_ID: {
+		uint64_t ns;
+		k_thread_runtime_stats_t stats;
+		k_tid_t thread = k_current_get();
+
+		if (!k_thread_runtime_stats_is_enabled(thread)) {
+			errno = EINVAL;
+			return -1;
+		}
+		k_thread_runtime_stats_get(thread, &stats);
+		ns = k_cyc_to_ns_floor64(stats.execution_cycles);
+		base->tv_sec = ns / NSEC_PER_SEC;
+		base->tv_nsec = ns % NSEC_PER_SEC;
+		break;
+	}
+#endif /* CONFIG_POSIX_THREAD_CPUTIME */
 
 	default:
 		errno = EINVAL;
@@ -75,6 +92,13 @@ int clock_gettime(clockid_t clock_id, struct timespec *ts)
 		(void)__posix_clock_get_base(clock_id, &base);
 		break;
 
+#ifdef CONFIG_POSIX_THREAD_CPUTIME
+	case CLOCK_THREAD_CPUTIME_ID:
+		(void)__posix_clock_get_base(clock_id, &base);
+		*ts = base;
+		return 0;
+#endif /* CONFIG_POSIX_THREAD_CPUTIME */
+
 	default:
 		errno = EINVAL;
 		return -1;

tests/kernel/usage/thread_runtime_stats/src/test_thread_runtime_stats.c

@@ -211,7 +211,9 @@ ZTEST(usage_api, test_thread_stats_enable_disable)
 
 	k_thread_runtime_stats_get(_current, &stats1);
 	k_thread_runtime_stats_get(tid, &helper_stats1);
+	zassert_true(k_thread_runtime_stats_is_enabled(tid));
 	k_thread_runtime_stats_disable(tid);
+	zassert_false(k_thread_runtime_stats_is_enabled(tid));
 
 	/*
 	 * Busy wait for the remaining tick before re-enabling the thread

tests/posix/timers/src/clock.c

@@ -22,11 +22,17 @@ static const struct timespec ref_ts = {1514821501, NSEC_PER_SEC / 2U};
 static const clockid_t clocks[] = {
 	CLOCK_MONOTONIC,
 	CLOCK_REALTIME,
+#ifdef CONFIG_POSIX_THREAD_CPUTIME
+	CLOCK_THREAD_CPUTIME_ID,
+#endif /* CONFIG_POSIX_THREAD_CPUTIME */
 };
 
 static const bool settable[] = {
 	false,
 	true,
+#ifdef CONFIG_POSIX_THREAD_CPUTIME
+	false,
+#endif /* CONFIG_POSIX_THREAD_CPUTIME */
 };
 
 static inline int64_t ts_to_ns(const struct timespec *ts)