posix: implement clock_getcpuclockid function

implements clock_getcpuclockid function and adds zephyr test. Fixes zephyrproject-rtos#59954 Signed-off-by: Jai Arora <infolinesoni@gmail.com>
jaiiarora · Dec 28, 2023 · f7a4377 · f7a4377
1 parent 87d056b
commit f7a4377
Show file tree

Hide file tree

Showing 3 changed files with 34 additions and 0 deletions.
diff --git a/include/zephyr/posix/time.h b/include/zephyr/posix/time.h
@@ -88,6 +88,7 @@ int clock_gettime(clockid_t clock_id, struct timespec *ts);
 __syscall int clock_gettime(clockid_t clock_id, struct timespec *ts);
 #endif /* CONFIG_ARCH_POSIX */
 int clock_settime(clockid_t clock_id, const struct timespec *ts);
+int clock_getcpuclockid(pid_t pid, clockid_t *clock_id);
 /* Timer APIs */
 int timer_create(clockid_t clockId, struct sigevent *evp, timer_t *timerid);
 int timer_delete(timer_t timerid);

diff --git a/lib/posix/clock.c b/lib/posix/clock.c
@@ -195,3 +195,28 @@ int gettimeofday(struct timeval *tv, void *tz)
 
 	return res;
 }
+
+/**
+ * @brief Get current real time.
+ *
+ * See IEEE 1003.1
+ */
+int clock_getcpuclockid(pid_t pid, clockid_t *clock_id)
+{
+	/* We don't allow any process ID but our own.  */
+	if (pid != 0 && pid != getpid())
+		return EPERM;
+
+#ifdef CLOCK_MONOTONIC
+	*clock_id = CLOCK_MONOTONIC;
+	return 0;
+#else
+#ifdef	CLOCK_REALTIME
+	*clock_id = CLOCK_REALTIME;
+	return 0;
+#endif
+#endif
+
+	/* We don't have a timer for that.  */
+	return ENOENT;
+}
diff --git a/tests/posix/common/src/clock.c b/tests/posix/common/src/clock.c
@@ -14,8 +14,10 @@
 
 ZTEST(posix_apis, test_clock)
 {
+	int ret;
 	int64_t nsecs_elapsed, secs_elapsed;
 	struct timespec ts, te;
+	clockid_t clock_id;
 
 	printk("POSIX clock APIs\n");
 
@@ -40,6 +42,12 @@ ZTEST(posix_apis, test_clock)
 	zassert_equal(secs_elapsed, SLEEP_SECONDS,
 			"POSIX clock API test failed");
 
+	ret = clock_getcpuclockid(0, &clock_id);
+	zassert_equal(ret, 0, "POSIX clock_getcpuclock id failed");
+
+	ret = clock_getcpuclockid((pid_t)2482, &clock_id);
+	zassert_equal(ret, EPERM, "POSIX clock_getcpuclock id failed");
+
 	printk("POSIX clock APIs test done\n");
 }