tst: Provide test for sched_rr_get_interval

This change adds new test to assess sched_rr_get_interval's
functionality.

To be more specific - following use cases are checked:
- If the read interval is correct
- If the proper ABI is used - to check if adjacent data is not
  overwritten

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

2 files changed, 46 insertions, 1 deletions

diff --git a/posix/Makefile b/posix/Makefile
index f54015b..239fbb3 100644
--- a/posix/Makefile
+++ b/posix/Makefile
@@ -108,7 +108,7 @@ tests-internal	:= bug-regex5 bug-regex20 bug-regex33 \
 		   tst-rfc3484 tst-rfc3484-2 tst-rfc3484-3 \
 		   tst-glob_lstat_compat tst-spawn4-compat
 tests-container := bug-ga2
-xtests		:= tst-getaddrinfo4 tst-getaddrinfo5
+xtests		:= tst-getaddrinfo4 tst-getaddrinfo5 tst-sched_rr_get_interval
 ifeq (yes,$(build-shared))
 test-srcs	:= globtest
 tests           += wordexp-test tst-exec tst-spawn tst-spawn2 tst-spawn3
diff --git a/posix/tst-sched_rr_get_interval.c b/posix/tst-sched_rr_get_interval.c
new file mode 100644
index 0000000..96da602
--- /dev/null
+++ b/posix/tst-sched_rr_get_interval.c
@@ -0,0 +1,45 @@
+/* Test for sched_rr_get_interval
+   Copyright (C) 2021 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <time.h>
+#include <sched.h>
+#include <support/check.h>
+
+static int
+do_test (void)
+{
+  struct timespec ts[2] = { { -1, -1 }, { -1, -1 } };
+  const struct sched_param param = {
+    .sched_priority = sched_get_priority_max (SCHED_RR) - 10,
+  };
+  int result = sched_setscheduler (0, SCHED_RR, &param);
+
+  if (result != 0)
+    FAIL_UNSUPPORTED ("sched_setscheduler error: %m\n");
+
+  TEST_COMPARE (sched_rr_get_interval (0, ts), 0);
+
+  /* Check if returned time values are correct.  */
+  TEST_VERIFY (ts[0].tv_sec >= 0);
+  TEST_VERIFY (ts[0].tv_nsec >= 0 && ts[0].tv_nsec < 1000000000);
+  TEST_VERIFY (ts[1].tv_sec == -1 && ts[1].tv_nsec == -1);
+
+  return 0;
+}
+
+#include <support/test-driver.c>