time: Add getitimer and setitimer basic tests

Checked on i686-linux-gnu and x86_64-linux-gnu.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

2 files changed, 176 insertions, 1 deletions

diff --git a/time/Makefile b/time/Makefile
index 99b5d42666..91cb02a003 100644
--- a/time/Makefile
+++ b/time/Makefile
@@ -49,7 +49,7 @@ tests	:= test_time clocktest tst-posixtz tst-strptime tst_wcsftime \
 	   tst-tzname tst-y2039 bug-mktime4 tst-strftime2 tst-strftime3 \
 	   tst-clock tst-clock2 tst-clock_nanosleep tst-cpuclock1 \
 	   tst-adjtime tst-ctime tst-difftime tst-mktime4 tst-clock_settime \
-	   tst-settimeofday
+	   tst-settimeofday tst-itimer
 
 include ../Rules
 
diff --git a/time/tst-itimer.c b/time/tst-itimer.c
new file mode 100644
index 0000000000..929c2b74c7
--- /dev/null
+++ b/time/tst-itimer.c
@@ -0,0 +1,175 @@
+/* Basic tests for getitimer and setitimer.
+   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 <array_length.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <sys/time.h>
+#include <support/check.h>
+#include <support/xsignal.h>
+#include <unistd.h>
+#include <time.h>
+
+static sig_atomic_t cnt;
+
+static void
+alrm_handler (int sig)
+{
+  if (++cnt > 3)
+    cnt = 3;
+}
+
+static void
+intr_sleep (int sec)
+{
+  struct timespec ts = { .tv_sec = sec, .tv_nsec = 0 };
+  while (nanosleep (&ts, &ts) == -1 && errno == EINTR)
+    ;
+}
+
+static int
+do_test (void)
+{
+  struct itimerval it, it_old;
+  const int timers[] = { ITIMER_REAL, ITIMER_VIRTUAL, ITIMER_PROF };
+  for (int i = 0; i < array_length (timers); i++)
+    {
+      TEST_COMPARE (getitimer (timers[i], &it), 0);
+
+      /* No timer set, all value should be 0.  */
+      TEST_COMPARE (it.it_interval.tv_sec, 0);
+      TEST_COMPARE (it.it_interval.tv_usec, 0);
+      TEST_COMPARE (it.it_value.tv_sec, 0);
+      TEST_COMPARE (it.it_value.tv_usec, 0);
+
+      it.it_interval.tv_sec = 10;
+      it.it_interval.tv_usec = 20;
+      TEST_COMPARE (setitimer (timers[i], &it, NULL), 0);
+
+      TEST_COMPARE (setitimer (timers[i], &(struct itimerval) { 0 }, &it_old),
+		    0);
+      /* ITIMER_REAL returns { 0, 0 } for single-shot timers, while
+	 other timers returns setitimer value.  */
+      if (timers[i] == ITIMER_REAL)
+	{
+	  TEST_COMPARE (it_old.it_interval.tv_sec, 0);
+	  TEST_COMPARE (it_old.it_interval.tv_usec, 0);
+	}
+      else
+	{
+	  TEST_COMPARE (it_old.it_interval.tv_sec, 10);
+	  TEST_COMPARE (it_old.it_interval.tv_usec, 20);
+	}
+
+      /* Create a periodic timer and check if the return value is the one
+	 previously set.  */
+      it.it_interval.tv_sec = 10;
+      it.it_interval.tv_usec = 20;
+      it.it_value.tv_sec = 30;
+      it.it_value.tv_usec = 40;
+      TEST_COMPARE (setitimer (timers[i], &it, NULL), 0);
+
+      TEST_COMPARE (setitimer (timers[i], &(struct itimerval) { 0 }, &it_old),
+		    0);
+      TEST_COMPARE (it.it_interval.tv_sec, it_old.it_interval.tv_sec);
+      TEST_COMPARE (it.it_interval.tv_usec, it_old.it_interval.tv_usec);
+
+      if (sizeof (time_t) == 4)
+	continue;
+
+      /* Same as before, but with a 64 bit time_t value.  */
+      it.it_interval.tv_sec = (time_t) 0x1ffffffffull;
+      it.it_interval.tv_usec = 20;
+      it.it_value.tv_sec = 0;
+      it.it_value.tv_usec = 0;
+
+      /* Linux does not provide 64 bit time_t support for getitimer and
+	 setitimer on architectures with 32 bit time_t support.  */
+      if (sizeof (__time_t) == 8)
+	{
+	  TEST_COMPARE (setitimer (timers[i], &it, NULL), 0);
+	  TEST_COMPARE (setitimer (timers[i], &(struct itimerval) { 0 },
+				   &it_old),
+			0);
+	  /* ITIMER_REAL returns { 0, 0 } for single-sort timers, while other
+	     timers returns setitimer value.  */
+	  if (timers[i] == ITIMER_REAL)
+	    {
+	      TEST_COMPARE (it_old.it_interval.tv_sec, 0ull);
+	      TEST_COMPARE (it_old.it_interval.tv_usec, 0);
+	    }
+	  else
+	    {
+	      TEST_COMPARE (it_old.it_interval.tv_sec, 0x1ffffffffull);
+	      TEST_COMPARE (it_old.it_interval.tv_usec, 20);
+	    }
+	}
+      else
+	{
+	  TEST_COMPARE (setitimer (timers[i], &it, NULL), -1);
+	  TEST_COMPARE (errno, EOVERFLOW);
+	}
+
+      /* Create a periodic timer and check if the return value is the one
+	 previously set.  */
+      it.it_interval.tv_sec = (time_t) 0x1ffffffffull;
+      it.it_interval.tv_usec = 20;
+      it.it_value.tv_sec = 30;
+      it.it_value.tv_usec = 40;
+      if (sizeof (__time_t) == 8)
+	{
+	  TEST_COMPARE (setitimer (timers[i], &it, NULL), 0);
+
+	  TEST_COMPARE (setitimer (timers[i], &(struct itimerval) { 0 },
+				   &it_old),
+			0);
+	  TEST_COMPARE (it.it_interval.tv_sec, it_old.it_interval.tv_sec);
+	  TEST_COMPARE (it.it_interval.tv_usec, it_old.it_interval.tv_usec);
+	}
+      else
+	{
+	  TEST_COMPARE (setitimer (timers[i], &it, NULL), -1);
+	  TEST_COMPARE (errno, EOVERFLOW);
+	}
+  }
+
+  {
+    struct sigaction sa = { .sa_handler = alrm_handler, .sa_flags = 0 };
+    sigemptyset (&sa.sa_mask);
+    xsigaction (SIGALRM, &sa, NULL);
+  }
+
+  /* Setup a timer to 0.1s and sleep for 1s and check to 3 signal handler
+     execution.  */
+  it.it_interval.tv_sec = 0;
+  it.it_interval.tv_usec = 100000;
+  it.it_value.tv_sec = 0;
+  it.it_value.tv_usec = 100000;
+
+  /* Check ITIMER_VIRTUAL and ITIMER_PROF would require to generate load
+     and be subject to system load.  */
+  cnt = 0;
+  TEST_COMPARE (setitimer (ITIMER_REAL, &it, NULL), 0);
+  intr_sleep (1);
+  TEST_COMPARE (cnt, 3);
+  TEST_COMPARE (setitimer (ITIMER_REAL, &(struct itimerval) { 0 }, NULL), 0);
+
+  return 0;
+}
+
+#include <support/test-driver.c>