[PATCH 1/1] Newlib01: Add tests for rand() and lrand48()

[Matthew Joyce]

From: Matt Joyce <matthew.joyce at embedded-brains.de>

Check that the state of rand() and lrand48() is thread-specific,
that they are properly initialized, and return the expected
sequence of pseudo-random numbers for default seed values.
---
 testsuites/libtests/newlib01/init.c       | 50 +++++++++++++++++++++++
 testsuites/libtests/newlib01/newlib01.doc |  3 ++
 2 files changed, 53 insertions(+)

diff --git a/testsuites/libtests/newlib01/init.c b/testsuites/libtests/newlib01/init.c
index 8975a72fad..0bb3c4628b 100644
--- a/testsuites/libtests/newlib01/init.c
+++ b/testsuites/libtests/newlib01/init.c
@@ -82,6 +82,50 @@ static void wait(void)
   rtems_test_assert(sc == RTEMS_SUCCESSFUL);
 }
 
+/*
+ * Check that rand() is properly initialized and returns the expected sequence
+ * for default seed values. A call to rand() without any previous call to
+ * srand() generates the same sequence as when srand() is first called with a
+ * seed value of 1.
+ */
+static void test_rand(void)
+{
+  int rv;
+
+  rv = rand();
+  rtems_test_assert(rv == 1481765933);
+  rv = rand();
+  rtems_test_assert(rv == 1085377743);
+  rv = rand();
+  rtems_test_assert(rv == 1270216262);
+
+  srand(1);
+  rv = rand();
+  rtems_test_assert(rv == 1481765933);
+  rv = rand();
+  rtems_test_assert(rv == 1085377743);
+  rv = rand();
+  rtems_test_assert(rv == 1270216262);
+}
+
+/*
+ * Check that lrand48() is properly initialized and returns the expected
+ * sequence for default seed values. A call to lrand48() without any previous
+ * call to srand48() uses default constant initializer values set in the _seed
+ * member of struct _rand48.
+ */
+static void test_lrand48(void)
+{
+  long rv;
+
+  rv = lrand48();
+  rtems_test_assert(rv == 851401618);
+  rv = lrand48();
+  rtems_test_assert(rv == 1804928587);
+  rv = lrand48();
+  rtems_test_assert(rv == 758783491);
+}
+
 static void stdio_file_worker(rtems_task_argument arg)
 {
   test_context *ctx = &test_instance;
@@ -90,6 +134,9 @@ static void stdio_file_worker(rtems_task_argument arg)
   char buf[1] = { 'x' };
   size_t n;
 
+  test_rand();
+  test_lrand48();
+
   rtems_test_assert(reent->__cleanup == NULL);
 
   output = stdout = fopen(&stdio_file_path[0], "r+");
@@ -454,6 +501,9 @@ static void Init(rtems_task_argument arg)
   int rv;
 
   TEST_BEGIN();
+  test_rand();
+  test_lrand48();
+
   ctx->main_task_id = rtems_task_self();
 
   /* Fill dynamic file pool in Newlib */
diff --git a/testsuites/libtests/newlib01/newlib01.doc b/testsuites/libtests/newlib01/newlib01.doc
index fbda12aa98..dc16584418 100644
--- a/testsuites/libtests/newlib01/newlib01.doc
+++ b/testsuites/libtests/newlib01/newlib01.doc
@@ -19,3 +19,6 @@ concepts:
   - Check that exit procedures provide proper resource cleanup. Ensure that
     a file opened from a worker task--but that is not assigned to a stdio
     stream--is not closed during thread termination.
+  - Check that the state of random number generators is thread-specific, they
+    are properly initialized, and return the expected sequence for default
+    seed values.
-- 
2.31.1