1 files changed, 148 insertions, 0 deletions
diff --git a/src/vppinfra/test_random.c b/src/vppinfra/test_random.c
new file mode 100644
index 00000000000..49759eacb97
--- /dev/null
+++ b/src/vppinfra/test_random.c
@@ -0,0 +1,148 @@
+/*
+ * Copyright (c) 2015 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/*
+  Copyright (c) 2001, 2002, 2003 Eliot Dresselhaus
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be
+  included in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+#include <vppinfra/format.h>
+#include <vppinfra/bitmap.h>
+
+static u32 known_random_sequence[] = {
+  0x00000000, 0x3c6ef35f, 0x47502932, 0xd1ccf6e9,
+  0xaaf95334, 0x6252e503, 0x9f2ec686, 0x57fe6c2d,
+  0xa3d95fa8, 0x81fdbee7, 0x94f0af1a, 0xcbf633b1,
+};
+
+
+int
+test_random_main (unformat_input_t * input)
+{
+  uword n_iterations;
+  uword i, repeat_count;
+  uword *bitmap = 0;
+  uword print;
+  u32 seed;
+  u32 *seedp = &seed;
+
+  /* first, check known sequence from Numerical Recipes in C, 2nd ed.
+     page 284 */
+  seed = known_random_sequence[0];
+  for (i = 0; i < ARRAY_LEN (known_random_sequence) - 1; i++)
+    {
+      u32 rv;
+      rv = random_u32 (seedp);
+      if (rv != known_random_sequence[i + 1])
+	{
+	  fformat (stderr, "known sequence check FAILS at index %d", i + 1);
+	  break;
+	}
+    }
+
+  clib_warning ("known sequence check passes");
+
+  n_iterations = 1000;
+  seed = 0;
+  print = 1 << 24;
+
+  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (0 == unformat (input, "iter %d", &n_iterations)
+	  && 0 == unformat (input, "print %d", &print)
+	  && 0 == unformat (input, "seed %d", &seed))
+	clib_error ("unknown input `%U'", format_unformat_error, input);
+    }
+
+  if (!seed)
+    seed = random_default_seed ();
+
+  if (n_iterations == 0)
+    n_iterations = random_u32_max ();
+
+  clib_warning ("%d iterations, seed %d\n", n_iterations, seed);
+
+  repeat_count = 0;
+  for (i = 0; i < n_iterations; i++)
+    {
+      uword r = random_u32 (&seed);
+      uword b, ri, rj;
+
+      ri = r / BITS (bitmap[0]);
+      rj = (uword) 1 << (r % BITS (bitmap[0]));
+
+      vec_validate (bitmap, ri);
+      b = bitmap[ri];
+
+      if (b & rj)
+	goto repeat;
+      b |= rj;
+      bitmap[ri] = b;
+
+      if (0 == (i & (print - 1)))
+	fformat (stderr, "0x%08x iterations %d repeats\n", i, repeat_count);
+      continue;
+
+    repeat:
+      fformat (stderr, "repeat found at iteration  %d/%d\n", i, n_iterations);
+      repeat_count++;
+      continue;
+    }
+
+  return 0;
+}
+
+#ifdef CLIB_UNIX
+int
+main (int argc, char *argv[])
+{
+  unformat_input_t i;
+  int ret;
+
+  clib_mem_init (0, 3ULL << 30);
+
+  unformat_init_command_line (&i, argv);
+  ret = test_random_main (&i);
+  unformat_free (&i);
+
+  return ret;
+}
+#endif /* CLIB_UNIX */
+
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */