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Re: [PATCH][BZ 14561] Testcase


On Thu, May 23, 2013 at 06:10:59PM -0400, Carlos O'Donell wrote:
> On 05/20/2013 03:06 PM, OndÅej BÃlka wrote:
> > Hi, 
> > Functions rand calls random which causes seed to be shared between them.
> > 
> > This patch causes rand and random use separate seeds.
> > 
> > Comments?
> > 
> > Ondra
> > 
> > 	* stdlib/rand.c: Include stdlib/random.c
> > 	* stdlib/random.c: Separate rand and random.
> 
> This is user visible change and needs a BZ#.
>
Its 14561.

> This also needs a test case similar to what Rich posted
> with a comment indicating the rationale from the standards
> perspective.
> 
> Repost with test, BZ#, and fixes below.
> 
As testcases can be written independently I decided to post testcase
separetely

Ondra

	* bug-srand-srandom-dependency.c: New file.
	* Makefile (tests) : Add bug-srand-srandom-dependency.

---
 stdlib/Makefile                       |    3 +-
 stdlib/bug-srand-srandom-dependency.c |   65 +++++++++++++++++++++++++++++++++
 2 files changed, 67 insertions(+), 1 deletion(-)
 create mode 100644 stdlib/bug-srand-srandom-dependency.c

diff --git a/stdlib/Makefile b/stdlib/Makefile
index 17d80e0..d635371 100644
--- a/stdlib/Makefile
+++ b/stdlib/Makefile
@@ -71,7 +71,8 @@ tests		:= tst-strtol tst-strtod testmb testrand testsort testdiv   \
 		   tst-makecontext2 tst-strtod6 tst-unsetenv1		    \
 		   tst-makecontext3 bug-getcontext bug-fmtmsg1		    \
 		   tst-secure-getenv tst-strtod-overflow tst-strtod-round   \
-		   tst-tininess tst-strtod-underflow tst-tls-atexit
+		   tst-tininess tst-strtod-underflow tst-tls-atexit         \
+		   bug-srand-srandom-dependency
 tests-static	:= tst-secure-getenv
 
 modules-names	= tst-tls-atexit-lib
diff --git a/stdlib/bug-srand-srandom-dependency.c b/stdlib/bug-srand-srandom-dependency.c
new file mode 100644
index 0000000..42ed02f
--- /dev/null
+++ b/stdlib/bug-srand-srandom-dependency.c
@@ -0,0 +1,65 @@
+/* Test that srand and srandom do not interact.
+   Copyright (C) 2013 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
+   <http://www.gnu.org/licenses/>.  */
+
+
+
+#include <stdlib.h>
+
+int
+do_test (int argc, char **argv)
+{
+  int rand1, rand2;
+  int random1, random2;
+  srand (43);
+  rand1 = rand ();
+  rand2 = rand ();
+  srandom (42);
+  random1 = random ();
+  random2 = random ();
+   
+  /* We enumerate all combinations how rand and random
+     can be interleaved and test independency.  */
+  for (int com = 0; com < 64; com++)
+    {
+      int randstate = 0, randomstate = 0;
+      for (int i = 0; i < 6; i++)
+	if (com & (1 << i))
+	  {
+	    if (randstate == 0)
+	      srand (43);
+	    if (randstate == 1 && rand1 != rand ())
+	      return 1;
+	    if (randstate == 2 && rand2 != rand ())
+	      return 1;
+	    randstate++;
+	  }
+	else
+	  {
+	    if (randomstate == 0)
+	      srandom (42);
+	    if (randomstate == 1 && random1 != random ())
+	      return 1;
+	    if (randomstate == 2 && random2 != random ())
+	      return 1;
+	    randomstate++;
+	  }
+    }
+  return 0;
+}
+
+#include "../test-skeleton.c"
-- 
1.7.10.4


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