Re: [PATCH v2][BZ 14561] Separate rand and random seeds.

[OndÅej BÃlka <neleai at seznam dot cz>]

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#.
> 
> 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.
> 
Here is v2

	* stdlib/rand.c: Include stdlib/random.c
	* stdlib/random.c: Separate rand and random.


---
 stdlib/rand.c   |   19 +++++++++++--------
 stdlib/random.c |   30 +++++++++++++++++++++++-------
 2 files changed, 34 insertions(+), 15 deletions(-)

diff --git a/stdlib/rand.c b/stdlib/rand.c
index 3e0839f..290e574 100644
--- a/stdlib/rand.c
+++ b/stdlib/rand.c
@@ -15,14 +15,17 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <stdlib.h>
-
-#undef	rand
 
 
 /* Return a random integer between 0 and RAND_MAX.  */
-int
-rand ()
-{
-  return (int) __random ();
-}
+
+#define SRANDOM srand
+#define __SRANDOM __srand
+
+#define RANDOM_RET int
+#define RANDOM rand
+#define __RANDOM __rand
+
+#define USE_AS_RAND
+
+#include "stdlib/random.c"
diff --git a/stdlib/random.c b/stdlib/random.c
index 967dec3..61483bd 100644
--- a/stdlib/random.c
+++ b/stdlib/random.c
@@ -204,8 +204,14 @@ __libc_lock_define_initialized (static, lock)
    information a given number of times to get rid of any initial dependencies
    introduced by the L.C.R.N.G.  Note that the initialization of randtbl[]
    for default usage relies on values produced by this routine.  */
+
+#ifndef USE_AS_RAND
+# define __SRANDOM __srandom
+# define SRANDOM srandom
+#endif
+
 void
-__srandom (x)
+__SRANDOM (x)
      unsigned int x;
 {
   __libc_lock_lock (lock);
@@ -213,8 +219,10 @@ __srandom (x)
   __libc_lock_unlock (lock);
 }
 
-weak_alias (__srandom, srandom)
-weak_alias (__srandom, srand)
+weak_alias (__SRANDOM, SRANDOM)
+
+#ifndef USE_AS_RAND
+
 
 /* Initialize the state information in the given array of N bytes for
    future random number generation.  Based on the number of bytes we
@@ -276,7 +284,9 @@ __setstate (arg_state)
 }
 
 weak_alias (__setstate, setstate)
-
+
+#endif
+
 /* If we are using the trivial TYPE_0 R.N.G., just do the old linear
    congruential bit.  Otherwise, we do our fancy trinomial stuff, which is the
    same in all the other cases due to all the global variables that have been
@@ -288,8 +298,13 @@ weak_alias (__setstate, setstate)
    rear pointers can't wrap on the same call by not testing the rear
    pointer if the front one has wrapped.  Returns a 31-bit random number.  */
 
-long int
-__random ()
+#ifndef USE_AS_RAND
+# define RANDOM_RET long int
+# define RANDOM __random
+#endif
+
+RANDOM_RET
+RANDOM ()
 {
   int32_t retval;
 
@@ -301,5 +316,6 @@ __random ()
 
   return retval;
 }
-
+#ifndef USE_AS_RAND
 weak_alias (__random, random)
+#endif
-- 
1.7.10.4