src/lib/libc/stdlib/rand.c, branch release/5.3.0_cvs FreeBSD source tree This commit was manufactured by cvs2svn to create tag 2004-11-04T19:12:42+00:00 cvs2svn cvs2svn@FreeBSD.org 2004-11-04T19:12:42+00:00 3f86d8a2ea3f3265afaa1fd263b0004c5c000e69 'RELENG_5_3_0_RELEASE'. This commit was manufactured to restore the state of the 5.3-RELEASE image. 
'RELENG_5_3_0_RELEASE'.

This commit was manufactured to restore the state of the 5.3-RELEASE image.
Back out "drop first N values" method of removing monotonically increased 2003-02-17T03:52:35+00:00 Andrey A. Chernov ache@FreeBSD.org 2003-02-17T03:52:35+00:00 49abb2a4f8eaa957bcbcd1966ba2cc0ba09c0662 seed->first value correlation. It breaks rand_r()... Other possible methods like shuffling inside aray will breaks rand_r() too, because it assumes only one word state, i.e. nothing extra can be added after seed assignment in srand(). BTW, for old formulae seed->first value correlation is not so monotonically increased as with other Linear Congruential Generators of this type only becase arithmetic overflow happens. But overflow affects distribution and lower bits very badly, as many articles says, such type of overflow not improves PRNG. So, monotonically increased seed->first value correlation problem remains... 
seed->first value correlation. It breaks rand_r()... Other possible methods
like shuffling inside aray will breaks rand_r() too, because it assumes
only one word state, i.e. nothing extra can be added after seed assignment
in srand().

BTW, for old formulae seed->first value correlation is not so monotonically
increased as with other Linear Congruential Generators of this type only
becase arithmetic overflow happens. But overflow affects distribution
and lower bits very badly, as many articles says, such type of overflow
not improves PRNG.

So, monotonically increased seed->first value correlation problem remains...
Since we drop NSHUFF values now, set default seed to what it becomes 2003-02-05T21:25:50+00:00 Andrey A. Chernov ache@FreeBSD.org 2003-02-05T21:25:50+00:00 f3047249d4caf0e02dce97c8bc0f0ce2eda7ee78 after srand(1) 
after srand(1)
For rand(3) and random(3) TYPE_0 drop NSHUFF values right after srand{om}() 2003-02-04T11:24:08+00:00 Andrey A. Chernov ache@FreeBSD.org 2003-02-04T11:24:08+00:00 ddd972a9bd5f8a73cd9eb33181072d07ea99aa73 to remove part of seed -> 1st value correlation. Correlation still remains because of algorithm limits. Note that old algorithm have even stronger correlation, especially in the lower bits area, but not eye-visible, as current one. 
to remove part of seed -> 1st value correlation. Correlation still remains
because of algorithm limits. Note that old algorithm have even stronger
correlation, especially in the lower bits area, but not eye-visible, as
current one.
Park & Miller PRNG can be safely initialized with any value but 0 and stuck 2003-02-03T10:22:12+00:00 Andrey A. Chernov ache@FreeBSD.org 2003-02-03T10:22:12+00:00 2f5ef51de2995dce0f81042d954bb9c8f00e7d9f at 0 as designed. Its BSD adaptation tries to fight it by mapping 0 to 2147483647 after calculation, but this method not works since 2147483647 seed returns to 0 again on the next interation. Instead of after calculation mapping, map 0 to another value _before_ calculation, so it never stucks. 
at 0 as designed. Its BSD adaptation tries to fight it by mapping 0 to
2147483647 after calculation, but this method not works since 2147483647
seed returns to 0 again on the next interation. Instead of after calculation
mapping, map 0 to another value _before_ calculation, so it never stucks.
For some combinations of variable sizes and RAND_MAX value rand_r() 2003-02-02T14:27:51+00:00 Andrey A. Chernov ache@FreeBSD.org 2003-02-02T14:27:51+00:00 62c4150e1ed8059b8c394ef1a53dd50641c7c664 may store less amount bits for seed, than available. Fix it. 
may store less amount bits for seed, than available. Fix it.
Add missing #include "namespace.h". 2003-01-03T23:38:21+00:00 Tim J. Robbins tjr@FreeBSD.org 2003-01-03T23:38:21+00:00 2b6839cf10a12ec5c06f05566c6b0fd243476363 






Fix the style of the SCM ID's.
2002-03-22T21:53:29+00:00

David E. O'Brien
obrien@FreeBSD.org

2002-03-22T21:53:29+00:00

333fc21e3cd79bca0c94d7722c5a56cb5ad078d1

I believe have made all of libc .c's as consistent as possible.





I believe have made all of libc .c's as consistent as possible.







Add a long-overdue nail to the deprecated /dev/urandom interface
2001-10-30T21:26:50+00:00

Mark Murray
markm@FreeBSD.org

2001-10-30T21:26:50+00:00

724641c6f4800f0ca277f82746e01dd761af3534

by asking some things that need unpredictable numbers to read
/dev/random instead.





by asking some things that need unpredictable numbers to read
/dev/random instead.







urandom(4) -> random(4) in comments.
2001-06-07T02:32:18+00:00

Dima Dorfman
dd@FreeBSD.org

2001-06-07T02:32:18+00:00

a7d81577d674ff427670a0d34c7ce6d9c5949132

PR:		27858
Submitted by:	Yoshihiro Koya <Yoshihiro.Koya@math.yokohama-cu.ac.jp>
Reviewed by:	md5(1)
Approved by:	markm





PR:		27858
Submitted by:	Yoshihiro Koya <Yoshihiro.Koya@math.yokohama-cu.ac.jp>
Reviewed by:	md5(1)
Approved by:	markm