-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Robert Noland wrote: > I guess that I am still trying to understand the original bug... The > demo program that was included in the bug report seems to work fine > here, unless I don't know what the output *should* look like. It seems > to work both before and after this change on FreeBSD. FWIW, we use mesa > glut, not freeglut. > > balrog% ./opengl-demo > These numbers are random > 1219944491 > 1580682328 > 7689659 > 391079993 > 1581482531 > 571799598 > 246523261 > 820492564 > 1026025761 > 121279717 > IRQ's not enabled, falling back to busy waits: 2 0 > > These numbers are not > 386222616 > 1547925878 > 1373331788 > 433122960 > 1675509037 > 327321748 > 1590998669 > 1595741086 > 1844648666 > 1936201370
I believe that running the test multiple times will generate the same output after "These numbers are not". That's the bug. The code calls HASH_RANDOM_INIT with a constant value. If HASH_RANDOM_INIT modifies the global random number generator state (e.g., by calling srandom), applications will get a predictable random number sequence after calling into GLX... whether they want it or not. The available choices for fixing the bug seemed to be: 1. Use our own random number generator that doesn't modify the global state. 2. Just don't call srandom, but use random anyway. This also modifies the global state and could break other applications. This seems unlikely, but it is possible. 3. Use a system random number generator that doesn't modify the global state. I picked option 3. Option 2 was my second choice. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkq5SnoACgkQX1gOwKyEAw/H6ACeNo9DP7wTYMLecSA+z0FAUPRr oewAnRiR4KTaq+izFYGNreYzaY6Et1Ox =ueET -----END PGP SIGNATURE----- ------------------------------------------------------------------------------ Come build with us! The BlackBerry® Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9-12, 2009. Register now! http://p.sf.net/sfu/devconf -- _______________________________________________ Dri-devel mailing list Dri-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dri-devel
