The RandomNumberGenerator is a pseudorandom number generator
with 48-bit state. It is properly seeded using either
(1) the --random-seed if specified, or
(2) the entropy_source function if configured, or
(3) /dev/urandom if available, or
(4) falls back to Time and TimeTicks based seeding.
Each Isolate now contains a RandomNumberGenerator, which replaces
the previous private_random_seed.
Every native context still has its own random_seed. But this random
seed is now properly initialized during bootstrapping,
instead of on-demand initialization. This will allow us to cleanup
and speedup the HRandom implementation quite a lot (this is delayed
for a followup CL)!
Also stop messing with the system rand()/random(), which should
not be done from a library anyway! We probably re-seeded the
libc rand()/random() after the application (i.e. Chrome) already
seeded it (with better entropy than what we used).
Another followup CL will replace the use of the per-isolate
random number generator for the address randomization and
thereby get rid of the Isolate::UncheckedCurrent() usage in
the platform code.
TEST=cctest/test-random-number-generator,cctest/test-random
R=mstarzinger@chromium.org
Review URL: https://codereview.chromium.org/23548024
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16612 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
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