This appears to be the implementation:
http://cvs.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/lib/libc/port/gen/drand48.c
In that code, it looks to me like nrand48() locks the mutex and then calls
_nrand48_u(), an internal function. The _nrand48_u() function saves the
global data, copi
The disassembly of the nrand48() routine (Solaris 10, AMD64) shows that it is
protected with a call to the lmutex_lock routine. Replacing the nrand48() call
with a call to my own random-number generator (with per-thread private state)
shaves off 33% of running time just with two threads.
Since
