is done in rumpuser for simplicity, since on the kernel side things
we assume we have only one pointer of space). As a side-effect,
we can no longer know if the current thread is holding on to a
mutex locked without curlwp context (basically all mutexes inited
outside of mutex_init()). The only thing that called rumpuser_mutex_held()
for a non-kmutex was the giant lock. So, instead implement recursive
locking for the giant lock in the rump kernel and get rid of the
now-unused recursive pthread mutex in the hypercall interface.
interlock. This is applicable in cases where the actual interlock
is the CPU the currently running thread is scheduled on. Borrowing
the scheduler lock as the mutex mandated by pthread_cond_wait()
does away with need to have an additional mutex. This both optimizes
runtime execution and simplifies code, as the extra lock typically
lead to quite some trickeries to avoid the dungeon collapsing due
to zaps from the wand of deadlock.
the source files from src/sys/rump/librump/rumpuser to src/lib/librumpuser
(from where it is already built). Even so, keep rumpuser.h in
sys/rump/include for kernel source tree self-containment.
yamt