exit function has invalidated the need for _spin[un]lock_pthread().
The _spin[un]lock() functions can now dereference curthread without
the danger that the ldtentry containing the pointer to the thread
has been cleared out from under them.
that take the address of a struct pthread as their first argument.
_spin[un]lock() just become wrappers arround these two functions.
These new functions are for use in situations where curthread can't be
used. One example is _thread_retire(), where we invalidate the array index
curthread uses to get its pointer..
Approved by: re/blanket libthr
in thr_private.h
o Lock down the ldt_entries array and ldt_free, which points to
the next free slot. As noted in the comments, it's necessary
to special case the initial_thread because %gs is not setup
for it yet. This is ok because that early in the program there
won't be any reentrancy issues anyways.
Approved by: re/blanket libthr
Note that the tp register (r13) is reserved as the TLS pointer in
the same way that that gp register (r1) is reserved as the global
pointer. This implementation uses the tp register to point to the
thread structure used by the threads implementation. This is not
in violation with the runtime specification provided the TLS is
a fixed distance from the thread structure. This is only an issue
when code used the __thread keyword to create TLS. This is not
supported at the moment.
as curthread in the new context, so that it will be set automatically when
the thread is switched to. This fixes a race where we'd run for a little
while with curthread unset in _thread_start.
Reviewed by: jeff
