103 Commits

Author	SHA1	Message	Date
Jeff Roberson	0003d1b74e	- Create a new lock, umtx_lock, for use instead of the proc lock for ... protecting the umtx queues. We can't use the proc lock because we need to hold the lock across calls to casuptr, which can fault. Approved by: re	2003-05-25 18:18:32 +00:00
Jake Burkholder	cef57e7624	- Make casuptr return the old value of the location we're trying to update, ... and change the umtx code to expect this. Reviewed by: jeff	2003-04-02 08:02:27 +00:00
Jeff Roberson	69404b5090	- Add an api for doing smp safe locks in userland. ... - umtx_lock() is defined as an inline in umtx.h. It tries to do an uncontested acquire of a lock which falls back to the _umtx_lock() system-call if that fails. - umtx_unlock() is also an inline which falls back to _umtx_unlock() if the uncontested unlock fails. - Locks are keyed off of the thr_id_t of the currently running thread which is currently just the pointer to the 'struct thread' in kernel. - _umtx_lock() uses the proc pointer to synchronize access to blocked thread queues which are stored in the first blocked thread.	2003-04-01 01:10:42 +00:00