requeue_pi_wake_futex (9) Linux Manual Page
requeue_pi_wake_futex – Wake a task that acquired the lock during requeue
Synopsis
void requeue_pi_wake_futex(struct futex_q *q, union futex_key *key, struct futex_hash_bucket *hb);Arguments
q
-
- the futex_q
key
- the key of the requeue target futex
hb
- the hash_bucket of the requeue target futex
Description
During futex_requeue, with requeue_pi=1, it is possible to acquire the target futex if it is uncontended or via a lock steal. Set the futex_q key to the requeue target futex so the waiter can detect the wakeup on the right futex, but remove it from the hb and NULL the rt_waiter so it can detect atomic lock acquisition. Set the q->lock_ptr to the requeue target hb->lock to protect access to the pi_state to fixup the owner later. Must be called with both q->lock_ptr and hb->lock held.
Author
Rusty Russell <rusty [at] rustcorp.com.au>
- Author.