futex_wait_setup (9) Linux Manual Page
futex_wait_setup – Prepare to wait on a futex
Synopsis
int futex_wait_setup(u32 __user *uaddr, u32 val, unsigned int flags, struct futex_q *q, struct futex_hash_bucket **hb);Arguments
uaddr
-
- the futex userspace address
val
- the expected value
flags
- futex flags (FLAGS_SHARED, etc.)
q
- the associated futex_q
hb
- storage for hash_bucket pointer to be returned to caller
Description
Setup the futex_q and locate the hash_bucket. Get the futex value and compare it with the expected value. Handle atomic faults internally. Return with the hb lock held and a q.key reference on success, and unlocked with no q.key reference on failure.
Return
0 – uaddr contains val and hb has been locked; <1 – -EFAULT or -EWOULDBLOCK (uaddr does not contain val) and hb is unlocked
Author
Rusty Russell <rusty [at] rustcorp.com.au>
- Author.