address `addr` still contains the value `val` (in the fashion of `futex(2)`).
If it doesn't then the call doesn't block. Else the calling thread is blocked
until a `PWQR_WAKE` command is received.
address `addr` still contains the value `val` (in the fashion of `futex(2)`).
If it doesn't then the call doesn't block. Else the calling thread is blocked
until a `PWQR_WAKE` command is received.