FUTEX_REQUEUE(2const)                                    FUTEX_REQUEUE(2const)

NAME
       FUTEX_REQUEUE - wake some waiters, and requeue others

LIBRARY
       Standard C library (libc, -lc)

SYNOPSIS
       #include <linux/futex.h>  /* Definition of FUTEX_* constants */
       #include <sys/syscall.h>  /* Definition of SYS_* constants */
       #include <unistd.h>

       long syscall(SYS_futex, uint32_t *uaddr, FUTEX_REQUEUE,
                    uint32_t val, uint32_t val2, uint32_t *uaddr2);

DESCRIPTION
       This operation performs the same task as FUTEX_CMP_REQUEUE(2const),
       except that the futex word isn't compared.

RETURN VALUE
       On error, -1 is returned, and errno is set to indicate the error.

       On success, FUTEX_REQUEUE returns the number of waiters that were woken
       up.

ERRORS
       See futex(2).

       EFAULT uaddr2 did not point to a valid user-space address.

       EINVAL uaddr2 does not point to a valid object--that is, the address is
              not four-byte-aligned.

       EINVAL The kernel detected an inconsistency between the user-space
              state at uaddr and the kernel state--that is, it detected a
              waiter which waits in FUTEX_LOCK_PI(2const) or
              FUTEX_LOCK_PI2(2const) on uaddr.

STANDARDS
       Linux.

HISTORY
       Linux 2.6.0.

SEE ALSO
       futex(2)

Linux man-pages 6.15              2025-05-30             FUTEX_REQUEUE(2const)