FUTEX_REQUEUE(2const) — Linux manual page

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | STANDARDS | HISTORY | SEE ALSO | COLOPHON

FUTEX_REQUEUE(2const)                               FUTEX_REQUEUE(2const)

NAME         top

       FUTEX_REQUEUE - wake some waiters, and requeue others

LIBRARY         top

       Standard C library (libc, -lc)

SYNOPSIS         top

       #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         top

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

RETURN VALUE         top

       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         top

       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         top

       Linux.

HISTORY         top

       Linux 2.6.0.

SEE ALSO         top

       futex(2)

COLOPHON         top

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

Pages that refer to this page: futex(2)FUTEX_CMP_REQUEUE(2const)