get_robust_list, set_robust_list - get/set list of robust futexes
long get_robust_list(int pid, struct robust_list_head **head_ptr,
long set_robust_list(struct robust_list_head *head, size_t len);
Note: There are no glibc wrappers for these system calls; see NOTES.
The robust futex implementation needs to maintain per-thread lists of
robust futexes which are unlocked when the thread exits. These lists
are managed in user space; the kernel is notified about only the
location of the head of the list.
The get_robust_list() system call returns the head of the robust futex
list of the thread whose thread ID is specified in pid. If pid is 0,
the head of the list for the calling thread is returned. The list head
is stored in the location pointed to by head_ptr. The size of the
object pointed to by **head_ptr is stored in len_ptr.
The set_robust_list() system call requests the kernel to record the
head of the list of robust futexes owned by the calling thread. The
head argument is the list head to record. The len argument should be
The set_robust_list() and get_robust_list() system calls return zero
when the operation is successful, an error code otherwise.
The set_robust_list() system call can fail with the following error:
EINVAL len does not match the size of structure struct robust_list_head
expected by kernel.
The get_robust_list() system call can fail with the following errors:
EPERM The calling process does not have permission to see the robust
futex list of the thread with the thread ID pid, and does not
have the CAP_SYS_PTRACE capability.
ESRCH No thread with the thread ID pid could be found.
EFAULT The head of the robust futex list can't be stored at the
These system calls were added in Linux 2.6.17. No library support is
provided; use syscall(2).
These system calls are not needed by normal applications. No support
for them is provided in glibc. In the unlikely event that you want to
call them directly, use syscall(2).
A thread can have only one robust futex list; therefore applications
that wish to use this functionality should use the robust mutexes
provided by glibc.
Documentation/robust-futexes.txt and Documentation/robust-futex-ABI.txt
in the Linux kernel source tree
This page is part of release 3.65 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.