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NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | STANDARDS | HISTORY | SEE ALSO | COLOPHON |
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FUTEX_TRYLOCK_PI(2const) FUTEX_TRYLOCK_PI(2const)
FUTEX_TRYLOCK_PI - try to lock a priority-inheritance futex
Standard C library (libc, -lc)
#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_TRYLOCK_PI);
This operation tries to acquire the lock at uaddr. It is invoked
when a user-space atomic acquire did not succeed because the futex
word was not 0.
Because the kernel has access to more state information than user
space, acquisition of the lock might succeed if performed by the
kernel in cases where the futex word (i.e., the state information
accessible to use-space) contains stale state (FUTEX_WAITERS
and/or FUTEX_OWNER_DIED). This can happen when the owner of the
futex died. User space cannot handle this condition in a race-
free manner, but the kernel can fix this up and acquire the futex.
On error, -1 is returned, and errno is set to indicate the error.
On success, FUTEX_TRYLOCK_PI Returns 0 if the futex was
successfully locked.
See futex(2).
EAGAIN The futex owner thread ID of uaddr is about to exit, but
has not yet handled the internal state cleanup. Try again.
EDEADLK
The futex word at uaddr is already locked by the caller.
EINVAL The kernel detected an inconsistency between the user-space
state at uaddr and the kernel state. This indicates either
state corruption or that the kernel found a waiter on uaddr
which is waiting via FUTEX_WAIT(2const) or
FUTEX_WAIT_BITSET(2const).
ENOMEM The kernel could not allocate memory to hold state
information.
ENOSYS A run-time check determined that the operation is not
available. The PI-futex operations are not implemented on
all architectures and are not supported on some CPU
variants.
EPERM The caller is not allowed to attach itself to the futex at
uaddr. (This may be caused by a state corruption in user
space.)
ESRCH The thread ID in the futex word at uaddr does not exist.
Linux.
Linux 2.6.18.
futex(2)
This page is part of the man-pages (Linux kernel and C library
user-space interface documentation) project. Information about
the project can be found at
⟨https://www.kernel.org/doc/man-pages/⟩. If you have a bug report
for this manual page, see
⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
This page was obtained from the tarball man-pages-6.15.tar.gz
fetched from
⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
2025-08-11. If you discover any rendering problems in this HTML
version of the page, or you believe there is a better or more up-
to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not
part of the original manual page), send a mail to
man-pages@man7.org
Linux man-pages 6.15 2025-05-30 FUTEX_TRYLOCK_PI(2const)
Pages that refer to this page: futex(2)
Copyright and license for this manual page
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HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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