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Diffstat (limited to 'sysdeps/nptl/lowlevellock-futex.h')
| -rw-r--r-- | sysdeps/nptl/lowlevellock-futex.h | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/sysdeps/nptl/lowlevellock-futex.h b/sysdeps/nptl/lowlevellock-futex.h new file mode 100644 index 0000000000..12f3876cd5 --- /dev/null +++ b/sysdeps/nptl/lowlevellock-futex.h @@ -0,0 +1,86 @@ +/* Low-level locking access to futex facilities. Stub version. + Copyright (C) 2014 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library. If not, see + <http://www.gnu.org/licenses/>. */ + +#ifndef _LOWLEVELLOCK_FUTEX_H +#define _LOWLEVELLOCK_FUTEX_H 1 + +#include <errno.h> + + +/* Values for 'private' parameter of locking macros. Note pthreadP.h + optimizes for these exact values, though they are not required. */ +#define LLL_PRIVATE 0 +#define LLL_SHARED 128 + + +/* For most of these macros, the return value is never really used. + Nevertheless, the protocol is that each one returns a negated errno + code for failure or zero for success. (Note that the corresponding + Linux system calls can sometimes return positive values for success + cases too. We never use those values.) */ + + +/* Wait while *FUTEXP == VAL for an lll_futex_wake call on FUTEXP. */ +#define lll_futex_wait(futexp, val, private) \ + lll_futex_timed_wait (futexp, val, NULL, private) + +/* Wait until a lll_futex_wake call on FUTEXP, or TIMEOUT elapses. */ +#define lll_futex_timed_wait(futexp, val, timeout, private) \ + -ENOSYS + +/* This macro should be defined only if FUTEX_CLOCK_REALTIME is also defined. + If CLOCKBIT is zero, this is identical to lll_futex_timed_wait. + If CLOCKBIT has FUTEX_CLOCK_REALTIME set, then it's the same but + TIMEOUT is counted by CLOCK_REALTIME rather than CLOCK_MONOTONIC. */ +#define lll_futex_timed_wait_bitset(futexp, val, timeout, clockbit, private) \ + -ENOSYS + +/* Wake up up to NR waiters on FUTEXP. */ +#define lll_futex_wake(futexp, nr, private) \ + -ENOSYS + +/* Wake up up to NR_WAKE waiters on FUTEXP. Move up to NR_MOVE of the + rest from waiting on FUTEXP to waiting on MUTEX (a different futex). */ +#define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \ + -ENOSYS + +/* Wake up up to NR_WAKE waiters on FUTEXP and NR_WAKE2 on FUTEXP2. */ +#define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) \ + -ENOSYS + + +/* Like lll_futex_wait (FUTEXP, VAL, PRIVATE) but with the expectation + that lll_futex_cmp_requeue_pi (FUTEXP, _, _, MUTEX, _, PRIVATE) will + be used to do the wakeup. Confers priority-inheritance behavior on + the waiter. */ +#define lll_futex_wait_requeue_pi(futexp, val, mutex, private) \ + lll_futex_timed_wait_requeue_pi (futexp, val, NULL, 0, mutex, private) + +/* Like lll_futex_wait_requeue_pi, but with a timeout. */ +#define lll_futex_timed_wait_requeue_pi(futexp, val, timeout, clockbit, \ + mutex, private) \ + -ENOSYS + +/* Like lll_futex_requeue, but pairs with lll_futex_wait_requeue_pi + and inherits priority from the waiter. */ +#define lll_futex_cmp_requeue_pi(futexp, nr_wake, nr_move, mutex, \ + val, private) \ + -ENOSYS + + +#endif /* lowlevellock-futex.h */ |