glibc/sysdeps/nptl/lowlevellock-futex.h
Mike Crowe 99d01ffcc3 nptl: Add clockid parameter to futex timed wait calls
In preparation for adding POSIX clockwait variants of timedwait functions,
add a clockid_t parameter to futex_abstimed_wait functions and pass
CLOCK_REALTIME from all callers for the time being.

Replace lll_futex_timed_wait_bitset with lll_futex_clock_wait_bitset
which takes a clockid_t parameter rather than the magic clockbit.

	* sysdeps/nptl/lowlevellock-futex.h,
	sysdeps/unix/sysv/linux/lowlevellock-futex.h: Replace
	lll_futex_timed_wait_bitset with lll_futex_clock_wait_bitset that
	takes a clockid rather than a special clockbit.
	* sysdeps/nptl/lowlevellock-futex.h: Add
	lll_futex_supported_clockid so that client functions can check
	whether their clockid parameter is valid even if they don't
	ultimately end up calling lll_futex_clock_wait_bitset.
	* sysdeps/nptl/futex-internal.h,
	sysdeps/unix/sysv/linux/futex-internal.h
	(futex_abstimed_wait, futex_abstimed_wait_cancelable): Add
	clockid_t parameter to indicate which clock the absolute time
	passed should be measured against. Pass that clockid onto
	lll_futex_clock_wait_bitset. Add invalid clock as reason for
	returning -EINVAL.
	* sysdeps/nptl/futex-internal.h,
	sysdeps/unix/sysv/linux/futex-internal.h: Introduce
	futex_abstimed_supported_clockid so that client functions can check
	whether their clockid parameter is valid even if they don't
	ultimately end up calling futex_abstimed_wait.
	* nptl/pthread_cond_wait.c (__pthread_cond_wait_common): Remove
	code to calculate relative timeout for
	__PTHREAD_COND_CLOCK_MONOTONIC_MASK and just pass CLOCK_MONOTONIC
	or CLOCK_REALTIME as required to futex_abstimed_wait_cancelable.
	* nptl/pthread_rwlock_common (__pthread_rwlock_rdlock_full)
	(__pthread_wrlock_full), nptl/sem_waitcommon (do_futex_wait): Pass
	additional CLOCK_REALTIME to futex_abstimed_wait_cancelable.
	* nptl/pthread_mutex_timedlock.c (__pthread_mutex_timedlock):
	Switch to lll_futex_clock_wait_bitset and pass CLOCK_REALTIME

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2019-07-12 13:36:23 +00:00

98 lines
3.8 KiB
C

/* Low-level locking access to futex facilities. Stub version.
Copyright (C) 2014-2019 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
/* Verify whether the supplied clockid is supported by
lll_futex_clock_wait_bitset. */
#define lll_futex_supported_clockid(clockid) \
(0)
/* Wait until a lll_futex_wake call on FUTEXP, or the absolute TIMEOUT
measured against CLOCKID elapses. CLOCKID may be CLOCK_REALTIME or
CLOCK_MONOTONIC. */
#define lll_futex_clock_wait_bitset(futexp, val, clockid, timeout, 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
/* Like lll_futex_wait, but acting as a cancellable entrypoint. */
#define lll_futex_wait_cancel(futexp, val, private) \
-ENOSYS
/* Like lll_futex_timed_wait, but acting as a cancellable entrypoint. */
#define lll_futex_timed_wait_cancel(futexp, val, timeout, private) \
-ENOSYS
#endif /* lowlevellock-futex.h */