glibc/sysdeps/nptl/aio_misc.h
Lukasz Majewski cc5d5852c6 y2038: Convert aio_suspend to support 64 bit time
The aio_suspend function has been converted to support 64 bit time.

This change uses (in aio_misc.h):
- __futex_abstimed_wait64 (instead of futex_reltimed_wait)
- __futex_abstimed_wait_cancellable64
	(instead of futex_reltimed_wait_cancellable)
    from ./sysdeps/nptl/futex-helpers.h

The aio_suspend() accepts relative timeout, which then is converted to
absolute one.

The i686-gnu port (HURD) do not define DONT_NEED_AIO_MISC_COND and as it
doesn't (yet) support 64 bit time it uses not converted
pthread_cond_timedwait().

The __aio_suspend() is supposed to be run on ports with __TIMESIZE !=64 and
__WORDSIZE==32. It internally utilizes __aio_suspend_time64() and hence the
conversion from 32 bit struct timespec to 64 bit one is required.

For ports supporting 64 bit time the __aio_suspend_time64() will be used
either via alias (to __aio_suspend when __TIMESIZE==64) or redirection
(when -D_TIME_BITS=64 is passed).

Build tests:
./src/scripts/build-many-glibcs.py glibcs

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-11-30 14:08:44 +01:00

75 lines
2.7 KiB
C

/* Copyright (C) 2006-2020 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
<https://www.gnu.org/licenses/>. */
/* We define a special synchronization primitive for AIO. POSIX
conditional variables would be ideal but the pthread_cond_*wait
operations do not return on EINTR. This is a requirement for
correct aio_suspend and lio_listio implementations. */
#include <assert.h>
#include <nptl/pthreadP.h>
#include <futex-internal.h>
#define DONT_NEED_AIO_MISC_COND 1
#define AIO_MISC_NOTIFY(waitlist) \
do { \
if (*waitlist->counterp > 0 && --*waitlist->counterp == 0) \
futex_wake ((unsigned int *) waitlist->counterp, 1, FUTEX_PRIVATE); \
} while (0)
#define AIO_MISC_WAIT(result, futex, timeout, cancel) \
do { \
volatile unsigned int *futexaddr = &futex; \
unsigned int oldval = futex; \
\
if (oldval != 0) \
{ \
pthread_mutex_unlock (&__aio_requests_mutex); \
\
int status; \
do \
{ \
if (cancel) \
status = __futex_abstimed_wait_cancelable64 ( \
(unsigned int *) futexaddr, oldval, CLOCK_MONOTONIC, timeout, \
FUTEX_PRIVATE); \
else \
status = __futex_abstimed_wait64 ((unsigned int *) futexaddr, \
oldval, CLOCK_REALTIME, timeout, FUTEX_PRIVATE); \
if (status != EAGAIN) \
break; \
\
oldval = *futexaddr; \
} \
while (oldval != 0); \
\
if (status == EINTR) \
result = EINTR; \
else if (status == ETIMEDOUT) \
result = EAGAIN; \
else if (status == EOVERFLOW) \
result = EOVERFLOW; \
else \
assert (status == 0 || status == EAGAIN); \
\
pthread_mutex_lock (&__aio_requests_mutex); \
} \
} while (0)
#include_next <aio_misc.h>