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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 | /* low level locking for pthread library. Generic futex-using version.
Copyright (C) 2003, 2005, 2007 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <errno.h>
#include <sysdep.h>
#include <lowlevellock.h>
#include <sys/time.h>
#include <tls.h>
void
#ifndef IS_IN_libpthread
weak_function
#endif
__lll_lock_wait_private (int *futex)
{
do
{
int oldval = atomic_compare_and_exchange_val_acq (futex, 2, 1);
if (oldval != 0)
lll_futex_wait (futex, 2, LLL_PRIVATE);
}
while (atomic_compare_and_exchange_bool_acq (futex, 2, 0) != 0);
}
/* These functions don't get included in libc.so */
#ifdef IS_IN_libpthread
void
__lll_lock_wait (int *futex, int private)
{
do
{
int oldval = atomic_compare_and_exchange_val_acq (futex, 2, 1);
if (oldval != 0)
lll_futex_wait (futex, 2, private);
}
while (atomic_compare_and_exchange_bool_acq (futex, 2, 0) != 0);
}
int
__lll_timedlock_wait (int *futex, const struct timespec *abstime, int private)
{
struct timespec rt;
/* Reject invalid timeouts. */
if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
return EINVAL;
/* Upgrade the lock. */
if (atomic_exchange_acq (futex, 2) == 0)
return 0;
do
{
struct timeval tv;
/* Get the current time. */
(void) gettimeofday (&tv, NULL);
/* Compute relative timeout. */
rt.tv_sec = abstime->tv_sec - tv.tv_sec;
rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000;
if (rt.tv_nsec < 0)
{
rt.tv_nsec += 1000000000;
--rt.tv_sec;
}
/* Already timed out? */
if (rt.tv_sec < 0)
return ETIMEDOUT;
// XYZ: Lost the lock to check whether it was private.
lll_futex_timed_wait (futex, 2, &rt, private);
}
while (atomic_compare_and_exchange_bool_acq (futex, 2, 0) != 0);
return 0;
}
int
__lll_timedwait_tid (int *tidp, const struct timespec *abstime)
{
int tid;
if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
return EINVAL;
/* Repeat until thread terminated. */
while ((tid = *tidp) != 0)
{
struct timeval tv;
struct timespec rt;
/* Get the current time. */
(void) gettimeofday (&tv, NULL);
/* Compute relative timeout. */
rt.tv_sec = abstime->tv_sec - tv.tv_sec;
rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000;
if (rt.tv_nsec < 0)
{
rt.tv_nsec += 1000000000;
--rt.tv_sec;
}
/* Already timed out? */
if (rt.tv_sec < 0)
return ETIMEDOUT;
/* Wait until thread terminates. */
// XYZ: Lost the lock to check whether it was private.
if (lll_futex_timed_wait (tidp, tid, &rt, LLL_SHARED) == -ETIMEDOUT)
return ETIMEDOUT;
}
return 0;
}
#endif
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