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136 lines
3.2 KiB
C
136 lines
3.2 KiB
C
/* low level locking for pthread library. Generic futex-using version.
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Copyright (C) 2003 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#include <errno.h>
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#include <sysdep.h>
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#include <lowlevellock.h>
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#include <sys/time.h>
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void
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__lll_lock_wait (int *futex, int val)
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{
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do
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{
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lll_futex_wait (futex, val + 1);
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val = atomic_exchange_and_add (futex, 1);
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}
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while (val != 0);
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*futex = 2;
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}
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hidden_proto (__lll_lock_wait)
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int
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__lll_timedlock_wait (int *futex, int val, const struct timespec *abstime)
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{
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/* Reject invalid timeouts. */
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if (abstime->tv_nsec >= 1000000000)
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return EINVAL;
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do
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{
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struct timeval tv;
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struct timespec rt;
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/* Get the current time. */
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(void) __gettimeofday (&tv, NULL);
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/* Compute relative timeout. */
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rt.tv_sec = abstime->tv_sec - tv.tv_sec;
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rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000;
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if (rt.tv_nsec < 0)
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{
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rt.tv_nsec += 1000000000;
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--rt.tv_sec;
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}
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/* Already timed out? */
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if (rt.tv_sec < 0)
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return ETIMEDOUT;
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/* Wait. */
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if (lll_futex_timed_wait (futex, val + 1, &rt) == -ETIMEDOUT)
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return ETIMEDOUT;
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}
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while ((val = atomic_exchange_and_add (futex, 1)) != 0);
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*futex = 2;
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return 0;
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}
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hidden_proto (__lll_timedlock_wait)
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/* These don't get included in libc.so */
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#ifdef IS_IN_libpthread
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int
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lll_unlock_wake_cb (int *futex)
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{
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int val = atomic_exchange (futex, 0);
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if (__builtin_expect (val > 1, 0))
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lll_futex_wake (futex, 1);
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return 0;
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}
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hidden_proto (lll_unlock_wake_cb)
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int
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__lll_timedwait_tid (int *tidp, const struct timespec *abstime)
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{
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int tid;
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if (abstime->tv_nsec >= 1000000000)
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return EINVAL;
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/* Repeat until thread terminated. */
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while ((tid = *tidp) != 0)
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{
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struct timeval tv;
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struct timespec rt;
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/* Get the current time. */
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(void) __gettimeofday (&tv, NULL);
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/* Compute relative timeout. */
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rt.tv_sec = abstime->tv_sec - tv.tv_sec;
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rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000;
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if (rt.tv_nsec < 0)
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{
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rt.tv_nsec += 1000000000;
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--rt.tv_sec;
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}
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/* Already timed out? */
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if (rt.tv_sec < 0)
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return ETIMEDOUT;
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/* Wait until thread terminates. */
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if (lll_futex_timed_wait (tidp, tid, &rt) == -ETIMEDOUT)
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return ETIMEDOUT;
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}
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return 0;
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}
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hidden_proto (__lll_timedwait_tid)
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#endif
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