1 /* low level locking for pthread library. Generic futex-using version.
2 Copyright (C) 2003, 2007 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, write to the Free
18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
23 #include <lowlevellock.h>
27 __lll_lock_wait (lll_lock_t *futex, int private)
31 int oldval = atomic_compare_and_exchange_val_acq (futex, 2, 1);
33 lll_futex_wait (futex, 2, private);
35 while (atomic_compare_and_exchange_val_acq (futex, 2, 0) != 0);
39 __lll_lock_wait_private (lll_lock_t *futex)
43 int oldval = atomic_compare_and_exchange_val_acq (futex, 2, 1);
45 lll_futex_wait (futex, 2, LLL_PRIVATE);
47 while (atomic_compare_and_exchange_val_acq (futex, 2, 0) != 0);
51 __lll_timedlock_wait (lll_lock_t *futex, const struct timespec *abstime, int private)
53 /* Reject invalid timeouts. */
54 if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
62 /* Get the current time. */
63 (void) __gettimeofday (&tv, NULL);
65 /* Compute relative timeout. */
66 rt.tv_sec = abstime->tv_sec - tv.tv_sec;
67 rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000;
70 rt.tv_nsec += 1000000000;
74 /* Already timed out? */
79 int oldval = atomic_compare_and_exchange_val_acq (futex, 2, 1);
81 lll_futex_timed_wait (futex, 2, &rt, private);
83 while (atomic_compare_and_exchange_bool_acq (futex, 2, 0) != 0);
88 /* These don't get included in libc.so */
89 #ifdef IS_IN_libpthread
91 lll_unlock_wake_cb (lll_lock_t *futex)
93 int val = atomic_exchange_rel (futex, 0);
95 if (__builtin_expect (val > 1, 0))
96 lll_private_futex_wake (futex, 1);
102 __lll_timedwait_tid (int *tidp, const struct timespec *abstime)
106 if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
109 /* Repeat until thread terminated. */
110 while ((tid = *tidp) != 0)
115 /* Get the current time. */
116 (void) __gettimeofday (&tv, NULL);
118 /* Compute relative timeout. */
119 rt.tv_sec = abstime->tv_sec - tv.tv_sec;
120 rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000;
123 rt.tv_nsec += 1000000000;
127 /* Already timed out? */
131 /* Wait until thread terminates. */
132 if (lll_futex_timed_wait (tidp, tid, &rt, LLL_SHARED) == -ETIMEDOUT)