| /* Copyright (C) 2006-2014 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Jakub Jelinek <jakub@redhat.com>, 2006. |
| |
| 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/>. */ |
| |
| #include <errno.h> |
| #include <sysdep.h> |
| #include <lowlevellock.h> |
| #include <sys/time.h> |
| #include <pthreadP.h> |
| |
| |
| int |
| __lll_robust_lock_wait (int *futex, int private) |
| { |
| int oldval = *futex; |
| int tid = THREAD_GETMEM (THREAD_SELF, tid); |
| |
| /* If the futex changed meanwhile try locking again. */ |
| if (oldval == 0) |
| goto try; |
| |
| do |
| { |
| if (__builtin_expect (oldval & FUTEX_OWNER_DIED, 0)) |
| return oldval; |
| |
| int newval = oldval | FUTEX_WAITERS; |
| if (oldval != newval |
| && atomic_compare_and_exchange_bool_acq (futex, newval, oldval)) |
| continue; |
| |
| lll_futex_wait (futex, newval, private); |
| |
| try: |
| ; |
| } |
| while ((oldval = atomic_compare_and_exchange_val_acq (futex, |
| tid | FUTEX_WAITERS, |
| 0)) != 0); |
| return 0; |
| } |
| |
| |
| int |
| __lll_robust_timedlock_wait (int *futex, const struct timespec *abstime, |
| int private) |
| { |
| /* Reject invalid timeouts. */ |
| if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000) |
| return EINVAL; |
| |
| int tid = THREAD_GETMEM (THREAD_SELF, tid); |
| int oldval = *futex; |
| |
| /* If the futex changed meanwhile try locking again. */ |
| if (oldval == 0) |
| goto try; |
| |
| /* Work around the fact that the kernel rejects negative timeout values |
| despite them being valid. */ |
| if (__builtin_expect (abstime->tv_sec < 0, 0)) |
| return ETIMEDOUT; |
| |
| do |
| { |
| #if (!defined __ASSUME_FUTEX_CLOCK_REALTIME \ |
| || !defined lll_futex_timed_wait_bitset) |
| 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; |
| #endif |
| |
| /* Wait. */ |
| if (__builtin_expect (oldval & FUTEX_OWNER_DIED, 0)) |
| return oldval; |
| |
| int newval = oldval | FUTEX_WAITERS; |
| if (oldval != newval |
| && atomic_compare_and_exchange_bool_acq (futex, newval, oldval)) |
| continue; |
| |
| #if (!defined __ASSUME_FUTEX_CLOCK_REALTIME \ |
| || !defined lll_futex_timed_wait_bitset) |
| lll_futex_timed_wait (futex, newval, &rt, private); |
| #else |
| lll_futex_timed_wait_bitset (futex, newval, abstime, |
| FUTEX_CLOCK_REALTIME, private); |
| #endif |
| |
| try: |
| ; |
| } |
| while ((oldval = atomic_compare_and_exchange_val_acq (futex, |
| tid | FUTEX_WAITERS, |
| 0)) != 0); |
| |
| return 0; |
| } |