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author | Jakub Jelinek <jakub@redhat.com> | 2007-07-12 18:26:36 +0000 |
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committer | Jakub Jelinek <jakub@redhat.com> | 2007-07-12 18:26:36 +0000 |
commit | 0ecb606cb6cf65de1d9fc8a919bceb4be476c602 (patch) | |
tree | 2ea1f8305970753e4a657acb2ccc15ca3eec8e2c /nptl/sysdeps/unix/sysv/linux/lowlevelrobustlock.c | |
parent | 7d58530341304d403a6626d7f7a1913165fe2f32 (diff) | |
download | glibc-0ecb606cb6cf65de1d9fc8a919bceb4be476c602.tar.gz glibc-0ecb606cb6cf65de1d9fc8a919bceb4be476c602.tar.xz glibc-0ecb606cb6cf65de1d9fc8a919bceb4be476c602.zip |
2.5-18.1
Diffstat (limited to 'nptl/sysdeps/unix/sysv/linux/lowlevelrobustlock.c')
-rw-r--r-- | nptl/sysdeps/unix/sysv/linux/lowlevelrobustlock.c | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/nptl/sysdeps/unix/sysv/linux/lowlevelrobustlock.c b/nptl/sysdeps/unix/sysv/linux/lowlevelrobustlock.c new file mode 100644 index 0000000000..30ef991bd0 --- /dev/null +++ b/nptl/sysdeps/unix/sysv/linux/lowlevelrobustlock.c @@ -0,0 +1,113 @@ +/* Copyright (C) 2006, 2007 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, 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 <pthreadP.h> + + +int +__lll_robust_lock_wait (int *futex) +{ + 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); + + 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) +{ + /* 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; + + do + { + 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. */ + 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_timed_wait (futex, newval, &rt); + + try: + ; + } + while ((oldval = atomic_compare_and_exchange_val_acq (futex, + tid | FUTEX_WAITERS, + 0)) != 0); + + return 0; +} |