diff options
Diffstat (limited to 'libpthread/nptl/sysdeps/unix/sysv/linux')
-rw-r--r-- | libpthread/nptl/sysdeps/unix/sysv/linux/lowlevelrobustlock.c | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/lowlevelrobustlock.c b/libpthread/nptl/sysdeps/unix/sysv/linux/lowlevelrobustlock.c new file mode 100644 index 000000000..3830f94da --- /dev/null +++ b/libpthread/nptl/sysdeps/unix/sysv/linux/lowlevelrobustlock.c @@ -0,0 +1,114 @@ +/* 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 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; + + 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, private); + + try: + ; + } + while ((oldval = atomic_compare_and_exchange_val_acq (futex, + tid | FUTEX_WAITERS, + 0)) != 0); + + return 0; +} |