diff options
Diffstat (limited to 'nptl/sysdeps/unix/sysv/solaris2/kopensolaris-gnu/rw_timedrdlock.c')
-rw-r--r-- | nptl/sysdeps/unix/sysv/solaris2/kopensolaris-gnu/rw_timedrdlock.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/nptl/sysdeps/unix/sysv/solaris2/kopensolaris-gnu/rw_timedrdlock.c b/nptl/sysdeps/unix/sysv/solaris2/kopensolaris-gnu/rw_timedrdlock.c new file mode 100644 index 0000000000..1fd5356f12 --- /dev/null +++ b/nptl/sysdeps/unix/sysv/solaris2/kopensolaris-gnu/rw_timedrdlock.c @@ -0,0 +1,79 @@ +/* Copyright (C) 2008 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by David Bartley <dtbartle@csclub.uwaterloo.ca>, 2008. + + 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 <pthreadP.h> +#include <synch.h> +#include <abstime-to-reltime.h> + + +int __rw_timedrdlock (rwlock, abstime) + rwlock_t *rwlock; + struct timespec *abstime; +{ + /* Reject invalid timeouts. */ + if (INVALID_TIMESPEC (abstime)) + return EINVAL; + + struct timespec _reltime; + struct timespec *reltime = abstime_to_reltime (abstime, &_reltime); + if (reltime && reltime->tv_sec < 0) + return ETIME; + + int errval = mutex_lock (&rwlock->mutex); + if (errval != 0) + return errval; + + /* Check for deadlock. */ + if (__builtin_expect (rwlock->owner == (uintptr_t)THREAD_SELF, 0) || + ((rwlock->type & LOCK_SHARED) && __builtin_expect ( + rwlock->ownerpid == THREAD_GETMEM (THREAD_SELF, pid), 0))) + { + (void)mutex_unlock (&rwlock->mutex); + return EDEADLK; + } + + /* Wait until we can acquire the read lock. */ + while ((rwlock->readers & _RWLOCK_WR_LOCK) || + (__cond_has_waiters (&rwlock->writercv) && + !PTHREAD_RWLOCK_PREFER_READER_P (rwlock))) + { + /* Wait for writer to wake us up. */ + errval = __cond_reltimedwait_internal ((cond_t *)&rwlock->readercv, + (mutex_t *)&rwlock->mutex, reltime, 0); + if (errval != 0 && errval != EINTR) + { + (void)mutex_unlock (&rwlock->mutex); + return errval; + } + } + + /* Increment readers (note that no other bits are set). */ + if (rwlock->readers == _RWLOCK_RD_MAX) + { + /* XXX: Solaris mutexes have no overflow check and don't know about + EAGAIN; in practice overflow will not occur so we don't care. */ + (void)mutex_unlock (&rwlock->mutex); + return EAGAIN; + } + ++rwlock->readers; + + (void)mutex_unlock (&rwlock->mutex); + return 0; +} |