diff options
Diffstat (limited to 'sysdeps/sparc/sparc32/pthread_barrier_wait.c')
| -rw-r--r-- | sysdeps/sparc/sparc32/pthread_barrier_wait.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/sysdeps/sparc/sparc32/pthread_barrier_wait.c b/sysdeps/sparc/sparc32/pthread_barrier_wait.c new file mode 100644 index 0000000000..0fed908865 --- /dev/null +++ b/sysdeps/sparc/sparc32/pthread_barrier_wait.c @@ -0,0 +1,93 @@ +/* Copyright (C) 2003-2014 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Martin Schwidefsky <schwidefsky@de.ibm.com>, 2003. + + 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 <pthreadP.h> + +/* Wait on barrier. */ +int +pthread_barrier_wait (barrier) + pthread_barrier_t *barrier; +{ + union sparc_pthread_barrier *ibarrier + = (union sparc_pthread_barrier *) barrier; + int result = 0; + int private = ibarrier->s.pshared ? LLL_SHARED : LLL_PRIVATE; + + /* Make sure we are alone. */ + lll_lock (ibarrier->b.lock, private); + + /* One more arrival. */ + --ibarrier->b.left; + + /* Are these all? */ + if (ibarrier->b.left == 0) + { + /* Yes. Increment the event counter to avoid invalid wake-ups and + tell the current waiters that it is their turn. */ + ++ibarrier->b.curr_event; + + /* Wake up everybody. */ + lll_futex_wake (&ibarrier->b.curr_event, INT_MAX, private); + + /* This is the thread which finished the serialization. */ + result = PTHREAD_BARRIER_SERIAL_THREAD; + } + else + { + /* The number of the event we are waiting for. The barrier's event + number must be bumped before we continue. */ + unsigned int event = ibarrier->b.curr_event; + + /* Before suspending, make the barrier available to others. */ + lll_unlock (ibarrier->b.lock, private); + + /* Wait for the event counter of the barrier to change. */ + do + lll_futex_wait (&ibarrier->b.curr_event, event, private); + while (event == ibarrier->b.curr_event); + } + + /* Make sure the init_count is stored locally or in a register. */ + unsigned int init_count = ibarrier->b.init_count; + + /* If this was the last woken thread, unlock. */ + if (__atomic_is_v9 || ibarrier->s.pshared == 0) + { + if (atomic_increment_val (&ibarrier->b.left) == init_count) + /* We are done. */ + lll_unlock (ibarrier->b.lock, private); + } + else + { + unsigned int left; + /* Slightly more complicated. On pre-v9 CPUs, atomic_increment_val + is only atomic for threads within the same process, not for + multiple processes. */ + __sparc32_atomic_do_lock24 (&ibarrier->s.left_lock); + left = ++ibarrier->b.left; + __sparc32_atomic_do_unlock24 (&ibarrier->s.left_lock); + if (left == init_count) + /* We are done. */ + lll_unlock (ibarrier->b.lock, private); + } + + return result; +} |