diff options
Diffstat (limited to 'libpthread/sysdeps/generic/pt-barrier-wait.c')
-rw-r--r-- | libpthread/sysdeps/generic/pt-barrier-wait.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/libpthread/sysdeps/generic/pt-barrier-wait.c b/libpthread/sysdeps/generic/pt-barrier-wait.c new file mode 100644 index 00000000..f1de250a --- /dev/null +++ b/libpthread/sysdeps/generic/pt-barrier-wait.c @@ -0,0 +1,61 @@ +/* pthread_barrier_wait. Generic version. + Copyright (C) 2002 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <pthread.h> +#include <assert.h> + +#include <pt-internal.h> + +int +pthread_barrier_wait (pthread_barrier_t *barrier) +{ + __pthread_spin_lock (&barrier->lock); + if (-- barrier->pending == 0) + { + barrier->pending = barrier->count; + + if (barrier->count > 1) + { + struct __pthread *wakeup; + + wakeup = barrier->queue; + barrier->queue = NULL; + __pthread_spin_unlock (&barrier->lock); + + /* We can safely walk the list of waiting threads without + holding the lock since it is decoupled from the barrier + variable now. */ + __pthread_dequeuing_iterate (wakeup, wakeup) + __pthread_wakeup (wakeup); + } + + return PTHREAD_BARRIER_SERIAL_THREAD; + } + else + { + struct __pthread *self = _pthread_self (); + + /* Add ourselves to the list of waiters. */ + __pthread_enqueue (&barrier->queue, self); + __pthread_spin_unlock (&barrier->lock); + + __pthread_block (self); + return 0; + } +} |