1 /* Copyright (C) 2003, 2004, 2007 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Martin Schwidefsky <schwidefsky@de.ibm.com>, 2003.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
22 #include <lowlevellock.h>
26 /* Wait on barrier. */
28 pthread_barrier_wait (barrier
)
29 pthread_barrier_t
*barrier
;
31 struct pthread_barrier
*ibarrier
= (struct pthread_barrier
*) barrier
;
34 /* Make sure we are alone. */
35 lll_lock (ibarrier
->lock
);
37 /* One more arrival. */
41 if (ibarrier
->left
== 0)
43 /* Yes. Increment the event counter to avoid invalid wake-ups and
44 tell the current waiters that it is their turn. */
45 ++ibarrier
->curr_event
;
47 /* Wake up everybody. */
48 lll_futex_wake (&ibarrier
->curr_event
, INT_MAX
,
49 // XYZ check mutex flag
52 /* This is the thread which finished the serialization. */
53 result
= PTHREAD_BARRIER_SERIAL_THREAD
;
57 /* The number of the event we are waiting for. The barrier's event
58 number must be bumped before we continue. */
59 unsigned int event
= ibarrier
->curr_event
;
61 /* Before suspending, make the barrier available to others. */
62 lll_unlock (ibarrier
->lock
);
64 /* Wait for the event counter of the barrier to change. */
66 lll_futex_wait (&ibarrier
->curr_event
, event
,
67 // XYZ check mutex flag
69 while (event
== ibarrier
->curr_event
);
72 /* Make sure the init_count is stored locally or in a register. */
73 unsigned int init_count
= ibarrier
->init_count
;
75 /* If this was the last woken thread, unlock. */
76 if (atomic_increment_val (&ibarrier
->left
) == init_count
)
78 lll_unlock (ibarrier
->lock
);