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1 | /* Copyright (C) 2003, 2004, 2006, 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. | |
4 | ||
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. | |
9 | ||
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. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public | |
59ba27a6 PE |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ | |
e51deae7 UD |
18 | |
19 | #include <errno.h> | |
20 | #include <sysdep.h> | |
21 | #include <lowlevellock.h> | |
22 | #include <pthreadP.h> | |
23 | ||
24 | /* Wait on barrier. */ | |
25 | int | |
26 | pthread_barrier_wait (barrier) | |
27 | pthread_barrier_t *barrier; | |
28 | { | |
29 | union sparc_pthread_barrier *ibarrier | |
30 | = (union sparc_pthread_barrier *) barrier; | |
31 | int result = 0; | |
32 | int private = ibarrier->s.pshared ? LLL_SHARED : LLL_PRIVATE; | |
33 | ||
34 | /* Make sure we are alone. */ | |
35 | lll_lock (ibarrier->b.lock, private); | |
36 | ||
37 | /* One more arrival. */ | |
38 | --ibarrier->b.left; | |
39 | ||
40 | /* Are these all? */ | |
41 | if (ibarrier->b.left == 0) | |
42 | { | |
43 | /* Yes. Increment the event counter to avoid invalid wake-ups and | |
44 | tell the current waiters that it is their turn. */ | |
45 | ++ibarrier->b.curr_event; | |
46 | ||
47 | /* Wake up everybody. */ | |
48 | lll_futex_wake (&ibarrier->b.curr_event, INT_MAX, private); | |
49 | ||
50 | /* This is the thread which finished the serialization. */ | |
51 | result = PTHREAD_BARRIER_SERIAL_THREAD; | |
52 | } | |
53 | else | |
54 | { | |
55 | /* The number of the event we are waiting for. The barrier's event | |
56 | number must be bumped before we continue. */ | |
57 | unsigned int event = ibarrier->b.curr_event; | |
58 | ||
59 | /* Before suspending, make the barrier available to others. */ | |
60 | lll_unlock (ibarrier->b.lock, private); | |
61 | ||
62 | /* Wait for the event counter of the barrier to change. */ | |
63 | do | |
64 | lll_futex_wait (&ibarrier->b.curr_event, event, private); | |
65 | while (event == ibarrier->b.curr_event); | |
66 | } | |
67 | ||
68 | /* Make sure the init_count is stored locally or in a register. */ | |
69 | unsigned int init_count = ibarrier->b.init_count; | |
70 | ||
71 | /* If this was the last woken thread, unlock. */ | |
72 | if (atomic_increment_val (&ibarrier->b.left) == init_count) | |
73 | /* We are done. */ | |
74 | lll_unlock (ibarrier->b.lock, private); | |
75 | ||
76 | return result; | |
77 | } |