1 /* Copyright (C) 2005, 2008, 2009 Free Software Foundation, Inc.
2 Contributed by Richard Henderson <rth@redhat.com>.
3
4 This file is part of the GNU OpenMP Library (libgomp).
5
6 Libgomp is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3, or (at your option)
9 any later version.
10
11 Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
13 FOR A PARTICULAR PURPOSE. See the GNU General Public License for
14 more details.
15
16 Under Section 7 of GPL version 3, you are granted additional
17 permissions described in the GCC Runtime Library Exception, version
18 3.1, as published by the Free Software Foundation.
19
20 You should have received a copy of the GNU General Public License and
21 a copy of the GCC Runtime Library Exception along with this program;
22 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 <http://www.gnu.org/licenses/>. */
24
25 /* This is the default implementation of a barrier synchronization mechanism
26 for libgomp. This type is private to the library. Note that we rely on
27 being able to adjust the barrier count while threads are blocked, so the
28 POSIX pthread_barrier_t won't work. */
29
30 #ifndef GOMP_BARRIER_H
31 #define GOMP_BARRIER_H 1
32
33 #include <pthread.h>
34
35 typedef struct
36 {
37 gomp_mutex_t mutex1;
38 #ifndef HAVE_SYNC_BUILTINS
39 gomp_mutex_t mutex2;
40 #endif
41 gomp_sem_t sem1;
42 gomp_sem_t sem2;
43 unsigned total;
44 unsigned arrived;
45 unsigned generation;
46 } gomp_barrier_t;
47 typedef unsigned int gomp_barrier_state_t;
48
49 extern void gomp_barrier_init (gomp_barrier_t *, unsigned);
50 extern void gomp_barrier_reinit (gomp_barrier_t *, unsigned);
51 extern void gomp_barrier_destroy (gomp_barrier_t *);
52
53 extern void gomp_barrier_wait (gomp_barrier_t *);
54 extern void gomp_barrier_wait_end (gomp_barrier_t *, gomp_barrier_state_t);
55 extern void gomp_team_barrier_wait (gomp_barrier_t *);
56 extern void gomp_team_barrier_wait_end (gomp_barrier_t *,
57 gomp_barrier_state_t);
58 extern void gomp_team_barrier_wake (gomp_barrier_t *, int);
59
60 static inline gomp_barrier_state_t
gomp_barrier_wait_start(gomp_barrier_t * bar)61 gomp_barrier_wait_start (gomp_barrier_t *bar)
62 {
63 unsigned int ret;
64 gomp_mutex_lock (&bar->mutex1);
65 ret = bar->generation & ~3;
66 ret += ++bar->arrived == bar->total;
67 return ret;
68 }
69
70 static inline bool
gomp_barrier_last_thread(gomp_barrier_state_t state)71 gomp_barrier_last_thread (gomp_barrier_state_t state)
72 {
73 return state & 1;
74 }
75
76 static inline void
gomp_barrier_wait_last(gomp_barrier_t * bar)77 gomp_barrier_wait_last (gomp_barrier_t *bar)
78 {
79 gomp_barrier_wait (bar);
80 }
81
82 /* All the inlines below must be called with team->task_lock
83 held. */
84
85 static inline void
gomp_team_barrier_set_task_pending(gomp_barrier_t * bar)86 gomp_team_barrier_set_task_pending (gomp_barrier_t *bar)
87 {
88 bar->generation |= 1;
89 }
90
91 static inline void
gomp_team_barrier_clear_task_pending(gomp_barrier_t * bar)92 gomp_team_barrier_clear_task_pending (gomp_barrier_t *bar)
93 {
94 bar->generation &= ~1;
95 }
96
97 static inline void
gomp_team_barrier_set_waiting_for_tasks(gomp_barrier_t * bar)98 gomp_team_barrier_set_waiting_for_tasks (gomp_barrier_t *bar)
99 {
100 bar->generation |= 2;
101 }
102
103 static inline bool
gomp_team_barrier_waiting_for_tasks(gomp_barrier_t * bar)104 gomp_team_barrier_waiting_for_tasks (gomp_barrier_t *bar)
105 {
106 return (bar->generation & 2) != 0;
107 }
108
109 static inline void
gomp_team_barrier_done(gomp_barrier_t * bar,gomp_barrier_state_t state)110 gomp_team_barrier_done (gomp_barrier_t *bar, gomp_barrier_state_t state)
111 {
112 bar->generation = (state & ~3) + 4;
113 }
114
115 #endif /* GOMP_BARRIER_H */
116