summaryrefslogtreecommitdiff
path: root/libgomp/config/linux/bar.h
diff options
context:
space:
mode:
Diffstat (limited to 'libgomp/config/linux/bar.h')
-rw-r--r--libgomp/config/linux/bar.h118
1 files changed, 118 insertions, 0 deletions
diff --git a/libgomp/config/linux/bar.h b/libgomp/config/linux/bar.h
new file mode 100644
index 000000000..9c1a8a076
--- /dev/null
+++ b/libgomp/config/linux/bar.h
@@ -0,0 +1,118 @@
+/* Copyright (C) 2005, 2008, 2009 Free Software Foundation, Inc.
+ Contributed by Richard Henderson <rth@redhat.com>.
+
+ This file is part of the GNU OpenMP Library (libgomp).
+
+ Libgomp is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3, or (at your option)
+ any later version.
+
+ Libgomp 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 General Public License for
+ more details.
+
+ Under Section 7 of GPL version 3, you are granted additional
+ permissions described in the GCC Runtime Library Exception, version
+ 3.1, as published by the Free Software Foundation.
+
+ You should have received a copy of the GNU General Public License and
+ a copy of the GCC Runtime Library Exception along with this program;
+ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+ <http://www.gnu.org/licenses/>. */
+
+/* This is a Linux specific implementation of a barrier synchronization
+ mechanism for libgomp. This type is private to the library. This
+ implementation uses atomic instructions and the futex syscall. */
+
+#ifndef GOMP_BARRIER_H
+#define GOMP_BARRIER_H 1
+
+#include "mutex.h"
+
+typedef struct
+{
+ /* Make sure total/generation is in a mostly read cacheline, while
+ awaited in a separate cacheline. */
+ unsigned total __attribute__((aligned (64)));
+ unsigned generation;
+ unsigned awaited __attribute__((aligned (64)));
+} gomp_barrier_t;
+typedef unsigned int gomp_barrier_state_t;
+
+static inline void gomp_barrier_init (gomp_barrier_t *bar, unsigned count)
+{
+ bar->total = count;
+ bar->awaited = count;
+ bar->generation = 0;
+}
+
+static inline void gomp_barrier_reinit (gomp_barrier_t *bar, unsigned count)
+{
+ __sync_fetch_and_add (&bar->awaited, count - bar->total);
+ bar->total = count;
+}
+
+static inline void gomp_barrier_destroy (gomp_barrier_t *bar)
+{
+}
+
+extern void gomp_barrier_wait (gomp_barrier_t *);
+extern void gomp_barrier_wait_last (gomp_barrier_t *);
+extern void gomp_barrier_wait_end (gomp_barrier_t *, gomp_barrier_state_t);
+extern void gomp_team_barrier_wait (gomp_barrier_t *);
+extern void gomp_team_barrier_wait_end (gomp_barrier_t *,
+ gomp_barrier_state_t);
+extern void gomp_team_barrier_wake (gomp_barrier_t *, int);
+
+static inline gomp_barrier_state_t
+gomp_barrier_wait_start (gomp_barrier_t *bar)
+{
+ unsigned int ret = bar->generation & ~3;
+ /* Do we need any barrier here or is __sync_add_and_fetch acting
+ as the needed LoadLoad barrier already? */
+ ret += __sync_add_and_fetch (&bar->awaited, -1) == 0;
+ return ret;
+}
+
+static inline bool
+gomp_barrier_last_thread (gomp_barrier_state_t state)
+{
+ return state & 1;
+}
+
+/* All the inlines below must be called with team->task_lock
+ held. */
+
+static inline void
+gomp_team_barrier_set_task_pending (gomp_barrier_t *bar)
+{
+ bar->generation |= 1;
+}
+
+static inline void
+gomp_team_barrier_clear_task_pending (gomp_barrier_t *bar)
+{
+ bar->generation &= ~1;
+}
+
+static inline void
+gomp_team_barrier_set_waiting_for_tasks (gomp_barrier_t *bar)
+{
+ bar->generation |= 2;
+}
+
+static inline bool
+gomp_team_barrier_waiting_for_tasks (gomp_barrier_t *bar)
+{
+ return (bar->generation & 2) != 0;
+}
+
+static inline void
+gomp_team_barrier_done (gomp_barrier_t *bar, gomp_barrier_state_t state)
+{
+ bar->generation = (state & ~3) + 4;
+}
+
+#endif /* GOMP_BARRIER_H */