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Diffstat (limited to 'libgomp/config/rtems/bar.h')
| -rw-r--r-- | libgomp/config/rtems/bar.h | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/libgomp/config/rtems/bar.h b/libgomp/config/rtems/bar.h new file mode 100644 index 00000000000..c85dce3c86e --- /dev/null +++ b/libgomp/config/rtems/bar.h @@ -0,0 +1,170 @@ +/* Copyright (C) 2005-2015 Free Software Foundation, Inc. + Contributed by Sebastian Huber <sebastian.huber@embedded-brains.de>. + + 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 the RTEMS implementation of a barrier synchronization + mechanism for libgomp. It is identical to the Linux implementation, except + that the futex API is slightly different. This type is private to the + library. */ + +#ifndef GOMP_BARRIER_H +#define GOMP_BARRIER_H 1 + +#include <sys/lock.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; + struct _Futex_Control futex; + unsigned awaited __attribute__((aligned (64))); + unsigned awaited_final; +} gomp_barrier_t; + +typedef unsigned int gomp_barrier_state_t; + +/* The generation field contains a counter in the high bits, with a few + low bits dedicated to flags. Note that TASK_PENDING and WAS_LAST can + share space because WAS_LAST is never stored back to generation. */ +#define BAR_TASK_PENDING 1 +#define BAR_WAS_LAST 1 +#define BAR_WAITING_FOR_TASK 2 +#define BAR_CANCELLED 4 +#define BAR_INCR 8 + +static inline void gomp_barrier_init (gomp_barrier_t *bar, unsigned count) +{ + bar->total = count; + bar->awaited = count; + bar->awaited_final = count; + bar->generation = 0; + _Futex_Initialize (&bar->futex); +} + +static inline void gomp_barrier_reinit (gomp_barrier_t *bar, unsigned count) +{ + __atomic_add_fetch (&bar->awaited, count - bar->total, MEMMODEL_ACQ_REL); + 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_final (gomp_barrier_t *); +extern void gomp_team_barrier_wait_end (gomp_barrier_t *, + gomp_barrier_state_t); +extern bool gomp_team_barrier_wait_cancel (gomp_barrier_t *); +extern bool gomp_team_barrier_wait_cancel_end (gomp_barrier_t *, + gomp_barrier_state_t); +extern void gomp_team_barrier_wake (gomp_barrier_t *, int); +struct gomp_team; +extern void gomp_team_barrier_cancel (struct gomp_team *); + +static inline gomp_barrier_state_t +gomp_barrier_wait_start (gomp_barrier_t *bar) +{ + unsigned int ret = __atomic_load_n (&bar->generation, MEMMODEL_ACQUIRE); + ret &= -BAR_INCR | BAR_CANCELLED; + /* A memory barrier is needed before exiting from the various forms + of gomp_barrier_wait, to satisfy OpenMP API version 3.1 section + 2.8.6 flush Construct, which says there is an implicit flush during + a barrier region. This is a convenient place to add the barrier, + so we use MEMMODEL_ACQ_REL here rather than MEMMODEL_ACQUIRE. */ + if (__atomic_add_fetch (&bar->awaited, -1, MEMMODEL_ACQ_REL) == 0) + ret |= BAR_WAS_LAST; + return ret; +} + +static inline gomp_barrier_state_t +gomp_barrier_wait_cancel_start (gomp_barrier_t *bar) +{ + return gomp_barrier_wait_start (bar); +} + +/* This is like gomp_barrier_wait_start, except it decrements + bar->awaited_final rather than bar->awaited and should be used + for the gomp_team_end barrier only. */ +static inline gomp_barrier_state_t +gomp_barrier_wait_final_start (gomp_barrier_t *bar) +{ + unsigned int ret = __atomic_load_n (&bar->generation, MEMMODEL_ACQUIRE); + ret &= -BAR_INCR | BAR_CANCELLED; + /* See above gomp_barrier_wait_start comment. */ + if (__atomic_add_fetch (&bar->awaited_final, -1, MEMMODEL_ACQ_REL) == 0) + ret |= BAR_WAS_LAST; + return ret; +} + +static inline bool +gomp_barrier_last_thread (gomp_barrier_state_t state) +{ + return state & BAR_WAS_LAST; +} + +/* 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 |= BAR_TASK_PENDING; +} + +static inline void +gomp_team_barrier_clear_task_pending (gomp_barrier_t *bar) +{ + bar->generation &= ~BAR_TASK_PENDING; +} + +static inline void +gomp_team_barrier_set_waiting_for_tasks (gomp_barrier_t *bar) +{ + bar->generation |= BAR_WAITING_FOR_TASK; +} + +static inline bool +gomp_team_barrier_waiting_for_tasks (gomp_barrier_t *bar) +{ + return (bar->generation & BAR_WAITING_FOR_TASK) != 0; +} + +static inline bool +gomp_team_barrier_cancelled (gomp_barrier_t *bar) +{ + return __builtin_expect ((bar->generation & BAR_CANCELLED) != 0, 0); +} + +static inline void +gomp_team_barrier_done (gomp_barrier_t *bar, gomp_barrier_state_t state) +{ + bar->generation = (state & -BAR_INCR) + BAR_INCR; +} + +#endif /* GOMP_BARRIER_H */ |