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Diffstat (limited to 'libgomp/sections.c')
-rw-r--r-- | libgomp/sections.c | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/libgomp/sections.c b/libgomp/sections.c new file mode 100644 index 00000000000..de0acd843ea --- /dev/null +++ b/libgomp/sections.c @@ -0,0 +1,131 @@ +/* Copyright (C) 2005 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 Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, 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 Lesser General Public License for + more details. + + You should have received a copy of the GNU Lesser General Public License + along with libgomp; see the file COPYING.LIB. If not, write to the + Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, + MA 02110-1301, USA. */ + +/* As a special exception, if you link this library with other files, some + of which are compiled with GCC, to produce an executable, this library + does not by itself cause the resulting executable to be covered by the + GNU General Public License. This exception does not however invalidate + any other reasons why the executable file might be covered by the GNU + General Public License. */ + +/* This file handles the SECTIONS construct. */ + +#include "libgomp.h" + + +/* Initialize the given work share construct from the given arguments. */ + +static inline void +gomp_sections_init (struct gomp_work_share *ws, unsigned count) +{ + ws->sched = GFS_DYNAMIC; + ws->chunk_size = 1; + ws->end = count + 1; + ws->incr = 1; + ws->next = 1; +} + +/* This routine is called when first encountering a sections construct + that is not bound directly to a parallel construct. The first thread + that arrives will create the work-share construct; subsequent threads + will see the construct exists and allocate work from it. + + COUNT is the number of sections in this construct. + + Returns the 1-based section number for this thread to perform, or 0 if + all work was assigned to other threads prior to this thread's arrival. */ + +unsigned +GOMP_sections_start (unsigned count) +{ + struct gomp_thread *thr = gomp_thread (); + long s, e, ret; + + if (gomp_work_share_start (false)) + gomp_sections_init (thr->ts.work_share, count); + + if (gomp_iter_dynamic_next_locked (&s, &e)) + ret = s; + else + ret = 0; + + gomp_mutex_unlock (&thr->ts.work_share->lock); + + return ret; +} + +/* This routine is called when the thread completes processing of the + section currently assigned to it. If the work-share construct is + bound directly to a parallel construct, then the construct may have + been set up before the parallel. In which case, this may be the + first iteration for the thread. + + Returns the 1-based section number for this thread to perform, or 0 if + all work was assigned to other threads prior to this thread's arrival. */ + +unsigned +GOMP_sections_next (void) +{ + struct gomp_thread *thr = gomp_thread (); + long s, e, ret; + + gomp_mutex_lock (&thr->ts.work_share->lock); + if (gomp_iter_dynamic_next_locked (&s, &e)) + ret = s; + else + ret = 0; + gomp_mutex_unlock (&thr->ts.work_share->lock); + + return ret; +} + +/* This routine pre-initializes a work-share construct to avoid one + synchronization once we get into the loop. */ + +void +GOMP_parallel_sections_start (void (*fn) (void *), void *data, + unsigned num_threads, unsigned count) +{ + struct gomp_work_share *ws; + + num_threads = gomp_resolve_num_threads (num_threads); + if (num_threads > count) + num_threads = count; + + ws = gomp_new_work_share (false, num_threads); + gomp_sections_init (ws, count); + gomp_team_start (fn, data, num_threads, ws); +} + +/* The GOMP_section_end* routines are called after the thread is told + that all sections are complete. This first version synchronizes + all threads; the nowait version does not. */ + +void +GOMP_sections_end (void) +{ + gomp_work_share_end (); +} + +void +GOMP_sections_end_nowait (void) +{ + gomp_work_share_end_nowait (); +} |