| /* 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 (bare) PARALLEL construct. */ |
| |
| #include "libgomp.h" |
| |
| |
| /* Determine the number of threads to be launched for a PARALLEL construct. |
| This algorithm is explicitly described in OpenMP 2.5 section 2.4.1. |
| SPECIFIED is a combination of the NUM_THREADS clause and the IF clause. |
| If the IF clause is false, SPECIFIED is forced to 1. When NUM_THREADS |
| is not present, SPECIFIED is 0. */ |
| |
| unsigned |
| gomp_resolve_num_threads (unsigned specified) |
| { |
| /* Early exit for false IF condition or degenerate NUM_THREADS. */ |
| if (specified == 1) |
| return 1; |
| |
| /* If this is a nested region, and nested regions are disabled, force |
| this team to use only one thread. */ |
| if (gomp_thread()->ts.team && !gomp_nest_var) |
| return 1; |
| |
| /* If NUM_THREADS not specified, use nthreads_var. */ |
| if (specified == 0) |
| specified = gomp_nthreads_var; |
| |
| /* If dynamic threads are enabled, bound the number of threads |
| that we launch. */ |
| if (gomp_dyn_var) |
| { |
| unsigned dyn = gomp_dynamic_max_threads (); |
| if (dyn < specified) |
| return dyn; |
| } |
| |
| return specified; |
| } |
| |
| void |
| GOMP_parallel_start (void (*fn) (void *), void *data, unsigned num_threads) |
| { |
| num_threads = gomp_resolve_num_threads (num_threads); |
| gomp_team_start (fn, data, num_threads, NULL); |
| } |
| |
| void |
| GOMP_parallel_end (void) |
| { |
| gomp_team_end (); |
| } |
| |
| |
| /* The public OpenMP API for thread and team related inquiries. */ |
| |
| int |
| omp_get_num_threads (void) |
| { |
| struct gomp_team *team = gomp_thread ()->ts.team; |
| return team ? team->nthreads : 1; |
| } |
| |
| /* ??? Does this function need to disregard dyn_var? I don't see |
| how else one could get a useable "maximum". */ |
| |
| int |
| omp_get_max_threads (void) |
| { |
| return gomp_resolve_num_threads (0); |
| } |
| |
| int |
| omp_get_thread_num (void) |
| { |
| return gomp_thread ()->ts.team_id; |
| } |
| |
| /* ??? This isn't right. The definition of this function is false if any |
| of the IF clauses for any of the parallels is false. Which is not the |
| same thing as any outer team having more than one thread. */ |
| |
| int omp_in_parallel (void) |
| { |
| struct gomp_team *team = gomp_thread ()->ts.team; |
| |
| while (team) |
| { |
| if (team->nthreads > 1) |
| return true; |
| team = team->prev_ts.team; |
| } |
| |
| return false; |
| } |
| |
| ialias (omp_get_num_threads) |
| ialias (omp_get_max_threads) |
| ialias (omp_get_thread_num) |
| ialias (omp_in_parallel) |