libgomp/lock.c

   1 /* Copyright (C) 2005-2018 Free Software Foundation, Inc.
   2    Contributed by Richard Henderson <rth@redhat.com>.
   3
   4    This file is part of the GNU Offloading and Multi Processing Library
   5    (libgomp).
   6
   7    Libgomp is free software; you can redistribute it and/or modify it
   8    under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3, or (at your option)
  10    any later version.
  11
  12    Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
  13    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  14    FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  15    more details.
  16
  17    Under Section 7 of GPL version 3, you are granted additional
  18    permissions described in the GCC Runtime Library Exception, version
  19    3.1, as published by the Free Software Foundation.
  20
  21    You should have received a copy of the GNU General Public License and
  22    a copy of the GCC Runtime Library Exception along with this program;
  23    see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24    <http://www.gnu.org/licenses/>.  */
  25
  26 /* This is a generic implementation of the public OpenMP locking primitives in
  27    terms of internal gomp_mutex_t.  It is not meant to be compiled on its own.
  28    It is #include'd from config/{linux,nvptx}/lock.c.  */
  29
  30 #include <string.h>
  31 #include "libgomp.h"
  32
  33 /* The internal gomp_mutex_t and the external non-recursive omp_lock_t
  34    have the same form.  Re-use it.  */
  35
  36 void
  37 gomp_init_lock_30 (omp_lock_t *lock)
  38 {
  39   gomp_mutex_init (lock);
  40 }
  41
  42 void
  43 gomp_destroy_lock_30 (omp_lock_t *lock)
  44 {
  45   gomp_mutex_destroy (lock);
  46 }
  47
  48 void
  49 gomp_set_lock_30 (omp_lock_t *lock)
  50 {
  51   gomp_mutex_lock (lock);
  52 }
  53
  54 void
  55 gomp_unset_lock_30 (omp_lock_t *lock)
  56 {
  57   gomp_mutex_unlock (lock);
  58 }
  59
  60 int
  61 gomp_test_lock_30 (omp_lock_t *lock)
  62 {
  63   int oldval = 0;
  64
  65   return __atomic_compare_exchange_n (lock, &oldval, 1, false,
  66                                       MEMMODEL_ACQUIRE, MEMMODEL_RELAXED);
  67 }
  68
  69 void
  70 gomp_init_nest_lock_30 (omp_nest_lock_t *lock)
  71 {
  72   memset (lock, '\0', sizeof (*lock));
  73 }
  74
  75 void
  76 gomp_destroy_nest_lock_30 (omp_nest_lock_t *lock)
  77 {
  78 }
  79
  80 void
  81 gomp_set_nest_lock_30 (omp_nest_lock_t *lock)
  82 {
  83   void *me = gomp_icv (true);
  84
  85   if (lock->owner != me)
  86     {
  87       gomp_mutex_lock (&lock->lock);
  88       lock->owner = me;
  89     }
  90
  91   lock->count++;
  92 }
  93
  94 void
  95 gomp_unset_nest_lock_30 (omp_nest_lock_t *lock)
  96 {
  97   if (--lock->count == 0)
  98     {
  99       lock->owner = NULL;
 100       gomp_mutex_unlock (&lock->lock);
 101     }
 102 }
 103
 104 int
 105 gomp_test_nest_lock_30 (omp_nest_lock_t *lock)
 106 {
 107   void *me = gomp_icv (true);
 108   int oldval;
 109
 110   if (lock->owner == me)
 111     return ++lock->count;
 112
 113   oldval = 0;
 114   if (__atomic_compare_exchange_n (&lock->lock, &oldval, 1, false,
 115                                    MEMMODEL_ACQUIRE, MEMMODEL_RELAXED))
 116     {
 117       lock->owner = me;
 118       lock->count = 1;
 119       return 1;
 120     }
 121
 122   return 0;
 123 }