82 lines
2.3 KiB
C
82 lines
2.3 KiB
C
/*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*
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* The Original Code is Copyright (C) 2018 Blender Foundation.
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* All rights reserved.
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*/
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/** \file
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* \ingroup bli
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*/
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#include "MEM_guardedalloc.h"
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#include "BLI_linklist_lockfree.h"
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#include "BLI_strict_flags.h"
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#include "atomic_ops.h"
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void BLI_linklist_lockfree_init(LockfreeLinkList *list)
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{
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list->dummy_node.next = NULL;
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list->head = list->tail = &list->dummy_node;
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}
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void BLI_linklist_lockfree_free(LockfreeLinkList *list, LockfreeeLinkNodeFreeFP free_func)
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{
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if (free_func != NULL) {
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/* NOTE: We start from a first user-added node. */
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LockfreeLinkNode *node = list->head->next;
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while (node != NULL) {
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LockfreeLinkNode *node_next = node->next;
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free_func(node);
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node = node_next;
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}
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}
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}
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void BLI_linklist_lockfree_clear(LockfreeLinkList *list, LockfreeeLinkNodeFreeFP free_func)
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{
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BLI_linklist_lockfree_free(list, free_func);
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BLI_linklist_lockfree_init(list);
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}
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void BLI_linklist_lockfree_insert(LockfreeLinkList *list, LockfreeLinkNode *node)
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{
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/* Based on:
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*
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* John D. Valois
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* Implementing Lock-Free Queues
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*
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* http://people.csail.mit.edu/bushl2/rpi/portfolio/lockfree-grape/documents/lock-free-linked-lists.pdf
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*/
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bool keep_working;
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LockfreeLinkNode *tail_node;
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node->next = NULL;
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do {
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tail_node = list->tail;
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keep_working = (atomic_cas_ptr((void **)&tail_node->next, NULL, node) != NULL);
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if (keep_working) {
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atomic_cas_ptr((void **)&list->tail, tail_node, tail_node->next);
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}
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} while (keep_working);
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atomic_cas_ptr((void **)&list->tail, tail_node, node);
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}
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LockfreeLinkNode *BLI_linklist_lockfree_begin(LockfreeLinkList *list)
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{
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return list->head->next;
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}
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