mono/utils/lock-free-queue.h

   1 /**
   2  * \file
   3  * Lock free queue.
   4  *
   5  * (C) Copyright 2011 Novell, Inc
   6  *
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining
   9  * a copy of this software and associated documentation files (the
  10  * "Software"), to deal in the Software without restriction, including
  11  * without limitation the rights to use, copy, modify, merge, publish,
  12  * distribute, sublicense, and/or sell copies of the Software, and to
  13  * permit persons to whom the Software is furnished to do so, subject to
  14  * the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be
  17  * included in all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  20  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  21  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  22  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  23  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  24  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  25  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  26  */
  27
  28
  29 #ifndef __MONO_LOCKFREEQUEUE_H__
  30 #define __MONO_LOCKFREEQUEUE_H__
  31
  32 #include <glib.h>
  33 #include <mono/utils/mono-publib.h>
  34
  35 //#define QUEUE_DEBUG   1
  36
  37 typedef struct _MonoLockFreeQueueNode MonoLockFreeQueueNode;
  38
  39 struct _MonoLockFreeQueueNode {
  40         MonoLockFreeQueueNode * volatile next;
  41 #ifdef QUEUE_DEBUG
  42         gint32 in_queue;
  43 #endif
  44 };
  45
  46 typedef struct {
  47         MonoLockFreeQueueNode node;
  48         volatile gint32 in_use;
  49 } MonoLockFreeQueueDummy;
  50
  51 #define MONO_LOCK_FREE_QUEUE_NUM_DUMMIES        2
  52
  53 typedef struct {
  54         MonoLockFreeQueueNode * volatile head;
  55         MonoLockFreeQueueNode * volatile tail;
  56         MonoLockFreeQueueDummy dummies [MONO_LOCK_FREE_QUEUE_NUM_DUMMIES];
  57         volatile gint32 has_dummy;
  58 } MonoLockFreeQueue;
  59
  60 MONO_API void mono_lock_free_queue_init (MonoLockFreeQueue *q);
  61
  62 MONO_API void mono_lock_free_queue_node_init (MonoLockFreeQueueNode *node, gboolean poison);
  63 MONO_API void mono_lock_free_queue_node_unpoison (MonoLockFreeQueueNode *node);
  64
  65 MONO_API void mono_lock_free_queue_enqueue (MonoLockFreeQueue *q, MonoLockFreeQueueNode *node);
  66
  67 MONO_API MonoLockFreeQueueNode* mono_lock_free_queue_dequeue (MonoLockFreeQueue *q);
  68
  69 #endif