1 files changed, 133 insertions, 0 deletions
diff --git a/storage/innobase/ut/ut0wqueue.cc b/storage/innobase/ut/ut0wqueue.cc
new file mode 100644
index 00000000..53bb0c8b
--- /dev/null
+++ b/storage/innobase/ut/ut0wqueue.cc
@@ -0,0 +1,133 @@
+/*****************************************************************************
+
+Copyright (c) 2006, 2015, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2019, 2020, MariaDB Corporation.
+
+This program is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation; version 2 of the License.
+
+This program 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 General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
+
+*****************************************************************************/
+
+#include "ut0list.h"
+#include "mem0mem.h"
+#include "ut0wqueue.h"
+
+/*******************************************************************//**
+@file ut/ut0wqueue.cc
+A work queue
+
+Created 4/26/2006 Osku Salerma
+************************************************************************/
+
+/****************************************************************//**
+Create a new work queue.
+@return work queue */
+ib_wqueue_t*
+ib_wqueue_create(void)
+/*===================*/
+{
+	ib_wqueue_t*	wq = static_cast<ib_wqueue_t*>(
+		ut_malloc_nokey(sizeof(*wq)));
+
+	/* Function ib_wqueue_create() has not been used anywhere,
+	not necessary to instrument this mutex */
+
+	mutex_create(LATCH_ID_WORK_QUEUE, &wq->mutex);
+
+	wq->items = ib_list_create();
+
+	return(wq);
+}
+
+/****************************************************************//**
+Free a work queue. */
+void
+ib_wqueue_free(
+/*===========*/
+	ib_wqueue_t*	wq)	/*!< in: work queue */
+{
+	mutex_free(&wq->mutex);
+	ib_list_free(wq->items);
+
+	ut_free(wq);
+}
+
+/** Add a work item to the queue.
+@param[in,out]	wq		work queue
+@param[in]	item		work item
+@param[in,out]	heap		memory heap to use for allocating list node
+@param[in]	wq_locked	work queue mutex locked */
+void
+ib_wqueue_add(ib_wqueue_t* wq, void* item, mem_heap_t* heap, bool wq_locked)
+{
+	if (!wq_locked) {
+		mutex_enter(&wq->mutex);
+	}
+
+	ib_list_add_last(wq->items, item, heap);
+
+	if (!wq_locked) {
+		mutex_exit(&wq->mutex);
+	}
+}
+
+/********************************************************************
+Return first item on work queue or NULL if queue is empty
+@return work item or NULL */
+void*
+ib_wqueue_nowait(
+/*=============*/
+	ib_wqueue_t*	wq)		/*<! in: work queue */
+{
+	ib_list_node_t*	node = NULL;
+
+	mutex_enter(&wq->mutex);
+
+	if(!ib_list_is_empty(wq->items)) {
+		node = ib_list_get_first(wq->items);
+
+		if (node) {
+			ib_list_remove(wq->items, node);
+		}
+	}
+
+	mutex_exit(&wq->mutex);
+
+	return (node ? node->data : NULL);
+}
+/** Check if queue is empty.
+@param wq wait queue
+@return whether the queue is empty */
+bool ib_wqueue_is_empty(ib_wqueue_t* wq)
+{
+	mutex_enter(&wq->mutex);
+	bool is_empty = ib_list_is_empty(wq->items);
+	mutex_exit(&wq->mutex);
+	return is_empty;
+}
+
+/********************************************************************
+Get number of items on queue.
+@return number of items on queue */
+ulint
+ib_wqueue_len(
+/*==========*/
+	ib_wqueue_t*	wq)		/*<! in: work queue */
+{
+	ulint len = 0;
+
+	mutex_enter(&wq->mutex);
+	len = ib_list_len(wq->items);
+	mutex_exit(&wq->mutex);
+
+        return(len);
+}