1 /*
2 * Copyright (c) 2020 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15 #include "lock_free_queue.h"
16 #include <ohos_errno.h>
17 #include <securec.h>
18 #include <memory_adapter.h>
19
LFQUE_Create(int size,int count)20 LockFreeQueue *LFQUE_Create(int size, int count)
21 {
22 if (size <= 0 || count <= 0) {
23 return NULL;
24 }
25
26 int total = size * count + 1;
27 if (total <= 0) {
28 return NULL;
29 }
30
31 register LockFreeQueue *queue = (LockFreeQueue *)SAMGR_Malloc(sizeof(LockFreeQueue) + total);
32 if (queue == NULL) {
33 return NULL;
34 }
35 queue->write = 0;
36 queue->read = 0;
37 queue->itemSize = size;
38 queue->totalSize = total;
39 return queue;
40 }
41
LFQUE_IsFull(LockFreeQueue * queue)42 BOOL LFQUE_IsFull(LockFreeQueue *queue)
43 {
44 uint32 nextWrite = queue->write + 1;
45 if (nextWrite >= queue->totalSize) {
46 nextWrite = 0;
47 }
48 return (nextWrite == queue->read);
49 }
50
LFQUE_IsEmpty(LockFreeQueue * queue)51 BOOL LFQUE_IsEmpty(LockFreeQueue *queue)
52 {
53 return (queue->write == queue->read);
54 }
55
LFQUE_Push(LockFreeQueue * queue,const void * element,uint8 pri)56 int LFQUE_Push(LockFreeQueue *queue, const void *element, uint8 pri)
57 {
58 (void)pri;
59 if (queue == NULL || element == NULL) {
60 return EC_INVALID;
61 }
62
63 if (LFQUE_IsFull(queue)) {
64 return EC_BUSBUSY;
65 }
66 uint32 copyLen = (queue->totalSize - queue->write < queue->itemSize) ?
67 (queue->totalSize - queue->write) : queue->itemSize;
68 if (memcpy_s(&queue->buffer[queue->write], copyLen, element, copyLen) != EOK) {
69 return EC_INVALID;
70 }
71
72 element += copyLen;
73 copyLen = queue->itemSize - copyLen;
74 if (copyLen > 0) {
75 if (memcpy_s(queue->buffer, copyLen, element, copyLen) != EOK) {
76 return EC_INVALID;
77 }
78 }
79
80 uint32 write = queue->write + queue->itemSize;
81 if (write >= queue->totalSize) {
82 write = write - queue->totalSize;
83 }
84 queue->write = write;
85 return EC_SUCCESS;
86 }
87
LFQUE_Pop(LockFreeQueue * queue,void * element,uint8 * pri)88 int LFQUE_Pop(LockFreeQueue *queue, void *element, uint8 *pri)
89 {
90 (void)pri;
91 if (queue == NULL || element == NULL) {
92 return EC_INVALID;
93 }
94 if (LFQUE_IsEmpty(queue)) {
95 return EC_FAILURE;
96 }
97
98 uint32 copyLen = (queue->totalSize - queue->read < queue->itemSize) ?
99 (queue->totalSize - queue->read) : queue->itemSize;
100 if (memcpy_s(element, copyLen, &queue->buffer[queue->read], copyLen) != EOK) {
101 return EC_FAILURE;
102 }
103
104 element += copyLen;
105 copyLen = queue->itemSize - copyLen;
106 if (copyLen > 0) {
107 if (memcpy_s(element, copyLen, queue->buffer, copyLen) != EOK) {
108 return EC_FAILURE;
109 }
110 }
111
112 uint32 read = queue->read + queue->itemSize;
113 if (read >= queue->totalSize) {
114 read = read - queue->totalSize;
115 }
116 queue->read = read;
117 return EC_SUCCESS;
118 }