1 /*
2  * Copyright (C) 2021 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 "nstackx_event.h"
16 #include "nstackx_log.h"
17 #include "nstackx_error.h"
18 #include "nstackx_util.h"
19 #include "nstackx_epoll.h"
20 #include "securec.h"
21 
22 #define TAG "nStackXEvent"
23 
24 typedef struct {
25     EventHandle handle;
26     void *arg;
27 } EventInfo;
28 
29 EventNode *SearchEventNode(const List *eventNodeChain, EpollDesc epollfd);
30 
CloseNodePipe(const EventNode * node)31 void CloseNodePipe(const EventNode *node)
32 {
33     CloseDesc(node->pipeFd[PIPE_OUT]);
34     CloseDesc(node->pipeFd[PIPE_IN]);
35 }
36 
EventProcessHandle(void * arg)37 static void EventProcessHandle(void *arg)
38 {
39     int32_t ret;
40     EventInfo event = {0};
41     EpollTask *task = arg;
42     EventNode *node = container_of(task, EventNode, task);
43 
44 #ifdef NSTACKX_WITH_LITEOS_M
45     ret = (int32_t)recvfrom(node->pipeFd[PIPE_OUT], &event, sizeof(event), 0, NULL, NULL);
46 #else
47     ret = (int32_t)read(node->pipeFd[PIPE_OUT], &event, sizeof(event));
48 #endif
49     if (ret != (int32_t)sizeof(event)) {
50         LOGE(TAG, "failed to read from pipe: %d", GetErrno());
51         return;
52     }
53 
54     if (event.handle != NULL) {
55         event.handle(event.arg);
56     }
57 }
58 
PostEvent(const List * eventNodeChain,EpollDesc epollfd,EventHandle handle,void * arg)59 int32_t PostEvent(const List *eventNodeChain, EpollDesc epollfd, EventHandle handle, void *arg)
60 {
61     int32_t ret;
62     EventNode *node = NULL;
63     EventInfo event = {
64         .handle = handle,
65         .arg = arg,
66     };
67 
68     if (eventNodeChain == NULL || handle == NULL) {
69         return NSTACKX_EINVAL;
70     }
71 
72     node = SearchEventNode(eventNodeChain, epollfd);
73     if (node == NULL) {
74         LOGE(TAG, "Cannot find event node for %d", epollfd->recvFd);
75         return NSTACKX_EFAILED;
76     }
77 #ifdef NSTACKX_WITH_LITEOS_M
78     ret = (int32_t)sendto(node->pipeFd[PIPE_IN], &event, sizeof(event), 0, NULL, 0);
79 #else
80     ret = (int32_t)write(node->pipeFd[PIPE_IN], &event, sizeof(event));
81 #endif
82     if (ret != (int32_t)sizeof(event)) {
83         LOGE(TAG, "failed to write to pipe: %d", errno);
84         return NSTACKX_EFAILED;
85     }
86 
87     return NSTACKX_EOK;
88 }
89 
ClearEvent(const List * eventNodeChain,EpollDesc epollfd)90 void ClearEvent(const List *eventNodeChain, EpollDesc epollfd)
91 {
92     EventNode *node = NULL;
93     EventInfo event = {0};
94     int32_t eventLen = (int32_t)sizeof(event);
95     if (eventNodeChain == NULL) {
96         LOGE(TAG, "eventNodeChain is null");
97         return;
98     }
99 
100     node = SearchEventNode(eventNodeChain, epollfd);
101     if (node == NULL) {
102         return;
103     }
104 
105     int32_t ret = eventLen;
106     while (ret == eventLen) {
107 #ifdef NSTACKX_WITH_LITEOS_M
108         ret = (int32_t)recvfrom(node->pipeFd[PIPE_OUT], &event, sizeof(event), 0, NULL, NULL);
109 #else
110         ret = (int32_t)read(node->pipeFd[PIPE_OUT], &event, sizeof(event));
111 #endif
112         if (ret != eventLen) {
113             break;
114         }
115 
116         if (event.handle != NULL) {
117             event.handle(event.arg);
118         }
119     }
120 }
121 
CreateNonBlockPipe(EventNode * node)122 static int32_t CreateNonBlockPipe(EventNode *node)
123 {
124     struct EpollDescStr fds;
125 
126     if (CreateEpollFdPair(&fds) != NSTACKX_EOK) {
127         LOGE(TAG, "CreateEpollFdPair failed");
128         return NSTACKX_EFAILED;
129     }
130 
131     node->pipeFd[PIPE_OUT] = fds.recvFd;
132     node->pipeFd[PIPE_IN] = fds.sendFd;
133 
134     return NSTACKX_EOK;
135 }
136 
EventModuleInit(List * eventNodeChain,EpollDesc epollfd)137 int32_t EventModuleInit(List *eventNodeChain, EpollDesc epollfd)
138 {
139     List *pos = NULL;
140     EventNode *node = NULL;
141     if (eventNodeChain == NULL) {
142         LOGE(TAG, "eventNodeChain is null");
143         return NSTACKX_EINVAL;
144     }
145     LIST_FOR_EACH(pos, eventNodeChain) {
146         node = (EventNode *)pos;
147         if (IsEpollDescEqual(node->epollfd, epollfd)) {
148             return NSTACKX_EOK;
149         }
150     }
151 
152     node = calloc(1, sizeof(EventNode));
153     if (node == NULL) {
154         LOGE(TAG, "calloc failed");
155         return NSTACKX_ENOMEM;
156     }
157 
158     if (CreateNonBlockPipe(node) != NSTACKX_EOK) {
159         LOGE(TAG, "create pipe failed");
160         goto L_ERR_FAILED;
161     }
162 
163     node->task.taskfd = node->pipeFd[PIPE_OUT];
164     node->task.epollfd = epollfd;
165     node->task.readHandle = EventProcessHandle;
166 
167     node->epollfd = epollfd;
168     if (RegisterEpollTask(&node->task, EPOLLIN) != NSTACKX_EOK) {
169         LOGE(TAG, "RegisterEpollTask failed");
170         CloseNodePipe(node);
171         goto L_ERR_FAILED;
172     }
173 
174     ListInsertTail(eventNodeChain, &(node->list));
175     return NSTACKX_EOK;
176 L_ERR_FAILED:
177     free(node);
178     return NSTACKX_EFAILED;
179 }
180 
DeleteEventNode(EventNode * node)181 void DeleteEventNode(EventNode *node)
182 {
183     ListRemoveNode(&node->list);
184     if (DeRegisterEpollTask(&node->task) != NSTACKX_EOK) {
185         LOGE(TAG, "DeRegisterEpollTask failed");
186     }
187     CloseNodePipe(node);
188     free(node);
189 }
190