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
16 #include "event_demultiplexer.h"
17 #include "event_reactor.h"
18 #include "event_handler.h"
19 #include "common_timer_errors.h"
20 #include "utils_log.h"
21
22 #include <vector>
23 #include <cstdio>
24 #include <strings.h>
25 #include <unistd.h>
26 #include <sys/epoll.h>
27
28 namespace OHOS {
29 namespace Utils {
30
31 static const int EPOLL_MAX_EVENS_INIT = 8;
32 static const int HALF_OF_MAX_EVENT = 2;
33 static const int EPOLL_INVALID_FD = -1;
34
EventDemultiplexer()35 EventDemultiplexer::EventDemultiplexer()
36 : epollFd_(epoll_create1(EPOLL_CLOEXEC)), maxEvents_(EPOLL_MAX_EVENS_INIT), mutex_(), eventHandlers_()
37 {
38 }
39
~EventDemultiplexer()40 EventDemultiplexer::~EventDemultiplexer()
41 {
42 CleanUp();
43 }
44
StartUp()45 uint32_t EventDemultiplexer::StartUp()
46 {
47 if (epollFd_ < 0) {
48 epollFd_ = epoll_create1(EPOLL_CLOEXEC);
49 if (epollFd_ < 0) {
50 UTILS_LOGE("epoll_create1 failed.");
51 return TIMER_ERR_BADF;
52 }
53 }
54 return TIMER_ERR_OK;
55 }
56
CleanUp()57 void EventDemultiplexer::CleanUp()
58 {
59 if (epollFd_ != EPOLL_INVALID_FD) {
60 close(epollFd_);
61 epollFd_ = EPOLL_INVALID_FD;
62 }
63 }
64
UpdateEventHandler(EventHandler * handler)65 uint32_t EventDemultiplexer::UpdateEventHandler(EventHandler* handler)
66 {
67 if (handler == nullptr) {
68 UTILS_LOGE("event handler is null.");
69 return TIMER_ERR_INVALID_VALUE;
70 }
71
72 std::lock_guard<std::recursive_mutex> lock(mutex_);
73 auto itor = eventHandlers_.find(handler->GetHandle());
74 if (itor == eventHandlers_.end()) {
75 eventHandlers_.insert(std::make_pair(handler->GetHandle(), handler));
76 return Update(EPOLL_CTL_ADD, handler);
77 }
78
79 if (handler->Events() == EventReactor::NONE_EVENT) {
80 eventHandlers_.erase(itor);
81 return Update(EPOLL_CTL_DEL, handler);
82 }
83
84 if (handler != itor->second) {
85 UTILS_LOGE("invalid event handler!");
86 return TIMER_ERR_DEAL_FAILED;
87 }
88 return Update(EPOLL_CTL_MOD, handler);
89 }
90
RemoveEventHandler(EventHandler * handler)91 uint32_t EventDemultiplexer::RemoveEventHandler(EventHandler* handler)
92 {
93 if (handler == nullptr) {
94 UTILS_LOGE("event handler is null.");
95 return TIMER_ERR_INVALID_VALUE;
96 }
97
98 std::lock_guard<std::recursive_mutex> lock(mutex_);
99 auto itor = eventHandlers_.find(handler->GetHandle());
100 if (itor == eventHandlers_.end()) {
101 return TIMER_ERR_OK;
102 }
103
104 eventHandlers_.erase(itor);
105 if (static_cast<int>(eventHandlers_.size()) < maxEvents_) {
106 maxEvents_ = eventHandlers_.size() / HALF_OF_MAX_EVENT;
107 }
108
109 return Update(EPOLL_CTL_DEL, handler);
110 }
111
Update(int operation,EventHandler * handler)112 uint32_t EventDemultiplexer::Update(int operation, EventHandler* handler)
113 {
114 struct epoll_event event;
115 bzero(&event, sizeof(event));
116 event.events = Reactor2Epoll(handler->Events());
117 event.data.ptr = reinterpret_cast<void*>(handler);
118
119 if (epoll_ctl(epollFd_, operation, handler->GetHandle(), &event) != 0) {
120 UTILS_LOGE("epoll_ctl %{public}d operation %{public}d on handle %{public}d failed",
121 epollFd_, operation, handler->GetHandle());
122 return TIMER_ERR_DEAL_FAILED;
123 }
124 return TIMER_ERR_OK;
125 }
126
Polling(int timeout)127 void EventDemultiplexer::Polling(int timeout /* ms */)
128 {
129 std::vector<struct epoll_event> epollEvents(maxEvents_);
130 int nfds = epoll_wait(epollFd_, &epollEvents[0], static_cast<int>(epollEvents.size()), timeout);
131 if (nfds == 0) {
132 return;
133 }
134 if (nfds == -1) {
135 UTILS_LOGE("epoll_wait failed.");
136 return;
137 }
138
139 for (int idx = 0; idx < nfds; ++idx) {
140 int events = epollEvents[idx].events;
141 void* ptr = epollEvents[idx].data.ptr;
142 auto handler = reinterpret_cast<EventHandler*>(ptr);
143 if (handler != nullptr) {
144 handler->HandleEvents(Epoll2Reactor(events));
145 }
146 }
147
148 if (nfds == maxEvents_) {
149 maxEvents_ *= HALF_OF_MAX_EVENT;
150 }
151 }
152
Epoll2Reactor(uint32_t epollEvents)153 uint32_t EventDemultiplexer::Epoll2Reactor(uint32_t epollEvents)
154 {
155 if ((epollEvents & EPOLLHUP) && !(epollEvents & EPOLLIN)) {
156 return EventReactor::CLOSE_EVENT;
157 }
158
159 if (epollEvents & EPOLLERR) {
160 return EventReactor::ERROR_EVENT;
161 }
162
163 if (epollEvents & (EPOLLIN | EPOLLPRI | EPOLLRDHUP)) {
164 return EventReactor::READ_EVENT;
165 }
166
167 if (epollEvents & EPOLLOUT) {
168 return EventReactor::WRITE_EVENT;
169 }
170
171 return EventReactor::NONE_EVENT;
172 }
173
Reactor2Epoll(uint32_t reactorEvent)174 uint32_t EventDemultiplexer::Reactor2Epoll(uint32_t reactorEvent)
175 {
176 switch (reactorEvent) {
177 case EventReactor::NONE_EVENT:
178 return TIMER_ERR_OK;
179 case EventReactor::READ_EVENT:
180 return EPOLLIN | EPOLLPRI;
181 case EventReactor::WRITE_EVENT:
182 return EPOLLOUT;
183 case EventReactor::READ_EVENT | EventReactor::WRITE_EVENT:
184 return EPOLLIN | EPOLLPRI | EPOLLOUT;
185 default:
186 UTILS_LOGE("invalid event %{public}u.", reactorEvent);
187 return TIMER_ERR_DEAL_FAILED;
188 }
189 }
190
191 }
192 }
193