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 static const int INTERRUPTED_SYS_CALL = 4;
35
EventDemultiplexer()36 EventDemultiplexer::EventDemultiplexer()
37 : epollFd_(epoll_create1(EPOLL_CLOEXEC)), maxEvents_(EPOLL_MAX_EVENS_INIT), mutex_(), eventHandlers_()
38 {
39 }
40
~EventDemultiplexer()41 EventDemultiplexer::~EventDemultiplexer()
42 {
43 CleanUp();
44 }
45
StartUp()46 uint32_t EventDemultiplexer::StartUp()
47 {
48 if (epollFd_ < 0) {
49 epollFd_ = epoll_create1(EPOLL_CLOEXEC);
50 if (epollFd_ < 0) {
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 return TIMER_ERR_INVALID_VALUE;
69 }
70
71 std::lock_guard<std::recursive_mutex> lock(mutex_);
72 auto itor = eventHandlers_.find(handler->GetHandle());
73 if (itor == eventHandlers_.end()) {
74 eventHandlers_.insert(std::make_pair(handler->GetHandle(), handler->shared_from_this()));
75 return Update(EPOLL_CTL_ADD, handler);
76 }
77
78 if (handler->Events() == EventReactor::NONE_EVENT) {
79 eventHandlers_.erase(itor);
80 return Update(EPOLL_CTL_DEL, handler);
81 }
82
83 if (handler != itor->second.get()) {
84 return TIMER_ERR_DEAL_FAILED;
85 }
86 return Update(EPOLL_CTL_MOD, handler);
87 }
88
Update(int operation,EventHandler * handler)89 uint32_t EventDemultiplexer::Update(int operation, EventHandler* handler)
90 {
91 struct epoll_event event;
92 bzero(&event, sizeof(event));
93 event.events = Reactor2Epoll(handler->Events());
94 event.data.fd = handler->GetHandle();
95
96 if (epoll_ctl(epollFd_, operation, handler->GetHandle(), &event) != 0) {
97 UTILS_LOGD("epoll_ctl %{public}d operation %{public}d on handle %{public}d failed",
98 epollFd_, operation, handler->GetHandle());
99 return TIMER_ERR_DEAL_FAILED;
100 }
101 return TIMER_ERR_OK;
102 }
103
Polling(int timeout)104 void EventDemultiplexer::Polling(int timeout /* ms */)
105 {
106 std::vector<struct epoll_event> epollEvents(maxEvents_);
107 std::vector<std::shared_ptr<EventHandler>> taskQue;
108 std::vector<uint32_t> eventQue;
109
110 int nfds = epoll_wait(epollFd_, &epollEvents[0], static_cast<int>(epollEvents.size()), timeout);
111 if (nfds == 0) {
112 return;
113 }
114 if (nfds == -1) {
115 if (errno != INTERRUPTED_SYS_CALL) {
116 UTILS_LOGE("epoll_wait failed, errno %{public}d", errno);
117 }
118 return;
119 }
120
121 {
122 std::lock_guard<std::recursive_mutex> lock(mutex_);
123 for (int idx = 0; idx < nfds; ++idx) {
124 int targetFd = epollEvents[idx].data.fd;
125 uint32_t events = epollEvents[idx].events;
126
127 auto itor = eventHandlers_.find(targetFd);
128 if (itor != eventHandlers_.end()) {
129 taskQue.emplace_back(itor->second);
130 eventQue.emplace_back(events);
131 }
132 }
133 }
134
135 for (size_t idx = 0u; idx < taskQue.size() && idx < eventQue.size(); idx++) {
136 taskQue[idx]->HandleEvents(eventQue[idx]);
137 }
138
139 if (nfds == maxEvents_) {
140 maxEvents_ *= HALF_OF_MAX_EVENT;
141 }
142 }
143
Epoll2Reactor(uint32_t epollEvents)144 uint32_t EventDemultiplexer::Epoll2Reactor(uint32_t epollEvents)
145 {
146 if (epollEvents & (EPOLLIN | EPOLLPRI | EPOLLRDHUP)) {
147 return EventReactor::READ_EVENT;
148 }
149
150 return EventReactor::NONE_EVENT;
151 }
152
Reactor2Epoll(uint32_t reactorEvent)153 uint32_t EventDemultiplexer::Reactor2Epoll(uint32_t reactorEvent)
154 {
155 switch (reactorEvent) {
156 case EventReactor::NONE_EVENT:
157 return TIMER_ERR_OK;
158 case EventReactor::READ_EVENT:
159 return EPOLLIN | EPOLLPRI;
160 default:
161 UTILS_LOGD("invalid event %{public}u.", reactorEvent);
162 return TIMER_ERR_DEAL_FAILED;
163 }
164 }
165
166 }
167 }
168