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 static const int EPOLL_ERROR_BADF = 9;
36 static const int EPOLL_ERROR_EINVAL = 22;
37
EventDemultiplexer()38 EventDemultiplexer::EventDemultiplexer()
39 : epollFd_(epoll_create1(EPOLL_CLOEXEC)), maxEvents_(EPOLL_MAX_EVENS_INIT), mutex_(), eventHandlers_()
40 {
41 }
42
~EventDemultiplexer()43 EventDemultiplexer::~EventDemultiplexer()
44 {
45 CleanUp();
46 }
47
StartUp()48 uint32_t EventDemultiplexer::StartUp()
49 {
50 if (epollFd_ < 0) {
51 epollFd_ = epoll_create1(EPOLL_CLOEXEC);
52 if (epollFd_ < 0) {
53 return TIMER_ERR_BADF;
54 }
55 }
56 return TIMER_ERR_OK;
57 }
58
CleanUp()59 void EventDemultiplexer::CleanUp()
60 {
61 if (epollFd_ != EPOLL_INVALID_FD) {
62 close(epollFd_);
63 epollFd_ = EPOLL_INVALID_FD;
64 }
65 }
66
UpdateEventHandler(EventHandler* handler)67 uint32_t EventDemultiplexer::UpdateEventHandler(EventHandler* handler)
68 {
69 if (handler == nullptr) {
70 return TIMER_ERR_INVALID_VALUE;
71 }
72
73 std::lock_guard<std::recursive_mutex> lock(mutex_);
74 auto itor = eventHandlers_.find(handler->GetHandle());
75 if (itor == eventHandlers_.end()) {
76 eventHandlers_.insert(std::make_pair(handler->GetHandle(), handler->shared_from_this()));
77 return Update(EPOLL_CTL_ADD, handler);
78 }
79
80 if (handler->Events() == EventReactor::NONE_EVENT) {
81 eventHandlers_.erase(itor);
82 return Update(EPOLL_CTL_DEL, handler);
83 }
84
85 if (handler != itor->second.get()) {
86 return TIMER_ERR_DEAL_FAILED;
87 }
88 return Update(EPOLL_CTL_MOD, handler);
89 }
90
Update(int operation, EventHandler* handler)91 uint32_t EventDemultiplexer::Update(int operation, EventHandler* handler)
92 {
93 struct epoll_event event;
94 bzero(&event, sizeof(event));
95 event.events = Reactor2Epoll(handler->Events());
96 event.data.fd = handler->GetHandle();
97
98 if (epoll_ctl(epollFd_, operation, handler->GetHandle(), &event) != 0) {
99 UTILS_LOGD("epoll_ctl %{public}d operation %{public}d on handle %{public}d failed",
100 epollFd_, operation, handler->GetHandle());
101 return TIMER_ERR_DEAL_FAILED;
102 }
103 return TIMER_ERR_OK;
104 }
105
Polling(int timeout )106 int EventDemultiplexer::Polling(int timeout /* ms */)
107 {
108 std::vector<struct epoll_event> epollEvents(maxEvents_);
109 std::vector<std::shared_ptr<EventHandler>> taskQue;
110 std::vector<uint32_t> eventQue;
111
112 int nfds = epoll_wait(epollFd_, &epollEvents[0], static_cast<int>(epollEvents.size()), timeout);
113 if (nfds == 0) {
114 return nfds;
115 }
116 if (nfds == -1) {
117 if (errno != INTERRUPTED_SYS_CALL) {
118 UTILS_LOGE("epoll_wait failed, errno %{public}d, epollFd_: %{public}d, pollEvents.size: %{public}zu",
119 errno, epollFd_, epollEvents.size());
120 }
121 if (errno == EPOLL_ERROR_BADF || errno == EPOLL_ERROR_EINVAL) {
122 UTILS_LOGE("epoll_wait critical error, thread exit");
123 return EPOLL_CRITICAL_ERROR;
124 }
125 return nfds;
126 }
127
128 {
129 std::lock_guard<std::recursive_mutex> lock(mutex_);
130 for (int idx = 0; idx < nfds; ++idx) {
131 int targetFd = epollEvents[idx].data.fd;
132 uint32_t events = epollEvents[idx].events;
133
134 auto itor = eventHandlers_.find(targetFd);
135 if (itor != eventHandlers_.end()) {
136 taskQue.emplace_back(itor->second);
137 eventQue.emplace_back(events);
138 } else {
139 UTILS_LOGE("fd not found in eventHandlers_, fd=%{public}d", targetFd);
140 }
141 }
142 }
143
144 for (size_t idx = 0u; idx < taskQue.size() && idx < eventQue.size(); idx++) {
145 taskQue[idx]->HandleEvents(eventQue[idx]);
146 }
147
148 if (nfds == maxEvents_) {
149 maxEvents_ *= HALF_OF_MAX_EVENT;
150 }
151 return nfds;
152 }
153
Epoll2Reactor(uint32_t epollEvents)154 uint32_t EventDemultiplexer::Epoll2Reactor(uint32_t epollEvents)
155 {
156 if (epollEvents & (EPOLLIN | EPOLLPRI | EPOLLRDHUP)) {
157 return EventReactor::READ_EVENT;
158 }
159
160 return EventReactor::NONE_EVENT;
161 }
162
Reactor2Epoll(uint32_t reactorEvent)163 uint32_t EventDemultiplexer::Reactor2Epoll(uint32_t reactorEvent)
164 {
165 switch (reactorEvent) {
166 case EventReactor::NONE_EVENT:
167 return TIMER_ERR_OK;
168 case EventReactor::READ_EVENT:
169 return EPOLLIN | EPOLLPRI;
170 default:
171 UTILS_LOGD("invalid event %{public}u.", reactorEvent);
172 return TIMER_ERR_DEAL_FAILED;
173 }
174 }
175
176 }
177 }
178