Josh Gao | dd71642 | 2019-07-11 13:47:44 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2019 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #include "fdevent_epoll.h" |
| 18 | |
| 19 | #if defined(__linux__) |
| 20 | |
| 21 | #include <sys/epoll.h> |
| 22 | #include <sys/eventfd.h> |
| 23 | |
| 24 | #include <android-base/logging.h> |
| 25 | #include <android-base/threads.h> |
| 26 | |
| 27 | #include "adb_unique_fd.h" |
| 28 | #include "fdevent.h" |
| 29 | |
| 30 | static void fdevent_interrupt(int fd, unsigned, void*) { |
| 31 | uint64_t buf; |
| 32 | ssize_t rc = TEMP_FAILURE_RETRY(adb_read(fd, &buf, sizeof(buf))); |
| 33 | if (rc == -1) { |
| 34 | PLOG(FATAL) << "failed to read from fdevent interrupt fd"; |
| 35 | } |
| 36 | } |
| 37 | |
| 38 | fdevent_context_epoll::fdevent_context_epoll() { |
| 39 | epoll_fd_.reset(epoll_create1(EPOLL_CLOEXEC)); |
| 40 | |
| 41 | unique_fd interrupt_fd(eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK)); |
| 42 | if (interrupt_fd == -1) { |
| 43 | PLOG(FATAL) << "failed to create fdevent interrupt eventfd"; |
| 44 | } |
| 45 | |
| 46 | unique_fd interrupt_fd_dup(fcntl(interrupt_fd.get(), F_DUPFD_CLOEXEC, 3)); |
| 47 | if (interrupt_fd_dup == -1) { |
| 48 | PLOG(FATAL) << "failed to dup fdevent interrupt eventfd"; |
| 49 | } |
| 50 | |
| 51 | this->interrupt_fd_ = std::move(interrupt_fd_dup); |
| 52 | fdevent* fde = this->Create(std::move(interrupt_fd), fdevent_interrupt, nullptr); |
| 53 | CHECK(fde != nullptr); |
| 54 | this->Add(fde, FDE_READ); |
| 55 | } |
| 56 | |
| 57 | fdevent_context_epoll::~fdevent_context_epoll() { |
| 58 | // Destroy calls virtual methods, but this class is final, so that's okay. |
| 59 | this->Destroy(this->interrupt_fde_); |
| 60 | } |
| 61 | |
| 62 | static epoll_event calculate_epoll_event(fdevent* fde) { |
| 63 | epoll_event result; |
| 64 | result.events = 0; |
| 65 | if (fde->state & FDE_READ) { |
| 66 | result.events |= EPOLLIN; |
| 67 | } |
| 68 | if (fde->state & FDE_WRITE) { |
| 69 | result.events |= EPOLLOUT; |
| 70 | } |
| 71 | if (fde->state & FDE_ERROR) { |
| 72 | result.events |= EPOLLERR; |
| 73 | } |
| 74 | result.events |= EPOLLRDHUP; |
| 75 | result.data.ptr = fde; |
| 76 | return result; |
| 77 | } |
| 78 | |
| 79 | void fdevent_context_epoll::Register(fdevent* fde) { |
| 80 | epoll_event ev = calculate_epoll_event(fde); |
| 81 | if (epoll_ctl(epoll_fd_.get(), EPOLL_CTL_ADD, fde->fd.get(), &ev) != 0) { |
| 82 | PLOG(FATAL) << "failed to register fd " << fde->fd.get() << " with epoll"; |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | void fdevent_context_epoll::Unregister(fdevent* fde) { |
| 87 | if (epoll_ctl(epoll_fd_.get(), EPOLL_CTL_DEL, fde->fd.get(), nullptr) != 0) { |
| 88 | PLOG(FATAL) << "failed to unregister fd " << fde->fd.get() << " with epoll"; |
| 89 | } |
| 90 | } |
| 91 | |
| 92 | void fdevent_context_epoll::Set(fdevent* fde, unsigned events) { |
| 93 | unsigned previous_state = fde->state; |
| 94 | fde->state = events; |
| 95 | |
| 96 | // If the state is the same, or only differed by FDE_TIMEOUT, we don't need to modify epoll. |
| 97 | if ((previous_state & ~FDE_TIMEOUT) == (events & ~FDE_TIMEOUT)) { |
| 98 | return; |
| 99 | } |
| 100 | |
| 101 | epoll_event ev = calculate_epoll_event(fde); |
| 102 | if (epoll_ctl(epoll_fd_.get(), EPOLL_CTL_MOD, fde->fd.get(), &ev) != 0) { |
| 103 | PLOG(FATAL) << "failed to modify fd " << fde->fd.get() << " with epoll"; |
| 104 | } |
| 105 | } |
| 106 | |
| 107 | void fdevent_context_epoll::Loop() { |
| 108 | main_thread_id_ = android::base::GetThreadId(); |
| 109 | |
| 110 | std::vector<fdevent_event> fde_events; |
| 111 | std::vector<epoll_event> epoll_events; |
| 112 | epoll_events.resize(this->installed_fdevents_.size()); |
| 113 | |
| 114 | while (true) { |
| 115 | if (terminate_loop_) { |
| 116 | break; |
| 117 | } |
| 118 | |
| 119 | int rc = -1; |
| 120 | while (rc == -1) { |
| 121 | std::optional<std::chrono::milliseconds> timeout = CalculatePollDuration(); |
| 122 | int timeout_ms; |
| 123 | if (!timeout) { |
| 124 | timeout_ms = -1; |
| 125 | } else { |
| 126 | timeout_ms = timeout->count(); |
| 127 | } |
| 128 | |
| 129 | rc = epoll_wait(epoll_fd_.get(), epoll_events.data(), epoll_events.size(), timeout_ms); |
| 130 | if (rc == -1 && errno != EINTR) { |
| 131 | PLOG(FATAL) << "epoll_wait failed"; |
| 132 | } |
| 133 | } |
| 134 | |
| 135 | auto post_poll = std::chrono::steady_clock::now(); |
| 136 | std::unordered_map<fdevent*, unsigned> event_map; |
| 137 | for (int i = 0; i < rc; ++i) { |
| 138 | fdevent* fde = static_cast<fdevent*>(epoll_events[i].data.ptr); |
| 139 | |
| 140 | unsigned events = 0; |
| 141 | if (epoll_events[i].events & EPOLLIN) { |
| 142 | CHECK(fde->state & FDE_READ); |
| 143 | events |= FDE_READ; |
| 144 | } |
| 145 | if (epoll_events[i].events & EPOLLOUT) { |
| 146 | CHECK(fde->state & FDE_WRITE); |
| 147 | events |= FDE_WRITE; |
| 148 | } |
| 149 | if (epoll_events[i].events & (EPOLLERR | EPOLLHUP | EPOLLRDHUP)) { |
| 150 | // We fake a read, as the rest of the code assumes that errors will |
| 151 | // be detected at that point. |
| 152 | events |= FDE_READ | FDE_ERROR; |
| 153 | } |
| 154 | |
| 155 | event_map[fde] = events; |
| 156 | } |
| 157 | |
Yurii Zubrytskyi | 22863bd | 2020-03-18 22:29:10 -0700 | [diff] [blame^] | 158 | for (auto& [fd, fde] : installed_fdevents_) { |
Josh Gao | dd71642 | 2019-07-11 13:47:44 -0700 | [diff] [blame] | 159 | unsigned events = 0; |
Yurii Zubrytskyi | 22863bd | 2020-03-18 22:29:10 -0700 | [diff] [blame^] | 160 | if (auto it = event_map.find(&fde); it != event_map.end()) { |
Josh Gao | dd71642 | 2019-07-11 13:47:44 -0700 | [diff] [blame] | 161 | events = it->second; |
| 162 | } |
| 163 | |
| 164 | if (events == 0) { |
Yurii Zubrytskyi | 22863bd | 2020-03-18 22:29:10 -0700 | [diff] [blame^] | 165 | if (fde.timeout) { |
| 166 | auto deadline = fde.last_active + *fde.timeout; |
Josh Gao | dd71642 | 2019-07-11 13:47:44 -0700 | [diff] [blame] | 167 | if (deadline < post_poll) { |
| 168 | events |= FDE_TIMEOUT; |
| 169 | } |
| 170 | } |
| 171 | } |
| 172 | |
| 173 | if (events != 0) { |
Yurii Zubrytskyi | 22863bd | 2020-03-18 22:29:10 -0700 | [diff] [blame^] | 174 | LOG(DEBUG) << dump_fde(&fde) << " got events " << std::hex << std::showbase |
Josh Gao | dd71642 | 2019-07-11 13:47:44 -0700 | [diff] [blame] | 175 | << events; |
Yurii Zubrytskyi | 22863bd | 2020-03-18 22:29:10 -0700 | [diff] [blame^] | 176 | fde_events.push_back({&fde, events}); |
| 177 | fde.last_active = post_poll; |
Josh Gao | dd71642 | 2019-07-11 13:47:44 -0700 | [diff] [blame] | 178 | } |
| 179 | } |
Yurii Zubrytskyi | 22863bd | 2020-03-18 22:29:10 -0700 | [diff] [blame^] | 180 | this->HandleEvents(fde_events); |
Josh Gao | dd71642 | 2019-07-11 13:47:44 -0700 | [diff] [blame] | 181 | fde_events.clear(); |
| 182 | } |
| 183 | |
| 184 | main_thread_id_.reset(); |
| 185 | } |
| 186 | |
| 187 | size_t fdevent_context_epoll::InstalledCount() { |
| 188 | // We always have an installed fde for interrupt. |
| 189 | return this->installed_fdevents_.size() - 1; |
| 190 | } |
| 191 | |
| 192 | void fdevent_context_epoll::Interrupt() { |
| 193 | uint64_t i = 1; |
| 194 | ssize_t rc = TEMP_FAILURE_RETRY(adb_write(this->interrupt_fd_, &i, sizeof(i))); |
| 195 | if (rc != sizeof(i)) { |
| 196 | PLOG(FATAL) << "failed to write to fdevent interrupt eventfd"; |
| 197 | } |
| 198 | } |
| 199 | |
| 200 | #endif // defined(__linux__) |