1 /*
2  * Copyright (C) 2017 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 specic language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include <android-base/logging.h>
18 
19 #include "libappfuse/EpollController.h"
20 
21 namespace android {
22 namespace fuse {
23 
EpollController(base::unique_fd && poll_fd)24 EpollController::EpollController(base::unique_fd&& poll_fd) : poll_fd_(std::move(poll_fd)) {
25 }
26 
Wait(size_t event_count)27 bool EpollController::Wait(size_t event_count) {
28     events_.resize(event_count);
29     const int result = TEMP_FAILURE_RETRY(epoll_wait(poll_fd_, events_.data(), event_count, -1));
30     if (result == -1) {
31         PLOG(ERROR) << "Failed to wait for epoll";
32         return false;
33     }
34     events_.resize(result);
35     return true;
36 }
37 
AddFd(int fd,int events,void * data)38 bool EpollController::AddFd(int fd, int events, void* data) {
39     return InvokeControl(EPOLL_CTL_ADD, fd, events, data);
40 }
41 
UpdateFd(int fd,int events,void * data)42 bool EpollController::UpdateFd(int fd, int events, void* data) {
43     return InvokeControl(EPOLL_CTL_MOD, fd, events, data);
44 }
45 
RemoveFd(int fd)46 bool EpollController::RemoveFd(int fd) {
47     return InvokeControl(EPOLL_CTL_DEL, fd, /* events */ 0, nullptr);
48 }
49 
events() const50 const std::vector<epoll_event>& EpollController::events() const {
51     return events_;
52 }
53 
InvokeControl(int op,int fd,int events,void * data) const54 bool EpollController::InvokeControl(int op, int fd, int events, void* data) const {
55     epoll_event event;
56     memset(&event, 0, sizeof(event));
57     event.events = events;
58     event.data.ptr = data;
59     if (epoll_ctl(poll_fd_, op, fd, &event) == -1) {
60         PLOG(ERROR) << "epoll_ctl() error op=" << op;
61         return false;
62     }
63     return true;
64 }
65 }
66 }
67