1/*
2 * Copyright (c) Huawei Technologies Co., Ltd. 2021. All rights reserved.
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#include "event_notifier.h"
16
17#include <cerrno>
18#include <climits>
19#include <cstring>
20#include <fcntl.h>
21#include <sys/eventfd.h>
22#include <unistd.h>
23#include "logging.h"
24
25#ifndef EFD_SEMAPHORE
26#define EFD_SEMAPHORE 1
27#endif
28
29EventNotifierPtr EventNotifier::Create(unsigned int initValue, unsigned int mask)
30{
31    return std::make_shared<EventNotifier>(initValue, mask);
32}
33
34EventNotifierPtr EventNotifier::CreateWithFd(int fd)
35{
36    return std::make_shared<EventNotifier>(fd);
37}
38
39EventNotifier::EventNotifier(unsigned int initValue, unsigned int mask) : fd_(-1), flags_(O_CLOEXEC)
40{
41    if (mask & NONBLOCK) {
42        flags_ |= O_NONBLOCK;
43    }
44    if (mask & SEMAPHORE) {
45        flags_ |= EFD_SEMAPHORE;
46    }
47    fd_ = eventfd(initValue, flags_);
48    CHECK_TRUE(fd_ >= 0, NO_RETVAL, "create eventfd FAILED, %d", errno);
49    PROFILER_LOG_DEBUG(LOG_CORE, "EventNotifier create eventfd %d done!", fd_);
50}
51
52EventNotifier::EventNotifier(int fd) : fd_(fd), flags_(0)
53{
54    int flags = fcntl(fd_, F_GETFL);
55    CHECK_TRUE(flags >= 0, NO_RETVAL, "get flags of fd %d FAILED, %d", fd, errno);
56    PROFILER_LOG_DEBUG(LOG_CORE, "EventNotifier bind eventfd %d done!", fd_);
57}
58
59EventNotifier::~EventNotifier()
60{
61    PROFILER_LOG_DEBUG(LOG_CORE, "EventNotifier close eventfd %d", fd_);
62    close(fd_);
63}
64
65int EventNotifier::GetFd() const
66{
67    return fd_;
68}
69
70uint64_t EventNotifier::Take() const
71{
72    uint64_t value = UINT64_MAX;
73    int retval = TEMP_FAILURE_RETRY(read(fd_, &value, sizeof(value)));
74    CHECK_TRUE(retval == sizeof(value), 0, "read value from eventfd %d failed, %d!", fd_, errno);
75    return value;
76}
77
78bool EventNotifier::Post(uint64_t value) const
79{
80    int retval = TEMP_FAILURE_RETRY(write(fd_, &value, sizeof(value)));
81    CHECK_TRUE(retval == sizeof(value), false, "write value to eventfd %d failed, %d!", fd_, errno);
82    return true;
83}
84