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 #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
24 #include "logging.h"
25
26 #ifndef EFD_SEMAPHORE
27 #define EFD_SEMAPHORE 1
28 #endif
29
Create(unsigned int initValue,unsigned int mask)30 EventNotifierPtr EventNotifier::Create(unsigned int initValue, unsigned int mask)
31 {
32 return std::make_shared<EventNotifier>(initValue, mask);
33 }
34
CreateWithFd(int fd)35 EventNotifierPtr EventNotifier::CreateWithFd(int fd)
36 {
37 return std::make_shared<EventNotifier>(fd);
38 }
39
EventNotifier(unsigned int initValue,unsigned int mask)40 EventNotifier::EventNotifier(unsigned int initValue, unsigned int mask) : fd_(-1), flags_(O_CLOEXEC)
41 {
42 if (mask & NONBLOCK) {
43 flags_ |= O_NONBLOCK;
44 }
45 if (mask & SEMAPHORE) {
46 flags_ |= EFD_SEMAPHORE;
47 }
48 fd_ = eventfd(initValue, flags_);
49 CHECK_TRUE(fd_ >= 0, NO_RETVAL, "create eventfd FAILED, %d", errno);
50 HILOG_DEBUG(LOG_CORE, "EventNotifier create eventfd %d done!", fd_);
51 }
52
EventNotifier(int fd)53 EventNotifier::EventNotifier(int fd) : fd_(fd), flags_(0)
54 {
55 int flags = fcntl(fd_, F_GETFL);
56 CHECK_TRUE(flags >= 0, NO_RETVAL, "get flags of fd %d FAILED, %d", fd, errno);
57 HILOG_DEBUG(LOG_CORE, "EventNotifier bind eventfd %d done!", fd_);
58 }
59
~EventNotifier()60 EventNotifier::~EventNotifier()
61 {
62 HILOG_DEBUG(LOG_CORE, "EventNotifier close eventfd %d", fd_);
63 close(fd_);
64 }
65
GetFd() const66 int EventNotifier::GetFd() const
67 {
68 return fd_;
69 }
70
IsNonBlocking() const71 bool EventNotifier::IsNonBlocking() const
72 {
73 return flags_ & O_NONBLOCK;
74 }
75
IsSemaphore() const76 bool EventNotifier::IsSemaphore() const
77 {
78 return flags_ & EFD_SEMAPHORE;
79 }
80
Take() const81 uint64_t EventNotifier::Take() const
82 {
83 uint64_t value = UINT64_MAX;
84 int retval = TEMP_FAILURE_RETRY(read(fd_, &value, sizeof(value)));
85 CHECK_TRUE(retval == sizeof(value), false, "read value from eventfd %d failed, %d!", fd_, errno);
86 return value;
87 }
88
Post(uint64_t value) const89 bool EventNotifier::Post(uint64_t value) const
90 {
91 int retval = TEMP_FAILURE_RETRY(write(fd_, &value, sizeof(value)));
92 CHECK_TRUE(retval == sizeof(value), false, "write value to eventfd %d failed, %d!", fd_, errno);
93 return true;
94 }
95