1 /*
2 * Copyright 2020 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 "os/fake_timer/fake_timerfd.h"
18
19 #include <sys/eventfd.h>
20 #include <unistd.h>
21
22 #include <cstdint>
23 #include <map>
24
25 namespace bluetooth {
26 namespace os {
27 namespace fake_timer {
28
29 class FakeTimerFd {
30 public:
31 int fd;
32 bool active;
33 uint64_t trigger_ms;
34 uint64_t period_ms;
35 };
36
37 static std::map<int, FakeTimerFd*> fake_timers;
38 static uint64_t clock = 0;
39 static uint64_t max_clock = UINT64_MAX;
40
timespec_to_ms(const timespec * t)41 static uint64_t timespec_to_ms(const timespec* t) {
42 return t->tv_sec * 1000 + t->tv_nsec / 1000000;
43 }
44
fake_timerfd_create(int,int)45 int fake_timerfd_create(int /* clockid */, int /* flags */) {
46 int fd = eventfd(0, EFD_SEMAPHORE);
47 if (fd == -1) {
48 return fd;
49 }
50
51 FakeTimerFd* entry = new FakeTimerFd();
52 fake_timers[fd] = entry;
53 entry->fd = fd;
54 return fd;
55 }
56
fake_timerfd_settime(int fd,int,const struct itimerspec * new_value,struct itimerspec *)57 int fake_timerfd_settime(int fd, int /* flags */, const struct itimerspec* new_value,
58 struct itimerspec* /* old_value */) {
59 if (fake_timers.find(fd) == fake_timers.end()) {
60 return -1;
61 }
62
63 FakeTimerFd* entry = fake_timers[fd];
64
65 uint64_t trigger_delta_ms = timespec_to_ms(&new_value->it_value);
66 entry->active = trigger_delta_ms != 0;
67 if (!entry->active) {
68 return 0;
69 }
70
71 uint64_t period_ms = timespec_to_ms(&new_value->it_interval);
72 entry->trigger_ms = clock + trigger_delta_ms;
73 entry->period_ms = period_ms;
74 return 0;
75 }
76
fake_timerfd_close(int fd)77 int fake_timerfd_close(int fd) {
78 auto timer_iterator = fake_timers.find(fd);
79 if (timer_iterator != fake_timers.end()) {
80 delete timer_iterator->second;
81 fake_timers.erase(timer_iterator);
82 }
83 return close(fd);
84 }
85
fake_timerfd_reset()86 void fake_timerfd_reset() {
87 clock = 0;
88 max_clock = UINT64_MAX;
89 // if there are entries still here, it is a failure of our users to clean up
90 // so let them leak and trigger errors
91 fake_timers.clear();
92 }
93
fire_next_event(uint64_t new_clock)94 static bool fire_next_event(uint64_t new_clock) {
95 uint64_t earliest_time = new_clock;
96 FakeTimerFd* to_fire = nullptr;
97 for (auto it = fake_timers.begin(); it != fake_timers.end(); it++) {
98 FakeTimerFd* entry = it->second;
99 if (!entry->active) {
100 continue;
101 }
102
103 if (entry->trigger_ms > clock && entry->trigger_ms <= new_clock) {
104 if (to_fire == nullptr || entry->trigger_ms < earliest_time) {
105 to_fire = entry;
106 earliest_time = entry->trigger_ms;
107 }
108 }
109 }
110
111 if (to_fire == nullptr) {
112 return false;
113 }
114
115 bool is_periodic = to_fire->period_ms != 0;
116 if (is_periodic) {
117 to_fire->trigger_ms += to_fire->period_ms;
118 }
119 to_fire->active = is_periodic;
120 uint64_t value = 1;
121 (void)write(to_fire->fd, &value, sizeof(uint64_t));
122 return true;
123 }
124
fake_timerfd_advance(uint64_t ms)125 void fake_timerfd_advance(uint64_t ms) {
126 uint64_t new_clock = clock + ms;
127 if (new_clock < clock) {
128 new_clock = max_clock;
129 }
130 while (fire_next_event(new_clock)) {
131 }
132 clock = new_clock;
133 }
134
fake_timerfd_cap_at(uint64_t ms)135 void fake_timerfd_cap_at(uint64_t ms) { max_clock = ms; }
136
fake_timerfd_get_clock()137 uint64_t fake_timerfd_get_clock() { return clock; }
138
139 } // namespace fake_timer
140 } // namespace os
141 } // namespace bluetooth
142