1 /*
2  * Copyright (C) 2016 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 "chre/platform/system_time.h"
18 
19 #include <cerrno>
20 #include <cstring>
21 #include <ctime>
22 
23 #include "chre/platform/assert.h"
24 #include "chre/util/optional.h"
25 
26 namespace chre {
27 namespace {
28 
29 chre::Optional<Nanoseconds> gTimeOverride;
30 
31 }  // anonymous namespace
32 
getMonotonicTime()33 Nanoseconds SystemTime::getMonotonicTime() {
34   if (gTimeOverride.has_value()) {
35     return gTimeOverride.value();
36   }
37 
38   struct timespec timeNow;
39   if (clock_gettime(CLOCK_MONOTONIC, &timeNow)) {
40     CHRE_ASSERT_LOG(false, "Failed to obtain time with error: %s",
41                     strerror(errno));
42     return Nanoseconds(UINT64_MAX);
43   }
44 
45   // The C++11 spec guarantees that tv_sec and tv_nsec only have values >= 0 and
46   // [0, 999999999]. It is safe to static cast these to their unsigned
47   // counterpart.
48   return Seconds(static_cast<uint64_t>(timeNow.tv_sec)) +
49          Nanoseconds(static_cast<uint64_t>(timeNow.tv_nsec));
50 }
51 
getEstimatedHostTimeOffset()52 int64_t SystemTime::getEstimatedHostTimeOffset() {
53   return 0;
54 }
55 
56 namespace platform_linux {
57 
overrideMonotonicTime(Nanoseconds ns)58 void overrideMonotonicTime(Nanoseconds ns) {
59   gTimeOverride = ns;
60 }
61 
clearMonotonicTimeOverride(void)62 void clearMonotonicTimeOverride(void) {
63   gTimeOverride.reset();
64 }
65 
66 }  // namespace platform_linux
67 }  // namespace chre
68