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1 /*
2  * Copyright (C) 2008 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 
18 /*
19  * System clock functions.
20  */
21 
22 #ifdef HAVE_ANDROID_OS
23 #include <linux/ioctl.h>
24 #include <linux/rtc.h>
25 #include <utils/Atomic.h>
26 #include <linux/android_alarm.h>
27 #endif
28 
29 #include <sys/time.h>
30 #include <limits.h>
31 #include <fcntl.h>
32 #include <errno.h>
33 #include <string.h>
34 
35 #include <utils/SystemClock.h>
36 #include <utils/Timers.h>
37 
38 #define LOG_TAG "SystemClock"
39 #include "utils/Log.h"
40 
41 namespace android {
42 
43 /*
44  * Set the current time.  This only works when running as root.
45  */
setCurrentTimeMillis(int64_t millis)46 int setCurrentTimeMillis(int64_t millis)
47 {
48 #if WIN32
49     // not implemented
50     return -1;
51 #else
52     struct timeval tv;
53 #ifdef HAVE_ANDROID_OS
54     struct timespec ts;
55     int fd;
56     int res;
57 #endif
58     int ret = 0;
59 
60     if (millis <= 0 || millis / 1000LL >= INT_MAX) {
61         return -1;
62     }
63 
64     tv.tv_sec = (time_t) (millis / 1000LL);
65     tv.tv_usec = (suseconds_t) ((millis % 1000LL) * 1000LL);
66 
67     LOGD("Setting time of day to sec=%d\n", (int) tv.tv_sec);
68 
69 #ifdef HAVE_ANDROID_OS
70     fd = open("/dev/alarm", O_RDWR);
71     if(fd < 0) {
72         LOGW("Unable to open alarm driver: %s\n", strerror(errno));
73         return -1;
74     }
75     ts.tv_sec = tv.tv_sec;
76     ts.tv_nsec = tv.tv_usec * 1000;
77     res = ioctl(fd, ANDROID_ALARM_SET_RTC, &ts);
78     if(res < 0) {
79         LOGW("Unable to set rtc to %ld: %s\n", tv.tv_sec, strerror(errno));
80         ret = -1;
81     }
82     close(fd);
83 #else
84     if (settimeofday(&tv, NULL) != 0) {
85         LOGW("Unable to set clock to %d.%d: %s\n",
86             (int) tv.tv_sec, (int) tv.tv_usec, strerror(errno));
87         ret = -1;
88     }
89 #endif
90 
91     return ret;
92 #endif // WIN32
93 }
94 
95 /*
96  * native public static long uptimeMillis();
97  */
uptimeMillis()98 int64_t uptimeMillis()
99 {
100     int64_t when = systemTime(SYSTEM_TIME_MONOTONIC);
101     return (int64_t) nanoseconds_to_milliseconds(when);
102 }
103 
104 /*
105  * native public static long elapsedRealtime();
106  */
elapsedRealtime()107 int64_t elapsedRealtime()
108 {
109 #ifdef HAVE_ANDROID_OS
110     static int s_fd = -1;
111 
112     if (s_fd == -1) {
113         int fd = open("/dev/alarm", O_RDONLY);
114         if (android_atomic_cmpxchg(-1, fd, &s_fd)) {
115             close(fd);
116         }
117     }
118 
119     struct timespec ts;
120     int result = ioctl(s_fd,
121             ANDROID_ALARM_GET_TIME(ANDROID_ALARM_ELAPSED_REALTIME), &ts);
122 
123     if (result == 0) {
124         int64_t when = seconds_to_nanoseconds(ts.tv_sec) + ts.tv_nsec;
125         return (int64_t) nanoseconds_to_milliseconds(when);
126     } else {
127         // XXX: there was an error, probably because the driver didn't
128         // exist ... this should return
129         // a real error, like an exception!
130         int64_t when = systemTime(SYSTEM_TIME_MONOTONIC);
131         return (int64_t) nanoseconds_to_milliseconds(when);
132     }
133 #else
134     int64_t when = systemTime(SYSTEM_TIME_MONOTONIC);
135     return (int64_t) nanoseconds_to_milliseconds(when);
136 #endif
137 }
138 
139 }; // namespace android
140