1 /******************************************************************************
2  *
3  *  Copyright 2015 Google, Inc.
4  *
5  *  Licensed under the Apache License, Version 2.0 (the "License");
6  *  you may not use this file except in compliance with the License.
7  *  You may obtain a copy of the License at:
8  *
9  *  http://www.apache.org/licenses/LICENSE-2.0
10  *
11  *  Unless required by applicable law or agreed to in writing, software
12  *  distributed under the License is distributed on an "AS IS" BASIS,
13  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  *  See the License for the specific language governing permissions and
15  *  limitations under the License.
16  *
17  ******************************************************************************/
18 
19 #pragma once
20 
21 #include <stdint.h>
22 
23 typedef uint64_t period_ms_t;
24 
25 // Get the OS boot time in milliseconds.
26 //
27 // NOTE: The return value will rollover every 49.7 days,
28 // hence it cannot be used for absolute time comparison.
29 // Relative time comparison using 32-bits integers such
30 // as (t2_u32 - t1_u32 < delta_u32) should work as expected as long
31 // as there is no multiple rollover between t2_u32 and t1_u32.
32 //
33 // TODO: This function's return type should be modified to |period_ms_t|.
34 // Be careful: some of the code that is using it assumes the return type
35 // is uint32_t.
36 uint32_t time_get_os_boottime_ms(void);
37 
38 // Get the OS boot time in microseconds.
39 uint64_t time_get_os_boottime_us(void);
40 
41 // Get the current wall clock time in microseconds.
42 uint64_t time_gettimeofday_us(void);
43