1 /*
2  * Copyright (C) 2015 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 #ifndef ART_RUNTIME_BASE_TIME_UTILS_H_
18 #define ART_RUNTIME_BASE_TIME_UTILS_H_
19 
20 #include <stdint.h>
21 #include <string>
22 #include <time.h>
23 
24 #include "base/macros.h"
25 
26 namespace art {
27 
28 enum TimeUnit {
29   kTimeUnitNanosecond,
30   kTimeUnitMicrosecond,
31   kTimeUnitMillisecond,
32   kTimeUnitSecond,
33 };
34 
35 // Returns a human-readable time string which prints every nanosecond while trying to limit the
36 // number of trailing zeros. Prints using the largest human readable unit up to a second.
37 // e.g. "1ms", "1.000000001s", "1.001us"
38 std::string PrettyDuration(uint64_t nano_duration, size_t max_fraction_digits = 3);
39 
40 // Format a nanosecond time to specified units.
41 std::string FormatDuration(uint64_t nano_duration, TimeUnit time_unit,
42                            size_t max_fraction_digits);
43 
44 // Get the appropriate unit for a nanosecond duration.
45 TimeUnit GetAppropriateTimeUnit(uint64_t nano_duration);
46 
47 // Get the divisor to convert from a nanoseconds to a time unit.
48 uint64_t GetNsToTimeUnitDivisor(TimeUnit time_unit);
49 
50 // Returns the current date in ISO yyyy-mm-dd hh:mm:ss format.
51 std::string GetIsoDate();
52 
53 // Returns the monotonic time since some unspecified starting point in milliseconds.
54 uint64_t MilliTime();
55 
56 // Returns the monotonic time since some unspecified starting point in microseconds.
57 uint64_t MicroTime();
58 
59 // Returns the monotonic time since some unspecified starting point in nanoseconds.
60 uint64_t NanoTime();
61 
62 // Returns the thread-specific CPU-time clock in nanoseconds or -1 if unavailable.
63 uint64_t ThreadCpuNanoTime();
64 
65 // Returns the process CPU-time clock in nanoseconds or -1 if unavailable.
66 uint64_t ProcessCpuNanoTime();
67 
68 // Converts the given number of nanoseconds to milliseconds.
NsToMs(uint64_t ns)69 static constexpr inline uint64_t NsToMs(uint64_t ns) {
70   return ns / 1000 / 1000;
71 }
72 
73 // Converts the given number of milliseconds to nanoseconds
MsToNs(uint64_t ms)74 static constexpr inline uint64_t MsToNs(uint64_t ms) {
75   return ms * 1000 * 1000;
76 }
77 
78 #if defined(__APPLE__)
79 #ifndef CLOCK_REALTIME
80 // No clocks to specify on OS/X < 10.12, fake value to pass to routines that require a clock.
81 #define CLOCK_REALTIME 0xebadf00d
82 #endif
83 #endif
84 
85 // Sleep for the given number of nanoseconds, a bad way to handle contention.
86 void NanoSleep(uint64_t ns);
87 
88 // Initialize a timespec to either a relative time (ms,ns), or to the absolute
89 // time corresponding to the indicated clock value plus the supplied offset.
90 void InitTimeSpec(bool absolute, int clock, int64_t ms, int32_t ns, timespec* ts);
91 
92 }  // namespace art
93 
94 #endif  // ART_RUNTIME_BASE_TIME_UTILS_H_
95