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      1 /*
      2  * Copyright (C) 2005 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 // Timer functions.
     19 //
     20 #ifndef _LIBS_UTILS_TIMERS_H
     21 #define _LIBS_UTILS_TIMERS_H
     22 
     23 #include <stdint.h>
     24 #include <sys/types.h>
     25 #include <sys/time.h>
     26 
     27 #include <utils/Compat.h>
     28 
     29 // ------------------------------------------------------------------
     30 // C API
     31 
     32 #ifdef __cplusplus
     33 extern "C" {
     34 #endif
     35 
     36 typedef int64_t nsecs_t;       // nano-seconds
     37 
     38 static CONSTEXPR inline nsecs_t seconds_to_nanoseconds(nsecs_t secs)
     39 {
     40     return secs*1000000000;
     41 }
     42 
     43 static CONSTEXPR inline nsecs_t milliseconds_to_nanoseconds(nsecs_t secs)
     44 {
     45     return secs*1000000;
     46 }
     47 
     48 static CONSTEXPR inline nsecs_t microseconds_to_nanoseconds(nsecs_t secs)
     49 {
     50     return secs*1000;
     51 }
     52 
     53 static CONSTEXPR inline nsecs_t nanoseconds_to_seconds(nsecs_t secs)
     54 {
     55     return secs/1000000000;
     56 }
     57 
     58 static CONSTEXPR inline nsecs_t nanoseconds_to_milliseconds(nsecs_t secs)
     59 {
     60     return secs/1000000;
     61 }
     62 
     63 static CONSTEXPR inline nsecs_t nanoseconds_to_microseconds(nsecs_t secs)
     64 {
     65     return secs/1000;
     66 }
     67 
     68 static CONSTEXPR inline nsecs_t s2ns(nsecs_t v)  {return seconds_to_nanoseconds(v);}
     69 static CONSTEXPR inline nsecs_t ms2ns(nsecs_t v) {return milliseconds_to_nanoseconds(v);}
     70 static CONSTEXPR inline nsecs_t us2ns(nsecs_t v) {return microseconds_to_nanoseconds(v);}
     71 static CONSTEXPR inline nsecs_t ns2s(nsecs_t v)  {return nanoseconds_to_seconds(v);}
     72 static CONSTEXPR inline nsecs_t ns2ms(nsecs_t v) {return nanoseconds_to_milliseconds(v);}
     73 static CONSTEXPR inline nsecs_t ns2us(nsecs_t v) {return nanoseconds_to_microseconds(v);}
     74 
     75 static CONSTEXPR inline nsecs_t seconds(nsecs_t v)      { return s2ns(v); }
     76 static CONSTEXPR inline nsecs_t milliseconds(nsecs_t v) { return ms2ns(v); }
     77 static CONSTEXPR inline nsecs_t microseconds(nsecs_t v) { return us2ns(v); }
     78 
     79 enum {
     80     SYSTEM_TIME_REALTIME = 0,  // system-wide realtime clock
     81     SYSTEM_TIME_MONOTONIC = 1, // monotonic time since unspecified starting point
     82     SYSTEM_TIME_PROCESS = 2,   // high-resolution per-process clock
     83     SYSTEM_TIME_THREAD = 3,    // high-resolution per-thread clock
     84     SYSTEM_TIME_BOOTTIME = 4   // same as SYSTEM_TIME_MONOTONIC, but including CPU suspend time
     85 };
     86 
     87 // return the system-time according to the specified clock
     88 #ifdef __cplusplus
     89 nsecs_t systemTime(int clock = SYSTEM_TIME_MONOTONIC);
     90 #else
     91 nsecs_t systemTime(int clock);
     92 #endif // def __cplusplus
     93 
     94 /**
     95  * Returns the number of milliseconds to wait between the reference time and the timeout time.
     96  * If the timeout is in the past relative to the reference time, returns 0.
     97  * If the timeout is more than INT_MAX milliseconds in the future relative to the reference time,
     98  * such as when timeoutTime == LLONG_MAX, returns -1 to indicate an infinite timeout delay.
     99  * Otherwise, returns the difference between the reference time and timeout time
    100  * rounded up to the next millisecond.
    101  */
    102 int toMillisecondTimeoutDelay(nsecs_t referenceTime, nsecs_t timeoutTime);
    103 
    104 #ifdef __cplusplus
    105 } // extern "C"
    106 #endif
    107 
    108 #endif // _LIBS_UTILS_TIMERS_H
    109