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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 #include <sys/time.h>
     23 #include <limits.h>
     24 #include <fcntl.h>
     25 #include <errno.h>
     26 #include <string.h>
     27 
     28 #include <nativehelper/JNIHelp.h>
     29 #include "jni.h"
     30 #include "core_jni_helpers.h"
     31 
     32 #include <sys/time.h>
     33 #include <time.h>
     34 
     35 #include <utils/SystemClock.h>
     36 
     37 namespace android {
     38 
     39 static_assert(std::is_same<int64_t, jlong>::value, "jlong isn't an int64_t");
     40 static_assert(std::is_same<decltype(uptimeMillis()), int64_t>::value,
     41         "uptimeMillis signature change, expected int64_t return value");
     42 static_assert(std::is_same<decltype(elapsedRealtime()), int64_t>::value,
     43         "uptimeMillis signature change, expected int64_t return value");
     44 static_assert(std::is_same<decltype(elapsedRealtimeNano()), int64_t>::value,
     45         "uptimeMillis signature change, expected int64_t return value");
     46 
     47 /*
     48  * native public static long currentThreadTimeMillis();
     49  */
     50 static jlong android_os_SystemClock_currentThreadTimeMillis()
     51 {
     52     struct timespec tm;
     53 
     54     clock_gettime(CLOCK_THREAD_CPUTIME_ID, &tm);
     55 
     56     return tm.tv_sec * 1000LL + tm.tv_nsec / 1000000;
     57 }
     58 
     59 /*
     60  * native public static long currentThreadTimeMicro();
     61  */
     62 static jlong android_os_SystemClock_currentThreadTimeMicro()
     63 {
     64     struct timespec tm;
     65 
     66     clock_gettime(CLOCK_THREAD_CPUTIME_ID, &tm);
     67 
     68     return tm.tv_sec * 1000000LL + tm.tv_nsec / 1000;
     69 }
     70 
     71 /*
     72  * native public static long currentTimeMicro();
     73  */
     74 static jlong android_os_SystemClock_currentTimeMicro()
     75 {
     76     struct timeval tv;
     77 
     78     gettimeofday(&tv, NULL);
     79     return tv.tv_sec * 1000000LL + tv.tv_usec;
     80 }
     81 
     82 /*
     83  * JNI registration.
     84  */
     85 static const JNINativeMethod gMethods[] = {
     86     // All of these are @CriticalNative, so we can defer directly to SystemClock.h for
     87     // some of these
     88     { "uptimeMillis", "()J", (void*) uptimeMillis },
     89     { "elapsedRealtime", "()J", (void*) elapsedRealtime },
     90     { "elapsedRealtimeNanos", "()J", (void*) elapsedRealtimeNano },
     91 
     92     // SystemClock doesn't have an implementation for these that we can directly call
     93     { "currentThreadTimeMillis", "()J",
     94             (void*) android_os_SystemClock_currentThreadTimeMillis },
     95     { "currentThreadTimeMicro", "()J",
     96             (void*) android_os_SystemClock_currentThreadTimeMicro },
     97     { "currentTimeMicro", "()J",
     98             (void*) android_os_SystemClock_currentTimeMicro },
     99 };
    100 int register_android_os_SystemClock(JNIEnv* env)
    101 {
    102     return RegisterMethodsOrDie(env, "android/os/SystemClock", gMethods, NELEM(gMethods));
    103 }
    104 
    105 }; // namespace android
    106 
    107