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 #define LOG_TAG "SystemClock" 23 24 #include <utils/SystemClock.h> 25 26 #include <string.h> 27 #include <errno.h> 28 #include <time.h> 29 30 #include <cutils/compiler.h> 31 32 #include <utils/Timers.h> 33 #include <utils/Log.h> 34 35 namespace android { 36 37 /* 38 * native public static long uptimeMillis(); 39 */ uptimeMillis()40int64_t uptimeMillis() 41 { 42 return nanoseconds_to_milliseconds(uptimeNanos()); 43 } 44 45 /* 46 * public static native long uptimeNanos(); 47 */ uptimeNanos()48int64_t uptimeNanos() 49 { 50 return systemTime(SYSTEM_TIME_MONOTONIC); 51 } 52 53 /* 54 * native public static long elapsedRealtime(); 55 */ elapsedRealtime()56int64_t elapsedRealtime() 57 { 58 return nanoseconds_to_milliseconds(elapsedRealtimeNano()); 59 } 60 61 /* 62 * native public static long elapsedRealtimeNano(); 63 */ elapsedRealtimeNano()64int64_t elapsedRealtimeNano() 65 { 66 #if defined(__linux__) 67 struct timespec ts; 68 int err = clock_gettime(CLOCK_BOOTTIME, &ts); 69 if (CC_UNLIKELY(err)) { 70 // This should never happen, but just in case ... 71 ALOGE("clock_gettime(CLOCK_BOOTTIME) failed: %s", strerror(errno)); 72 return 0; 73 } 74 75 return seconds_to_nanoseconds(ts.tv_sec) + ts.tv_nsec; 76 #else 77 return systemTime(SYSTEM_TIME_MONOTONIC); 78 #endif 79 } 80 81 }; // namespace android 82