1 /* 2 * Copyright (C) 2016 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 SIMPLE_PERF_PERF_CLOCK_H_ 18 #define SIMPLE_PERF_PERF_CLOCK_H_ 19 20 #include <stdint.h> 21 22 // Perf clock is the clock used by the kernel to generate timestamps in perf 23 // event records. We use a separate init function because it allocates a mapped 24 // buffer for perf event file, which might not be available during profiling. 25 // And we'd better call the init function before profiling. 26 // InitPerfClock() must be called before GetPerfClock(). 27 bool InitPerfClock(); 28 29 uint64_t GetPerfClock(); 30 31 #endif // SIMPLE_PERF_PERF_CLOCK_H_ 32