1 /* 2 * Copyright (C) 2017 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 _SIMPLEPERF_H 18 #define _SIMPLEPERF_H 19 20 #include <sys/types.h> 21 22 #include <string> 23 #include <vector> 24 25 #ifndef SIMPLEPERF_EXPORT 26 #define SIMPLEPERF_EXPORT 27 #endif 28 29 namespace simpleperf { 30 31 std::vector<std::string> GetAllEvents() SIMPLEPERF_EXPORT; 32 bool IsEventSupported(const std::string& name) SIMPLEPERF_EXPORT; 33 34 struct Counter { 35 std::string event; 36 uint64_t value; 37 // If there is not enough hardware counters, kernel will share counters between events. 38 // time_enabled_in_ns is the period when counting is enabled, and time_running_in_ns is 39 // the period when counting really happens in hardware. 40 uint64_t time_enabled_in_ns; 41 uint64_t time_running_in_ns; 42 }; 43 44 // PerfEventSet can be used to count perf events or record perf events in perf.data. 45 // To count perf events, you can do as follows: 46 // 1. Create PerfEventSet instance. 47 // 2. Select perf events to count. You can add more than one events. 48 // 3. Set monitored targets. 49 // 4. Start/stop/read counters when needed. 50 // An example is as below: 51 // PerfEventSet* perf = PerfEventSet::CreateInstance(PerfEventSetType::kPerfForCounting); 52 // perf->AddEvent("cpu-cycles"); 53 // perf->AddEvent("instructions"); 54 // perf->MonitorCurrentProcess(); 55 // perf->StartCounters(); 56 // perf->StopCounters(); 57 // perf->ReadCounters(&counters); 58 // 59 // PerfEventSet is not thread-safe. To access it from different threads, please protect 60 // it under locks. 61 class SIMPLEPERF_EXPORT PerfEventSet { 62 public: 63 enum Type { 64 kPerfForCounting, 65 kPerfForRecording, 66 }; 67 68 static PerfEventSet* CreateInstance(Type type); ~PerfEventSet()69 virtual ~PerfEventSet() {} 70 71 // Add event in the set. All valid events are returned by GetAllEvents(). 72 // To only monitor events happen in user space, add :u suffix, like cpu-cycles:u. 73 virtual bool AddEvent(const std::string& name); 74 75 // Set monitored target. You can only monitor threads in current process. 76 virtual bool MonitorCurrentProcess(); 77 virtual bool MonitorCurrentThread(); 78 virtual bool MonitorThreadsInCurrentProcess(const std::vector<pid_t>& threads); 79 80 // Counting interface: 81 // Start counters. When the PerfEventSet instance is created, the counters are stopped. 82 virtual bool StartCounters(); 83 // Stop counters. The values of the counters will not change until the next StartCounters(). 84 virtual bool StopCounters(); 85 // Read counter values. There is a value for each event. You don't need to stop counters before 86 // reading them. The counter values are the accumulated value from the first StartCounters(). 87 virtual bool ReadCounters(std::vector<Counter>* counters); 88 89 protected: PerfEventSet()90 PerfEventSet() {} 91 }; 92 93 } // namespace simpleperf 94 95 #undef SIMPLEPERF_EXPORT 96 97 #endif // _SIMPLEPERF_H 98