1 // Copyright 2016 The Chromium OS Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef CHROMIUMOS_WIDE_PROFILING_PERF_DATA_UTILS_H_ 6 #define CHROMIUMOS_WIDE_PROFILING_PERF_DATA_UTILS_H_ 7 8 #include <stddef.h> // for size_t 9 #include <stdlib.h> // for free() 10 11 #include <memory> 12 13 #include "binary_data_utils.h" // for Align<T> 14 #include "compat/string.h" 15 #include "kernel/perf_internals.h" 16 17 namespace quipper { 18 19 class PerfDataProto_PerfEvent; 20 class PerfDataProto_SampleInfo; 21 22 // Based on kernel/perf_internals.h 23 const size_t kBuildIDArraySize = 20; 24 const size_t kBuildIDStringLength = kBuildIDArraySize * 2; 25 26 // Used by malloced_unique_ptr. 27 struct FreeDeleter { 28 inline void operator()(void* pointer) { free(pointer); } 29 }; 30 31 // A modified version of std::unique_ptr that holds a pointer allocated by 32 // malloc or its cousins rather than by new. Calls free() to free the pointer 33 // when it is destroyed. 34 template <typename T> 35 using malloced_unique_ptr = std::unique_ptr<T, FreeDeleter>; 36 37 // Allocate |size| bytes of heap memory using calloc, returning the allocated 38 // memory as the variable-sized type event_t. 39 event_t* CallocMemoryForEvent(size_t size); 40 41 // Reallocate |event| which was previously allocated by CallocMemoryForEvent() 42 // to memory with a new size |new_size|. 43 event_t* ReallocMemoryForEvent(event_t* event, size_t new_size); 44 45 // Allocate |size| bytes of heap memory using calloc, returning the allocated 46 // memory as the variable-sized build ID type. 47 build_id_event* CallocMemoryForBuildID(size_t size); 48 49 // In perf data, strings are packed into the smallest number of 8-byte blocks 50 // possible, including a null terminator. 51 // e.g. 52 // "0123" -> 5 bytes -> packed into 8 bytes 53 // "0123456" -> 8 bytes -> packed into 8 bytes 54 // "01234567" -> 9 bytes -> packed into 16 bytes 55 // "0123456789abcd" -> 15 bytes -> packed into 16 bytes 56 // "0123456789abcde" -> 16 bytes -> packed into 16 bytes 57 // "0123456789abcdef" -> 17 bytes -> packed into 24 bytes 58 // 59 // Returns the size of the 8-byte-aligned memory for storing |string|. 60 inline size_t GetUint64AlignedStringLength(const string& str) { 61 return Align<uint64_t>(str.size() + 1); 62 } 63 64 // Makes |build_id| fit the perf format, by either truncating it or adding 65 // zeroes to the end so that it has length kBuildIDStringLength. 66 void PerfizeBuildIDString(string* build_id); 67 68 // Changes |build_id| to the best guess of what the build id was before going 69 // through perf. Specifically, it keeps removing trailing sequences of four 70 // zero bytes (or eight '0' characters) until there are no more such sequences, 71 // or the build id would be empty if the process were repeated. 72 void TrimZeroesFromBuildIDString(string* build_id); 73 74 // If |event| is not of type PERF_RECORD_SAMPLE, returns the SampleInfo field 75 // within it. Otherwise returns nullptr. 76 const PerfDataProto_SampleInfo* GetSampleInfoForEvent( 77 const PerfDataProto_PerfEvent& event); 78 79 // Returns the correct |sample_time_ns| field of a PerfEvent. 80 uint64_t GetTimeFromPerfEvent(const PerfDataProto_PerfEvent& event); 81 82 } // namespace quipper 83 84 #endif // CHROMIUMOS_WIDE_PROFILING_PERF_DATA_UTILS_H_ 85