1 //===-- xray_records.h ------------------------------------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file is a part of XRay, a dynamic runtime instrumentation system. 11 // 12 // This header exposes some record types useful for the XRay in-memory logging 13 // implementation. 14 // 15 //===----------------------------------------------------------------------===// 16 17 #ifndef XRAY_XRAY_RECORDS_H 18 #define XRAY_XRAY_RECORDS_H 19 20 namespace __xray { 21 22 enum FileTypes { 23 NAIVE_LOG = 0, 24 FDR_LOG = 1, 25 }; 26 27 // FDR mode use of the union field in the XRayFileHeader. 28 struct alignas(16) FdrAdditionalHeaderData { 29 uint64_t ThreadBufferSize; 30 }; 31 32 static_assert(sizeof(FdrAdditionalHeaderData) == 16, 33 "FdrAdditionalHeaderData != 16 bytes"); 34 35 // This data structure is used to describe the contents of the file. We use this 36 // for versioning the supported XRay file formats. 37 struct alignas(32) XRayFileHeader { 38 uint16_t Version = 0; 39 40 // The type of file we're writing out. See the FileTypes enum for more 41 // information. This allows different implementations of the XRay logging to 42 // have different files for different information being stored. 43 uint16_t Type = 0; 44 45 // What follows are a set of flags that indicate useful things for when 46 // reading the data in the file. 47 bool ConstantTSC : 1; 48 bool NonstopTSC : 1; 49 50 // The frequency by which TSC increases per-second. 51 alignas(8) uint64_t CycleFrequency = 0; 52 53 union { 54 char FreeForm[16]; 55 // The current civiltime timestamp, as retrived from 'clock_gettime'. This 56 // allows readers of the file to determine when the file was created or 57 // written down. 58 struct timespec TS; 59 60 struct FdrAdditionalHeaderData FdrData; 61 }; 62 } __attribute__((packed)); 63 64 static_assert(sizeof(XRayFileHeader) == 32, "XRayFileHeader != 32 bytes"); 65 66 enum RecordTypes { 67 NORMAL = 0, 68 }; 69 70 struct alignas(32) XRayRecord { 71 // This is the type of the record being written. We use 16 bits to allow us to 72 // treat this as a discriminant, and so that the first 4 bytes get packed 73 // properly. See RecordTypes for more supported types. 74 uint16_t RecordType = 0; 75 76 // The CPU where the thread is running. We assume number of CPUs <= 256. 77 uint8_t CPU = 0; 78 79 // The type of the event. Usually either ENTER = 0 or EXIT = 1. 80 uint8_t Type = 0; 81 82 // The function ID for the record. 83 int32_t FuncId = 0; 84 85 // Get the full 8 bytes of the TSC when we get the log record. 86 uint64_t TSC = 0; 87 88 // The thread ID for the currently running thread. 89 uint32_t TId = 0; 90 91 // Use some bytes in the end of the record for buffers. 92 char Buffer[4] = {}; 93 } __attribute__((packed)); 94 95 static_assert(sizeof(XRayRecord) == 32, "XRayRecord != 32 bytes"); 96 97 } // namespace __xray 98 99 #endif // XRAY_XRAY_RECORDS_H 100
