1 //===-- xray_records.h ------------------------------------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file is a part of XRay, a dynamic runtime instrumentation system. 10 // 11 // This header exposes some record types useful for the XRay in-memory logging 12 // implementation. 13 // 14 //===----------------------------------------------------------------------===// 15 16 #ifndef XRAY_XRAY_RECORDS_H 17 #define XRAY_XRAY_RECORDS_H 18 19 #include <cstdint> 20 21 namespace __xray { 22 23 enum FileTypes { 24 NAIVE_LOG = 0, 25 FDR_LOG = 1, 26 }; 27 28 // FDR mode use of the union field in the XRayFileHeader. 29 struct alignas(16) FdrAdditionalHeaderData { 30 uint64_t ThreadBufferSize; 31 }; 32 33 static_assert(sizeof(FdrAdditionalHeaderData) == 16, 34 "FdrAdditionalHeaderData != 16 bytes"); 35 36 // This data structure is used to describe the contents of the file. We use this 37 // for versioning the supported XRay file formats. 38 struct alignas(32) XRayFileHeader { 39 uint16_t Version = 0; 40 41 // The type of file we're writing out. See the FileTypes enum for more 42 // information. This allows different implementations of the XRay logging to 43 // have different files for different information being stored. 44 uint16_t Type = 0; 45 46 // What follows are a set of flags that indicate useful things for when 47 // reading the data in the file. 48 bool ConstantTSC : 1; 49 bool NonstopTSC : 1; 50 51 // The frequency by which TSC increases per-second. 52 alignas(8) uint64_t CycleFrequency = 0; 53 54 union { 55 char FreeForm[16]; 56 // The current civiltime timestamp, as retrieved from 'clock_gettime'. This 57 // allows readers of the file to determine when the file was created or 58 // written down. 59 struct timespec TS; 60 61 struct FdrAdditionalHeaderData FdrData; 62 }; 63 } __attribute__((packed)); 64 65 static_assert(sizeof(XRayFileHeader) == 32, "XRayFileHeader != 32 bytes"); 66 67 enum RecordTypes { 68 NORMAL = 0, 69 ARG_PAYLOAD = 1, 70 }; 71 72 struct alignas(32) XRayRecord { 73 // This is the type of the record being written. We use 16 bits to allow us to 74 // treat this as a discriminant, and so that the first 4 bytes get packed 75 // properly. See RecordTypes for more supported types. 76 uint16_t RecordType = RecordTypes::NORMAL; 77 78 // The CPU where the thread is running. We assume number of CPUs <= 256. 79 uint8_t CPU = 0; 80 81 // The type of the event. One of the following: 82 // ENTER = 0 83 // EXIT = 1 84 // TAIL_EXIT = 2 85 // ENTER_ARG = 3 86 uint8_t Type = 0; 87 88 // The function ID for the record. 89 int32_t FuncId = 0; 90 91 // Get the full 8 bytes of the TSC when we get the log record. 92 uint64_t TSC = 0; 93 94 // The thread ID for the currently running thread. 95 uint32_t TId = 0; 96 97 // The ID of process that is currently running 98 uint32_t PId = 0; 99 100 // Use some bytes in the end of the record for buffers. 101 char Buffer[8] = {}; 102 } __attribute__((packed)); 103 104 static_assert(sizeof(XRayRecord) == 32, "XRayRecord != 32 bytes"); 105 106 struct alignas(32) XRayArgPayload { 107 // We use the same 16 bits as a discriminant for the records in the log here 108 // too, and so that the first 4 bytes are packed properly. 109 uint16_t RecordType = RecordTypes::ARG_PAYLOAD; 110 111 // Add a few bytes to pad. 112 uint8_t Padding[2] = {}; 113 114 // The function ID for the record. 115 int32_t FuncId = 0; 116 117 // The thread ID for the currently running thread. 118 uint32_t TId = 0; 119 120 // The ID of process that is currently running 121 uint32_t PId = 0; 122 123 // The argument payload. 124 uint64_t Arg = 0; 125 126 // The rest of this record ought to be left as padding. 127 uint8_t TailPadding[8] = {}; 128 } __attribute__((packed)); 129 130 static_assert(sizeof(XRayArgPayload) == 32, "XRayArgPayload != 32 bytes"); 131 132 } // namespace __xray 133 134 #endif // XRAY_XRAY_RECORDS_H 135