include/llvm/XRay/XRayRecord.h

   1 //===- XRayRecord.h - XRay Trace Record -----------------------------------===//
   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 replicates the record definition for XRay log entries. This should
  10 // follow the evolution of the log record versions supported in the compiler-rt
  11 // xray project.
  12 //
  13 //===----------------------------------------------------------------------===//
  14 #ifndef LLVM_XRAY_XRAY_RECORD_H
  15 #define LLVM_XRAY_XRAY_RECORD_H
  16
  17 #include <cstdint>
  18 #include <vector>
  19 #include <string>
  20
  21 namespace llvm {
  22 namespace xray {
  23
  24 /// XRay traces all have a header providing some top-matter information useful
  25 /// to help tools determine how to interpret the information available in the
  26 /// trace.
  27 struct XRayFileHeader {
  28   /// Version of the XRay implementation that produced this file.
  29   uint16_t Version = 0;
  30
  31   /// A numeric identifier for the type of file this is. Best used in
  32   /// combination with Version.
  33   uint16_t Type = 0;
  34
  35   /// Whether the CPU that produced the timestamp counters (TSC) move at a
  36   /// constant rate.
  37   bool ConstantTSC;
  38
  39   /// Whether the CPU that produced the timestamp counters (TSC) do not stop.
  40   bool NonstopTSC;
  41
  42   /// The number of cycles per second for the CPU that produced the timestamp
  43   /// counter (TSC) values. Useful for estimating the amount of time that
  44   /// elapsed between two TSCs on some platforms.
  45   uint64_t CycleFrequency = 0;
  46
  47   // This is different depending on the type of xray record. The naive format
  48   // stores a Wallclock timespec. FDR logging stores the size of a thread
  49   // buffer.
  50   char FreeFormData[16];
  51 };
  52
  53 /// Determines the supported types of records that could be seen in XRay traces.
  54 /// This may or may not correspond to actual record types in the raw trace (as
  55 /// the loader implementation may synthesize this information in the process of
  56 /// of loading).
  57 enum class RecordTypes {
  58   ENTER,
  59   EXIT,
  60   TAIL_EXIT,
  61   ENTER_ARG,
  62   CUSTOM_EVENT,
  63   TYPED_EVENT
  64 };
  65
  66 /// An XRayRecord is the denormalized view of data associated in a trace. These
  67 /// records may not correspond to actual entries in the raw traces, but they are
  68 /// the logical representation of records in a higher-level event log.
  69 struct XRayRecord {
  70   /// RecordType values are used as "sub-types" which have meaning in the
  71   /// context of the `Type` below. For function call and custom event records,
  72   /// the RecordType is always 0, while for typed events we store the type in
  73   /// the RecordType field.
  74   uint16_t RecordType;
  75
  76   /// The CPU where the thread is running. We assume number of CPUs <= 65536.
  77   uint16_t CPU;
  78
  79   /// Identifies the type of record.
  80   RecordTypes Type;
  81
  82   /// The function ID for the record, if this is a function call record.
  83   int32_t FuncId;
  84
  85   /// Get the full 8 bytes of the TSC when we get the log record.
  86   uint64_t TSC;
  87
  88   /// The thread ID for the currently running thread.
  89   uint32_t TId;
  90
  91   /// The process ID for the currently running process.
  92   uint32_t PId;
  93
  94   /// The function call arguments.
  95   std::vector<uint64_t> CallArgs;
  96
  97   /// For custom and typed events, we provide the raw data from the trace.
  98   std::string Data;
  99 };
 100
 101 } // namespace xray
 102 } // namespace llvm
 103
 104 #endif // LLVM_XRAY_XRAY_RECORD_H