llvm/XRay/XRayRecord.h

0001 //===- XRayRecord.h - XRay Trace Record -----------------------------------===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008 //
0009 // This file replicates the record definition for XRay log entries. This should
0010 // follow the evolution of the log record versions supported in the compiler-rt
0011 // xray project.
0012 //
0013 //===----------------------------------------------------------------------===//
0014 #ifndef LLVM_XRAY_XRAYRECORD_H
0015 #define LLVM_XRAY_XRAYRECORD_H
0016
0017 #include <cstdint>
0018 #include <vector>
0019 #include <string>
0020
0021 namespace llvm {
0022 namespace xray {
0023
0024 /// XRay traces all have a header providing some top-matter information useful
0025 /// to help tools determine how to interpret the information available in the
0026 /// trace.
0027 struct XRayFileHeader {
0028   /// Version of the XRay implementation that produced this file.
0029   uint16_t Version = 0;
0030
0031   /// A numeric identifier for the type of file this is. Best used in
0032   /// combination with Version.
0033   uint16_t Type = 0;
0034
0035   /// Whether the CPU that produced the timestamp counters (TSC) move at a
0036   /// constant rate.
0037   bool ConstantTSC = false;
0038
0039   /// Whether the CPU that produced the timestamp counters (TSC) do not stop.
0040   bool NonstopTSC = false;
0041
0042   /// The number of cycles per second for the CPU that produced the timestamp
0043   /// counter (TSC) values. Useful for estimating the amount of time that
0044   /// elapsed between two TSCs on some platforms.
0045   uint64_t CycleFrequency = 0;
0046
0047   // This is different depending on the type of xray record. The naive format
0048   // stores a Wallclock timespec. FDR logging stores the size of a thread
0049   // buffer.
0050   char FreeFormData[16] = {};
0051 };
0052
0053 /// Determines the supported types of records that could be seen in XRay traces.
0054 /// This may or may not correspond to actual record types in the raw trace (as
0055 /// the loader implementation may synthesize this information in the process of
0056 /// of loading).
0057 enum class RecordTypes {
0058   ENTER,
0059   EXIT,
0060   TAIL_EXIT,
0061   ENTER_ARG,
0062   CUSTOM_EVENT,
0063   TYPED_EVENT
0064 };
0065
0066 /// An XRayRecord is the denormalized view of data associated in a trace. These
0067 /// records may not correspond to actual entries in the raw traces, but they are
0068 /// the logical representation of records in a higher-level event log.
0069 struct XRayRecord {
0070   /// RecordType values are used as "sub-types" which have meaning in the
0071   /// context of the `Type` below. For function call and custom event records,
0072   /// the RecordType is always 0, while for typed events we store the type in
0073   /// the RecordType field.
0074   uint16_t RecordType;
0075
0076   /// The CPU where the thread is running. We assume number of CPUs <= 65536.
0077   uint16_t CPU;
0078
0079   /// Identifies the type of record.
0080   RecordTypes Type;
0081
0082   /// The function ID for the record, if this is a function call record.
0083   int32_t FuncId;
0084
0085   /// Get the full 8 bytes of the TSC when we get the log record.
0086   uint64_t TSC;
0087
0088   /// The thread ID for the currently running thread.
0089   uint32_t TId;
0090
0091   /// The process ID for the currently running process.
0092   uint32_t PId;
0093
0094   /// The function call arguments.
0095   std::vector<uint64_t> CallArgs;
0096
0097   /// For custom and typed events, we provide the raw data from the trace.
0098   std::string Data;
0099 };
0100
0101 } // namespace xray
0102 } // namespace llvm
0103
0104 #endif // LLVM_XRAY_XRAYRECORD_H