1317021Sdim//===-- xray_fdr_log_records.h -------------------------------------------===// 2317021Sdim// 3353358Sdim// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4353358Sdim// See https://llvm.org/LICENSE.txt for license information. 5353358Sdim// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6317021Sdim// 7317021Sdim//===----------------------------------------------------------------------===// 8317021Sdim// 9317021Sdim// This file is a part of XRay, a function call tracing system. 10317021Sdim// 11317021Sdim//===----------------------------------------------------------------------===// 12317021Sdim#ifndef XRAY_XRAY_FDR_LOG_RECORDS_H 13317021Sdim#define XRAY_XRAY_FDR_LOG_RECORDS_H 14344779Sdim#include <cstdint> 15317021Sdim 16344779Sdimnamespace __xray { 17344779Sdim 18317021Sdimenum class RecordType : uint8_t { Function, Metadata }; 19317021Sdim 20317021Sdim// A MetadataRecord encodes the kind of record in its first byte, and have 15 21317021Sdim// additional bytes in the end to hold free-form data. 22317021Sdimstruct alignas(16) MetadataRecord { 23317021Sdim // A MetadataRecord must always have a type of 1. 24317021Sdim /* RecordType */ uint8_t Type : 1; 25317021Sdim 26317021Sdim // Each kind of record is represented as a 7-bit value (even though we use an 27317021Sdim // unsigned 8-bit enum class to do so). 28317021Sdim enum class RecordKinds : uint8_t { 29317021Sdim NewBuffer, 30317021Sdim EndOfBuffer, 31317021Sdim NewCPUId, 32317021Sdim TSCWrap, 33317021Sdim WalltimeMarker, 34318384Sdim CustomEventMarker, 35327952Sdim CallArgument, 36327952Sdim BufferExtents, 37341825Sdim TypedEventMarker, 38341825Sdim Pid, 39317021Sdim }; 40327952Sdim 41317021Sdim // Use 7 bits to identify this record type. 42317021Sdim /* RecordKinds */ uint8_t RecordKind : 7; 43317021Sdim char Data[15]; 44317021Sdim} __attribute__((packed)); 45317021Sdim 46317021Sdimstatic_assert(sizeof(MetadataRecord) == 16, "Wrong size for MetadataRecord."); 47317021Sdim 48317021Sdimstruct alignas(8) FunctionRecord { 49317021Sdim // A FunctionRecord must always have a type of 0. 50317021Sdim /* RecordType */ uint8_t Type : 1; 51317021Sdim enum class RecordKinds { 52317021Sdim FunctionEnter = 0x00, 53317021Sdim FunctionExit = 0x01, 54317021Sdim FunctionTailExit = 0x02, 55317021Sdim }; 56317021Sdim /* RecordKinds */ uint8_t RecordKind : 3; 57317021Sdim 58317021Sdim // We only use 28 bits of the function ID, so that we can use as few bytes as 59317021Sdim // possible. This means we only support 2^28 (268,435,456) unique function ids 60317021Sdim // in a single binary. 61317021Sdim int FuncId : 28; 62317021Sdim 63317021Sdim // We use another 4 bytes to hold the delta between the previous entry's TSC. 64317021Sdim // In case we've found that the distance is greater than the allowable 32 bits 65317021Sdim // (either because we are running in a different CPU and the TSC might be 66317021Sdim // different then), we should use a MetadataRecord before this FunctionRecord 67317021Sdim // that will contain the full TSC for that CPU, and keep this to 0. 68317021Sdim uint32_t TSCDelta; 69317021Sdim} __attribute__((packed)); 70317021Sdim 71317021Sdimstatic_assert(sizeof(FunctionRecord) == 8, "Wrong size for FunctionRecord."); 72317021Sdim 73344779Sdim} // namespace __xray 74344779Sdim 75317021Sdim#endif // XRAY_XRAY_FDR_LOG_RECORDS_H 76