111 lines · c
1//===-- TraceIntelPTMultiCpuDecoder.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-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef LLDB_SOURCE_PLUGINS_TRACE_INTEL_PT_TRACEINTELPTMULTICPUDECODER_H10#define LLDB_SOURCE_PLUGINS_TRACE_INTEL_PT_TRACEINTELPTMULTICPUDECODER_H11 12#include "LibiptDecoder.h"13#include "PerfContextSwitchDecoder.h"14#include "ThreadDecoder.h"15#include "forward-declarations.h"16#include <optional>17 18namespace lldb_private {19namespace trace_intel_pt {20 21/// Class used to decode a multi-cpu Intel PT trace. It assumes that each22/// thread could have potentially been executed on different cpu cores. It uses23/// a context switch trace per CPU with timestamps to identify which thread owns24/// each Intel PT decoded instruction and in which order. It also assumes that25/// the Intel PT data and context switches might have gaps in their traces due26/// to contention or race conditions. Finally, it assumes that a tid is not27/// repeated twice for two different threads because of the shortness of the28/// intel pt trace.29///30/// This object should be recreated after every stop in the case of live31/// processes.32class TraceIntelPTMultiCpuDecoder {33public:34 /// \param[in] TraceIntelPT35 /// The trace object to be decoded36 TraceIntelPTMultiCpuDecoder(TraceIntelPTSP trace_sp);37 38 /// \return39 /// A \a DecodedThread for the \p thread by decoding its instructions on all40 /// CPUs, sorted by TSCs. An \a llvm::Error is returned if the decoder41 /// couldn't be properly set up.42 llvm::Expected<DecodedThreadSP> Decode(Thread &thread);43 44 /// \return45 /// \b true if the given \p tid is managed by this decoder, regardless of46 /// whether there's tracing data associated to it or not.47 bool TracesThread(lldb::tid_t tid) const;48 49 /// \return50 /// The number of continuous executions found for the given \p tid.51 size_t GetNumContinuousExecutionsForThread(lldb::tid_t tid) const;52 53 /// \return54 /// The number of PSB blocks for a given thread in all cores.55 size_t GePSBBlocksCountForThread(lldb::tid_t tid) const;56 57 /// \return58 /// The total number of continuous executions found across CPUs.59 size_t GetTotalContinuousExecutionsCount() const;60 61 /// \return62 /// The number of psb blocks in all cores that couldn't be matched with a63 /// thread execution coming from context switch traces.64 size_t GetUnattributedPSBBlocksCount() const;65 66 /// \return67 /// The total number of PSB blocks in all cores.68 size_t GetTotalPSBBlocksCount() const;69 70 /// \return71 /// The lowest TSC value in this trace if available, \a std::nullopt if72 /// the trace is empty or the trace contains no timing information, or an73 /// \a llvm::Error if it was not possible to set up the decoder.74 llvm::Expected<std::optional<uint64_t>> FindLowestTSC();75 76private:77 /// Traverse the context switch traces and the basic intel pt continuous78 /// subtraces and produce a list of continuous executions for each process and79 /// thread.80 ///81 /// See \a DoCorrelateContextSwitchesAndIntelPtTraces.82 ///83 /// Any errors are stored in \a m_setup_error.84 llvm::Error CorrelateContextSwitchesAndIntelPtTraces();85 86 /// Produce a mapping from thread ids to the list of continuos executions with87 /// their associated intel pt subtraces.88 llvm::Expected<89 llvm::DenseMap<lldb::tid_t, std::vector<IntelPTThreadContinousExecution>>>90 DoCorrelateContextSwitchesAndIntelPtTraces();91 92 TraceIntelPTSP GetTrace();93 94 std::weak_ptr<TraceIntelPT> m_trace_wp;95 std::set<lldb::tid_t> m_tids;96 std::optional<97 llvm::DenseMap<lldb::tid_t, std::vector<IntelPTThreadContinousExecution>>>98 m_continuous_executions_per_thread;99 llvm::DenseMap<lldb::tid_t, DecodedThreadSP> m_decoded_threads;100 /// This variable will not be std::nullopt if a severe error happened during101 /// the setup of the decoder and we don't want decoding to be reattempted.102 std::optional<std::string> m_setup_error;103 uint64_t m_unattributed_psb_blocks = 0;104 uint64_t m_total_psb_blocks = 0;105};106 107} // namespace trace_intel_pt108} // namespace lldb_private109 110#endif // LLDB_SOURCE_PLUGINS_TRACE_INTEL_PT_TRACEINTELPTMULTICPUDECODER_H111