//===-- TraceIntelPTMultiCpuDecoder.h ---------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef LLDB_SOURCE_PLUGINS_TRACE_INTEL_PT_TRACEINTELPTMULTICPUDECODER_H
#define LLDB_SOURCE_PLUGINS_TRACE_INTEL_PT_TRACEINTELPTMULTICPUDECODER_H
#include "LibiptDecoder.h"
#include "PerfContextSwitchDecoder.h"
#include "ThreadDecoder.h"
#include "forward-declarations.h"
#include <optional>
namespace lldb_private {
namespace trace_intel_pt {
/// Class used to decode a multi-cpu Intel PT trace. It assumes that each
/// thread could have potentially been executed on different cpu cores. It uses
/// a context switch trace per CPU with timestamps to identify which thread owns
/// each Intel PT decoded instruction and in which order. It also assumes that
/// the Intel PT data and context switches might have gaps in their traces due
/// to contention or race conditions. Finally, it assumes that a tid is not
/// repeated twice for two different threads because of the shortness of the
/// intel pt trace.
///
/// This object should be recreated after every stop in the case of live
/// processes.
class TraceIntelPTMultiCpuDecoder {
public:
/// \param[in] TraceIntelPT
/// The trace object to be decoded
TraceIntelPTMultiCpuDecoder(TraceIntelPTSP trace_sp);
/// \return
/// A \a DecodedThread for the \p thread by decoding its instructions on all
/// CPUs, sorted by TSCs. An \a llvm::Error is returned if the decoder
/// couldn't be properly set up.
llvm::Expected<DecodedThreadSP> Decode(Thread &thread);
/// \return
/// \b true if the given \p tid is managed by this decoder, regardless of
/// whether there's tracing data associated to it or not.
bool TracesThread(lldb::tid_t tid) const;
/// \return
/// The number of continuous executions found for the given \p tid.
size_t GetNumContinuousExecutionsForThread(lldb::tid_t tid) const;
/// \return
/// The number of PSB blocks for a given thread in all cores.
size_t GePSBBlocksCountForThread(lldb::tid_t tid) const;
/// \return
/// The total number of continuous executions found across CPUs.
size_t GetTotalContinuousExecutionsCount() const;
/// \return
/// The number of psb blocks in all cores that couldn't be matched with a
/// thread execution coming from context switch traces.
size_t GetUnattributedPSBBlocksCount() const;
/// \return
/// The total number of PSB blocks in all cores.
size_t GetTotalPSBBlocksCount() const;
/// \return
/// The lowest TSC value in this trace if available, \a std::nullopt if
/// the trace is empty or the trace contains no timing information, or an
/// \a llvm::Error if it was not possible to set up the decoder.
llvm::Expected<std::optional<uint64_t>> FindLowestTSC();
private:
/// Traverse the context switch traces and the basic intel pt continuous
/// subtraces and produce a list of continuous executions for each process and
/// thread.
///
/// See \a DoCorrelateContextSwitchesAndIntelPtTraces.
///
/// Any errors are stored in \a m_setup_error.
llvm::Error CorrelateContextSwitchesAndIntelPtTraces();
/// Produce a mapping from thread ids to the list of continuos executions with
/// their associated intel pt subtraces.
llvm::Expected<
llvm::DenseMap<lldb::tid_t, std::vector<IntelPTThreadContinousExecution>>>
DoCorrelateContextSwitchesAndIntelPtTraces();
TraceIntelPTSP GetTrace();
std::weak_ptr<TraceIntelPT> m_trace_wp;
std::set<lldb::tid_t> m_tids;
std::optional<
llvm::DenseMap<lldb::tid_t, std::vector<IntelPTThreadContinousExecution>>>
m_continuous_executions_per_thread;
llvm::DenseMap<lldb::tid_t, DecodedThreadSP> m_decoded_threads;
/// This variable will not be std::nullopt if a severe error happened during
/// the setup of the decoder and we don't want decoding to be reattempted.
std::optional<std::string> m_setup_error;
uint64_t m_unattributed_psb_blocks = 0;
uint64_t m_total_psb_blocks = 0;
};
} // namespace trace_intel_pt
} // namespace lldb_private
#endif // LLDB_SOURCE_PLUGINS_TRACE_INTEL_PT_TRACEINTELPTMULTICPUDECODER_H
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