1 //===-- ThreadDecoder.cpp --======-----------------------------------------===//
2 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
3 // See https://llvm.org/LICENSE.txt for license information.
4 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
5 //
6 //===----------------------------------------------------------------------===//
7
8 #include "ThreadDecoder.h"
9 #include "../common/ThreadPostMortemTrace.h"
10 #include "LibiptDecoder.h"
11 #include "TraceIntelPT.h"
12 #include "llvm/Support/MemoryBuffer.h"
13 #include <optional>
14 #include <utility>
15
16 using namespace lldb;
17 using namespace lldb_private;
18 using namespace lldb_private::trace_intel_pt;
19 using namespace llvm;
20
ThreadDecoder(const ThreadSP & thread_sp,TraceIntelPT & trace)21 ThreadDecoder::ThreadDecoder(const ThreadSP &thread_sp, TraceIntelPT &trace)
22 : m_thread_sp(thread_sp), m_trace(trace) {}
23
FindLowestTSC()24 Expected<std::optional<uint64_t>> ThreadDecoder::FindLowestTSC() {
25 std::optional<uint64_t> lowest_tsc;
26 Error err = m_trace.OnThreadBufferRead(
27 m_thread_sp->GetID(), [&](llvm::ArrayRef<uint8_t> data) -> llvm::Error {
28 Expected<std::optional<uint64_t>> tsc =
29 FindLowestTSCInTrace(m_trace, data);
30 if (!tsc)
31 return tsc.takeError();
32 lowest_tsc = *tsc;
33 return Error::success();
34 });
35 if (err)
36 return std::move(err);
37 return lowest_tsc;
38 }
39
Decode()40 Expected<DecodedThreadSP> ThreadDecoder::Decode() {
41 if (!m_decoded_thread.has_value()) {
42 if (Expected<DecodedThreadSP> decoded_thread = DoDecode()) {
43 m_decoded_thread = *decoded_thread;
44 } else {
45 return decoded_thread.takeError();
46 }
47 }
48 return *m_decoded_thread;
49 }
50
DoDecode()51 llvm::Expected<DecodedThreadSP> ThreadDecoder::DoDecode() {
52 return m_trace.GetThreadTimer(m_thread_sp->GetID())
53 .TimeTask("Decoding instructions", [&]() -> Expected<DecodedThreadSP> {
54 DecodedThreadSP decoded_thread_sp = std::make_shared<DecodedThread>(
55 m_thread_sp, m_trace.GetPerfZeroTscConversion());
56
57 Error err = m_trace.OnThreadBufferRead(
58 m_thread_sp->GetID(), [&](llvm::ArrayRef<uint8_t> data) {
59 return DecodeSingleTraceForThread(*decoded_thread_sp, m_trace,
60 data);
61 });
62
63 if (err)
64 return std::move(err);
65 return decoded_thread_sp;
66 });
67 }
68