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
10 #include "llvm/Support/MemoryBuffer.h"
11
12 #include "../common/ThreadPostMortemTrace.h"
13 #include "LibiptDecoder.h"
14 #include "TraceIntelPT.h"
15
16 #include <utility>
17
18 using namespace lldb;
19 using namespace lldb_private;
20 using namespace lldb_private::trace_intel_pt;
21 using namespace llvm;
22
ThreadDecoder(const ThreadSP & thread_sp,TraceIntelPT & trace)23 ThreadDecoder::ThreadDecoder(const ThreadSP &thread_sp, TraceIntelPT &trace)
24 : m_thread_sp(thread_sp), m_trace(trace) {}
25
FindLowestTSC()26 Expected<Optional<uint64_t>> ThreadDecoder::FindLowestTSC() {
27 Optional<uint64_t> lowest_tsc;
28 Error err = m_trace.OnThreadBufferRead(
29 m_thread_sp->GetID(), [&](llvm::ArrayRef<uint8_t> data) -> llvm::Error {
30 Expected<Optional<uint64_t>> tsc = FindLowestTSCInTrace(m_trace, data);
31 if (!tsc)
32 return tsc.takeError();
33 lowest_tsc = *tsc;
34 return Error::success();
35 });
36 if (err)
37 return std::move(err);
38 return lowest_tsc;
39 }
40
Decode()41 Expected<DecodedThreadSP> ThreadDecoder::Decode() {
42 if (!m_decoded_thread.hasValue()) {
43 if (Expected<DecodedThreadSP> decoded_thread = DoDecode()) {
44 m_decoded_thread = *decoded_thread;
45 } else {
46 return decoded_thread.takeError();
47 }
48 }
49 return *m_decoded_thread;
50 }
51
DoDecode()52 llvm::Expected<DecodedThreadSP> ThreadDecoder::DoDecode() {
53 return m_trace.GetThreadTimer(m_thread_sp->GetID())
54 .TimeTask(
55 "Decoding instructions", [&]() -> Expected<DecodedThreadSP> {
56 DecodedThreadSP decoded_thread_sp = std::make_shared<DecodedThread>(
57 m_thread_sp, m_trace.GetPerfZeroTscConversion());
58
59 Error err = m_trace.OnThreadBufferRead(
60 m_thread_sp->GetID(), [&](llvm::ArrayRef<uint8_t> data) {
61 return DecodeSingleTraceForThread(*decoded_thread_sp, m_trace,
62 data);
63 });
64
65 if (err)
66 return std::move(err);
67 return decoded_thread_sp;
68 });
69 }
70