[Lldb-commits] [PATCH] D120762: [lldb] Protect control variables in IOHandler with a mutex to avoid a data race

[Jonas Devlieghere via Phabricator via lldb-commits]

JDevlieghere created this revision.
JDevlieghere added reviewers: clayborg, jingham, labath.
Herald added a subscriber: kristof.beyls.
Herald added a project: All.
JDevlieghere requested review of this revision.

Fixes a data race between the main thread and the process handling thread:

  WARNING: ThreadSanitizer: data race (pid=13380)
    Write of size 1 at 0x0001067646e8 by thread T8 (mutexes: write M2862):
      #0 lldb_private::IOHandler::SetIsDone(bool) IOHandler.h:90 (liblldb.15.0.0git.dylib:arm64+0x971d84)
      #1 IOHandlerProcessSTDIO::Cancel() Process.cpp:4376 (liblldb.15.0.0git.dylib:arm64+0x5de0ec)
      #2 lldb_private::Debugger::PopIOHandler(std::__1::shared_ptr<lldb_private::IOHandler> const&) Debugger.cpp:1156 (liblldb.15.0.0git.dylib:arm64+0x3cb264)
      #3 lldb_private::Debugger::RemoveIOHandler(std::__1::shared_ptr<lldb_private::IOHandler> const&) Debugger.cpp:1063 (liblldb.15.0.0git.dylib:arm64+0x3cbce8)
      #4 lldb_private::Process::PopProcessIOHandler() Process.cpp:4480 (liblldb.15.0.0git.dylib:arm64+0x5c57f8)
      #5 lldb_private::Debugger::HandleProcessEvent(std::__1::shared_ptr<lldb_private::Event> const&) Debugger.cpp:1549 (liblldb.15.0.0git.dylib:arm64+0x3cea78)
      #6 lldb_private::Debugger::DefaultEventHandler() Debugger.cpp:1622 (liblldb.15.0.0git.dylib:arm64+0x3cf27c)
      #7 std::__1::__function::__func<lldb_private::Debugger::StartEventHandlerThread()::$_2, std::__1::allocator<lldb_private::Debugger::StartEventHandlerThread()::$_2>, void* ()>::operator()() function.h:352 (liblldb.15.0.0git.dylib:arm64+0x3d1b94)
      #8 lldb_private::HostNativeThreadBase::ThreadCreateTrampoline(void*) HostNativeThreadBase.cpp:62 (liblldb.15.0.0git.dylib:arm64+0x4c7168)
      #9 lldb_private::HostThreadMacOSX::ThreadCreateTrampoline(void*) HostThreadMacOSX.mm:18 (liblldb.15.0.0git.dylib:arm64+0x29ef544)
  
    Previous write of size 1 at 0x0001067646e8 by main thread:
      #0 lldb_private::IOHandler::SetIsDone(bool) IOHandler.h:90 (liblldb.15.0.0git.dylib:arm64+0x971d84)
      #1 IOHandlerProcessSTDIO::Run() Process.cpp:4323 (liblldb.15.0.0git.dylib:arm64+0x5ddc2c)
      #2 lldb_private::Debugger::RunIOHandlers() Debugger.cpp:982 (liblldb.15.0.0git.dylib:arm64+0x3cb448)
      #3 lldb_private::CommandInterpreter::RunCommandInterpreter(lldb_private::CommandInterpreterRunOptions&) CommandInterpreter.cpp:3298 (liblldb.15.0.0git.dylib:arm64+0x506434)
      #4 lldb::SBDebugger::RunCommandInterpreter(bool, bool) SBDebugger.cpp:1166 (liblldb.15.0.0git.dylib:arm64+0x535c0)
      #5 Driver::MainLoop() Driver.cpp:634 (lldb:arm64+0x100006294)
      #6 main Driver.cpp:853 (lldb:arm64+0x100007344)


https://reviews.llvm.org/D120762

Files:
  lldb/include/lldb/Core/IOHandler.h
  lldb/source/Core/IOHandler.cpp
  lldb/source/Target/Process.cpp

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