[lldb-dev] Process::SyncIOHandler(), everyone please try out the following patch
Pavel Labath
labath at google.com
Fri May 15 09:53:34 PDT 2015
Thanks for the explanation.
I don't think this is related to attaching, because when attaching you
are not redirecting stdio, so the situation is much simpler on the
input side. In fact, I don't know if this is causing any problems now,
but it has manifested itself when I applied the last version version
of Greg's patch. When SyncIOHandlers is removed you can enter fgets
before you push ProcessIOHandler and then there is no way back.
However, I think I can get it working by keeping a (corrected) version
of SyncIOHandlers alive and fixing the remaining races.
cheers,
pl
On 15 May 2015 at 17:13, Zachary Turner <zturner at google.com> wrote:
> By the way is this related to lldb not returning to the prompt after
> launching/attaching? If so that's currently blocking me from getting attach
> to process working (lldb deadlocks and won't return to the prompt after
> attaching to an inferior). If this is related, happy to jump in and help, or
> even implement the windows side of this
>
> On Fri, May 15, 2015 at 9:07 AM Zachary Turner <zturner at google.com> wrote:
>>
>> You can use GetConsoleMode in a way similar to isatty to determine if
>> stdin is a terminal. If it is a terminal, you can use PeekConsoleInput or
>> GetNumberOfConsoleInputEvents to determine if there's data waiting without
>> blocking. The two of these combined should allow you to implement a
>> select-like loop, but this loop will structurally be very different from
>> what the non windows side will look like.
>>
>> As far as I know there is no better way to achieve this.
>> On Fri, May 15, 2015 at 3:57 AM Pavel Labath <labath at google.com> wrote:
>>>
>>> Hi all,
>>>
>>> I have identified a lot of IOHandler races by manual code inspection.
>>> I have a mostly-working fix for this, but I am still polishing it, and
>>> will send it for review shortly.
>>>
>>> The reason I say only "mostly" working is that I am not sure how to
>>> handle IOHandlerEditline::Cancel on windows. Specifically, the
>>> behavior of the handler when libedit is disabled. Currently Cancel()
>>> and Interrupt() correctly interrupt the handler, but only when libedit
>>> is in use. When libedit is off the IOHandler does a simple blocking
>>> fgets to read the command. This is a problem since we cannot interrupt
>>> the handler when we push another handler on top of the IO stack. Now,
>>> I could implement this to use select(), but this will not work work on
>>> windows.
>>>
>>> Zachary, do you have any idea how could the Cancel() functionality be
>>> implemented on windows? For now, I think I implement things in a way
>>> that the missing cancelation problem will not be extremely annoying,
>>> but in general, we should find a way to deal with this in the future.
>>> I think I remember seeing also other places that needed a select
>>> replacement on windows.
>>>
>>> cheers,
>>> pl
>>>
>>>
>>>
>>> On 15 May 2015 at 01:38, Zachary Turner <zturner at google.com> wrote:
>>> > Great results! I'm especially interested in these IOHandler issues,
>>> > since we
>>> > know for sure there are problems here.
>>> >
>>> > When you say Python can't find tsan, can you elaborate? I'm not sure
>>> > how
>>> > tsan works or the process used to run lldb under tsan, but i bet it's
>>> > something we can figure out with more information.
>>> >
>>> > Also, what os is this on?
>>> >
>>> > On Thu, May 14, 2015 at 5:01 PM Ryan Brown <ribrdb at google.com> wrote:
>>> >>
>>> >> I just built lldb with tsan. The tests don't seem to work because
>>> >> python
>>> >> can't find tsan, but a quick debugging session found a few issues:
>>> >>
>>> >> WARNING: ThreadSanitizer: data race (pid=64299)
>>> >> Write of size 1 at 0x7d4400004bb0 by thread T6:
>>> >> #0 lldb_private::IOHandler::SetIsDone(bool)
>>> >> tools/lldb/include/lldb/Core/IOHandler.h:107
>>> >> #1 lldb_private::Process::PushProcessIOHandler()
>>> >> tools/lldb/source/Target/Process.cpp:5279
>>> >> #2
>>> >>
>>> >> lldb_private::Process::HandlePrivateEvent(std::shared_ptr<lldb_private::Event>&)
>>> >> tools/lldb/source/Target/Process.cpp:4443
>>> >> #3 lldb_private::Process::RunPrivateStateThread()
>>> >> tools/lldb/source/Target/Process.cpp:4581
>>> >> #4 lldb_private::Process::PrivateStateThread(void*)
>>> >> tools/lldb/source/Target/Process.cpp:4505
>>> >> #5
>>> >> lldb_private::HostNativeThreadBase::ThreadCreateTrampoline(void*)
>>> >> tools/lldb/source/Host/common/HostNativeThreadBase.cpp:81
>>> >>
>>> >> Previous write of size 1 at 0x7d4400004bb0 by main thread:
>>> >> #0 lldb_private::IOHandler::SetIsDone(bool)
>>> >> tools/lldb/include/lldb/Core/IOHandler.h:107
>>> >> #1 IOHandlerProcessSTDIO::Run()
>>> >> tools/lldb/source/Target/Process.cpp:5096
>>> >> #2 lldb_private::Debugger::ExecuteIOHandlers()
>>> >> tools/lldb/source/Core/Debugger.cpp:907
>>> >> #3 lldb_private::CommandInterpreter::RunCommandInterpreter(bool,
>>> >> bool,
>>> >> lldb_private::CommandInterpreterRunOptions&)
>>> >> tools/lldb/source/Interpreter/CommandInterpreter.cpp:3234
>>> >> #4 lldb::SBDebugger::RunCommandInterpreter(bool, bool)
>>> >> tools/lldb/source/API/SBDebugger.cpp:980
>>> >> #5 Driver::MainLoop() tools/lldb/tools/driver/Driver.cpp:1152
>>> >> #6 main tools/lldb/tools/driver/Driver.cpp:1252
>>> >>
>>> >> ==================
>>> >> WARNING: ThreadSanitizer: lock-order-inversion (potential deadlock)
>>> >> (pid=64299)
>>> >> Cycle in lock order graph: M31728 (0x7d1000019e58) => M564
>>> >> (0x7d680001d0f8) => M31728
>>> >>
>>> >> Mutex M564 acquired here while holding mutex M31728 in main thread:
>>> >> #3 Locker tools/lldb/source/Host/common/Mutex.cpp:114
>>> >> #4
>>> >>
>>> >> lldb_private::ModuleList::FindSymbolsWithNameAndType(lldb_private::ConstString
>>> >> const&, lldb::SymbolType, lldb_private::SymbolContextList&, bool)
>>> >> const
>>> >> tools/lldb/source/Core/ModuleList.cpp:565
>>> >> #5 JITLoaderGDB::GetSymbolAddress(lldb_private::ModuleList&,
>>> >> lldb_private::ConstString const&, lldb::SymbolType) const
>>> >> tools/lldb/source/Plugins/JITLoader/GDB/JITLoaderGDB.cpp:432
>>> >> #6 JITLoaderGDB::SetJITBreakpoint(lldb_private::ModuleList&)
>>> >> tools/lldb/source/Plugins/JITLoader/GDB/JITLoaderGDB.cpp:109
>>> >> #7 JITLoaderGDB::DidLaunch()
>>> >> tools/lldb/source/Plugins/JITLoader/GDB/JITLoaderGDB.cpp:84
>>> >> #8 lldb_private::JITLoaderList::DidLaunch()
>>> >> tools/lldb/source/Target/JITLoaderList.cpp:60
>>> >> #9 lldb_private::Process::Launch(lldb_private::ProcessLaunchInfo&)
>>> >> tools/lldb/source/Target/Process.cpp:3177
>>> >> #10
>>> >>
>>> >> lldb_private::platform_linux::PlatformLinux::DebugProcess(lldb_private::ProcessLaunchInfo&,
>>> >> lldb_private::Debugger&, lldb_private::Target*, lldb_private::Error&)
>>> >> tools/lldb/source/Plugins/Platform/Linux/PlatformLinux.cpp:805
>>> >> #11 lldb_private::Target::Launch(lldb_private::ProcessLaunchInfo&,
>>> >> lldb_private::Stream*) tools/lldb/source/Target/Target.cpp:2602
>>> >> #12 CommandObjectProcessLaunch::DoExecute(lldb_private::Args&,
>>> >> lldb_private::CommandReturnObject&)
>>> >> tools/lldb/source/Commands/CommandObjectProcess.cpp:263
>>> >> #13 lldb_private::CommandObjectParsed::Execute(char const*,
>>> >> lldb_private::CommandReturnObject&)
>>> >> tools/lldb/source/Interpreter/CommandObject.cpp:1075
>>> >> #14 lldb_private::CommandInterpreter::HandleCommand(char const*,
>>> >> lldb_private::LazyBool, lldb_private::CommandReturnObject&,
>>> >> lldb_private::ExecutionContext*, bool, bool)
>>> >> tools/lldb/source/Interpreter/CommandInterpreter.cpp:1812
>>> >> #15
>>> >>
>>> >> lldb_private::CommandInterpreter::IOHandlerInputComplete(lldb_private::IOHandler&,
>>> >> std::string&)
>>> >> tools/lldb/source/Interpreter/CommandInterpreter.cpp:2997
>>> >> #16 non-virtual thunk to
>>> >>
>>> >> lldb_private::CommandInterpreter::IOHandlerInputComplete(lldb_private::IOHandler&,
>>> >> std::string&)
>>> >> tools/lldb/source/Interpreter/CommandInterpreter.cpp:3076
>>> >> #17 lldb_private::IOHandlerEditline::Run()
>>> >> tools/lldb/source/Core/IOHandler.cpp:729
>>> >> #18 lldb_private::Debugger::ExecuteIOHandlers()
>>> >> tools/lldb/source/Core/Debugger.cpp:907
>>> >> #19 lldb_private::CommandInterpreter::RunCommandInterpreter(bool,
>>> >> bool, lldb_private::CommandInterpreterRunOptions&)
>>> >> tools/lldb/source/Interpreter/CommandInterpreter.cpp:3234
>>> >> #20 lldb::SBDebugger::RunCommandInterpreter(bool, bool)
>>> >> tools/lldb/source/API/SBDebugger.cpp:980
>>> >> #21 Driver::MainLoop() tools/lldb/tools/driver/Driver.cpp:1152
>>> >> #22 main tools/lldb/tools/driver/Driver.cpp:1252
>>> >>
>>> >> Mutex M31728 previously acquired by the same thread here:
>>> >> #3 Locker tools/lldb/source/Host/common/Mutex.cpp:114
>>> >> #4 lldb_private::JITLoaderList::DidLaunch()
>>> >> tools/lldb/source/Target/JITLoaderList.cpp:58
>>> >> #5 lldb_private::Process::Launch(lldb_private::ProcessLaunchInfo&)
>>> >> tools/lldb/source/Target/Process.cpp:3177
>>> >> #6
>>> >>
>>> >> lldb_private::platform_linux::PlatformLinux::DebugProcess(lldb_private::ProcessLaunchInfo&,
>>> >> lldb_private::Debugger&, lldb_private::Target*, lldb_private::Error&)
>>> >> tools/lldb/source/Plugins/Platform/Linux/PlatformLinux.cpp:805
>>> >> #7 lldb_private::Target::Launch(lldb_private::ProcessLaunchInfo&,
>>> >> lldb_private::Stream*) tools/lldb/source/Target/Target.cpp:2602
>>> >> #8 CommandObjectProcessLaunch::DoExecute(lldb_private::Args&,
>>> >> lldb_private::CommandReturnObject&)
>>> >> tools/lldb/source/Commands/CommandObjectProcess.cpp:263
>>> >> #9 lldb_private::CommandObjectParsed::Execute(char const*,
>>> >> lldb_private::CommandReturnObject&)
>>> >> tools/lldb/source/Interpreter/CommandObject.cpp:1075
>>> >> #10 lldb_private::CommandInterpreter::HandleCommand(char const*,
>>> >> lldb_private::LazyBool, lldb_private::CommandReturnObject&,
>>> >> lldb_private::ExecutionContext*, bool, bool)
>>> >> tools/lldb/source/Interpreter/CommandInterpreter.cpp:1812
>>> >> #11
>>> >>
>>> >> lldb_private::CommandInterpreter::IOHandlerInputComplete(lldb_private::IOHandler&,
>>> >> std::string&)
>>> >> tools/lldb/source/Interpreter/CommandInterpreter.cpp:2997
>>> >> #12 non-virtual thunk to
>>> >>
>>> >> lldb_private::CommandInterpreter::IOHandlerInputComplete(lldb_private::IOHandler&,
>>> >> std::string&)
>>> >> tools/lldb/source/Interpreter/CommandInterpreter.cpp:3076
>>> >> #13 lldb_private::IOHandlerEditline::Run()
>>> >> tools/lldb/source/Core/IOHandler.cpp:729
>>> >> #14 lldb_private::Debugger::ExecuteIOHandlers()
>>> >> tools/lldb/source/Core/Debugger.cpp:907
>>> >> #15 lldb_private::CommandInterpreter::RunCommandInterpreter(bool,
>>> >> bool, lldb_private::CommandInterpreterRunOptions&)
>>> >> tools/lldb/source/Interpreter/CommandInterpreter.cpp:3234
>>> >> #16 lldb::SBDebugger::RunCommandInterpreter(bool, bool)
>>> >> tools/lldb/source/API/SBDebugger.cpp:980
>>> >> #17 Driver::MainLoop() tools/lldb/tools/driver/Driver.cpp:1152
>>> >> #18 main tools/lldb/tools/driver/Driver.cpp:1252
>>> >>
>>> >> Mutex M31728 acquired here while holding mutex M564 in thread T6:
>>> >> #3 Locker tools/lldb/source/Host/common/Mutex.cpp:114
>>> >> #4
>>> >> lldb_private::JITLoaderList::ModulesDidLoad(lldb_private::ModuleList&)
>>> >> tools/lldb/source/Target/JITLoaderList.cpp:74
>>> >> #5
>>> >> lldb_private::Process::ModulesDidLoad(lldb_private::ModuleList&)
>>> >> tools/lldb/source/Target/Process.cpp:6466
>>> >> #6 lldb_private::Target::ModulesDidLoad(lldb_private::ModuleList&)
>>> >> tools/lldb/source/Target/Target.cpp:1286
>>> >> #7 lldb_private::Target::ModuleAdded(lldb_private::ModuleList
>>> >> const&,
>>> >> std::shared_ptr<lldb_private::Module> const&)
>>> >> tools/lldb/source/Target/Target.cpp:1254
>>> >> #8 non-virtual thunk to
>>> >> lldb_private::Target::ModuleAdded(lldb_private::ModuleList const&,
>>> >> std::shared_ptr<lldb_private::Module> const&)
>>> >> tools/lldb/source/Target/Target.cpp:1256
>>> >> #9
>>> >>
>>> >> lldb_private::ModuleList::AppendImpl(std::shared_ptr<lldb_private::Module>
>>> >> const&, bool) tools/lldb/source/Core/ModuleList.cpp:111
>>> >> #10
>>> >> lldb_private::ModuleList::Append(std::shared_ptr<lldb_private::Module>
>>> >> const&) tools/lldb/source/Core/ModuleList.cpp:118
>>> >> #11 lldb_private::Target::GetSharedModule(lldb_private::ModuleSpec
>>> >> const&, lldb_private::Error*) tools/lldb/source/Target/Target.cpp:1810
>>> >> #12
>>> >>
>>> >> lldb_private::DynamicLoader::LoadModuleAtAddress(lldb_private::FileSpec
>>> >> const&, unsigned long, unsigned long)
>>> >> tools/lldb/source/Core/DynamicLoader.cpp:185
>>> >> #13 DynamicLoaderPOSIXDYLD::LoadAllCurrentModules()
>>> >>
>>> >> tools/lldb/source/Plugins/DynamicLoader/POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp:530
>>> >> #14 DynamicLoaderPOSIXDYLD::EntryBreakpointHit(void*,
>>> >> lldb_private::StoppointCallbackContext*, unsigned long, unsigned long)
>>> >>
>>> >> tools/lldb/source/Plugins/DynamicLoader/POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp:343
>>> >> #15
>>> >>
>>> >> lldb_private::BreakpointOptions::InvokeCallback(lldb_private::StoppointCallbackContext*,
>>> >> unsigned long, unsigned long)
>>> >> tools/lldb/source/Breakpoint/BreakpointOptions.cpp:147
>>> >> #16
>>> >>
>>> >> lldb_private::Breakpoint::InvokeCallback(lldb_private::StoppointCallbackContext*,
>>> >> int) tools/lldb/source/Breakpoint/Breakpoint.cpp:345
>>> >> #17
>>> >>
>>> >> lldb_private::BreakpointLocation::InvokeCallback(lldb_private::StoppointCallbackContext*)
>>> >> tools/lldb/source/Breakpoint/BreakpointLocation.cpp:222
>>> >> #18
>>> >>
>>> >> lldb_private::BreakpointLocation::ShouldStop(lldb_private::StoppointCallbackContext*)
>>> >> tools/lldb/source/Breakpoint/BreakpointLocation.cpp:465
>>> >> #19
>>> >>
>>> >> lldb_private::BreakpointLocationCollection::ShouldStop(lldb_private::StoppointCallbackContext*)
>>> >> tools/lldb/source/Breakpoint/BreakpointLocationCollection.cpp:144
>>> >> #20
>>> >>
>>> >> lldb_private::BreakpointSite::ShouldStop(lldb_private::StoppointCallbackContext*)
>>> >> tools/lldb/source/Breakpoint/BreakpointSite.cpp:69
>>> >> #21
>>> >>
>>> >> lldb_private::StopInfoBreakpoint::ShouldStopSynchronous(lldb_private::Event*)
>>> >> tools/lldb/source/Target/StopInfo.cpp:200
>>> >> #22 lldb_private::Thread::ShouldStop(lldb_private::Event*)
>>> >> tools/lldb/source/Target/Thread.cpp:845
>>> >> #23 lldb_private::ThreadList::ShouldStop(lldb_private::Event*)
>>> >> tools/lldb/source/Target/ThreadList.cpp:318
>>> >> #24
>>> >> lldb_private::Process::ShouldBroadcastEvent(lldb_private::Event*)
>>> >> tools/lldb/source/Target/Process.cpp:4181
>>> >> #25
>>> >>
>>> >> lldb_private::Process::HandlePrivateEvent(std::shared_ptr<lldb_private::Event>&)
>>> >> tools/lldb/source/Target/Process.cpp:4422
>>> >> #26 lldb_private::Process::RunPrivateStateThread()
>>> >> tools/lldb/source/Target/Process.cpp:4581
>>> >> #27 lldb_private::Process::PrivateStateThread(void*)
>>> >> tools/lldb/source/Target/Process.cpp:4505
>>> >> #28
>>> >> lldb_private::HostNativeThreadBase::ThreadCreateTrampoline(void*)
>>> >> tools/lldb/source/Host/common/HostNativeThreadBase.cpp:81
>>> >>
>>> >> Mutex M564 previously acquired by the same thread here:
>>> >> #3 Locker tools/lldb/source/Host/common/Mutex.cpp:114
>>> >> #4
>>> >>
>>> >> lldb_private::ModuleList::AppendImpl(std::shared_ptr<lldb_private::Module>
>>> >> const&, bool) tools/lldb/source/Core/ModuleList.cpp:108
>>> >> #5
>>> >> lldb_private::ModuleList::Append(std::shared_ptr<lldb_private::Module>
>>> >> const&) tools/lldb/source/Core/ModuleList.cpp:118
>>> >> #6 lldb_private::Target::GetSharedModule(lldb_private::ModuleSpec
>>> >> const&, lldb_private::Error*) tools/lldb/source/Target/Target.cpp:1810
>>> >> #7
>>> >>
>>> >> lldb_private::DynamicLoader::LoadModuleAtAddress(lldb_private::FileSpec
>>> >> const&, unsigned long, unsigned long)
>>> >> tools/lldb/source/Core/DynamicLoader.cpp:185
>>> >> #8 DynamicLoaderPOSIXDYLD::LoadAllCurrentModules()
>>> >>
>>> >> tools/lldb/source/Plugins/DynamicLoader/POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp:530
>>> >> #9 DynamicLoaderPOSIXDYLD::EntryBreakpointHit(void*,
>>> >> lldb_private::StoppointCallbackContext*, unsigned long, unsigned long)
>>> >>
>>> >> tools/lldb/source/Plugins/DynamicLoader/POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp:343
>>> >> #10
>>> >>
>>> >> lldb_private::BreakpointOptions::InvokeCallback(lldb_private::StoppointCallbackContext*,
>>> >> unsigned long, unsigned long)
>>> >> tools/lldb/source/Breakpoint/BreakpointOptions.cpp:147
>>> >> #11
>>> >>
>>> >> lldb_private::Breakpoint::InvokeCallback(lldb_private::StoppointCallbackContext*,
>>> >> int) tools/lldb/source/Breakpoint/Breakpoint.cpp:345
>>> >> #12
>>> >>
>>> >> lldb_private::BreakpointLocation::InvokeCallback(lldb_private::StoppointCallbackContext*)
>>> >> tools/lldb/source/Breakpoint/BreakpointLocation.cpp:222
>>> >> #13
>>> >>
>>> >> lldb_private::BreakpointLocation::ShouldStop(lldb_private::StoppointCallbackContext*)
>>> >> tools/lldb/source/Breakpoint/BreakpointLocation.cpp:465
>>> >> #14
>>> >>
>>> >> lldb_private::BreakpointLocationCollection::ShouldStop(lldb_private::StoppointCallbackContext*)
>>> >> tools/lldb/source/Breakpoint/BreakpointLocationCollection.cpp:144
>>> >> #15
>>> >>
>>> >> lldb_private::BreakpointSite::ShouldStop(lldb_private::StoppointCallbackContext*)
>>> >> tools/lldb/source/Breakpoint/BreakpointSite.cpp:69
>>> >> #16
>>> >>
>>> >> lldb_private::StopInfoBreakpoint::ShouldStopSynchronous(lldb_private::Event*)
>>> >> tools/lldb/source/Target/StopInfo.cpp:200
>>> >> #17 lldb_private::Thread::ShouldStop(lldb_private::Event*)
>>> >> tools/lldb/source/Target/Thread.cpp:845
>>> >> #18 lldb_private::ThreadList::ShouldStop(lldb_private::Event*)
>>> >> tools/lldb/source/Target/ThreadList.cpp:318
>>> >> #19
>>> >> lldb_private::Process::ShouldBroadcastEvent(lldb_private::Event*)
>>> >> tools/lldb/source/Target/Process.cpp:4181
>>> >> #20
>>> >>
>>> >> lldb_private::Process::HandlePrivateEvent(std::shared_ptr<lldb_private::Event>&)
>>> >> tools/lldb/source/Target/Process.cpp:4422
>>> >> #21 lldb_private::Process::RunPrivateStateThread()
>>> >> tools/lldb/source/Target/Process.cpp:4581
>>> >> #22 lldb_private::Process::PrivateStateThread(void*)
>>> >> tools/lldb/source/Target/Process.cpp:4505
>>> >> #23
>>> >> lldb_private::HostNativeThreadBase::ThreadCreateTrampoline(void*)
>>> >> tools/lldb/source/Host/common/HostNativeThreadBase.cpp:81
>>> >>
>>> >> ==================
>>> >> WARNING: ThreadSanitizer: data race (pid=64299)
>>> >> Write of size 1 at 0x7d4400004bb1 by thread T2 (mutexes: write
>>> >> M168):
>>> >> #0 lldb_private::IOHandler::Deactivate()
>>> >> tools/lldb/include/lldb/Core/IOHandler.h:131
>>> >> #1
>>> >>
>>> >> lldb_private::Debugger::PopIOHandler(std::shared_ptr<lldb_private::IOHandler>
>>> >> const&) tools/lldb/source/Core/Debugger.cpp:1064
>>> >> #2 lldb_private::Process::PopProcessIOHandler()
>>> >> tools/lldb/source/Target/Process.cpp:5291
>>> >> #3
>>> >>
>>> >> lldb_private::Debugger::HandleProcessEvent(std::shared_ptr<lldb_private::Event>
>>> >> const&) tools/lldb/source/Core/Debugger.cpp:1544
>>> >> #4 lldb_private::Debugger::DefaultEventHandler()
>>> >> tools/lldb/source/Core/Debugger.cpp:1634
>>> >> #5 lldb_private::Debugger::EventHandlerThread(void*)
>>> >> tools/lldb/source/Core/Debugger.cpp:1696
>>> >> #6
>>> >> lldb_private::HostNativeThreadBase::ThreadCreateTrampoline(void*)
>>> >> tools/lldb/source/Host/common/HostNativeThreadBase.cpp:81
>>> >>
>>> >> Previous write of size 1 at 0x7d4400004bb1 by main thread:
>>> >> #0 lldb_private::IOHandler::Activate()
>>> >> tools/lldb/include/lldb/Core/IOHandler.h:125
>>> >> #1 lldb_private::Debugger::ExecuteIOHandlers()
>>> >> tools/lldb/source/Core/Debugger.cpp:906
>>> >> #2 lldb_private::CommandInterpreter::RunCommandInterpreter(bool,
>>> >> bool,
>>> >> lldb_private::CommandInterpreterRunOptions&)
>>> >> tools/lldb/source/Interpreter/CommandInterpreter.cpp:3234
>>> >> #3 lldb::SBDebugger::RunCommandInterpreter(bool, bool)
>>> >> tools/lldb/source/API/SBDebugger.cpp:980
>>> >> #4 Driver::MainLoop() tools/lldb/tools/driver/Driver.cpp:1152
>>> >> #5 main tools/lldb/tools/driver/Driver.cpp:1252
>>> >>
>>> >> ==================
>>> >> WARNING: ThreadSanitizer: data race (pid=64299)
>>> >> Read of size 8 at 0x7da0000080c0 by thread T2 (mutexes: write M168):
>>> >> #0 write <null>:0
>>> >> #1 operator() tools/lldb/source/Host/posix/PipePosix.cpp:416
>>> >> #2 std::_Function_handler<lldb_private::Error (bool&),
>>> >> lldb_private::PipePosix::Write(void const*, unsigned long, unsigned
>>> >> long&)::$_1>::_M_invoke(std::_Any_data const&, bool&)
>>> >>
>>> >> /usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/functional:2056
>>> >> #3 std::function<lldb_private::Error (bool&)>::operator()(bool&)
>>> >> const
>>> >>
>>> >> /usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/functional:2464
>>> >> #4 (anonymous namespace)::SelectIO(int, bool,
>>> >> std::function<lldb_private::Error (bool&)> const&,
>>> >> std::chrono::duration<long, std::ratio<1l, 1000000l> > const&)
>>> >> tools/lldb/source/Host/posix/PipePosix.cpp:118
>>> >> #5 lldb_private::PipePosix::Write(void const*, unsigned long,
>>> >> unsigned
>>> >> long&) tools/lldb/source/Host/posix/PipePosix.cpp:411
>>> >> #6 IOHandlerProcessSTDIO::Cancel()
>>> >> tools/lldb/source/Target/Process.cpp:5192
>>> >> #7
>>> >>
>>> >> lldb_private::Debugger::PopIOHandler(std::shared_ptr<lldb_private::IOHandler>
>>> >> const&) tools/lldb/source/Core/Debugger.cpp:1065
>>> >> #8 lldb_private::Process::PopProcessIOHandler()
>>> >> tools/lldb/source/Target/Process.cpp:5291
>>> >> #9
>>> >>
>>> >> lldb_private::Debugger::HandleProcessEvent(std::shared_ptr<lldb_private::Event>
>>> >> const&) tools/lldb/source/Core/Debugger.cpp:1544
>>> >> #10 lldb_private::Debugger::DefaultEventHandler()
>>> >> tools/lldb/source/Core/Debugger.cpp:1634
>>> >> #11 lldb_private::Debugger::EventHandlerThread(void*)
>>> >> tools/lldb/source/Core/Debugger.cpp:1696
>>> >> #12
>>> >> lldb_private::HostNativeThreadBase::ThreadCreateTrampoline(void*)
>>> >> tools/lldb/source/Host/common/HostNativeThreadBase.cpp:81
>>> >>
>>> >> Previous write of size 8 at 0x7da0000080c0 by main thread:
>>> >> #0 pipe2 <null>:0
>>> >> #1 lldb_private::PipePosix::CreateNew(bool)
>>> >> tools/lldb/source/Host/posix/PipePosix.cpp:168
>>> >> #2 IOHandlerProcessSTDIO::OpenPipes()
>>> >> tools/lldb/source/Target/Process.cpp:5078
>>> >> #3 IOHandlerProcessSTDIO::Run()
>>> >> tools/lldb/source/Target/Process.cpp:5097
>>> >> #4 lldb_private::Debugger::ExecuteIOHandlers()
>>> >> tools/lldb/source/Core/Debugger.cpp:907
>>> >> #5 lldb_private::CommandInterpreter::RunCommandInterpreter(bool,
>>> >> bool,
>>> >> lldb_private::CommandInterpreterRunOptions&)
>>> >> tools/lldb/source/Interpreter/CommandInterpreter.cpp:3234
>>> >> #6 lldb::SBDebugger::RunCommandInterpreter(bool, bool)
>>> >> tools/lldb/source/API/SBDebugger.cpp:980
>>> >> #7 Driver::MainLoop() tools/lldb/tools/driver/Driver.cpp:1152
>>> >> #8 main tools/lldb/tools/driver/Driver.cpp:1252
>>> >>
>>> >> Location is file descriptor 12 created by main thread at:
>>> >> #0 pipe2 <null>:0
>>> >> #1 lldb_private::PipePosix::CreateNew(bool)
>>> >> tools/lldb/source/Host/posix/PipePosix.cpp:168
>>> >> #2 IOHandlerProcessSTDIO::OpenPipes()
>>> >> tools/lldb/source/Target/Process.cpp:5078
>>> >> #3 IOHandlerProcessSTDIO::Run()
>>> >> tools/lldb/source/Target/Process.cpp:5097
>>> >> #4 lldb_private::Debugger::ExecuteIOHandlers()
>>> >> tools/lldb/source/Core/Debugger.cpp:907
>>> >> #5 lldb_private::CommandInterpreter::RunCommandInterpreter(bool,
>>> >> bool,
>>> >> lldb_private::CommandInterpreterRunOptions&)
>>> >> tools/lldb/source/Interpreter/CommandInterpreter.cpp:3234
>>> >> #6 lldb::SBDebugger::RunCommandInterpreter(bool, bool)
>>> >> tools/lldb/source/API/SBDebugger.cpp:980
>>> >> #7 Driver::MainLoop() tools/lldb/tools/driver/Driver.cpp:1152
>>> >> #8 main tools/lldb/tools/driver/Driver.cpp:1252
>>> >>
>>> >> ==================
>>> >> WARNING: ThreadSanitizer: data race (pid=64299)
>>> >> Read of size 8 at 0x7d080001a5c8 by main thread:
>>> >> #0 lldb_private::HostNativeThreadBase::GetSystemHandle() const
>>> >> tools/lldb/source/Host/common/HostNativeThreadBase.cpp:35
>>> >> #1 lldb_private::HostThread::EqualsThread(unsigned long) const
>>> >> tools/lldb/source/Host/common/HostThread.cpp:77
>>> >> #2 lldb_private::Process::GetRunLock()
>>> >> tools/lldb/source/Target/Process.cpp:6373
>>> >> #3
>>> >> lldb_private::ExecutionContextRef::SetTargetPtr(lldb_private::Target*,
>>> >> bool)
>>> >> tools/lldb/source/Target/ExecutionContext.cpp:723
>>> >> #4
>>> >>
>>> >> lldb_private::CommandInterpreter::UpdateExecutionContext(lldb_private::ExecutionContext*)
>>> >> tools/lldb/source/Interpreter/CommandInterpreter.cpp:2940
>>> >> #5 lldb_private::CommandInterpreter::HandleCommand(char const*,
>>> >> lldb_private::LazyBool, lldb_private::CommandReturnObject&,
>>> >> lldb_private::ExecutionContext*, bool, bool)
>>> >> tools/lldb/source/Interpreter/CommandInterpreter.cpp:1668
>>> >> #6
>>> >>
>>> >> lldb_private::CommandInterpreter::IOHandlerInputComplete(lldb_private::IOHandler&,
>>> >> std::string&)
>>> >> tools/lldb/source/Interpreter/CommandInterpreter.cpp:2997
>>> >> #7 non-virtual thunk to
>>> >>
>>> >> lldb_private::CommandInterpreter::IOHandlerInputComplete(lldb_private::IOHandler&,
>>> >> std::string&)
>>> >> tools/lldb/source/Interpreter/CommandInterpreter.cpp:3076
>>> >> #8 lldb_private::IOHandlerEditline::Run()
>>> >> tools/lldb/source/Core/IOHandler.cpp:729
>>> >> #9 lldb_private::Debugger::ExecuteIOHandlers()
>>> >> tools/lldb/source/Core/Debugger.cpp:907
>>> >> #10 lldb_private::CommandInterpreter::RunCommandInterpreter(bool,
>>> >> bool, lldb_private::CommandInterpreterRunOptions&)
>>> >> tools/lldb/source/Interpreter/CommandInterpreter.cpp:3234
>>> >> #11 lldb::SBDebugger::RunCommandInterpreter(bool, bool)
>>> >> tools/lldb/source/API/SBDebugger.cpp:980
>>> >> #12 Driver::MainLoop() tools/lldb/tools/driver/Driver.cpp:1152
>>> >> #13 main tools/lldb/tools/driver/Driver.cpp:1252
>>> >>
>>> >> Previous write of size 8 at 0x7d080001a5c8 by thread T6:
>>> >> #0 memset <null>:0
>>> >> #1 lldb_private::HostNativeThreadBase::Reset()
>>> >> tools/lldb/source/Host/common/HostNativeThreadBase.cpp:54
>>> >> #2 lldb_private::HostThread::Reset()
>>> >> tools/lldb/source/Host/common/HostThread.cpp:41
>>> >> #3 lldb_private::Process::RunPrivateStateThread()
>>> >> tools/lldb/source/Target/Process.cpp:4604
>>> >> #4 lldb_private::Process::PrivateStateThread(void*)
>>> >> tools/lldb/source/Target/Process.cpp:4505
>>> >> #5
>>> >> lldb_private::HostNativeThreadBase::ThreadCreateTrampoline(void*)
>>> >> tools/lldb/source/Host/common/HostNativeThreadBase.cpp:81
>>> >>
>>> >> ==================
>>> >> WARNING: ThreadSanitizer: data race (pid=64299)
>>> >> Write of size 4 at 0x7d680001c8e8 by main thread:
>>> >> #0 lldb_private::Terminal::SetFileDescriptor(int)
>>> >> tools/lldb/include/lldb/Host/Terminal.h:46
>>> >> #1 lldb_private::TerminalState::Save(int, bool)
>>> >> tools/lldb/source/Host/common/Terminal.cpp:144
>>> >> #2 lldb_private::Debugger::SaveInputTerminalState()
>>> >> tools/lldb/source/Core/Debugger.cpp:825
>>> >> #3 lldb::SBDebugger::SaveInputTerminalState()
>>> >> tools/lldb/source/API/SBDebugger.cpp:395
>>> >> #4 sigtstp_handler(int) tools/lldb/tools/driver/Driver.cpp:1203
>>> >> #5 __tsan::CallUserSignalHandler(__tsan::ThreadState*, bool, bool,
>>> >> int, my_siginfo_t*, void*) tsan_interceptors.o:0
>>> >> #6 std::string::_Rep::_M_dispose(std::allocator<char> const&)
>>> >>
>>> >> /build/buildd/gcc-4.8-4.8.2/build/x86_64-linux-gnu/libstdc++-v3/include/bits/basic_string.h:538
>>> >> #7
>>> >>
>>> >> lldb_private::CommandInterpreter::IOHandlerInputComplete(lldb_private::IOHandler&,
>>> >> std::string&)
>>> >> tools/lldb/source/Interpreter/CommandInterpreter.cpp:2997
>>> >> #8 non-virtual thunk to
>>> >>
>>> >> lldb_private::CommandInterpreter::IOHandlerInputComplete(lldb_private::IOHandler&,
>>> >> std::string&)
>>> >> tools/lldb/source/Interpreter/CommandInterpreter.cpp:3076
>>> >> #9 lldb_private::IOHandlerEditline::Run()
>>> >> tools/lldb/source/Core/IOHandler.cpp:729
>>> >> #10 lldb_private::Debugger::ExecuteIOHandlers()
>>> >> tools/lldb/source/Core/Debugger.cpp:907
>>> >> #11 lldb_private::CommandInterpreter::RunCommandInterpreter(bool,
>>> >> bool, lldb_private::CommandInterpreterRunOptions&)
>>> >> tools/lldb/source/Interpreter/CommandInterpreter.cpp:3234
>>> >> #12 lldb::SBDebugger::RunCommandInterpreter(bool, bool)
>>> >> tools/lldb/source/API/SBDebugger.cpp:980
>>> >> #13 Driver::MainLoop() tools/lldb/tools/driver/Driver.cpp:1152
>>> >> #14 main tools/lldb/tools/driver/Driver.cpp:1252
>>> >>
>>> >> Previous write of size 4 at 0x7d680001c8e8 by thread T2 (mutexes:
>>> >> write
>>> >> M159):
>>> >> #0 lldb_private::Terminal::SetFileDescriptor(int)
>>> >> tools/lldb/include/lldb/Host/Terminal.h:46
>>> >> #1 lldb_private::TerminalState::Save(int, bool)
>>> >> tools/lldb/source/Host/common/Terminal.cpp:144
>>> >> #2 lldb_private::Debugger::SaveInputTerminalState()
>>> >> tools/lldb/source/Core/Debugger.cpp:825
>>> >> #3 lldb::SBDebugger::SaveInputTerminalState()
>>> >> tools/lldb/source/API/SBDebugger.cpp:395
>>> >> #4 sigtstp_handler(int) tools/lldb/tools/driver/Driver.cpp:1203
>>> >> #5 __tsan::CallUserSignalHandler(__tsan::ThreadState*, bool, bool,
>>> >> int, my_siginfo_t*, void*) tsan_interceptors.o:0
>>> >> #6 lldb_private::Condition::Wait(lldb_private::Mutex&,
>>> >> lldb_private::TimeValue const*, bool*)
>>> >> tools/lldb/source/Host/common/Condition.cpp:85
>>> >> #7 lldb_private::Predicate<bool>::WaitForValueEqualTo(bool,
>>> >> lldb_private::TimeValue const*, bool*)
>>> >> tools/lldb/include/lldb/Host/Predicate.h:339
>>> >> #8
>>> >> lldb_private::Listener::WaitForEventsInternal(lldb_private::TimeValue
>>> >> const*, lldb_private::Broadcaster*, lldb_private::ConstString const*,
>>> >> unsigned int, unsigned int, std::shared_ptr<lldb_private::Event>&)
>>> >> tools/lldb/source/Core/Listener.cpp:442
>>> >> #9 lldb_private::Listener::WaitForEvent(lldb_private::TimeValue
>>> >> const*, std::shared_ptr<lldb_private::Event>&)
>>> >> tools/lldb/source/Core/Listener.cpp:492
>>> >> #10 lldb_private::Debugger::DefaultEventHandler()
>>> >> tools/lldb/source/Core/Debugger.cpp:1623
>>> >> #11 lldb_private::Debugger::EventHandlerThread(void*)
>>> >> tools/lldb/source/Core/Debugger.cpp:1696
>>> >> #12
>>> >> lldb_private::HostNativeThreadBase::ThreadCreateTrampoline(void*)
>>> >> tools/lldb/source/Host/common/HostNativeThreadBase.cpp:81
>>> >>
>>> >> ==================
>>> >> WARNING: ThreadSanitizer: data race (pid=64299)
>>> >> Write of size 4 at 0x7d680001c8ec by main thread:
>>> >> #0 lldb_private::TerminalState::Save(int, bool)
>>> >> tools/lldb/source/Host/common/Terminal.cpp:148
>>> >> #1 lldb_private::Debugger::SaveInputTerminalState()
>>> >> tools/lldb/source/Core/Debugger.cpp:825
>>> >> #2 lldb::SBDebugger::SaveInputTerminalState()
>>> >> tools/lldb/source/API/SBDebugger.cpp:395
>>> >> #3 sigtstp_handler(int) tools/lldb/tools/driver/Driver.cpp:1203
>>> >> #4 __tsan::CallUserSignalHandler(__tsan::ThreadState*, bool, bool,
>>> >> int, my_siginfo_t*, void*) tsan_interceptors.o:0
>>> >> #5 std::string::_Rep::_M_dispose(std::allocator<char> const&)
>>> >>
>>> >> /build/buildd/gcc-4.8-4.8.2/build/x86_64-linux-gnu/libstdc++-v3/include/bits/basic_string.h:538
>>> >> #6
>>> >>
>>> >> lldb_private::CommandInterpreter::IOHandlerInputComplete(lldb_private::IOHandler&,
>>> >> std::string&)
>>> >> tools/lldb/source/Interpreter/CommandInterpreter.cpp:2997
>>> >> #7 non-virtual thunk to
>>> >>
>>> >> lldb_private::CommandInterpreter::IOHandlerInputComplete(lldb_private::IOHandler&,
>>> >> std::string&)
>>> >> tools/lldb/source/Interpreter/CommandInterpreter.cpp:3076
>>> >> #8 lldb_private::IOHandlerEditline::Run()
>>> >> tools/lldb/source/Core/IOHandler.cpp:729
>>> >> #9 lldb_private::Debugger::ExecuteIOHandlers()
>>> >> tools/lldb/source/Core/Debugger.cpp:907
>>> >> #10 lldb_private::CommandInterpreter::RunCommandInterpreter(bool,
>>> >> bool, lldb_private::CommandInterpreterRunOptions&)
>>> >> tools/lldb/source/Interpreter/CommandInterpreter.cpp:3234
>>> >> #11 lldb::SBDebugger::RunCommandInterpreter(bool, bool)
>>> >> tools/lldb/source/API/SBDebugger.cpp:980
>>> >> #12 Driver::MainLoop() tools/lldb/tools/driver/Driver.cpp:1152
>>> >> #13 main tools/lldb/tools/driver/Driver.cpp:1252
>>> >>
>>> >> Previous write of size 4 at 0x7d680001c8ec by thread T2 (mutexes:
>>> >> write
>>> >> M159):
>>> >> #0 lldb_private::TerminalState::Save(int, bool)
>>> >> tools/lldb/source/Host/common/Terminal.cpp:148
>>> >> #1 lldb_private::Debugger::SaveInputTerminalState()
>>> >> tools/lldb/source/Core/Debugger.cpp:825
>>> >> #2 lldb::SBDebugger::SaveInputTerminalState()
>>> >> tools/lldb/source/API/SBDebugger.cpp:395
>>> >> #3 sigtstp_handler(int) tools/lldb/tools/driver/Driver.cpp:1203
>>> >> #4 __tsan::CallUserSignalHandler(__tsan::ThreadState*, bool, bool,
>>> >> int, my_siginfo_t*, void*) tsan_interceptors.o:0
>>> >> #5 lldb_private::Condition::Wait(lldb_private::Mutex&,
>>> >> lldb_private::TimeValue const*, bool*)
>>> >> tools/lldb/source/Host/common/Condition.cpp:85
>>> >> #6 lldb_private::Predicate<bool>::WaitForValueEqualTo(bool,
>>> >> lldb_private::TimeValue const*, bool*)
>>> >> tools/lldb/include/lldb/Host/Predicate.h:339
>>> >> #7
>>> >> lldb_private::Listener::WaitForEventsInternal(lldb_private::TimeValue
>>> >> const*, lldb_private::Broadcaster*, lldb_private::ConstString const*,
>>> >> unsigned int, unsigned int, std::shared_ptr<lldb_private::Event>&)
>>> >> tools/lldb/source/Core/Listener.cpp:442
>>> >> #8 lldb_private::Listener::WaitForEvent(lldb_private::TimeValue
>>> >> const*, std::shared_ptr<lldb_private::Event>&)
>>> >> tools/lldb/source/Core/Listener.cpp:492
>>> >> #9 lldb_private::Debugger::DefaultEventHandler()
>>> >> tools/lldb/source/Core/Debugger.cpp:1623
>>> >> #10 lldb_private::Debugger::EventHandlerThread(void*)
>>> >> tools/lldb/source/Core/Debugger.cpp:1696
>>> >> #11
>>> >> lldb_private::HostNativeThreadBase::ThreadCreateTrampoline(void*)
>>> >> tools/lldb/source/Host/common/HostNativeThreadBase.cpp:81
>>> >>
>>> >>
>>> >> -- Ryan Brown
>>> >>
>>> >> On Mon, May 11, 2015 at 8:20 AM, Ed Maste <emaste at freebsd.org> wrote:
>>> >>>
>>> >>> On 11 May 2015 at 10:21, Pavel Labath <labath at google.com> wrote:
>>> >>> >
>>> >>> > BTW, I've noticed that PushIOHandler does not lock
>>> >>> > m_input_reader_stack.GetMutex(), unlike PopIOHandler, and all other
>>> >>> > functions which deal with handlers. Is that intentional? I think it
>>> >>> > should lock the mutex as well.
>>> >>>
>>> >>> A slight tangent here, but there's a lot of dubious thread behaviour
>>> >>> like this. One example I've run into is PR22611 - I see that if we
>>> >>> set
>>> >>> a prompt that fits in libc++'s short string optimization (that is, no
>>> >>> more than 22 characters) it works fine, but as soon as the prompt is
>>> >>> 23 characters long we end up pointing at uninitialized memory;
>>> >>> presumably the race window is much larger in that case.
>>> >>>
>>> >>> Unfortunately TSan isn't fully functional on FreeBSD at the moment,
>>> >>> so
>>> >>> it's not that easy for me to find other cases like this with a
>>> >>> systematic approach. I recall there was an effort to run LLDB under
>>> >>> TSan on Linux some time ago, and that found a number of issues. Is
>>> >>> anyone on the Linux side interested in picking that up again?
>>> >>> _______________________________________________
>>> >>> lldb-dev mailing list
>>> >>> lldb-dev at cs.uiuc.edu
>>> >>> http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
>>> >>
>>> >>
>>> >> _______________________________________________
>>> >> lldb-dev mailing list
>>> >> lldb-dev at cs.uiuc.edu
>>> >> http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
>>> >
>>> >
>>> > _______________________________________________
>>> > lldb-dev mailing list
>>> > lldb-dev at cs.uiuc.edu
>>> > http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
>>> >
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